Imaging

Iliosacral (SI) screws remain the standard of care for the vast majority of posterior pelvic ring disruptions.^1,2 However, despite their routine use, the procedure remains technically demanding with repeated cases of aberrant screw placement and complications.^3,4 Sacral morphology is extremely variable within a patient population and affects accurate placement and trajectory of percutaneous screws.⁵ Classically, it is taught that the external starting position/landmark is at an intersection point of the greater trochanter and the anterior superior iliac spine (ASIS). While this “one size fits all” approach will certainly help to coordinate a start position, it is our experience that multiple stab incisions are necessary to find the optimal start site. To our knowledge, the most common image-based technique used to guide start-point localization and placement of SI screws begins with drawing a virtual sacrum on the patient’s side, guided by the lateral image.⁵ This article provides a novel image-based technique to be used with, or as a replacement for, the traditional technique.

Techniques

The patient is brought to the operating room and placed supine on a radiolucent operating table. If the closed reduction of the pelvic ring is successful or can be achieved via anterior manipulation/traction, posterior percutaneous pinning is planned. Either a rolled towel or a bag of saline is used as a bolster and placed midline underneath the sacrum and lumbar spine to help “bump” the pelvis and improve the range of motion for the surgeon’s drill. The patient is brought to the edge of the table when possible (ie, a posterior ring injury requiring fixation from only 1 side) to further enhance drill motion. If bilateral screws are planned, surgeons must be careful not to position 1 side at the expense of screw placement on the contralateral side. Nitrous-based anesthetic agents are avoided, because they may collect in the bowel and obscure good radiographic visualization. Arms are placed perpendicular to the body to facilitate the inlet view. Pre-preparation anteroposterior pelvis, inlet, and outlet views are obtained to assure ability to accurately and safely assess landmarks on all projections, and to mark the C-arm position and angles. This process helps decrease “useless” radiographs obtained during the procedure. Acceptable inlet radiographs show the anterior cortex of the S1 body superimposed on the S2 body. Acceptable outlet radiographs show the superior pubic symphysis at the level of the S2 foramen and visualization of the S1/S2 sacral foramen.⁶ The patient is then prepared in the standard fashion. Reduction maneuvers are performed and, if acceptable alignment is achieved, posterior percutaneous screw placement begins.

Technique 1

To our knowledge, the most common image-based technique used to guide start-point localization and placement of SI screws begins with drawing a virtual sacrum on the patient’s side using the lateral image. The fluoroscopic machine is set up in a lateral position.⁵ A free guide wire is superimposed upon the iliac cortical density and anterior sacral slope, which is marked on the skin (Figure 1). The superior portion of S1, as well as the posterior sacral slope, can be marked as well. This process has outlined the sacrum and provides an external landmark for the “safe zone” for screw placement. The operation proceeds in the standard fashion using inlet, outlet, and lateral radiographs. However, the externally drawn sacrum can aid as a reference during guide-pin placement.

Technique 2

This technique takes into account bone anatomy and soft-tissue coverage. It is helpful to think of the abdomen/pelvis as a box. The anterior abdomen represents the top of the box and the lateral buttock represents the side of the box. The corner of the imaginary box is where the abdomen begins to slope down and transitions laterally to become the buttock. This will be referenced as the “down-sloping point” and typically corresponds to the level of the iliac crest (Figure 2).

To begin, a standard cannulated screw guide wire is placed flush on the skin of the abdomen. An inlet fluoroscopy image is taken with the guide pin on the abdomen. Imagine that the resulting image represents the planned screw trajectory (Figure 3A). When the position of the guide wire is deemed adequate, a line is marked on the abdomen, using a pen, directly adjacent to the guide wire. This line represents inlet line 1 (Figure 2). The line must continue laterally until the down-sloping point. The sagittal angle of the imaginary inlet fluoroscopic beam is noted, and a guide wire is placed in the same sagittal orientation flush with the skin on the lateral buttock (Figure 3B). The guide wire must be placed so that it intersects with the first line at the down-sloping point. The skin on the lateral aspect of buttock is marked with a second line, which represents inlet line 2 (Figure 2).

 

The same process is repeated using an outlet view to create outlet lines 1 and 2 (Figures 4A, 4B). At this point there are 4 lines drawn on the patient (Figure 2). A stab incision is made at the intersection of the 2 lines drawn on the lateral buttock; this represents the skin start point, labeled “start incision” (Figure 2). The procedure continues in standard fashion. 

The 4 external reference lines serve multiple purposes. First, the lines mark the true lateral start point for the pin at the level of the skin. This contrasts with the standard technique in which bony landmarks are marked on the skin and the surgeon must estimate a point on the skin that will provide an appropriate trajectory to the bony start point on the ilium. Further, the lines can also be used to reorient the cartesian plane so that adjustments can be isolated to a single plane, ensuring movements only alter the position on a single radiographic view (Figure 5).

Discussion

Despite the widespread use of percutaneous screw placement for posterior pelvic ring injuries, this remains a technically demanding surgery. Recent data suggest patient pelvic anatomy is extremely varied, especially the sacrum.⁷ Further, screw trajectories vary depending on surgical goals, fracture pattern, and number of screws. Taken together, this implies that there is no perfect universal starting site along the external ilium. Therefore, while classic teaching states to begin screw insertion within the vicinity of the intersection of the greater trochanter and the ASIS, it is our experience that this location is often not ideal.

The inlet, outlet, and lateral radiographs are all vital to assess correct trajectory of the guide pin and drill prior to final screw insertion, but the start site remains a critical step to assure a successful surgical outcome. We present 2 techniques, used together or separately, that allow the surgeon to place the initial guide pin more accurately for percutanous iliosacral screws. Though not specifically examined in this study, we think technique 2 has the potential to save operative time and use less fluoroscopic imaging because a lateral image is not required until later in the case. Technique 2 identifies the start point at the level of the skin. This is in contrast to technique 1, which identifies the desired sacral target and requires a surgeon to select a skin start site that will provide an optimal trajectory towards the desired target. Judging trajectory can be difficult, particularly in obese patients, and technique 2 eliminates this extra variable.

It is also important to consider that criteria-based nonorthogonal imaging is required for percutaneous screw placement. In these cases, it is more difficult to judge trajectory corrections because the fluoroscopic beam cannot guide perpendicular corrections as it can in operations that use orthogonal imaging. Adjustments made perpendicular to the fluoroscopic beam will change trajectory in multiple planes.⁸ Moreover, because the standard cartesian frame of reference is rotated, understanding the location of the sacrum in space can be especially challenging. When using the first technique, sacral landmarks are delineated, and a virtual sacrum drawn on the patient’s exterior helps with orientation. In the second technique, the ideal pin placement is mapped, and the external reference lines guide uniplanar changes. For example, the line drawn co-planar with the inlet view is essentially marking the sacral slope. Therefore, by following this line, uniplanar changes in the cranial and caudal direction are achieved on the outlet view (Figure 5). Because this line is also in reference to the already known ideal pin placement, ideal pin placement can be maintained in 1 radiographic projection while changing the start site in the appropriate direction. In a similar fashion, the co-planar line identified on the inlet view can be used on the outlet image to affect uniplanar changes in the anteroposterior direction. This technique effectively minimizes disorientation when placing percutaneous SI screws. This can be particularly beneficial when placing screws in the prone position.

Conclusion

We have shown 2 techniques that are routinely used at our institution to help identify an accurate starting position for percutaneous screw placement in posterior pelvic ring injuries. Even experienced traumatologists can more quickly and accurately identify the correct stab incisions leading to more confidently placed screws. Further, we believe understanding the usage of fluoroscopy and the concepts involved in drawing the lines enhance trainees’ comprehension of the complex anatomy of the sacrum.

Iliosacral (SI) screws remain the standard of care for the vast majority of posterior pelvic ring disruptions.^1,2 However, despite their routine use, the procedure remains technically demanding with repeated cases of aberrant screw placement and complications.^3,4 Sacral morphology is extremely variable within a patient population and affects accurate placement and trajectory of percutaneous screws.⁵ Classically, it is taught that the external starting position/landmark is at an intersection point of the greater trochanter and the anterior superior iliac spine (ASIS). While this “one size fits all” approach will certainly help to coordinate a start position, it is our experience that multiple stab incisions are necessary to find the optimal start site. To our knowledge, the most common image-based technique used to guide start-point localization and placement of SI screws begins with drawing a virtual sacrum on the patient’s side, guided by the lateral image.⁵ This article provides a novel image-based technique to be used with, or as a replacement for, the traditional technique.

Techniques

The patient is brought to the operating room and placed supine on a radiolucent operating table. If the closed reduction of the pelvic ring is successful or can be achieved via anterior manipulation/traction, posterior percutaneous pinning is planned. Either a rolled towel or a bag of saline is used as a bolster and placed midline underneath the sacrum and lumbar spine to help “bump” the pelvis and improve the range of motion for the surgeon’s drill. The patient is brought to the edge of the table when possible (ie, a posterior ring injury requiring fixation from only 1 side) to further enhance drill motion. If bilateral screws are planned, surgeons must be careful not to position 1 side at the expense of screw placement on the contralateral side. Nitrous-based anesthetic agents are avoided, because they may collect in the bowel and obscure good radiographic visualization. Arms are placed perpendicular to the body to facilitate the inlet view. Pre-preparation anteroposterior pelvis, inlet, and outlet views are obtained to assure ability to accurately and safely assess landmarks on all projections, and to mark the C-arm position and angles. This process helps decrease “useless” radiographs obtained during the procedure. Acceptable inlet radiographs show the anterior cortex of the S1 body superimposed on the S2 body. Acceptable outlet radiographs show the superior pubic symphysis at the level of the S2 foramen and visualization of the S1/S2 sacral foramen.⁶ The patient is then prepared in the standard fashion. Reduction maneuvers are performed and, if acceptable alignment is achieved, posterior percutaneous screw placement begins.

Technique 1

To our knowledge, the most common image-based technique used to guide start-point localization and placement of SI screws begins with drawing a virtual sacrum on the patient’s side using the lateral image. The fluoroscopic machine is set up in a lateral position.⁵ A free guide wire is superimposed upon the iliac cortical density and anterior sacral slope, which is marked on the skin (Figure 1). The superior portion of S1, as well as the posterior sacral slope, can be marked as well. This process has outlined the sacrum and provides an external landmark for the “safe zone” for screw placement. The operation proceeds in the standard fashion using inlet, outlet, and lateral radiographs. However, the externally drawn sacrum can aid as a reference during guide-pin placement.

Technique 2

This technique takes into account bone anatomy and soft-tissue coverage. It is helpful to think of the abdomen/pelvis as a box. The anterior abdomen represents the top of the box and the lateral buttock represents the side of the box. The corner of the imaginary box is where the abdomen begins to slope down and transitions laterally to become the buttock. This will be referenced as the “down-sloping point” and typically corresponds to the level of the iliac crest (Figure 2).

To begin, a standard cannulated screw guide wire is placed flush on the skin of the abdomen. An inlet fluoroscopy image is taken with the guide pin on the abdomen. Imagine that the resulting image represents the planned screw trajectory (Figure 3A). When the position of the guide wire is deemed adequate, a line is marked on the abdomen, using a pen, directly adjacent to the guide wire. This line represents inlet line 1 (Figure 2). The line must continue laterally until the down-sloping point. The sagittal angle of the imaginary inlet fluoroscopic beam is noted, and a guide wire is placed in the same sagittal orientation flush with the skin on the lateral buttock (Figure 3B). The guide wire must be placed so that it intersects with the first line at the down-sloping point. The skin on the lateral aspect of buttock is marked with a second line, which represents inlet line 2 (Figure 2).

 

The same process is repeated using an outlet view to create outlet lines 1 and 2 (Figures 4A, 4B). At this point there are 4 lines drawn on the patient (Figure 2). A stab incision is made at the intersection of the 2 lines drawn on the lateral buttock; this represents the skin start point, labeled “start incision” (Figure 2). The procedure continues in standard fashion. 

The 4 external reference lines serve multiple purposes. First, the lines mark the true lateral start point for the pin at the level of the skin. This contrasts with the standard technique in which bony landmarks are marked on the skin and the surgeon must estimate a point on the skin that will provide an appropriate trajectory to the bony start point on the ilium. Further, the lines can also be used to reorient the cartesian plane so that adjustments can be isolated to a single plane, ensuring movements only alter the position on a single radiographic view (Figure 5).

Discussion

Despite the widespread use of percutaneous screw placement for posterior pelvic ring injuries, this remains a technically demanding surgery. Recent data suggest patient pelvic anatomy is extremely varied, especially the sacrum.⁷ Further, screw trajectories vary depending on surgical goals, fracture pattern, and number of screws. Taken together, this implies that there is no perfect universal starting site along the external ilium. Therefore, while classic teaching states to begin screw insertion within the vicinity of the intersection of the greater trochanter and the ASIS, it is our experience that this location is often not ideal.

The inlet, outlet, and lateral radiographs are all vital to assess correct trajectory of the guide pin and drill prior to final screw insertion, but the start site remains a critical step to assure a successful surgical outcome. We present 2 techniques, used together or separately, that allow the surgeon to place the initial guide pin more accurately for percutanous iliosacral screws. Though not specifically examined in this study, we think technique 2 has the potential to save operative time and use less fluoroscopic imaging because a lateral image is not required until later in the case. Technique 2 identifies the start point at the level of the skin. This is in contrast to technique 1, which identifies the desired sacral target and requires a surgeon to select a skin start site that will provide an optimal trajectory towards the desired target. Judging trajectory can be difficult, particularly in obese patients, and technique 2 eliminates this extra variable.

It is also important to consider that criteria-based nonorthogonal imaging is required for percutaneous screw placement. In these cases, it is more difficult to judge trajectory corrections because the fluoroscopic beam cannot guide perpendicular corrections as it can in operations that use orthogonal imaging. Adjustments made perpendicular to the fluoroscopic beam will change trajectory in multiple planes.⁸ Moreover, because the standard cartesian frame of reference is rotated, understanding the location of the sacrum in space can be especially challenging. When using the first technique, sacral landmarks are delineated, and a virtual sacrum drawn on the patient’s exterior helps with orientation. In the second technique, the ideal pin placement is mapped, and the external reference lines guide uniplanar changes. For example, the line drawn co-planar with the inlet view is essentially marking the sacral slope. Therefore, by following this line, uniplanar changes in the cranial and caudal direction are achieved on the outlet view (Figure 5). Because this line is also in reference to the already known ideal pin placement, ideal pin placement can be maintained in 1 radiographic projection while changing the start site in the appropriate direction. In a similar fashion, the co-planar line identified on the inlet view can be used on the outlet image to affect uniplanar changes in the anteroposterior direction. This technique effectively minimizes disorientation when placing percutaneous SI screws. This can be particularly beneficial when placing screws in the prone position.

