Improved CPR Technique Would Increase Survival

WASHINGTON — Cardiopulmonary resuscitation is often poorly performed by paramedics, physicians, and other well-trained hospital staff, and several problems—mainly frequent pauses and slow compression rates, shallow compression depths, and hyperventilation—are significantly reducing survival from cardiac arrest, emergency medicine leaders said.

“We can triple survival to hospital discharge by [addressing these problems] and doing good basic life support,” said Dr. Ahamed H. Idris, director of emergency medicine research at Southwestern Medical Center, Dallas, during a panel discussion on resuscitation at the annual meeting of the Society of Academic Emergency Medicine.

Research presented earlier at the meeting by Dr. Henry Wang of the University of Pittsburgh was emblematic of the growing body of data. His study of out-of-hospital cardiac arrests treated by paramedics documented frequent and prolonged interruptions in chest compressions due to endotracheal intubation (ETI) efforts.

Of 129 cases of cardiac arrest, they identified ETI-associated chest compression interruptions in 64 cases. The median duration of all ETI-associated interruptions was 78 seconds, Dr. Wang reported, and 35% of the interruptions exceeded 120 seconds.

Published reports of in-hospital cardiac arrest care have similarly documented widely variable and suboptimal chest compression rates, among other problems.

“We need to better monitor the quality of CPR” in and out of our hospitals, said Dr. Benjamin Abella, clinical research director of the Center for Resuscitative Science at the University of Pennsylvania Health System, Philadelphia, during the panel discussion.

Among the most recent studies published on cardiac arrest care is one published in January 2008 showing that delayed defibrillation is common and is associated with lower rates of survival.

Investigators identified 6,789 patients who had cardiac arrest due to ventricular fibrillation or pulseless ventricular tachycardia at approximately 370 hospitals participating in the National Registry of Cardiopulmonary Resuscitation. They found that delayed defibrillation (more than a minute) was associated with a significantly lower probability of surviving to hospital discharge (22% vs. 39%) than was defibrillation that was not delayed (N. Engl. J. Med. 2008;358:9-17).

Dr. Abella said studies at his institution have shown that the chance of successful shock plummets with every 5, 10, or 15 seconds of additional pausing.

“If we can get the shock out in less than 10 seconds vs. 20 or 30 seconds, it makes a huge difference in terms of shock efficacy,” he said.

“We now know … that pauses [in CPR] are lethal,” Dr. Abella said in an interview, citing the landmark study published in 2000 that compared standard CPR (then cycles of 15 compressions and two breaths) with chest compression alone. The study utilized a dispatcher-assisted CPR program in Seattle, in which individuals who called 911 could be instructed in CPR. Investigators found that about 15% of the patients whose rescuers were instructed only in chest compression survived, compared with about 10% of those whose rescuers were instructed in rescue breathing and compression (Crit. Care Med. 2000;28:N190-2).

The study had significant limitations, but “at the time, this was shocking,” he said, “We all thought that breaths should be important.”

With respect to compression depth, animal studies have also shown that a coronary perfusion pressure of approximately 15 mm is necessary for resuscitation. In one study, that pressure (and a good survival rate) was achieved with compressions that were 2 inches deep, but not with compressions of 1.5 inches. In fact, all of the animals that received 2-inch-deep compressions survived, while very few of the animals that received 1.5-inch compressions survived.

Hyperventilation during CPR is also a problem. Changes to the American Heart Association's CPR guidelines published in 2005—namely, the change in the recommended ratio of compressions to breaths from 15:2 to 30:2—were intended to address this point.

With regard to the optimal rate of chest compression during CPR for cardiac arrest, new data come partly from prospective observational studies that Dr. Abella and his associates have performed of in-hospital cardiac arrests. The studies have revealed an inconsistent quality of CPR that often does not meet published guideline recommendations.

One of the studies, which covered 67 patients, documented chest compression rates of less than 90/min in 28% of recorded 30-second segments of CPR. Current guidelines recommend a rate of 100 compressions/min. The study also documented a shallow compression depth of less than 38 mm for 37% of compressions, as well as high ventilation rates, with more than 20 breaths/min given during 61% of CPR segments (JAMA 2005;293:305-10).