Conclusion

We have shown 2 techniques that are routinely used at our institution to help identify an accurate starting position for percutaneous screw placement in posterior pelvic ring injuries. Even experienced traumatologists can more quickly and accurately identify the correct stab incisions leading to more confidently placed screws. Further, we believe understanding the usage of fluoroscopy and the concepts involved in drawing the lines enhance trainees’ comprehension of the complex anatomy of the sacrum.

Iliosacral (SI) screws remain the standard of care for the vast majority of posterior pelvic ring disruptions.^1,2 However, despite their routine use, the procedure remains technically demanding with repeated cases of aberrant screw placement and complications.^3,4 Sacral morphology is extremely variable within a patient population and affects accurate placement and trajectory of percutaneous screws.⁵ Classically, it is taught that the external starting position/landmark is at an intersection point of the greater trochanter and the anterior superior iliac spine (ASIS). While this “one size fits all” approach will certainly help to coordinate a start position, it is our experience that multiple stab incisions are necessary to find the optimal start site. To our knowledge, the most common image-based technique used to guide start-point localization and placement of SI screws begins with drawing a virtual sacrum on the patient’s side, guided by the lateral image.⁵ This article provides a novel image-based technique to be used with, or as a replacement for, the traditional technique.

Techniques

The patient is brought to the operating room and placed supine on a radiolucent operating table. If the closed reduction of the pelvic ring is successful or can be achieved via anterior manipulation/traction, posterior percutaneous pinning is planned. Either a rolled towel or a bag of saline is used as a bolster and placed midline underneath the sacrum and lumbar spine to help “bump” the pelvis and improve the range of motion for the surgeon’s drill. The patient is brought to the edge of the table when possible (ie, a posterior ring injury requiring fixation from only 1 side) to further enhance drill motion. If bilateral screws are planned, surgeons must be careful not to position 1 side at the expense of screw placement on the contralateral side. Nitrous-based anesthetic agents are avoided, because they may collect in the bowel and obscure good radiographic visualization. Arms are placed perpendicular to the body to facilitate the inlet view. Pre-preparation anteroposterior pelvis, inlet, and outlet views are obtained to assure ability to accurately and safely assess landmarks on all projections, and to mark the C-arm position and angles. This process helps decrease “useless” radiographs obtained during the procedure. Acceptable inlet radiographs show the anterior cortex of the S1 body superimposed on the S2 body. Acceptable outlet radiographs show the superior pubic symphysis at the level of the S2 foramen and visualization of the S1/S2 sacral foramen.⁶ The patient is then prepared in the standard fashion. Reduction maneuvers are performed and, if acceptable alignment is achieved, posterior percutaneous screw placement begins.

Technique 1

To our knowledge, the most common image-based technique used to guide start-point localization and placement of SI screws begins with drawing a virtual sacrum on the patient’s side using the lateral image. The fluoroscopic machine is set up in a lateral position.⁵ A free guide wire is superimposed upon the iliac cortical density and anterior sacral slope, which is marked on the skin (Figure 1). The superior portion of S1, as well as the posterior sacral slope, can be marked as well. This process has outlined the sacrum and provides an external landmark for the “safe zone” for screw placement. The operation proceeds in the standard fashion using inlet, outlet, and lateral radiographs. However, the externally drawn sacrum can aid as a reference during guide-pin placement.

Technique 2

This technique takes into account bone anatomy and soft-tissue coverage. It is helpful to think of the abdomen/pelvis as a box. The anterior abdomen represents the top of the box and the lateral buttock represents the side of the box. The corner of the imaginary box is where the abdomen begins to slope down and transitions laterally to become the buttock. This will be referenced as the “down-sloping point” and typically corresponds to the level of the iliac crest (Figure 2).

To begin, a standard cannulated screw guide wire is placed flush on the skin of the abdomen. An inlet fluoroscopy image is taken with the guide pin on the abdomen. Imagine that the resulting image represents the planned screw trajectory (Figure 3A). When the position of the guide wire is deemed adequate, a line is marked on the abdomen, using a pen, directly adjacent to the guide wire. This line represents inlet line 1 (Figure 2). The line must continue laterally until the down-sloping point. The sagittal angle of the imaginary inlet fluoroscopic beam is noted, and a guide wire is placed in the same sagittal orientation flush with the skin on the lateral buttock (Figure 3B). The guide wire must be placed so that it intersects with the first line at the down-sloping point. The skin on the lateral aspect of buttock is marked with a second line, which represents inlet line 2 (Figure 2).

 

The same process is repeated using an outlet view to create outlet lines 1 and 2 (Figures 4A, 4B). At this point there are 4 lines drawn on the patient (Figure 2). A stab incision is made at the intersection of the 2 lines drawn on the lateral buttock; this represents the skin start point, labeled “start incision” (Figure 2). The procedure continues in standard fashion. 

The 4 external reference lines serve multiple purposes. First, the lines mark the true lateral start point for the pin at the level of the skin. This contrasts with the standard technique in which bony landmarks are marked on the skin and the surgeon must estimate a point on the skin that will provide an appropriate trajectory to the bony start point on the ilium. Further, the lines can also be used to reorient the cartesian plane so that adjustments can be isolated to a single plane, ensuring movements only alter the position on a single radiographic view (Figure 5).

Discussion

Despite the widespread use of percutaneous screw placement for posterior pelvic ring injuries, this remains a technically demanding surgery. Recent data suggest patient pelvic anatomy is extremely varied, especially the sacrum.⁷ Further, screw trajectories vary depending on surgical goals, fracture pattern, and number of screws. Taken together, this implies that there is no perfect universal starting site along the external ilium. Therefore, while classic teaching states to begin screw insertion within the vicinity of the intersection of the greater trochanter and the ASIS, it is our experience that this location is often not ideal.

The inlet, outlet, and lateral radiographs are all vital to assess correct trajectory of the guide pin and drill prior to final screw insertion, but the start site remains a critical step to assure a successful surgical outcome. We present 2 techniques, used together or separately, that allow the surgeon to place the initial guide pin more accurately for percutanous iliosacral screws. Though not specifically examined in this study, we think technique 2 has the potential to save operative time and use less fluoroscopic imaging because a lateral image is not required until later in the case. Technique 2 identifies the start point at the level of the skin. This is in contrast to technique 1, which identifies the desired sacral target and requires a surgeon to select a skin start site that will provide an optimal trajectory towards the desired target. Judging trajectory can be difficult, particularly in obese patients, and technique 2 eliminates this extra variable.

It is also important to consider that criteria-based nonorthogonal imaging is required for percutaneous screw placement. In these cases, it is more difficult to judge trajectory corrections because the fluoroscopic beam cannot guide perpendicular corrections as it can in operations that use orthogonal imaging. Adjustments made perpendicular to the fluoroscopic beam will change trajectory in multiple planes.⁸ Moreover, because the standard cartesian frame of reference is rotated, understanding the location of the sacrum in space can be especially challenging. When using the first technique, sacral landmarks are delineated, and a virtual sacrum drawn on the patient’s exterior helps with orientation. In the second technique, the ideal pin placement is mapped, and the external reference lines guide uniplanar changes. For example, the line drawn co-planar with the inlet view is essentially marking the sacral slope. Therefore, by following this line, uniplanar changes in the cranial and caudal direction are achieved on the outlet view (Figure 5). Because this line is also in reference to the already known ideal pin placement, ideal pin placement can be maintained in 1 radiographic projection while changing the start site in the appropriate direction. In a similar fashion, the co-planar line identified on the inlet view can be used on the outlet image to affect uniplanar changes in the anteroposterior direction. This technique effectively minimizes disorientation when placing percutaneous SI screws. This can be particularly beneficial when placing screws in the prone position.

Conclusion

We have shown 2 techniques that are routinely used at our institution to help identify an accurate starting position for percutaneous screw placement in posterior pelvic ring injuries. Even experienced traumatologists can more quickly and accurately identify the correct stab incisions leading to more confidently placed screws. Further, we believe understanding the usage of fluoroscopy and the concepts involved in drawing the lines enhance trainees’ comprehension of the complex anatomy of the sacrum.

Case

A 32-year-old woman presented to the ED with a 6-month history of worsening skin erosion along her right elbow and forearm. The patient described unremitting pain and progressive shortening of her forearm. Radiographs were obtained; representative images are shown above (Figures 1a and 1b).

What is the diagnosis?

***BREAKING***

Answer

Anteroposterior and lateral radiographs of the right elbow demonstrated a large soft tissue defect involving the proximal forearm (white arrows, Figures 2a and 2b) with extensive osseous destruction of the proximal radius (R) and ulna (U). Deformity of the forearm was apparent. There was marked periosteal reaction involving the distal humerus (black arrows, Figures 2a and 2b). A needle fragment projected over the antecubital space on both radiographs (red arrow, Figures 2a and 2b). These findings indicated the presence of osteomyelitis and septic arthritis. The needle fragment suggested drug abuse as the likely etiology.

This patient had a 2-year history of intravenous (IV) drug abuse. She initially noticed an open wound on her elbow about 6 months prior to presentation. As the wound worsened, she developed increasing pain, numbness, and weakness in her forearm and hand. Physical examination revealed a markedly contracted forearm. There was a large, deep ulcer at the lateral aspect of the elbow and proximal forearm, with exposed bone and surrounding necrotic tissue. Motor function was limited to minimal movement of the thumb and index finger, and there was complete loss of sensation in an ulnar distribution. A deep tissue culture grew methicillin-resistant Staphylococcus aureus, and a bone biopsy confirmed the diagnosis of osteomyelitis. The patient was treated with antibiotics but ultimately required transhumeral amputation.

Intravenous drug users are at risk for soft tissue and bone complications, including ulcer, abscess, septic bursitis, tenosynovitis, cellulitis, necrotizing fasciitis, septic arthritis, and osteomyelitis.¹ Osteomyelitis can arise from direct inoculation, hematogenous spread, or, as was the case in this patient, secondary to seeding from a contiguous soft tissue infection.² Unlike hematogenous osteomyelitis, contiguous focus osteomyelitis is often polymicrobial.

Radiographs are not sensitive for osteomyelitis, particularly early in the process, but may reveal loss of soft tissue planes prior to the development of focal osteopenia and osseous destruction.³ In this case, the diagnosis could be made through radiography given the marked osseous destruction, periosteal reaction, and soft tissue ulceration. However, in presentations in which there is a continued clinical suspicion for osteomyelitis despite normal or inconclusive radiographs, magnetic resonance imaging (MRI) with contrast is the preferred examination for further evaluation. While both contrast and noncontrast-enhanced MRI may show the bone marrow edema related to osteomyelitis, contrast is helpful in evaluating for soft tissue abscesses and in determining if there is an adequate blood supply for IV treatment to be effective. An alternative exam to MRI would be nuclear scintigraphy (a tagged, white blood cell scan and/or a three-phase bone scan). 

Later in the disease course, periosteal bone reaction and sclerotic reactive bone formation can be seen. A sequestrum forms when there is complete resorption of the bone adjacent to a devitalized segment of infected bone, leaving the isolated devitalized segment to function as a nidus for continued infection.³

Dr Spivey is a resident in the department of radiology at New York Presbyterian Hospital/Weill Cornell Medical College in New York City. Dr Bartolotta is an assistant professor of radiology at Weill Cornell Medical College in New York City and assistant attending radiologist at New York-Presbyterian Hospital/Weill Cornell Medical Center. Dr Hentel is an associate professor of clinical radiology at Weill Cornell Medical College in New York City. He is also chief of emergency/musculoskeletal imaging and executive vice-chairman for the department of radiology at New York-Presbyterian Hospital/Weill Cornell Medical Center; and associate editor, imaging, of the EMERGENCY MEDICINE editorial board.

Case

A 32-year-old woman presented to the ED with a 6-month history of worsening skin erosion along her right elbow and forearm. The patient described unremitting pain and progressive shortening of her forearm. Radiographs were obtained; representative images are shown above (Figures 1a and 1b).

What is the diagnosis?

***BREAKING***

Answer

Anteroposterior and lateral radiographs of the right elbow demonstrated a large soft tissue defect involving the proximal forearm (white arrows, Figures 2a and 2b) with extensive osseous destruction of the proximal radius (R) and ulna (U). Deformity of the forearm was apparent. There was marked periosteal reaction involving the distal humerus (black arrows, Figures 2a and 2b). A needle fragment projected over the antecubital space on both radiographs (red arrow, Figures 2a and 2b). These findings indicated the presence of osteomyelitis and septic arthritis. The needle fragment suggested drug abuse as the likely etiology.

This patient had a 2-year history of intravenous (IV) drug abuse. She initially noticed an open wound on her elbow about 6 months prior to presentation. As the wound worsened, she developed increasing pain, numbness, and weakness in her forearm and hand. Physical examination revealed a markedly contracted forearm. There was a large, deep ulcer at the lateral aspect of the elbow and proximal forearm, with exposed bone and surrounding necrotic tissue. Motor function was limited to minimal movement of the thumb and index finger, and there was complete loss of sensation in an ulnar distribution. A deep tissue culture grew methicillin-resistant Staphylococcus aureus, and a bone biopsy confirmed the diagnosis of osteomyelitis. The patient was treated with antibiotics but ultimately required transhumeral amputation.

Intravenous drug users are at risk for soft tissue and bone complications, including ulcer, abscess, septic bursitis, tenosynovitis, cellulitis, necrotizing fasciitis, septic arthritis, and osteomyelitis.¹ Osteomyelitis can arise from direct inoculation, hematogenous spread, or, as was the case in this patient, secondary to seeding from a contiguous soft tissue infection.² Unlike hematogenous osteomyelitis, contiguous focus osteomyelitis is often polymicrobial.

Radiographs are not sensitive for osteomyelitis, particularly early in the process, but may reveal loss of soft tissue planes prior to the development of focal osteopenia and osseous destruction.³ In this case, the diagnosis could be made through radiography given the marked osseous destruction, periosteal reaction, and soft tissue ulceration. However, in presentations in which there is a continued clinical suspicion for osteomyelitis despite normal or inconclusive radiographs, magnetic resonance imaging (MRI) with contrast is the preferred examination for further evaluation. While both contrast and noncontrast-enhanced MRI may show the bone marrow edema related to osteomyelitis, contrast is helpful in evaluating for soft tissue abscesses and in determining if there is an adequate blood supply for IV treatment to be effective. An alternative exam to MRI would be nuclear scintigraphy (a tagged, white blood cell scan and/or a three-phase bone scan). 

Later in the disease course, periosteal bone reaction and sclerotic reactive bone formation can be seen. A sequestrum forms when there is complete resorption of the bone adjacent to a devitalized segment of infected bone, leaving the isolated devitalized segment to function as a nidus for continued infection.³

Dr Spivey is a resident in the department of radiology at New York Presbyterian Hospital/Weill Cornell Medical College in New York City. Dr Bartolotta is an assistant professor of radiology at Weill Cornell Medical College in New York City and assistant attending radiologist at New York-Presbyterian Hospital/Weill Cornell Medical Center. Dr Hentel is an associate professor of clinical radiology at Weill Cornell Medical College in New York City. He is also chief of emergency/musculoskeletal imaging and executive vice-chairman for the department of radiology at New York-Presbyterian Hospital/Weill Cornell Medical Center; and associate editor, imaging, of the EMERGENCY MEDICINE editorial board.

Case

A 32-year-old woman presented to the ED with a 6-month history of worsening skin erosion along her right elbow and forearm. The patient described unremitting pain and progressive shortening of her forearm. Radiographs were obtained; representative images are shown above (Figures 1a and 1b).

What is the diagnosis?

***BREAKING***

Answer

Anteroposterior and lateral radiographs of the right elbow demonstrated a large soft tissue defect involving the proximal forearm (white arrows, Figures 2a and 2b) with extensive osseous destruction of the proximal radius (R) and ulna (U). Deformity of the forearm was apparent. There was marked periosteal reaction involving the distal humerus (black arrows, Figures 2a and 2b). A needle fragment projected over the antecubital space on both radiographs (red arrow, Figures 2a and 2b). These findings indicated the presence of osteomyelitis and septic arthritis. The needle fragment suggested drug abuse as the likely etiology.

This patient had a 2-year history of intravenous (IV) drug abuse. She initially noticed an open wound on her elbow about 6 months prior to presentation. As the wound worsened, she developed increasing pain, numbness, and weakness in her forearm and hand. Physical examination revealed a markedly contracted forearm. There was a large, deep ulcer at the lateral aspect of the elbow and proximal forearm, with exposed bone and surrounding necrotic tissue. Motor function was limited to minimal movement of the thumb and index finger, and there was complete loss of sensation in an ulnar distribution. A deep tissue culture grew methicillin-resistant Staphylococcus aureus, and a bone biopsy confirmed the diagnosis of osteomyelitis. The patient was treated with antibiotics but ultimately required transhumeral amputation.

Intravenous drug users are at risk for soft tissue and bone complications, including ulcer, abscess, septic bursitis, tenosynovitis, cellulitis, necrotizing fasciitis, septic arthritis, and osteomyelitis.¹ Osteomyelitis can arise from direct inoculation, hematogenous spread, or, as was the case in this patient, secondary to seeding from a contiguous soft tissue infection.² Unlike hematogenous osteomyelitis, contiguous focus osteomyelitis is often polymicrobial.

Radiographs are not sensitive for osteomyelitis, particularly early in the process, but may reveal loss of soft tissue planes prior to the development of focal osteopenia and osseous destruction.³ In this case, the diagnosis could be made through radiography given the marked osseous destruction, periosteal reaction, and soft tissue ulceration. However, in presentations in which there is a continued clinical suspicion for osteomyelitis despite normal or inconclusive radiographs, magnetic resonance imaging (MRI) with contrast is the preferred examination for further evaluation. While both contrast and noncontrast-enhanced MRI may show the bone marrow edema related to osteomyelitis, contrast is helpful in evaluating for soft tissue abscesses and in determining if there is an adequate blood supply for IV treatment to be effective. An alternative exam to MRI would be nuclear scintigraphy (a tagged, white blood cell scan and/or a three-phase bone scan). 

Later in the disease course, periosteal bone reaction and sclerotic reactive bone formation can be seen. A sequestrum forms when there is complete resorption of the bone adjacent to a devitalized segment of infected bone, leaving the isolated devitalized segment to function as a nidus for continued infection.³

Dr Spivey is a resident in the department of radiology at New York Presbyterian Hospital/Weill Cornell Medical College in New York City. Dr Bartolotta is an assistant professor of radiology at Weill Cornell Medical College in New York City and assistant attending radiologist at New York-Presbyterian Hospital/Weill Cornell Medical Center. Dr Hentel is an associate professor of clinical radiology at Weill Cornell Medical College in New York City. He is also chief of emergency/musculoskeletal imaging and executive vice-chairman for the department of radiology at New York-Presbyterian Hospital/Weill Cornell Medical Center; and associate editor, imaging, of the EMERGENCY MEDICINE editorial board.

SAN DIEGO – Children who have suffered blunt trauma are routinely screened in emergency departments for intra-abdominal injury via computed tomography of the abdomen and pelvis.

But concerns about excess exposure to CT radiation, particularly to the gonads, led one group of researchers to question whether it’s necessary to scan the entire abdominopelvic region in all of these patients to identify intra-abdominal injury (IAI).

Dr. Stacy Reynolds and her colleagues at the Carolinas Medical Center in Charlotte, N.C., hypothesized that CT limited to the radiographic abdomen – the region between the dome of the diaphragm to the top of the iliac crest – can capture the vast majority of IAIs in this population.

At the Society for Academic Emergency Medicine annual meeting, Dr. Reynolds presented results from a retrospective cohort study enrolling 313 hemodynamically stable pediatric patients (median age 14 years, 64% male) presenting to 12 EDs after blunt trauma. Patients with known pelvic fractures or hip dislocation were excluded, as they would have had a clear indication for a full abdominopelvic CT.

All subjects underwent axial abdominopelvic CT imaging. Researchers created matched pairs of images comprising the original scans and those that had been altered with software that truncated the pelvic portion of the study to create CT abdomen-only studies. Study radiologists were blinded to the results of the original scans.

Twenty-six IAI’s were diagnosed in 24 patients: 8 hepatic injuries, 12 splenic injuries, 5 renal injuries, and 1 retroperitoneal hemorrhage. Abdominal CT alone was 85% sensitive (95% confidence interval, 65%-96%) and 99% specific (95% CI, 97%-100%) in identifying IAIs. The four missed injuries were solid organ injuries within the radiographic abdomen. False positives occurred in two of the complete scans, both involving free fluid prompting suspicion of small bowel injury later ruled out by clinical observation.

Dr. Reynolds said in an interview said that the findings, while promising, were limited by the study’s small numbers, and its use of axial images alone, when sagittal images also would be required for the most accurate diagnoses. Also, physician suspicion of IAI prior to imaging was not captured because of the study’s retrospective design, she said. “The real key to whether or not this hypothesis is valuable is if physicians are able to target the right population of patients for application.”

Dr. Reynolds cautioned that the findings would need to be validated in a larger trial before any changes could be made to clinical practice. “Some of the outcomes that we need to make sure whether we’re missing are still rare,” she said. “You couldn’t feel confident that this is the right way to go with a study this small, but it establishes that we can safely and ethically pursue a multicenter trial that would examine the issue with bigger numbers.”

Other groups of investigators, including members of the Pediatric Emergency Care Applied Research Network (PECARN), also have taken up the question of identifying children at low risk of IAI who may not need CT screening after blunt trauma. In 2013, PECARN published a prediction rule using only patient history and physical examination findings intended to obviate use of CT in the lowest-risk patients (Ann. Emerg. Med. 2013;62:107-16.e2).

Dr. Reynolds said that while overuse of CT was a worrisome trend that could have long-term implications for patients, and that it was important to identify ways it might be limited, there is a reason it remains the go-to technology in the ED for detecting IAI. “It’s got very high sensitivity and specificity. If you’re a busy trauma surgeon who’s admitting 20 injured patients in a night, there’s no faster or more efficient way to determine whether the patient in front of you is injured.”

The study was funded by the Carolinas Trauma Network Research Center of Excellence. None of the investigators disclosed conflicts of interest.

SAN DIEGO – Children who have suffered blunt trauma are routinely screened in emergency departments for intra-abdominal injury via computed tomography of the abdomen and pelvis.

But concerns about excess exposure to CT radiation, particularly to the gonads, led one group of researchers to question whether it’s necessary to scan the entire abdominopelvic region in all of these patients to identify intra-abdominal injury (IAI).

Dr. Stacy Reynolds and her colleagues at the Carolinas Medical Center in Charlotte, N.C., hypothesized that CT limited to the radiographic abdomen – the region between the dome of the diaphragm to the top of the iliac crest – can capture the vast majority of IAIs in this population.

At the Society for Academic Emergency Medicine annual meeting, Dr. Reynolds presented results from a retrospective cohort study enrolling 313 hemodynamically stable pediatric patients (median age 14 years, 64% male) presenting to 12 EDs after blunt trauma. Patients with known pelvic fractures or hip dislocation were excluded, as they would have had a clear indication for a full abdominopelvic CT.

All subjects underwent axial abdominopelvic CT imaging. Researchers created matched pairs of images comprising the original scans and those that had been altered with software that truncated the pelvic portion of the study to create CT abdomen-only studies. Study radiologists were blinded to the results of the original scans.

Twenty-six IAI’s were diagnosed in 24 patients: 8 hepatic injuries, 12 splenic injuries, 5 renal injuries, and 1 retroperitoneal hemorrhage. Abdominal CT alone was 85% sensitive (95% confidence interval, 65%-96%) and 99% specific (95% CI, 97%-100%) in identifying IAIs. The four missed injuries were solid organ injuries within the radiographic abdomen. False positives occurred in two of the complete scans, both involving free fluid prompting suspicion of small bowel injury later ruled out by clinical observation.

Dr. Reynolds said in an interview said that the findings, while promising, were limited by the study’s small numbers, and its use of axial images alone, when sagittal images also would be required for the most accurate diagnoses. Also, physician suspicion of IAI prior to imaging was not captured because of the study’s retrospective design, she said. “The real key to whether or not this hypothesis is valuable is if physicians are able to target the right population of patients for application.”

Dr. Reynolds cautioned that the findings would need to be validated in a larger trial before any changes could be made to clinical practice. “Some of the outcomes that we need to make sure whether we’re missing are still rare,” she said. “You couldn’t feel confident that this is the right way to go with a study this small, but it establishes that we can safely and ethically pursue a multicenter trial that would examine the issue with bigger numbers.”

Other groups of investigators, including members of the Pediatric Emergency Care Applied Research Network (PECARN), also have taken up the question of identifying children at low risk of IAI who may not need CT screening after blunt trauma. In 2013, PECARN published a prediction rule using only patient history and physical examination findings intended to obviate use of CT in the lowest-risk patients (Ann. Emerg. Med. 2013;62:107-16.e2).

Dr. Reynolds said that while overuse of CT was a worrisome trend that could have long-term implications for patients, and that it was important to identify ways it might be limited, there is a reason it remains the go-to technology in the ED for detecting IAI. “It’s got very high sensitivity and specificity. If you’re a busy trauma surgeon who’s admitting 20 injured patients in a night, there’s no faster or more efficient way to determine whether the patient in front of you is injured.”

The study was funded by the Carolinas Trauma Network Research Center of Excellence. None of the investigators disclosed conflicts of interest.

SAN DIEGO – Children who have suffered blunt trauma are routinely screened in emergency departments for intra-abdominal injury via computed tomography of the abdomen and pelvis.

But concerns about excess exposure to CT radiation, particularly to the gonads, led one group of researchers to question whether it’s necessary to scan the entire abdominopelvic region in all of these patients to identify intra-abdominal injury (IAI).

Dr. Stacy Reynolds and her colleagues at the Carolinas Medical Center in Charlotte, N.C., hypothesized that CT limited to the radiographic abdomen – the region between the dome of the diaphragm to the top of the iliac crest – can capture the vast majority of IAIs in this population.

At the Society for Academic Emergency Medicine annual meeting, Dr. Reynolds presented results from a retrospective cohort study enrolling 313 hemodynamically stable pediatric patients (median age 14 years, 64% male) presenting to 12 EDs after blunt trauma. Patients with known pelvic fractures or hip dislocation were excluded, as they would have had a clear indication for a full abdominopelvic CT.

All subjects underwent axial abdominopelvic CT imaging. Researchers created matched pairs of images comprising the original scans and those that had been altered with software that truncated the pelvic portion of the study to create CT abdomen-only studies. Study radiologists were blinded to the results of the original scans.

Twenty-six IAI’s were diagnosed in 24 patients: 8 hepatic injuries, 12 splenic injuries, 5 renal injuries, and 1 retroperitoneal hemorrhage. Abdominal CT alone was 85% sensitive (95% confidence interval, 65%-96%) and 99% specific (95% CI, 97%-100%) in identifying IAIs. The four missed injuries were solid organ injuries within the radiographic abdomen. False positives occurred in two of the complete scans, both involving free fluid prompting suspicion of small bowel injury later ruled out by clinical observation.

Dr. Reynolds said in an interview said that the findings, while promising, were limited by the study’s small numbers, and its use of axial images alone, when sagittal images also would be required for the most accurate diagnoses. Also, physician suspicion of IAI prior to imaging was not captured because of the study’s retrospective design, she said. “The real key to whether or not this hypothesis is valuable is if physicians are able to target the right population of patients for application.”

Dr. Reynolds cautioned that the findings would need to be validated in a larger trial before any changes could be made to clinical practice. “Some of the outcomes that we need to make sure whether we’re missing are still rare,” she said. “You couldn’t feel confident that this is the right way to go with a study this small, but it establishes that we can safely and ethically pursue a multicenter trial that would examine the issue with bigger numbers.”

Other groups of investigators, including members of the Pediatric Emergency Care Applied Research Network (PECARN), also have taken up the question of identifying children at low risk of IAI who may not need CT screening after blunt trauma. In 2013, PECARN published a prediction rule using only patient history and physical examination findings intended to obviate use of CT in the lowest-risk patients (Ann. Emerg. Med. 2013;62:107-16.e2).

Dr. Reynolds said that while overuse of CT was a worrisome trend that could have long-term implications for patients, and that it was important to identify ways it might be limited, there is a reason it remains the go-to technology in the ED for detecting IAI. “It’s got very high sensitivity and specificity. If you’re a busy trauma surgeon who’s admitting 20 injured patients in a night, there’s no faster or more efficient way to determine whether the patient in front of you is injured.”

The study was funded by the Carolinas Trauma Network Research Center of Excellence. None of the investigators disclosed conflicts of interest.

BOSTON – An implantable cardioverter defibrillator device that can safely undergo magnetic resonance imaging may soon be a commercial reality as two different models from two different manufacturers showed safety and mostly uncompromised efficacy during and after MRI in two separate studies reported at the annual scientific sessions of the Heart Rhythm Society.

The impending availability of two different brands of implantable cardioverter defibrillators (ICDs) that allow patients to safely undergo MRI “will hopefully open a new era when most [ICDs] are designed” to be MRI safe, said Dr. Khaled A. Awad, an electrophysiologist at the University of Alabama at Birmingham, and lead investigator for one of the new studies.

“Within 10 years, all ICDs getting implanted will be MRI compatible,” predicted Dr. Michael R. Gold, chief of cardiology and medical director of the heart and vascular center at the Medical University of South Carolina in Charleston and lead investigator for the second study.

Until now, having an ICD in a patient created a contraindication for using MRI on the patient, a situation that would change once MRI-safe ICDs become routinely available, noted Dr. Gold. MRI-compatible implanted pacemakers have been on the U.S. market since 2011; ICDs able to safely undergo MRI exposure became the next frontier for creating implanted cardiovascular devices that allow MRIs. Both studies used MRI performed with a 1.5-T magnetic field, a strength commonly used in routine practice today.