Another of the studies similarly showed compression rates of less than 80/min in 37% of CPR segments, and rates of less than 70/min in 22% of segments. Such suboptimal rates were associated with poor return of spontaneous circulation, Dr. Abella explained (Circulation 2005;111:428-34).

The most important message from his own research, Dr. Idris said, is not that there is a specific ideal compression rate, but that the more chest compressions per minute a patient receives, the better the outcome. “If a patient receives 80-100 compressions/min, the survival rate more than triples, compared to 20 chest compressions/min,” he explained.

Dr. Abella and his colleagues at the University of Pennsylvania, Philadelphia, have recently increased their rates of survival to hospital discharge for cardiac arrest patients by using defibrillators that monitor CPR, recording and providing feedback on the depth and rate of compressions. They also have initiated a “debriefing” program in which leaders routinely meet with rescue teams to review CPR data immediately after care is given.

EMS programs in Seattle and other locations, in the meantime, have begun telling their paramedics “to start compressions immediately and not intubate—to bag only—for the first 10 minutes,” Dr. Idris said.

With 80-100 compressions/min, the survival rate more than triples, compared with 20 compressions/min. DR. IDRIS

Some EMS programs have begun telling paramedics to start compressions immediately and not intubate—to bag only—for the first 10 minutes. ©Nancy Louie/iStockphoto, Inc.

WASHINGTON — Cardiopulmonary resuscitation is often poorly performed by paramedics, physicians, and other well-trained hospital staff, and several problems—mainly frequent pauses and slow compression rates, shallow compression depths, and hyperventilation—are significantly reducing survival from cardiac arrest, emergency medicine leaders said.

“We can triple survival to hospital discharge by [addressing these problems] and doing good basic life support,” said Dr. Ahamed H. Idris, director of emergency medicine research at Southwestern Medical Center, Dallas, during a panel discussion on resuscitation at the annual meeting of the Society of Academic Emergency Medicine.

Research presented earlier at the meeting by Dr. Henry Wang of the University of Pittsburgh was emblematic of the growing body of data. His study of out-of-hospital cardiac arrests treated by paramedics documented frequent and prolonged interruptions in chest compressions due to endotracheal intubation (ETI) efforts.

Of 129 cases of cardiac arrest, they identified ETI-associated chest compression interruptions in 64 cases. The median duration of all ETI-associated interruptions was 78 seconds, Dr. Wang reported, and 35% of the interruptions exceeded 120 seconds.

Published reports of in-hospital cardiac arrest care have similarly documented widely variable and suboptimal chest compression rates, among other problems.

“We need to better monitor the quality of CPR” in and out of our hospitals, said Dr. Benjamin Abella, clinical research director of the Center for Resuscitative Science at the University of Pennsylvania Health System, Philadelphia, during the panel discussion.

Among the most recent studies published on cardiac arrest care is one published in January 2008 showing that delayed defibrillation is common and is associated with lower rates of survival.

Investigators identified 6,789 patients who had cardiac arrest due to ventricular fibrillation or pulseless ventricular tachycardia at approximately 370 hospitals participating in the National Registry of Cardiopulmonary Resuscitation. They found that delayed defibrillation (more than a minute) was associated with a significantly lower probability of surviving to hospital discharge (22% vs. 39%) than was defibrillation that was not delayed (N. Engl. J. Med. 2008;358:9-17).

Dr. Abella said studies at his institution have shown that the chance of successful shock plummets with every 5, 10, or 15 seconds of additional pausing.

“If we can get the shock out in less than 10 seconds vs. 20 or 30 seconds, it makes a huge difference in terms of shock efficacy,” he said.

“We now know … that pauses [in CPR] are lethal,” Dr. Abella said in an interview, citing the landmark study published in 2000 that compared standard CPR (then cycles of 15 compressions and two breaths) with chest compression alone. The study utilized a dispatcher-assisted CPR program in Seattle, in which individuals who called 911 could be instructed in CPR. Investigators found that about 15% of the patients whose rescuers were instructed only in chest compression survived, compared with about 10% of those whose rescuers were instructed in rescue breathing and compression (Crit. Care Med. 2000;28:N190-2).