The ProMRI study reported by Dr. Awad enrolled patients at 39 U.S. centers who at least 5 weeks previously had received an Iforia ICD made by Biotronik along with commercially available leads believed to be MRI safe. The researchers performed MRIs of the heart or thoracic spine on 154 patients, and then ran follow-up examinations on 150 patients 1 month after the MRI, and a second, 3-month follow-up on 92 of the enrolled patients. The study did not include any control patients who received the ICD and did not undergo MRI.

No patient had an adverse event related or possibly related to their ICD either at the time of the MRI or at follow-up, Dr. Awad reported. In addition, no patients had a significant change in their ICD’s ventricular capture threshold, and one patient had a significant change in the ICD’s ventricular sensing. During follow-up, the ICDs of enrolled patients detected a total of 403 ventricular arrhythmias in 39 patients, with all these episodes appropriately detected and treated.

The study reported by Dr. Gold enrolled patients at 42 centers in 13 countries including the United States. The investigators implanted ICDs into 263 patients using commercially available leads, and then 9-12 weeks after placement, they randomized patients at a 2:1 rate to either undergo MRI or receive no MRI and serve as controls. Of the 175 patients randomized to undergo MRI, 156 actually received the examination, a full-body examination, and 147 participated in follow-up to at least 1 month and were part of the safety analysis.

Patient follow-up showed no complications, no episodes of a significant change in ventricular-pacing sensing threshold, and one episode of a significant change in ventricular-sensing amplitude, Dr. Gold reported, showing safety and efficacy outcomes identical to those in the trial of the Biotronik device. During follow-up 34 episodes of ventricular tachycardia or fibrillation occurred in 24 patients in the MRI group, and the implanted ICDs detected and treated all episodes appropriately. Concurrent with Dr. Gold’s report, the results also appeared in an article published online (J. Am. Coll. Cardiol. 2015 [doi:10.1016/j.jacc.2015.04.047]).

[email protected]
On Twitter @mitchelzoler 

BOSTON – An implantable cardioverter defibrillator device that can safely undergo magnetic resonance imaging may soon be a commercial reality as two different models from two different manufacturers showed safety and mostly uncompromised efficacy during and after MRI in two separate studies reported at the annual scientific sessions of the Heart Rhythm Society.

The impending availability of two different brands of implantable cardioverter defibrillators (ICDs) that allow patients to safely undergo MRI “will hopefully open a new era when most [ICDs] are designed” to be MRI safe, said Dr. Khaled A. Awad, an electrophysiologist at the University of Alabama at Birmingham, and lead investigator for one of the new studies.

“Within 10 years, all ICDs getting implanted will be MRI compatible,” predicted Dr. Michael R. Gold, chief of cardiology and medical director of the heart and vascular center at the Medical University of South Carolina in Charleston and lead investigator for the second study.

Until now, having an ICD in a patient created a contraindication for using MRI on the patient, a situation that would change once MRI-safe ICDs become routinely available, noted Dr. Gold. MRI-compatible implanted pacemakers have been on the U.S. market since 2011; ICDs able to safely undergo MRI exposure became the next frontier for creating implanted cardiovascular devices that allow MRIs. Both studies used MRI performed with a 1.5-T magnetic field, a strength commonly used in routine practice today.

The ProMRI study reported by Dr. Awad enrolled patients at 39 U.S. centers who at least 5 weeks previously had received an Iforia ICD made by Biotronik along with commercially available leads believed to be MRI safe. The researchers performed MRIs of the heart or thoracic spine on 154 patients, and then ran follow-up examinations on 150 patients 1 month after the MRI, and a second, 3-month follow-up on 92 of the enrolled patients. The study did not include any control patients who received the ICD and did not undergo MRI.

No patient had an adverse event related or possibly related to their ICD either at the time of the MRI or at follow-up, Dr. Awad reported. In addition, no patients had a significant change in their ICD’s ventricular capture threshold, and one patient had a significant change in the ICD’s ventricular sensing. During follow-up, the ICDs of enrolled patients detected a total of 403 ventricular arrhythmias in 39 patients, with all these episodes appropriately detected and treated.

The study reported by Dr. Gold enrolled patients at 42 centers in 13 countries including the United States. The investigators implanted ICDs into 263 patients using commercially available leads, and then 9-12 weeks after placement, they randomized patients at a 2:1 rate to either undergo MRI or receive no MRI and serve as controls. Of the 175 patients randomized to undergo MRI, 156 actually received the examination, a full-body examination, and 147 participated in follow-up to at least 1 month and were part of the safety analysis.

Patient follow-up showed no complications, no episodes of a significant change in ventricular-pacing sensing threshold, and one episode of a significant change in ventricular-sensing amplitude, Dr. Gold reported, showing safety and efficacy outcomes identical to those in the trial of the Biotronik device. During follow-up 34 episodes of ventricular tachycardia or fibrillation occurred in 24 patients in the MRI group, and the implanted ICDs detected and treated all episodes appropriately. Concurrent with Dr. Gold’s report, the results also appeared in an article published online (J. Am. Coll. Cardiol. 2015 [doi:10.1016/j.jacc.2015.04.047]).

[email protected]
On Twitter @mitchelzoler 

BOSTON – An implantable cardioverter defibrillator device that can safely undergo magnetic resonance imaging may soon be a commercial reality as two different models from two different manufacturers showed safety and mostly uncompromised efficacy during and after MRI in two separate studies reported at the annual scientific sessions of the Heart Rhythm Society.

The impending availability of two different brands of implantable cardioverter defibrillators (ICDs) that allow patients to safely undergo MRI “will hopefully open a new era when most [ICDs] are designed” to be MRI safe, said Dr. Khaled A. Awad, an electrophysiologist at the University of Alabama at Birmingham, and lead investigator for one of the new studies.

“Within 10 years, all ICDs getting implanted will be MRI compatible,” predicted Dr. Michael R. Gold, chief of cardiology and medical director of the heart and vascular center at the Medical University of South Carolina in Charleston and lead investigator for the second study.

Until now, having an ICD in a patient created a contraindication for using MRI on the patient, a situation that would change once MRI-safe ICDs become routinely available, noted Dr. Gold. MRI-compatible implanted pacemakers have been on the U.S. market since 2011; ICDs able to safely undergo MRI exposure became the next frontier for creating implanted cardiovascular devices that allow MRIs. Both studies used MRI performed with a 1.5-T magnetic field, a strength commonly used in routine practice today.

The ProMRI study reported by Dr. Awad enrolled patients at 39 U.S. centers who at least 5 weeks previously had received an Iforia ICD made by Biotronik along with commercially available leads believed to be MRI safe. The researchers performed MRIs of the heart or thoracic spine on 154 patients, and then ran follow-up examinations on 150 patients 1 month after the MRI, and a second, 3-month follow-up on 92 of the enrolled patients. The study did not include any control patients who received the ICD and did not undergo MRI.

No patient had an adverse event related or possibly related to their ICD either at the time of the MRI or at follow-up, Dr. Awad reported. In addition, no patients had a significant change in their ICD’s ventricular capture threshold, and one patient had a significant change in the ICD’s ventricular sensing. During follow-up, the ICDs of enrolled patients detected a total of 403 ventricular arrhythmias in 39 patients, with all these episodes appropriately detected and treated.

The study reported by Dr. Gold enrolled patients at 42 centers in 13 countries including the United States. The investigators implanted ICDs into 263 patients using commercially available leads, and then 9-12 weeks after placement, they randomized patients at a 2:1 rate to either undergo MRI or receive no MRI and serve as controls. Of the 175 patients randomized to undergo MRI, 156 actually received the examination, a full-body examination, and 147 participated in follow-up to at least 1 month and were part of the safety analysis.

Patient follow-up showed no complications, no episodes of a significant change in ventricular-pacing sensing threshold, and one episode of a significant change in ventricular-sensing amplitude, Dr. Gold reported, showing safety and efficacy outcomes identical to those in the trial of the Biotronik device. During follow-up 34 episodes of ventricular tachycardia or fibrillation occurred in 24 patients in the MRI group, and the implanted ICDs detected and treated all episodes appropriately. Concurrent with Dr. Gold’s report, the results also appeared in an article published online (J. Am. Coll. Cardiol. 2015 [doi:10.1016/j.jacc.2015.04.047]).

[email protected]
On Twitter @mitchelzoler 

Emergency physicians (EPs) are always interested in what are the “tried-and-true” as well as the “latest-and-greatest” devices that will provide the best results for their patients. This article, while not a comprehensive list of every such device introduced over the past few years, does provide an overview of the most notable ones applicable for use in the ED.

Tonometry

TA01i Tonometer
The standard iCare tonometer device (TA01i; iCare Finland Oy, Vantaa, Finland),¹ began to gain acceptance in the United States in 2007 (Figure 1). Early studies² have shown its measurement accuracy of intraocular pressure (IOP) to be equivalent to traditional tonometers such as the Tono-Pen XL Applanation Tonometer (Reichert Techonologies, Depew, New York).³

The iCare tonometer is easy to calibrate and use. Consisting of a pin inserted into a magnetic housing, the magnet quickly pushes the blunt end of the pin out to make contact with the cornea. Six quick measurements provide the clinician with an average IOP. The device can be used without anesthesia and is also applicable for at-home use.

Airway Devices

C-MAC Tip System
While direct laryngoscopy will always have a role in clinical practice, there has been a revolution in airway management over the past  few years, with video laryngoscopy rapidly replacing direct laryngoscopy. The C-MAC Tip system (Karl Storz Endoscopy-America, Inc, El Segundo, California) is one of the devices currently available.^4,5 While this device is not at the lower end of the cost spectrum in airway devices, it is, in this author’s opinion, among the highest quality video laryngoscopes on the market. The hub of C-MAC Tip system is a video screen that accepts input from multiple devices. The most common is the video MacIntosh blade, which is shaped like a traditional MacIntosh but with a slightly thicker handle—allowing both direct and indirect intubation.

The C-MAC Tip system is a great teaching tool, allowing learners to perform direct laryngoscopy while providing reassuring visualization to the instructor of the intubation on the screen. (No longer does the instructor need to repeatedly ask the learner what he or she is viewing!) Moreover, when required, the clinician performing the intubation can look at the screen to benefit from the superior visualization of indirect laryngoscopy.

The C-MAC can also accept input from the D-Blade, which facilitates indirect intubation of anterior airways; however, it does not allow direct intubation when secretions or blood obscure the camera, though there is a suction channel that assists in clearing secretions. The clinician can also add a nasal pharyngeal scope as well as an adult or pediatric bronchoscope. The modularity of the C-MAC system is therefore a flexible addition to any airway armamentarium.

Regarding its use in emergency medicine, in addition to cost considerations, a potential concern is the ability of the plastic adapters to hold up to frequent, repetitive use in a setting such as a busy ED.

Wireless Vital Signs Monitoring Systems

Patient vital signs monitoring systems can currently double as four-point restraints. One new device, the ViSi Mobile Monitor System (Sotera Wireless, Inc, San Diego, CA), however,  may make this a thing of the past.⁶ This system allows for inpatient monitoring of respiratory rate (RR), pulse oximetry, continuous blood pressure (BP), and temperature, as well as a multilead electrocardiogram. The entire system attaches to a small wrist-mounted device, which connects to a hospital monitoring system through a WiFi network (Figures 2a and 2b).ViSi Mobile Monitor

EarlySense Chair Sensor System
Another example of a wireless monitoring device is the EarlySense Chair Sensor system (EarlySense, Ltd, Ramat Gan, Israel) (Figure 3).⁷ This device assesses heart rate (HR) and RR simply by seating the patient in a chair. In the near future, this device will likely have the ability to take full vital signs. While not quite ready for prime-time in the ED, systems such as the EarlySense Chair Sensor offer a glimpse of the future in vital sign monitoring technology.

Vascular Access

Traditional intravenous (IV) line placement continues to be the standard of care for vascular access, but is not always feasible. Intraosseous needles, which have been around for decades, are seeing a new renaissance of use thanks to devices such as the Arrow EZ-IO Intraosseous Vascular Access System (Teleflex, Shavano Park, Texas).⁸ With these standards in mind, some new considerations are on the market, including the AV400 vein visualization system (AccuVein, Inc, Huntington, New York).

Arrow EZ-IO Intraosseous Vascular  Access System
Teleflex, the maker of the EZ-IO, has recently made a push for humeral placement in order to achieve faster flow rates. Teleflex recommends using the longer needles (normally reserved for obese patients) with specific placement suggestions to facilitate retention of the needle. The Teleflex Web site⁸ and mobile application provide succinct, easy-to-understand instructions on placement. 

 

AV400 Vein Visualization System
In addition to the Intraosseous Vascular Access System, the placement of an IV line may also be facilitated by laser devices such as AccuVein’s AV400 vein visualization technology. While earlier versions of both of these systems were comparable to that of a skilled technician in obtaining line placement, the latest generations of these devices have improved depth and visualization of truly difficult vascular access.

Internet-Connected Smart Glasses

In addition to the above-mentioned evolutionary changes in facilitating venous access, revolutionary technological advancements have been in development and are forthcoming. One such technology is network-connected smart glasses.

Eyes-On Glasses
Among the first in network-connected eyewear is Eyes-On Glasses (Evena Medical Inc, Los Altos, California).⁹ This system functions in a similar manner as other laser systems, except that the screen is a display mounted on eyeglasses, making venous placement much more intuitive (This is especially helpful for those who have difficulty translating the three-dimensional world to a two-dimensional screen).

Google Glass
Another variation on head-mounted technology is General Electric’s (GE) beta software for Google Glass (Google Inc, Mountain View, California) (Figure 4). This prototype links a GE ultrasound machine to Google Glass via WiFi, again simultaneously facilitating visualization of the field and the screen.¹⁰ While Google Glass is not currently available for the general public, there is still a place for it in the clinical setting.

Both the Eyes-On Glasses and Google Glass devices share a common thread: to improve patient comfort and facilitate time-consuming procedures.

Wound Care

Aquacel Ag
The EP sees a fair share of burn victims, the standard of care for which has been silver sulfadiazine and daily dressing changes. Care for burn wounds is beginning to change with the introduction of antimicrobial impregnated dressings such as Aquacel Ag (ConvaTec Inc, Greensboro, North Carolina).¹¹ Aquacel Ag comes packaged in various forms and sizes ranging from large sheets for torsos to custom formed gloves for hands. This product is safe to use on the face and can be applied to partial thickness burns where the dermal layer is gone. The fluid from the wound moistens the bandage and helps it adhere to the skin. The dressings are then left in place until they slough-off on their own (approximately 7 to 10 days after placement). Consequently, no dressing changes are required, with cosmesis matching that of classic treatment.

While EPs may find Aquacel Ag useful in treating burns that do not require inpatient hospital admission, they also will find its use highly beneficial in treating patients with “road rash,” the abrasions that occur when one wipes-out at high speeds on asphalt (eg, motorcycle accidents). As with burn wounds, only a single application of Aquacel Ag is required on a debrided abrasion.

With respect to price, a single application of Aquacel Ag costs roughly the same as multiple dressing changes with other wound-care products.¹² One concern relating to the use of advanced silver-impregnated dressings is the cost of care since silver-impregnated dressings are relatively expensive compared to traditional dressings. The higher cost, however, is partially offset by the reduced use of secondary gauze, and retention dressings, as well as improved wound healing together with the reduced costs of other care. Cost-effectiveness calculations comparing Aquacel Ag to standard of care in patients with acute and chronic wounds showed favorable results using Aquacel Ag.^12-18

When using these dressings, the EP should make sure the follow-up clinic is familiar with their application so that they are not inadvertently removed at the patient’s first visit.

Medication Event Monitoring Systems

There have been a couple of recent changes in medication monitoring that are beginning to make manual pill-counting a thing of the past. Earlier generations of smart pill bottles came with a timer and an alarm that chimed and lit up to alert the patient when it was time to take his or her medication. Once the bottle was opened, the system reset itself. Unfortunately, the basic nature of these systems was not able to account for the number of pills a patient ingested at each scheduled dosing.

Smart Pill Bottle
An example of newer and more technologically advanced pill-monitoring systems is AdhereTech’s smart wireless pill bottle (AdhereTech, New York, New York). In this system, the pill bottle can be connected to a WiFi network, allowing medication information to be shared (Figure 5).¹⁹ For example, a user could have the bottle connected to his or her provider, home healthcare worker, and family member. If a patient misses a dose of medication, the appropriate person receives notification and can make contact with the patient or family member to intervene. As with earlier generation products, these systems cannot account for or prevent a patient from either overdosing or underdosing on a medication.

Ingestible Event Marker
The patch and sensor-enabled pill system, the Ingestible Event Marker, (Proteus Digital Health, Redwood City, California), which became available this past year, provides more advanced medication monitoring.²⁰  This system allows tracking of individual pills through small chips imbedded in the tablet (Figure 6). The chip is then monitored through a patch worn on the patient’s body. Once connected, the physician is able to not only track when a pill bottle is opened, but also when and how many tablets the patient is ingesting. Moreover, the system has the ability to perform physiologic tracking to monitor patient response to the medication.²¹

 

Each of the above systems is a huge benefit to elderly patients and their geographically-separated families. Through these devices, children and other family members can stay apprised of a parent or other loved one’s health through these at-home monitoring systems—in a similar manner as some parents track a new teenaged driver through his or her cell phone!

Other Smart Devices

Connected devices are moving past pill bottles and smart glasses. In the same manner that many people employ fitness trackers to monitor the number of steps taken and calories burned, multiple glucometers are available that sync with a patient’s smart phone, allowing upload of the data to his or her healthcare provider. This field is also growing into commercially available HR monitors that allow easy monitoring for arrhythmias in low-risk patients.

While these devices are a boon for primary care physicians and can greatly assist in determining medication noncompliance, some potential systems issues may result in a false emergency notification akin to patients presenting to the ED for evaluation after receiving an inaccurate high BP reading on a grocery-store or home monitoring device. For instance, HR monitors with a faulty lead may cause an alert from the monitoring system noting atrial fibrillation and recommending the patient seek immediate evaluation. Similarly, a smart phone-connected glucometer may note hyperglycemia in a patient after he or she has consumed a high-sugar meal.

Hemorrhage Control

While there has been a reemergence in the use of traditional tourniquets, they are not effective in controlling hemorrhage at junctional sites such as the groin or axilla as there is inadequate space to accommodate the tourniquet. Two recent solutions are the Combat Ready Clamp (CRoC) and SAM Junctional Tourniquet, which are specially designed to control bleeding in an improvised explosive device or blast-type injury. As with intraosseous access devices, the use of tourniquets is also making a comeback. Both owe their new-found popularity—at least in some part—to the involvement of the United States in the recent wars in Iraq and Afghanistan. High casualty rates from improvised explosive devices countered by significant improvements in body armor have resulted in preservation of the torso at the expense of extremities. Life-threatening hemorrhage from a distal extremity can easily be controlled by a tourniquet—something this author never used as an infantryman during Desert Storm, but which is now carried on the person of every soldier in the field.

Combat Ready Clamp and SAM Junctional Tourniquet
The Combat Ready Clamp (Combat Medical Systems, Harrisburg, North Carolina)²² compresses the aorta and vena cava though intra-abdominal pressure (Figure 7). While some may find this device a bit cumbersome for field use, it is definitely feasible and applicable for hospital use. A similar option, the SAM Junctional Tourniquet (SAM Medical Products, Wilsonville, Oregon),²³ (Figure 8) functions in a similar manner as the CROC but uses pneumatic instead of mechanical pressure. The SAM device is definitely more “rucksack friendly,” but both products are good alternatives for controlling hemorrhages in the ED. 

The XStat-30
Hemostatic agents such as QuickClot (Z-Medica, Wallingford, Connecticut)²⁴ have been in popular use for about a decade now, and the next generation of this family of treatment options has become available. The XStat-30 (RevMedx, Wilsonville, Oregon)²⁵ (Figure 9) is one such product. Its large syringe applicator (like a large Toomey syringe) is filled with tablets of chitin. The injector is designed to be inserted into a penetrating injury and its contents injected into the wound. Upon contact with blood, the chitin tablets expand in a similar manner as children’s “hatch-and-grow” toy eggs and capsules when immersed in water. The XStat-30 provides not only hemostasis, but also some level of tamponade.

Resuscitative Endovascular Balloon Occlusion of the Aorta
The final addition to the hemostasis comeback tour is the Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) device (Pryor Medical, San Antonio, Texas).²⁶ Like many of the products discussed in this article, REBOA has been around for some time, but its use had fallen out of practice. A recent reemergence has shown that REBOA benefits patients with lower abdominal, pelvic, and extremity injuries.

The principal of its use is simple: An occlusive balloon is inserted into the femoral artery and advanced to roughly the level of the midabdomen. Once inflated, the balloon stops blood flow distally. While more research needs to be done on indications and outcomes, REBOA has been successfully used in England in many hospitals and even in the field.²⁷

Summary

Some of the most notable recent evolutionary and revolutionary technological advancements to have a significant and beneficial impact on patient care have been seen in new noninvasive tonographic devices to measure IOP; video laryngoscopic devices for airway management; wireless patient vital signs monitoring systems; alternatives to traditional vascular access such as intraosseous vascular systems, laser-assisted vein visualization technology, and Internet-connected smart glasses; advances in wound-care dressings; medication monitoring systems; clamps and tourniquets to control junctional hemorrhage; and wireless, smart-phone connected glucometer devices and HR monitors. Many of these devices and systems are applicable and appropriate for use in the ED, the implementation of which will further facilitate and improve the quality of patient care.

 

Dr Wagner is an assistant professor of emergency medicine; program director for the emergency medicine residency program; and director of augmented learning at Barnes-Jewish Hospital, Saint Louis, Missouri.

The author invites readers to contact him via Twitter @TheTechDoc with suggestions for future devices.

The views expressed in this article are those of the author and do not represent the views or opinions of the editorial staff, the editorial board or the publisher.

Emergency physicians (EPs) are always interested in what are the “tried-and-true” as well as the “latest-and-greatest” devices that will provide the best results for their patients. This article, while not a comprehensive list of every such device introduced over the past few years, does provide an overview of the most notable ones applicable for use in the ED.

Tonometry

TA01i Tonometer
The standard iCare tonometer device (TA01i; iCare Finland Oy, Vantaa, Finland),¹ began to gain acceptance in the United States in 2007 (Figure 1). Early studies² have shown its measurement accuracy of intraocular pressure (IOP) to be equivalent to traditional tonometers such as the Tono-Pen XL Applanation Tonometer (Reichert Techonologies, Depew, New York).³

The iCare tonometer is easy to calibrate and use. Consisting of a pin inserted into a magnetic housing, the magnet quickly pushes the blunt end of the pin out to make contact with the cornea. Six quick measurements provide the clinician with an average IOP. The device can be used without anesthesia and is also applicable for at-home use.

Airway Devices

C-MAC Tip System
While direct laryngoscopy will always have a role in clinical practice, there has been a revolution in airway management over the past  few years, with video laryngoscopy rapidly replacing direct laryngoscopy. The C-MAC Tip system (Karl Storz Endoscopy-America, Inc, El Segundo, California) is one of the devices currently available.^4,5 While this device is not at the lower end of the cost spectrum in airway devices, it is, in this author’s opinion, among the highest quality video laryngoscopes on the market. The hub of C-MAC Tip system is a video screen that accepts input from multiple devices. The most common is the video MacIntosh blade, which is shaped like a traditional MacIntosh but with a slightly thicker handle—allowing both direct and indirect intubation.

The C-MAC Tip system is a great teaching tool, allowing learners to perform direct laryngoscopy while providing reassuring visualization to the instructor of the intubation on the screen. (No longer does the instructor need to repeatedly ask the learner what he or she is viewing!) Moreover, when required, the clinician performing the intubation can look at the screen to benefit from the superior visualization of indirect laryngoscopy.

The C-MAC can also accept input from the D-Blade, which facilitates indirect intubation of anterior airways; however, it does not allow direct intubation when secretions or blood obscure the camera, though there is a suction channel that assists in clearing secretions. The clinician can also add a nasal pharyngeal scope as well as an adult or pediatric bronchoscope. The modularity of the C-MAC system is therefore a flexible addition to any airway armamentarium.

Regarding its use in emergency medicine, in addition to cost considerations, a potential concern is the ability of the plastic adapters to hold up to frequent, repetitive use in a setting such as a busy ED.

Wireless Vital Signs Monitoring Systems

Patient vital signs monitoring systems can currently double as four-point restraints. One new device, the ViSi Mobile Monitor System (Sotera Wireless, Inc, San Diego, CA), however,  may make this a thing of the past.⁶ This system allows for inpatient monitoring of respiratory rate (RR), pulse oximetry, continuous blood pressure (BP), and temperature, as well as a multilead electrocardiogram. The entire system attaches to a small wrist-mounted device, which connects to a hospital monitoring system through a WiFi network (Figures 2a and 2b).ViSi Mobile Monitor

EarlySense Chair Sensor System
Another example of a wireless monitoring device is the EarlySense Chair Sensor system (EarlySense, Ltd, Ramat Gan, Israel) (Figure 3).⁷ This device assesses heart rate (HR) and RR simply by seating the patient in a chair. In the near future, this device will likely have the ability to take full vital signs. While not quite ready for prime-time in the ED, systems such as the EarlySense Chair Sensor offer a glimpse of the future in vital sign monitoring technology.

Vascular Access

Traditional intravenous (IV) line placement continues to be the standard of care for vascular access, but is not always feasible. Intraosseous needles, which have been around for decades, are seeing a new renaissance of use thanks to devices such as the Arrow EZ-IO Intraosseous Vascular Access System (Teleflex, Shavano Park, Texas).⁸ With these standards in mind, some new considerations are on the market, including the AV400 vein visualization system (AccuVein, Inc, Huntington, New York).

Arrow EZ-IO Intraosseous Vascular  Access System
Teleflex, the maker of the EZ-IO, has recently made a push for humeral placement in order to achieve faster flow rates. Teleflex recommends using the longer needles (normally reserved for obese patients) with specific placement suggestions to facilitate retention of the needle. The Teleflex Web site⁸ and mobile application provide succinct, easy-to-understand instructions on placement. 

 

AV400 Vein Visualization System
In addition to the Intraosseous Vascular Access System, the placement of an IV line may also be facilitated by laser devices such as AccuVein’s AV400 vein visualization technology. While earlier versions of both of these systems were comparable to that of a skilled technician in obtaining line placement, the latest generations of these devices have improved depth and visualization of truly difficult vascular access.

Internet-Connected Smart Glasses

In addition to the above-mentioned evolutionary changes in facilitating venous access, revolutionary technological advancements have been in development and are forthcoming. One such technology is network-connected smart glasses.

Eyes-On Glasses
Among the first in network-connected eyewear is Eyes-On Glasses (Evena Medical Inc, Los Altos, California).⁹ This system functions in a similar manner as other laser systems, except that the screen is a display mounted on eyeglasses, making venous placement much more intuitive (This is especially helpful for those who have difficulty translating the three-dimensional world to a two-dimensional screen).

Google Glass
Another variation on head-mounted technology is General Electric’s (GE) beta software for Google Glass (Google Inc, Mountain View, California) (Figure 4). This prototype links a GE ultrasound machine to Google Glass via WiFi, again simultaneously facilitating visualization of the field and the screen.¹⁰ While Google Glass is not currently available for the general public, there is still a place for it in the clinical setting.

Both the Eyes-On Glasses and Google Glass devices share a common thread: to improve patient comfort and facilitate time-consuming procedures.

Wound Care

Aquacel Ag
The EP sees a fair share of burn victims, the standard of care for which has been silver sulfadiazine and daily dressing changes. Care for burn wounds is beginning to change with the introduction of antimicrobial impregnated dressings such as Aquacel Ag (ConvaTec Inc, Greensboro, North Carolina).¹¹ Aquacel Ag comes packaged in various forms and sizes ranging from large sheets for torsos to custom formed gloves for hands. This product is safe to use on the face and can be applied to partial thickness burns where the dermal layer is gone. The fluid from the wound moistens the bandage and helps it adhere to the skin. The dressings are then left in place until they slough-off on their own (approximately 7 to 10 days after placement). Consequently, no dressing changes are required, with cosmesis matching that of classic treatment.

While EPs may find Aquacel Ag useful in treating burns that do not require inpatient hospital admission, they also will find its use highly beneficial in treating patients with “road rash,” the abrasions that occur when one wipes-out at high speeds on asphalt (eg, motorcycle accidents). As with burn wounds, only a single application of Aquacel Ag is required on a debrided abrasion.

With respect to price, a single application of Aquacel Ag costs roughly the same as multiple dressing changes with other wound-care products.¹² One concern relating to the use of advanced silver-impregnated dressings is the cost of care since silver-impregnated dressings are relatively expensive compared to traditional dressings. The higher cost, however, is partially offset by the reduced use of secondary gauze, and retention dressings, as well as improved wound healing together with the reduced costs of other care. Cost-effectiveness calculations comparing Aquacel Ag to standard of care in patients with acute and chronic wounds showed favorable results using Aquacel Ag.^12-18

When using these dressings, the EP should make sure the follow-up clinic is familiar with their application so that they are not inadvertently removed at the patient’s first visit.

Medication Event Monitoring Systems

There have been a couple of recent changes in medication monitoring that are beginning to make manual pill-counting a thing of the past. Earlier generations of smart pill bottles came with a timer and an alarm that chimed and lit up to alert the patient when it was time to take his or her medication. Once the bottle was opened, the system reset itself. Unfortunately, the basic nature of these systems was not able to account for the number of pills a patient ingested at each scheduled dosing.