The study had significant limitations, but “at the time, this was shocking,” he said, “We all thought that breaths should be important.”

With respect to compression depth, animal studies have also shown that a coronary perfusion pressure of approximately 15 mm is necessary for resuscitation. In one study, that pressure (and a good survival rate) was achieved with compressions that were 2 inches deep, but not with compressions of 1.5 inches. In fact, all of the animals that received 2-inch-deep compressions survived, while very few of the animals that received 1.5-inch compressions survived.

Hyperventilation during CPR is also a problem. Changes to the American Heart Association's CPR guidelines published in 2005—namely, the change in the recommended ratio of compressions to breaths from 15:2 to 30:2—were intended to address this point.

With regard to the optimal rate of chest compression during CPR for cardiac arrest, new data come partly from prospective observational studies that Dr. Abella and his associates have performed of in-hospital cardiac arrests. The studies have revealed an inconsistent quality of CPR that often does not meet published guideline recommendations.

One of the studies, which covered 67 patients, documented chest compression rates of less than 90/min in 28% of recorded 30-second segments of CPR. Current guidelines recommend a rate of 100 compressions/min. The study also documented a shallow compression depth of less than 38 mm for 37% of compressions, as well as high ventilation rates, with more than 20 breaths/min given during 61% of CPR segments (JAMA 2005;293:305-10).

Another of the studies similarly showed compression rates of less than 80/min in 37% of CPR segments, and rates of less than 70/min in 22% of segments. Such suboptimal rates were associated with poor return of spontaneous circulation, Dr. Abella explained (Circulation 2005;111:428-34).

The most important message from his own research, Dr. Idris said, is not that there is a specific ideal compression rate, but that the more chest compressions per minute a patient receives, the better the outcome. “If a patient receives 80-100 compressions/min, the survival rate more than triples, compared to 20 chest compressions/min,” he explained.

Dr. Abella and his colleagues at the University of Pennsylvania, Philadelphia, have recently increased their rates of survival to hospital discharge for cardiac arrest patients by using defibrillators that monitor CPR, recording and providing feedback on the depth and rate of compressions. They also have initiated a “debriefing” program in which leaders routinely meet with rescue teams to review CPR data immediately after care is given.

EMS programs in Seattle and other locations, in the meantime, have begun telling their paramedics “to start compressions immediately and not intubate—to bag only—for the first 10 minutes,” Dr. Idris said.

With 80-100 compressions/min, the survival rate more than triples, compared with 20 compressions/min. DR. IDRIS

Some EMS programs have begun telling paramedics to start compressions immediately and not intubate—to bag only—for the first 10 minutes. ©Nancy Louie/iStockphoto, Inc.

WASHINGTON — Cardiopulmonary resuscitation is often poorly performed by paramedics, physicians, and other well-trained hospital staff, and several problems—mainly frequent pauses and slow compression rates, shallow compression depths, and hyperventilation—are significantly reducing survival from cardiac arrest, emergency medicine leaders said.

“We can triple survival to hospital discharge by [addressing these problems] and doing good basic life support,” said Dr. Ahamed H. Idris, director of emergency medicine research at Southwestern Medical Center, Dallas, during a panel discussion on resuscitation at the annual meeting of the Society of Academic Emergency Medicine.

Research presented earlier at the meeting by Dr. Henry Wang of the University of Pittsburgh was emblematic of the growing body of data. His study of out-of-hospital cardiac arrests treated by paramedics documented frequent and prolonged interruptions in chest compressions due to endotracheal intubation (ETI) efforts.

Of 129 cases of cardiac arrest, they identified ETI-associated chest compression interruptions in 64 cases. The median duration of all ETI-associated interruptions was 78 seconds, Dr. Wang reported, and 35% of the interruptions exceeded 120 seconds.

Published reports of in-hospital cardiac arrest care have similarly documented widely variable and suboptimal chest compression rates, among other problems.

“We need to better monitor the quality of CPR” in and out of our hospitals, said Dr. Benjamin Abella, clinical research director of the Center for Resuscitative Science at the University of Pennsylvania Health System, Philadelphia, during the panel discussion.