Smart Pill Bottle
An example of newer and more technologically advanced pill-monitoring systems is AdhereTech’s smart wireless pill bottle (AdhereTech, New York, New York). In this system, the pill bottle can be connected to a WiFi network, allowing medication information to be shared (Figure 5).¹⁹ For example, a user could have the bottle connected to his or her provider, home healthcare worker, and family member. If a patient misses a dose of medication, the appropriate person receives notification and can make contact with the patient or family member to intervene. As with earlier generation products, these systems cannot account for or prevent a patient from either overdosing or underdosing on a medication.

Ingestible Event Marker
The patch and sensor-enabled pill system, the Ingestible Event Marker, (Proteus Digital Health, Redwood City, California), which became available this past year, provides more advanced medication monitoring.²⁰  This system allows tracking of individual pills through small chips imbedded in the tablet (Figure 6). The chip is then monitored through a patch worn on the patient’s body. Once connected, the physician is able to not only track when a pill bottle is opened, but also when and how many tablets the patient is ingesting. Moreover, the system has the ability to perform physiologic tracking to monitor patient response to the medication.²¹

 

Each of the above systems is a huge benefit to elderly patients and their geographically-separated families. Through these devices, children and other family members can stay apprised of a parent or other loved one’s health through these at-home monitoring systems—in a similar manner as some parents track a new teenaged driver through his or her cell phone!

Other Smart Devices

Connected devices are moving past pill bottles and smart glasses. In the same manner that many people employ fitness trackers to monitor the number of steps taken and calories burned, multiple glucometers are available that sync with a patient’s smart phone, allowing upload of the data to his or her healthcare provider. This field is also growing into commercially available HR monitors that allow easy monitoring for arrhythmias in low-risk patients.

While these devices are a boon for primary care physicians and can greatly assist in determining medication noncompliance, some potential systems issues may result in a false emergency notification akin to patients presenting to the ED for evaluation after receiving an inaccurate high BP reading on a grocery-store or home monitoring device. For instance, HR monitors with a faulty lead may cause an alert from the monitoring system noting atrial fibrillation and recommending the patient seek immediate evaluation. Similarly, a smart phone-connected glucometer may note hyperglycemia in a patient after he or she has consumed a high-sugar meal.

Hemorrhage Control

While there has been a reemergence in the use of traditional tourniquets, they are not effective in controlling hemorrhage at junctional sites such as the groin or axilla as there is inadequate space to accommodate the tourniquet. Two recent solutions are the Combat Ready Clamp (CRoC) and SAM Junctional Tourniquet, which are specially designed to control bleeding in an improvised explosive device or blast-type injury. As with intraosseous access devices, the use of tourniquets is also making a comeback. Both owe their new-found popularity—at least in some part—to the involvement of the United States in the recent wars in Iraq and Afghanistan. High casualty rates from improvised explosive devices countered by significant improvements in body armor have resulted in preservation of the torso at the expense of extremities. Life-threatening hemorrhage from a distal extremity can easily be controlled by a tourniquet—something this author never used as an infantryman during Desert Storm, but which is now carried on the person of every soldier in the field.

Combat Ready Clamp and SAM Junctional Tourniquet
The Combat Ready Clamp (Combat Medical Systems, Harrisburg, North Carolina)²² compresses the aorta and vena cava though intra-abdominal pressure (Figure 7). While some may find this device a bit cumbersome for field use, it is definitely feasible and applicable for hospital use. A similar option, the SAM Junctional Tourniquet (SAM Medical Products, Wilsonville, Oregon),²³ (Figure 8) functions in a similar manner as the CROC but uses pneumatic instead of mechanical pressure. The SAM device is definitely more “rucksack friendly,” but both products are good alternatives for controlling hemorrhages in the ED. 

The XStat-30
Hemostatic agents such as QuickClot (Z-Medica, Wallingford, Connecticut)²⁴ have been in popular use for about a decade now, and the next generation of this family of treatment options has become available. The XStat-30 (RevMedx, Wilsonville, Oregon)²⁵ (Figure 9) is one such product. Its large syringe applicator (like a large Toomey syringe) is filled with tablets of chitin. The injector is designed to be inserted into a penetrating injury and its contents injected into the wound. Upon contact with blood, the chitin tablets expand in a similar manner as children’s “hatch-and-grow” toy eggs and capsules when immersed in water. The XStat-30 provides not only hemostasis, but also some level of tamponade.

Resuscitative Endovascular Balloon Occlusion of the Aorta
The final addition to the hemostasis comeback tour is the Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) device (Pryor Medical, San Antonio, Texas).²⁶ Like many of the products discussed in this article, REBOA has been around for some time, but its use had fallen out of practice. A recent reemergence has shown that REBOA benefits patients with lower abdominal, pelvic, and extremity injuries.

The principal of its use is simple: An occlusive balloon is inserted into the femoral artery and advanced to roughly the level of the midabdomen. Once inflated, the balloon stops blood flow distally. While more research needs to be done on indications and outcomes, REBOA has been successfully used in England in many hospitals and even in the field.²⁷

Summary

Some of the most notable recent evolutionary and revolutionary technological advancements to have a significant and beneficial impact on patient care have been seen in new noninvasive tonographic devices to measure IOP; video laryngoscopic devices for airway management; wireless patient vital signs monitoring systems; alternatives to traditional vascular access such as intraosseous vascular systems, laser-assisted vein visualization technology, and Internet-connected smart glasses; advances in wound-care dressings; medication monitoring systems; clamps and tourniquets to control junctional hemorrhage; and wireless, smart-phone connected glucometer devices and HR monitors. Many of these devices and systems are applicable and appropriate for use in the ED, the implementation of which will further facilitate and improve the quality of patient care.

 

Dr Wagner is an assistant professor of emergency medicine; program director for the emergency medicine residency program; and director of augmented learning at Barnes-Jewish Hospital, Saint Louis, Missouri.

The author invites readers to contact him via Twitter @TheTechDoc with suggestions for future devices.

The views expressed in this article are those of the author and do not represent the views or opinions of the editorial staff, the editorial board or the publisher.

Emergency physicians (EPs) are always interested in what are the “tried-and-true” as well as the “latest-and-greatest” devices that will provide the best results for their patients. This article, while not a comprehensive list of every such device introduced over the past few years, does provide an overview of the most notable ones applicable for use in the ED.

Tonometry

TA01i Tonometer
The standard iCare tonometer device (TA01i; iCare Finland Oy, Vantaa, Finland),¹ began to gain acceptance in the United States in 2007 (Figure 1). Early studies² have shown its measurement accuracy of intraocular pressure (IOP) to be equivalent to traditional tonometers such as the Tono-Pen XL Applanation Tonometer (Reichert Techonologies, Depew, New York).³

The iCare tonometer is easy to calibrate and use. Consisting of a pin inserted into a magnetic housing, the magnet quickly pushes the blunt end of the pin out to make contact with the cornea. Six quick measurements provide the clinician with an average IOP. The device can be used without anesthesia and is also applicable for at-home use.

Airway Devices

C-MAC Tip System
While direct laryngoscopy will always have a role in clinical practice, there has been a revolution in airway management over the past  few years, with video laryngoscopy rapidly replacing direct laryngoscopy. The C-MAC Tip system (Karl Storz Endoscopy-America, Inc, El Segundo, California) is one of the devices currently available.^4,5 While this device is not at the lower end of the cost spectrum in airway devices, it is, in this author’s opinion, among the highest quality video laryngoscopes on the market. The hub of C-MAC Tip system is a video screen that accepts input from multiple devices. The most common is the video MacIntosh blade, which is shaped like a traditional MacIntosh but with a slightly thicker handle—allowing both direct and indirect intubation.

The C-MAC Tip system is a great teaching tool, allowing learners to perform direct laryngoscopy while providing reassuring visualization to the instructor of the intubation on the screen. (No longer does the instructor need to repeatedly ask the learner what he or she is viewing!) Moreover, when required, the clinician performing the intubation can look at the screen to benefit from the superior visualization of indirect laryngoscopy.

The C-MAC can also accept input from the D-Blade, which facilitates indirect intubation of anterior airways; however, it does not allow direct intubation when secretions or blood obscure the camera, though there is a suction channel that assists in clearing secretions. The clinician can also add a nasal pharyngeal scope as well as an adult or pediatric bronchoscope. The modularity of the C-MAC system is therefore a flexible addition to any airway armamentarium.

Regarding its use in emergency medicine, in addition to cost considerations, a potential concern is the ability of the plastic adapters to hold up to frequent, repetitive use in a setting such as a busy ED.

Wireless Vital Signs Monitoring Systems

Patient vital signs monitoring systems can currently double as four-point restraints. One new device, the ViSi Mobile Monitor System (Sotera Wireless, Inc, San Diego, CA), however,  may make this a thing of the past.⁶ This system allows for inpatient monitoring of respiratory rate (RR), pulse oximetry, continuous blood pressure (BP), and temperature, as well as a multilead electrocardiogram. The entire system attaches to a small wrist-mounted device, which connects to a hospital monitoring system through a WiFi network (Figures 2a and 2b).ViSi Mobile Monitor

EarlySense Chair Sensor System
Another example of a wireless monitoring device is the EarlySense Chair Sensor system (EarlySense, Ltd, Ramat Gan, Israel) (Figure 3).⁷ This device assesses heart rate (HR) and RR simply by seating the patient in a chair. In the near future, this device will likely have the ability to take full vital signs. While not quite ready for prime-time in the ED, systems such as the EarlySense Chair Sensor offer a glimpse of the future in vital sign monitoring technology.

Vascular Access

Traditional intravenous (IV) line placement continues to be the standard of care for vascular access, but is not always feasible. Intraosseous needles, which have been around for decades, are seeing a new renaissance of use thanks to devices such as the Arrow EZ-IO Intraosseous Vascular Access System (Teleflex, Shavano Park, Texas).⁸ With these standards in mind, some new considerations are on the market, including the AV400 vein visualization system (AccuVein, Inc, Huntington, New York).

Arrow EZ-IO Intraosseous Vascular  Access System
Teleflex, the maker of the EZ-IO, has recently made a push for humeral placement in order to achieve faster flow rates. Teleflex recommends using the longer needles (normally reserved for obese patients) with specific placement suggestions to facilitate retention of the needle. The Teleflex Web site⁸ and mobile application provide succinct, easy-to-understand instructions on placement. 

 

AV400 Vein Visualization System
In addition to the Intraosseous Vascular Access System, the placement of an IV line may also be facilitated by laser devices such as AccuVein’s AV400 vein visualization technology. While earlier versions of both of these systems were comparable to that of a skilled technician in obtaining line placement, the latest generations of these devices have improved depth and visualization of truly difficult vascular access.

Internet-Connected Smart Glasses

In addition to the above-mentioned evolutionary changes in facilitating venous access, revolutionary technological advancements have been in development and are forthcoming. One such technology is network-connected smart glasses.

Eyes-On Glasses
Among the first in network-connected eyewear is Eyes-On Glasses (Evena Medical Inc, Los Altos, California).⁹ This system functions in a similar manner as other laser systems, except that the screen is a display mounted on eyeglasses, making venous placement much more intuitive (This is especially helpful for those who have difficulty translating the three-dimensional world to a two-dimensional screen).

Google Glass
Another variation on head-mounted technology is General Electric’s (GE) beta software for Google Glass (Google Inc, Mountain View, California) (Figure 4). This prototype links a GE ultrasound machine to Google Glass via WiFi, again simultaneously facilitating visualization of the field and the screen.¹⁰ While Google Glass is not currently available for the general public, there is still a place for it in the clinical setting.

Both the Eyes-On Glasses and Google Glass devices share a common thread: to improve patient comfort and facilitate time-consuming procedures.

Wound Care

Aquacel Ag
The EP sees a fair share of burn victims, the standard of care for which has been silver sulfadiazine and daily dressing changes. Care for burn wounds is beginning to change with the introduction of antimicrobial impregnated dressings such as Aquacel Ag (ConvaTec Inc, Greensboro, North Carolina).¹¹ Aquacel Ag comes packaged in various forms and sizes ranging from large sheets for torsos to custom formed gloves for hands. This product is safe to use on the face and can be applied to partial thickness burns where the dermal layer is gone. The fluid from the wound moistens the bandage and helps it adhere to the skin. The dressings are then left in place until they slough-off on their own (approximately 7 to 10 days after placement). Consequently, no dressing changes are required, with cosmesis matching that of classic treatment.

While EPs may find Aquacel Ag useful in treating burns that do not require inpatient hospital admission, they also will find its use highly beneficial in treating patients with “road rash,” the abrasions that occur when one wipes-out at high speeds on asphalt (eg, motorcycle accidents). As with burn wounds, only a single application of Aquacel Ag is required on a debrided abrasion.

With respect to price, a single application of Aquacel Ag costs roughly the same as multiple dressing changes with other wound-care products.¹² One concern relating to the use of advanced silver-impregnated dressings is the cost of care since silver-impregnated dressings are relatively expensive compared to traditional dressings. The higher cost, however, is partially offset by the reduced use of secondary gauze, and retention dressings, as well as improved wound healing together with the reduced costs of other care. Cost-effectiveness calculations comparing Aquacel Ag to standard of care in patients with acute and chronic wounds showed favorable results using Aquacel Ag.^12-18

When using these dressings, the EP should make sure the follow-up clinic is familiar with their application so that they are not inadvertently removed at the patient’s first visit.

Medication Event Monitoring Systems

There have been a couple of recent changes in medication monitoring that are beginning to make manual pill-counting a thing of the past. Earlier generations of smart pill bottles came with a timer and an alarm that chimed and lit up to alert the patient when it was time to take his or her medication. Once the bottle was opened, the system reset itself. Unfortunately, the basic nature of these systems was not able to account for the number of pills a patient ingested at each scheduled dosing.

Smart Pill Bottle
An example of newer and more technologically advanced pill-monitoring systems is AdhereTech’s smart wireless pill bottle (AdhereTech, New York, New York). In this system, the pill bottle can be connected to a WiFi network, allowing medication information to be shared (Figure 5).¹⁹ For example, a user could have the bottle connected to his or her provider, home healthcare worker, and family member. If a patient misses a dose of medication, the appropriate person receives notification and can make contact with the patient or family member to intervene. As with earlier generation products, these systems cannot account for or prevent a patient from either overdosing or underdosing on a medication.

Ingestible Event Marker
The patch and sensor-enabled pill system, the Ingestible Event Marker, (Proteus Digital Health, Redwood City, California), which became available this past year, provides more advanced medication monitoring.²⁰  This system allows tracking of individual pills through small chips imbedded in the tablet (Figure 6). The chip is then monitored through a patch worn on the patient’s body. Once connected, the physician is able to not only track when a pill bottle is opened, but also when and how many tablets the patient is ingesting. Moreover, the system has the ability to perform physiologic tracking to monitor patient response to the medication.²¹

 

Each of the above systems is a huge benefit to elderly patients and their geographically-separated families. Through these devices, children and other family members can stay apprised of a parent or other loved one’s health through these at-home monitoring systems—in a similar manner as some parents track a new teenaged driver through his or her cell phone!

Other Smart Devices

Connected devices are moving past pill bottles and smart glasses. In the same manner that many people employ fitness trackers to monitor the number of steps taken and calories burned, multiple glucometers are available that sync with a patient’s smart phone, allowing upload of the data to his or her healthcare provider. This field is also growing into commercially available HR monitors that allow easy monitoring for arrhythmias in low-risk patients.

While these devices are a boon for primary care physicians and can greatly assist in determining medication noncompliance, some potential systems issues may result in a false emergency notification akin to patients presenting to the ED for evaluation after receiving an inaccurate high BP reading on a grocery-store or home monitoring device. For instance, HR monitors with a faulty lead may cause an alert from the monitoring system noting atrial fibrillation and recommending the patient seek immediate evaluation. Similarly, a smart phone-connected glucometer may note hyperglycemia in a patient after he or she has consumed a high-sugar meal.

Hemorrhage Control

While there has been a reemergence in the use of traditional tourniquets, they are not effective in controlling hemorrhage at junctional sites such as the groin or axilla as there is inadequate space to accommodate the tourniquet. Two recent solutions are the Combat Ready Clamp (CRoC) and SAM Junctional Tourniquet, which are specially designed to control bleeding in an improvised explosive device or blast-type injury. As with intraosseous access devices, the use of tourniquets is also making a comeback. Both owe their new-found popularity—at least in some part—to the involvement of the United States in the recent wars in Iraq and Afghanistan. High casualty rates from improvised explosive devices countered by significant improvements in body armor have resulted in preservation of the torso at the expense of extremities. Life-threatening hemorrhage from a distal extremity can easily be controlled by a tourniquet—something this author never used as an infantryman during Desert Storm, but which is now carried on the person of every soldier in the field.

Combat Ready Clamp and SAM Junctional Tourniquet
The Combat Ready Clamp (Combat Medical Systems, Harrisburg, North Carolina)²² compresses the aorta and vena cava though intra-abdominal pressure (Figure 7). While some may find this device a bit cumbersome for field use, it is definitely feasible and applicable for hospital use. A similar option, the SAM Junctional Tourniquet (SAM Medical Products, Wilsonville, Oregon),²³ (Figure 8) functions in a similar manner as the CROC but uses pneumatic instead of mechanical pressure. The SAM device is definitely more “rucksack friendly,” but both products are good alternatives for controlling hemorrhages in the ED. 

The XStat-30
Hemostatic agents such as QuickClot (Z-Medica, Wallingford, Connecticut)²⁴ have been in popular use for about a decade now, and the next generation of this family of treatment options has become available. The XStat-30 (RevMedx, Wilsonville, Oregon)²⁵ (Figure 9) is one such product. Its large syringe applicator (like a large Toomey syringe) is filled with tablets of chitin. The injector is designed to be inserted into a penetrating injury and its contents injected into the wound. Upon contact with blood, the chitin tablets expand in a similar manner as children’s “hatch-and-grow” toy eggs and capsules when immersed in water. The XStat-30 provides not only hemostasis, but also some level of tamponade.

Resuscitative Endovascular Balloon Occlusion of the Aorta
The final addition to the hemostasis comeback tour is the Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) device (Pryor Medical, San Antonio, Texas).²⁶ Like many of the products discussed in this article, REBOA has been around for some time, but its use had fallen out of practice. A recent reemergence has shown that REBOA benefits patients with lower abdominal, pelvic, and extremity injuries.

The principal of its use is simple: An occlusive balloon is inserted into the femoral artery and advanced to roughly the level of the midabdomen. Once inflated, the balloon stops blood flow distally. While more research needs to be done on indications and outcomes, REBOA has been successfully used in England in many hospitals and even in the field.²⁷

Summary

Some of the most notable recent evolutionary and revolutionary technological advancements to have a significant and beneficial impact on patient care have been seen in new noninvasive tonographic devices to measure IOP; video laryngoscopic devices for airway management; wireless patient vital signs monitoring systems; alternatives to traditional vascular access such as intraosseous vascular systems, laser-assisted vein visualization technology, and Internet-connected smart glasses; advances in wound-care dressings; medication monitoring systems; clamps and tourniquets to control junctional hemorrhage; and wireless, smart-phone connected glucometer devices and HR monitors. Many of these devices and systems are applicable and appropriate for use in the ED, the implementation of which will further facilitate and improve the quality of patient care.

 

Dr Wagner is an assistant professor of emergency medicine; program director for the emergency medicine residency program; and director of augmented learning at Barnes-Jewish Hospital, Saint Louis, Missouri.

The author invites readers to contact him via Twitter @TheTechDoc with suggestions for future devices.

The views expressed in this article are those of the author and do not represent the views or opinions of the editorial staff, the editorial board or the publisher.

Background

In practiced hands, ultrasound is more sensitive than chest X-ray in evaluating patients with suspected pneumothorax. Due to its portability, this modality can rapidly identify pathology and facilitate prompt intervention in a decompensating patient. This article reviews the proper techniques for evaluating patients for pneumothorax as well as the classic signs indicative of this condition.

Performing the Scan

The probe also should be oriented as perpendicular to the chest wall as possible, which will make the pleura appear brighter. Once this view is achieved, the clinician can evaluate for evidence of lung sliding. Since air in pneumothorax rises to the least dependent portion of the chest, this is the area that should be evaluated. In the supine patient, the probe is placed on the anterior chest wall in the second intercostal space, midclavicular line. A high-frequency linear probe is best for evaluating pneumothorax and should be positioned with the indicator marker toward the head. The clinician will need to adjust the probe to visualize the pleura, which will appear as a bright hyperechoic line outlined on both sides by a rib with shadowing beneath (Figure 1).

Identifying Pathology

Lung Siding and Comet-Tail Artifacts

The appearance of lung sliding or a comet-tail artifact on the ultrasound confirms the lung is inflated. Lung sliding has been described as a shimmering appearance of the pleura, or like tiny ants marching on a string. The pleura will seem to slide back and forth as the patient breathes. Comet tails, vertical artifacts originating from the pleura, may be visible on ultrasound, also proving the lung is inflated (Figure 2).

The Lung Point

By continuing to scan laterally down the chest, the clinician may encounter the “lung point”—the junction between the normally inflated lung and pneumothorax. This point moves with respiration, and if visualized, confirms pneumothorax.

Motion Mode

Since lung sliding is sometimes challenging to visualize, using the motion mode (M-mode) on ultrasound can help to confirm findings. The M-mode takes a single line of echoes from the two-dimensional image and plots it against time. (The manner in which the image is produced may be thought of as a graph, with the x-axis representing time and the y-axis the depth.) When using M-mode, the screen will vary in appearance depending on the type of ultrasound being used. While performing the ultrasound, it is important to always keep the probe as still as possible to identify independent motion at the pleura.

Sand-on-the-Beach Sign

In a normal lung, M-mode images are often described as having a “sand-on-the-beach” appearance (Figure 3). As a normal lung inflates, the motion of the lung changes the brightness of the echoes that return to the machine, creating a speckled appearance like grains of sand beneath the bright pleural line. The soft tissues above the pleural line do not vary with time and thus have a linear appearance.

Barcode or Stratosphere Sign

In pneumothorax, however, the granular sand appearance is absent. Instead, the M-mode shows a linear pattern below the pleural line. This pattern is described as the “barcode sign” or “stratosphere sign” (Figure 4).

Pitfalls

There are several pitfalls that can limit the ability to correctly diagnose a pneumothorax. The presence of scarring and adhesions may cause the patient to develop loculated air collections. If one evaluates only the anterior chest, air trapped in another location may be missed. The clinician should also be mindful of the presence of bullae as the appearance of sliding may be diminished in patients with bullous disease. Using the M-mode in these cases may help to identify inflated lung in patients with limited movement at the pleural line.

Furthermore, since it is easy to confuse a bright layer of fascia with the pleura, the clinician should always make sure to identify landmarks. In some cases of pneumothorax, subcutaneous air may obscure the pleura. The ribs should always be identified to ensure one is looking at the pleural line.

Although absence of lung sliding can suggest pneumothorax, other conditions, such as severe consolidation, acute respiratory distress syndrome, and mainstem intubation, can give a similar appearance. Remember, visualization of the lung point is pathnognomic for pneumothorax.

Conclusion

Pneumothorax is a medical emergency requiring immediate diagnosis and treatment. Patients presenting with suspected pneumothorax can be assessed quickly through bedside ultrasound. Once visualization of the pleura is established, the lung may be assessed for the presence or absence of normal lung sliding and comet-tail artifacts. The M-mode setting further enhances visualization and aids in the diagnosis of pneumothorax.

 

Dr Beck is an assistant professor, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. Dr Meer is an assistant professor and director of emergency ultrasound, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. Dr Taylor is an assistant professor and director of postgraduate medical education, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. 

Background

In practiced hands, ultrasound is more sensitive than chest X-ray in evaluating patients with suspected pneumothorax. Due to its portability, this modality can rapidly identify pathology and facilitate prompt intervention in a decompensating patient. This article reviews the proper techniques for evaluating patients for pneumothorax as well as the classic signs indicative of this condition.

Performing the Scan

The probe also should be oriented as perpendicular to the chest wall as possible, which will make the pleura appear brighter. Once this view is achieved, the clinician can evaluate for evidence of lung sliding. Since air in pneumothorax rises to the least dependent portion of the chest, this is the area that should be evaluated. In the supine patient, the probe is placed on the anterior chest wall in the second intercostal space, midclavicular line. A high-frequency linear probe is best for evaluating pneumothorax and should be positioned with the indicator marker toward the head. The clinician will need to adjust the probe to visualize the pleura, which will appear as a bright hyperechoic line outlined on both sides by a rib with shadowing beneath (Figure 1).

Identifying Pathology

Lung Siding and Comet-Tail Artifacts

The appearance of lung sliding or a comet-tail artifact on the ultrasound confirms the lung is inflated. Lung sliding has been described as a shimmering appearance of the pleura, or like tiny ants marching on a string. The pleura will seem to slide back and forth as the patient breathes. Comet tails, vertical artifacts originating from the pleura, may be visible on ultrasound, also proving the lung is inflated (Figure 2).

The Lung Point

By continuing to scan laterally down the chest, the clinician may encounter the “lung point”—the junction between the normally inflated lung and pneumothorax. This point moves with respiration, and if visualized, confirms pneumothorax.

Motion Mode

Since lung sliding is sometimes challenging to visualize, using the motion mode (M-mode) on ultrasound can help to confirm findings. The M-mode takes a single line of echoes from the two-dimensional image and plots it against time. (The manner in which the image is produced may be thought of as a graph, with the x-axis representing time and the y-axis the depth.) When using M-mode, the screen will vary in appearance depending on the type of ultrasound being used. While performing the ultrasound, it is important to always keep the probe as still as possible to identify independent motion at the pleura.

Sand-on-the-Beach Sign

In a normal lung, M-mode images are often described as having a “sand-on-the-beach” appearance (Figure 3). As a normal lung inflates, the motion of the lung changes the brightness of the echoes that return to the machine, creating a speckled appearance like grains of sand beneath the bright pleural line. The soft tissues above the pleural line do not vary with time and thus have a linear appearance.

Barcode or Stratosphere Sign

In pneumothorax, however, the granular sand appearance is absent. Instead, the M-mode shows a linear pattern below the pleural line. This pattern is described as the “barcode sign” or “stratosphere sign” (Figure 4).

Pitfalls

There are several pitfalls that can limit the ability to correctly diagnose a pneumothorax. The presence of scarring and adhesions may cause the patient to develop loculated air collections. If one evaluates only the anterior chest, air trapped in another location may be missed. The clinician should also be mindful of the presence of bullae as the appearance of sliding may be diminished in patients with bullous disease. Using the M-mode in these cases may help to identify inflated lung in patients with limited movement at the pleural line.

Furthermore, since it is easy to confuse a bright layer of fascia with the pleura, the clinician should always make sure to identify landmarks. In some cases of pneumothorax, subcutaneous air may obscure the pleura. The ribs should always be identified to ensure one is looking at the pleural line.

Although absence of lung sliding can suggest pneumothorax, other conditions, such as severe consolidation, acute respiratory distress syndrome, and mainstem intubation, can give a similar appearance. Remember, visualization of the lung point is pathnognomic for pneumothorax.

Conclusion

Pneumothorax is a medical emergency requiring immediate diagnosis and treatment. Patients presenting with suspected pneumothorax can be assessed quickly through bedside ultrasound. Once visualization of the pleura is established, the lung may be assessed for the presence or absence of normal lung sliding and comet-tail artifacts. The M-mode setting further enhances visualization and aids in the diagnosis of pneumothorax.

 

Dr Beck is an assistant professor, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. Dr Meer is an assistant professor and director of emergency ultrasound, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. Dr Taylor is an assistant professor and director of postgraduate medical education, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. 

Background

In practiced hands, ultrasound is more sensitive than chest X-ray in evaluating patients with suspected pneumothorax. Due to its portability, this modality can rapidly identify pathology and facilitate prompt intervention in a decompensating patient. This article reviews the proper techniques for evaluating patients for pneumothorax as well as the classic signs indicative of this condition.

Performing the Scan

The probe also should be oriented as perpendicular to the chest wall as possible, which will make the pleura appear brighter. Once this view is achieved, the clinician can evaluate for evidence of lung sliding. Since air in pneumothorax rises to the least dependent portion of the chest, this is the area that should be evaluated. In the supine patient, the probe is placed on the anterior chest wall in the second intercostal space, midclavicular line. A high-frequency linear probe is best for evaluating pneumothorax and should be positioned with the indicator marker toward the head. The clinician will need to adjust the probe to visualize the pleura, which will appear as a bright hyperechoic line outlined on both sides by a rib with shadowing beneath (Figure 1).

Identifying Pathology

Lung Siding and Comet-Tail Artifacts

The appearance of lung sliding or a comet-tail artifact on the ultrasound confirms the lung is inflated. Lung sliding has been described as a shimmering appearance of the pleura, or like tiny ants marching on a string. The pleura will seem to slide back and forth as the patient breathes. Comet tails, vertical artifacts originating from the pleura, may be visible on ultrasound, also proving the lung is inflated (Figure 2).

The Lung Point

By continuing to scan laterally down the chest, the clinician may encounter the “lung point”—the junction between the normally inflated lung and pneumothorax. This point moves with respiration, and if visualized, confirms pneumothorax.

Motion Mode

Since lung sliding is sometimes challenging to visualize, using the motion mode (M-mode) on ultrasound can help to confirm findings. The M-mode takes a single line of echoes from the two-dimensional image and plots it against time. (The manner in which the image is produced may be thought of as a graph, with the x-axis representing time and the y-axis the depth.) When using M-mode, the screen will vary in appearance depending on the type of ultrasound being used. While performing the ultrasound, it is important to always keep the probe as still as possible to identify independent motion at the pleura.