Among the most recent studies published on cardiac arrest care is one published in January 2008 showing that delayed defibrillation is common and is associated with lower rates of survival.

Investigators identified 6,789 patients who had cardiac arrest due to ventricular fibrillation or pulseless ventricular tachycardia at approximately 370 hospitals participating in the National Registry of Cardiopulmonary Resuscitation. They found that delayed defibrillation (more than a minute) was associated with a significantly lower probability of surviving to hospital discharge (22% vs. 39%) than was defibrillation that was not delayed (N. Engl. J. Med. 2008;358:9-17).

Dr. Abella said studies at his institution have shown that the chance of successful shock plummets with every 5, 10, or 15 seconds of additional pausing.

“If we can get the shock out in less than 10 seconds vs. 20 or 30 seconds, it makes a huge difference in terms of shock efficacy,” he said.

“We now know … that pauses [in CPR] are lethal,” Dr. Abella said in an interview, citing the landmark study published in 2000 that compared standard CPR (then cycles of 15 compressions and two breaths) with chest compression alone. The study utilized a dispatcher-assisted CPR program in Seattle, in which individuals who called 911 could be instructed in CPR. Investigators found that about 15% of the patients whose rescuers were instructed only in chest compression survived, compared with about 10% of those whose rescuers were instructed in rescue breathing and compression (Crit. Care Med. 2000;28:N190-2).

The study had significant limitations, but “at the time, this was shocking,” he said, “We all thought that breaths should be important.”

With respect to compression depth, animal studies have also shown that a coronary perfusion pressure of approximately 15 mm is necessary for resuscitation. In one study, that pressure (and a good survival rate) was achieved with compressions that were 2 inches deep, but not with compressions of 1.5 inches. In fact, all of the animals that received 2-inch-deep compressions survived, while very few of the animals that received 1.5-inch compressions survived.

Hyperventilation during CPR is also a problem. Changes to the American Heart Association's CPR guidelines published in 2005—namely, the change in the recommended ratio of compressions to breaths from 15:2 to 30:2—were intended to address this point.

With regard to the optimal rate of chest compression during CPR for cardiac arrest, new data come partly from prospective observational studies that Dr. Abella and his associates have performed of in-hospital cardiac arrests. The studies have revealed an inconsistent quality of CPR that often does not meet published guideline recommendations.

One of the studies, which covered 67 patients, documented chest compression rates of less than 90/min in 28% of recorded 30-second segments of CPR. Current guidelines recommend a rate of 100 compressions/min. The study also documented a shallow compression depth of less than 38 mm for 37% of compressions, as well as high ventilation rates, with more than 20 breaths/min given during 61% of CPR segments (JAMA 2005;293:305-10).

Another of the studies similarly showed compression rates of less than 80/min in 37% of CPR segments, and rates of less than 70/min in 22% of segments. Such suboptimal rates were associated with poor return of spontaneous circulation, Dr. Abella explained (Circulation 2005;111:428-34).

The most important message from his own research, Dr. Idris said, is not that there is a specific ideal compression rate, but that the more chest compressions per minute a patient receives, the better the outcome. “If a patient receives 80-100 compressions/min, the survival rate more than triples, compared to 20 chest compressions/min,” he explained.

Dr. Abella and his colleagues at the University of Pennsylvania, Philadelphia, have recently increased their rates of survival to hospital discharge for cardiac arrest patients by using defibrillators that monitor CPR, recording and providing feedback on the depth and rate of compressions. They also have initiated a “debriefing” program in which leaders routinely meet with rescue teams to review CPR data immediately after care is given.

EMS programs in Seattle and other locations, in the meantime, have begun telling their paramedics “to start compressions immediately and not intubate—to bag only—for the first 10 minutes,” Dr. Idris said.

With 80-100 compressions/min, the survival rate more than triples, compared with 20 compressions/min. DR. IDRIS

Some EMS programs have begun telling paramedics to start compressions immediately and not intubate—to bag only—for the first 10 minutes. ©Nancy Louie/iStockphoto, Inc.