Sand-on-the-Beach Sign

In a normal lung, M-mode images are often described as having a “sand-on-the-beach” appearance (Figure 3). As a normal lung inflates, the motion of the lung changes the brightness of the echoes that return to the machine, creating a speckled appearance like grains of sand beneath the bright pleural line. The soft tissues above the pleural line do not vary with time and thus have a linear appearance.

Barcode or Stratosphere Sign

In pneumothorax, however, the granular sand appearance is absent. Instead, the M-mode shows a linear pattern below the pleural line. This pattern is described as the “barcode sign” or “stratosphere sign” (Figure 4).

Pitfalls

There are several pitfalls that can limit the ability to correctly diagnose a pneumothorax. The presence of scarring and adhesions may cause the patient to develop loculated air collections. If one evaluates only the anterior chest, air trapped in another location may be missed. The clinician should also be mindful of the presence of bullae as the appearance of sliding may be diminished in patients with bullous disease. Using the M-mode in these cases may help to identify inflated lung in patients with limited movement at the pleural line.

Furthermore, since it is easy to confuse a bright layer of fascia with the pleura, the clinician should always make sure to identify landmarks. In some cases of pneumothorax, subcutaneous air may obscure the pleura. The ribs should always be identified to ensure one is looking at the pleural line.

Although absence of lung sliding can suggest pneumothorax, other conditions, such as severe consolidation, acute respiratory distress syndrome, and mainstem intubation, can give a similar appearance. Remember, visualization of the lung point is pathnognomic for pneumothorax.

Conclusion

Pneumothorax is a medical emergency requiring immediate diagnosis and treatment. Patients presenting with suspected pneumothorax can be assessed quickly through bedside ultrasound. Once visualization of the pleura is established, the lung may be assessed for the presence or absence of normal lung sliding and comet-tail artifacts. The M-mode setting further enhances visualization and aids in the diagnosis of pneumothorax.

 

Dr Beck is an assistant professor, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. Dr Meer is an assistant professor and director of emergency ultrasound, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. Dr Taylor is an assistant professor and director of postgraduate medical education, department of emergency medicine, Emory University School of Medicine, Atlanta, Georgia. 

PARIS – Noninvasive measurement of computed tomography–derived fractional flow reserve is a potential game changer in the management of patients with stable chest pain.

In a 200-patient proof-of-concept study known as FFR-CT RIPCORD, in which three experienced interventional cardiologists initially devised management plans based on coronary anatomy as defined by the results of CT angiography alone, subsequent knowledge of CT-derived fractional flow reserve (FFR-CT) caused them to change their management strategies in fully 36% of cases, Dr. Nick Curzen reported at the annual congress of the European Association of Percutaneous Cardiovascular Interventions.

“If this novel proof-of-concept result can be confirmed in large-scale trials, this suggests that noninvasive FFR-CT can be used as a clinically relevant tool that mimics the well-described ability of invasive FFR to refine management decisions for patients with chest pain that are made by invasive coronary angiography alone. This would indeed have important implications for routine clinical practice. FFR-CT may have potential as a noninvasive default method for simultaneous assessment of coronary anatomy and physiology in angina patients in order to define their management, which would completely change the way we look after them,” observed Dr. Curzen, professor of interventional cardiology at the University of Southampton (England).

EuroPCR codirector Dr. Williams Wijns was favorably impressed by the FFR-CT RIPCORD findings.

“This, I find just stunning. It’s really far reaching. This is a complete change in paradigm. Many patients that today undergo invasive angiography won’t even be sent to the cath lab. The invasive center becomes only for treatment,” commented Dr. Wijns, codirector of the cardiovascular center in Aalst, Belgium.

In FFR-CT RIPCORD, the cardiologists received information about a patient’s history and nonvasive CT angiography findings and were asked to reach consensus in selecting one of four management options: optimal medical therapy (OMT) alone, PCI plus OMT, CABG surgery and OMT, or ‘more information needed’ in the form of FFR findings, which identify those coronary lesions that are actually causing ischemia. Instead of receiving the results of conventional invasive FFR obtained using a pressure wire, however, the cardiologists were provided with the noninvasive FFR-CT findings in all 200 cases.

The resultant changes in management were substantial. Thirty percent of the patients initially slated for PCI were reallocated to OMT alone because no ischemic lesions were present. Twelve percent of patients assigned to OMT-only got reassigned to coronary revascularization. Moreover, in 18% of the PCI group, FFR-CT data led to a change in the vessel or vessels targeted for intervention.

“What particularly impressed me were two of those figures: that one-third of PCI patients are redirected to medical therapy, and – even more impressive to me – is the 18% of PCI patients who had a change in their target vessel. That’s a problem we often have in patients with multivessel disease and intermediate lesions: Sometimes we think, for example, the target is the LAD when in fact it’s another vessel,” commented Dr. Jean Fajadet, codirector of the interventional cardiovascular group at the Clinique Pasteur in Toulouse, France.

Dr. Curzen said the exciting thing about FFR-CT is that it could provide in one fell swoop a standardized way of obtaining both the anatomic and physiologic data necessary for informed clinical decision making, and without exposing patients needlessly to the risks of contrast and radiation exposure entailed in invasive coronary angiography.

“When we assess people with stable angina, if you have a room full of invasive cardiologists, we all do it differently at the moment. It’s crazy. A lot of us will do noninvasive tests like stress echo or MRI or some kind of exercise test, and then refer them for an invasive angiogram where we’ll also do an FFR. Some people will go straight for an angiogram. It’s a real mess. The thing I love about FFR-CT is it would be so slick for patients and their families: You see them in a chest pain clinic or your office and you put them in for this test. They don’t have to waste their time coming back several times for different tests. It’s a really beautiful concept,” Dr. Curzen continued.

Right now the turnaround time on FFR-CT is about 12 hours. The dataset has to be sent off to a supercomputer for a complex modeling analysis before the results come back.

“Of course, if this ever becomes clinically proven, I’m sure the turnaround time would become very quick,” according to the cardiologist.

A cost-effectiveness analysis of FFR-CT versus current standard care is ongoing and the results aren’t yet available. However, Dr. Curzen observed, “The cost to the patient is a very important issue: Who would want to have this done invasively if you have a test that proves you don’t need to have an invasive procedure?”

 

The FFR-CT RIPCORD study was sponsored by Heartflow. Dr. Curzen reported receiving research support from Heartflow, Boston Scientific, Haemonetics, and Medtronic.

[email protected]

PARIS – Noninvasive measurement of computed tomography–derived fractional flow reserve is a potential game changer in the management of patients with stable chest pain.

In a 200-patient proof-of-concept study known as FFR-CT RIPCORD, in which three experienced interventional cardiologists initially devised management plans based on coronary anatomy as defined by the results of CT angiography alone, subsequent knowledge of CT-derived fractional flow reserve (FFR-CT) caused them to change their management strategies in fully 36% of cases, Dr. Nick Curzen reported at the annual congress of the European Association of Percutaneous Cardiovascular Interventions.

“If this novel proof-of-concept result can be confirmed in large-scale trials, this suggests that noninvasive FFR-CT can be used as a clinically relevant tool that mimics the well-described ability of invasive FFR to refine management decisions for patients with chest pain that are made by invasive coronary angiography alone. This would indeed have important implications for routine clinical practice. FFR-CT may have potential as a noninvasive default method for simultaneous assessment of coronary anatomy and physiology in angina patients in order to define their management, which would completely change the way we look after them,” observed Dr. Curzen, professor of interventional cardiology at the University of Southampton (England).

EuroPCR codirector Dr. Williams Wijns was favorably impressed by the FFR-CT RIPCORD findings.

“This, I find just stunning. It’s really far reaching. This is a complete change in paradigm. Many patients that today undergo invasive angiography won’t even be sent to the cath lab. The invasive center becomes only for treatment,” commented Dr. Wijns, codirector of the cardiovascular center in Aalst, Belgium.

In FFR-CT RIPCORD, the cardiologists received information about a patient’s history and nonvasive CT angiography findings and were asked to reach consensus in selecting one of four management options: optimal medical therapy (OMT) alone, PCI plus OMT, CABG surgery and OMT, or ‘more information needed’ in the form of FFR findings, which identify those coronary lesions that are actually causing ischemia. Instead of receiving the results of conventional invasive FFR obtained using a pressure wire, however, the cardiologists were provided with the noninvasive FFR-CT findings in all 200 cases.

The resultant changes in management were substantial. Thirty percent of the patients initially slated for PCI were reallocated to OMT alone because no ischemic lesions were present. Twelve percent of patients assigned to OMT-only got reassigned to coronary revascularization. Moreover, in 18% of the PCI group, FFR-CT data led to a change in the vessel or vessels targeted for intervention.

“What particularly impressed me were two of those figures: that one-third of PCI patients are redirected to medical therapy, and – even more impressive to me – is the 18% of PCI patients who had a change in their target vessel. That’s a problem we often have in patients with multivessel disease and intermediate lesions: Sometimes we think, for example, the target is the LAD when in fact it’s another vessel,” commented Dr. Jean Fajadet, codirector of the interventional cardiovascular group at the Clinique Pasteur in Toulouse, France.

Dr. Curzen said the exciting thing about FFR-CT is that it could provide in one fell swoop a standardized way of obtaining both the anatomic and physiologic data necessary for informed clinical decision making, and without exposing patients needlessly to the risks of contrast and radiation exposure entailed in invasive coronary angiography.

“When we assess people with stable angina, if you have a room full of invasive cardiologists, we all do it differently at the moment. It’s crazy. A lot of us will do noninvasive tests like stress echo or MRI or some kind of exercise test, and then refer them for an invasive angiogram where we’ll also do an FFR. Some people will go straight for an angiogram. It’s a real mess. The thing I love about FFR-CT is it would be so slick for patients and their families: You see them in a chest pain clinic or your office and you put them in for this test. They don’t have to waste their time coming back several times for different tests. It’s a really beautiful concept,” Dr. Curzen continued.

Right now the turnaround time on FFR-CT is about 12 hours. The dataset has to be sent off to a supercomputer for a complex modeling analysis before the results come back.

“Of course, if this ever becomes clinically proven, I’m sure the turnaround time would become very quick,” according to the cardiologist.

A cost-effectiveness analysis of FFR-CT versus current standard care is ongoing and the results aren’t yet available. However, Dr. Curzen observed, “The cost to the patient is a very important issue: Who would want to have this done invasively if you have a test that proves you don’t need to have an invasive procedure?”

 

The FFR-CT RIPCORD study was sponsored by Heartflow. Dr. Curzen reported receiving research support from Heartflow, Boston Scientific, Haemonetics, and Medtronic.

[email protected]

PARIS – Noninvasive measurement of computed tomography–derived fractional flow reserve is a potential game changer in the management of patients with stable chest pain.

In a 200-patient proof-of-concept study known as FFR-CT RIPCORD, in which three experienced interventional cardiologists initially devised management plans based on coronary anatomy as defined by the results of CT angiography alone, subsequent knowledge of CT-derived fractional flow reserve (FFR-CT) caused them to change their management strategies in fully 36% of cases, Dr. Nick Curzen reported at the annual congress of the European Association of Percutaneous Cardiovascular Interventions.

“If this novel proof-of-concept result can be confirmed in large-scale trials, this suggests that noninvasive FFR-CT can be used as a clinically relevant tool that mimics the well-described ability of invasive FFR to refine management decisions for patients with chest pain that are made by invasive coronary angiography alone. This would indeed have important implications for routine clinical practice. FFR-CT may have potential as a noninvasive default method for simultaneous assessment of coronary anatomy and physiology in angina patients in order to define their management, which would completely change the way we look after them,” observed Dr. Curzen, professor of interventional cardiology at the University of Southampton (England).

EuroPCR codirector Dr. Williams Wijns was favorably impressed by the FFR-CT RIPCORD findings.

“This, I find just stunning. It’s really far reaching. This is a complete change in paradigm. Many patients that today undergo invasive angiography won’t even be sent to the cath lab. The invasive center becomes only for treatment,” commented Dr. Wijns, codirector of the cardiovascular center in Aalst, Belgium.

In FFR-CT RIPCORD, the cardiologists received information about a patient’s history and nonvasive CT angiography findings and were asked to reach consensus in selecting one of four management options: optimal medical therapy (OMT) alone, PCI plus OMT, CABG surgery and OMT, or ‘more information needed’ in the form of FFR findings, which identify those coronary lesions that are actually causing ischemia. Instead of receiving the results of conventional invasive FFR obtained using a pressure wire, however, the cardiologists were provided with the noninvasive FFR-CT findings in all 200 cases.

The resultant changes in management were substantial. Thirty percent of the patients initially slated for PCI were reallocated to OMT alone because no ischemic lesions were present. Twelve percent of patients assigned to OMT-only got reassigned to coronary revascularization. Moreover, in 18% of the PCI group, FFR-CT data led to a change in the vessel or vessels targeted for intervention.

“What particularly impressed me were two of those figures: that one-third of PCI patients are redirected to medical therapy, and – even more impressive to me – is the 18% of PCI patients who had a change in their target vessel. That’s a problem we often have in patients with multivessel disease and intermediate lesions: Sometimes we think, for example, the target is the LAD when in fact it’s another vessel,” commented Dr. Jean Fajadet, codirector of the interventional cardiovascular group at the Clinique Pasteur in Toulouse, France.

Dr. Curzen said the exciting thing about FFR-CT is that it could provide in one fell swoop a standardized way of obtaining both the anatomic and physiologic data necessary for informed clinical decision making, and without exposing patients needlessly to the risks of contrast and radiation exposure entailed in invasive coronary angiography.

“When we assess people with stable angina, if you have a room full of invasive cardiologists, we all do it differently at the moment. It’s crazy. A lot of us will do noninvasive tests like stress echo or MRI or some kind of exercise test, and then refer them for an invasive angiogram where we’ll also do an FFR. Some people will go straight for an angiogram. It’s a real mess. The thing I love about FFR-CT is it would be so slick for patients and their families: You see them in a chest pain clinic or your office and you put them in for this test. They don’t have to waste their time coming back several times for different tests. It’s a really beautiful concept,” Dr. Curzen continued.

Right now the turnaround time on FFR-CT is about 12 hours. The dataset has to be sent off to a supercomputer for a complex modeling analysis before the results come back.

“Of course, if this ever becomes clinically proven, I’m sure the turnaround time would become very quick,” according to the cardiologist.

A cost-effectiveness analysis of FFR-CT versus current standard care is ongoing and the results aren’t yet available. However, Dr. Curzen observed, “The cost to the patient is a very important issue: Who would want to have this done invasively if you have a test that proves you don’t need to have an invasive procedure?”

 

The FFR-CT RIPCORD study was sponsored by Heartflow. Dr. Curzen reported receiving research support from Heartflow, Boston Scientific, Haemonetics, and Medtronic.

[email protected]