Cigarette Smoke Raises Risk of Lung Injury After Trauma

HONOLULU – Both active smoking and secondhand smoke exposure are associated with increased susceptibility to acute lung injury in patients following blunt trauma, results from an ongoing cohort study demonstrated.

The researchers, led by Dr. Carolyn S. Calfee of the pulmonary and critical care division at the University of California, San Francisco, measured serum cotinine to quantify exposure to cigarette smoke, an approach that "transforms the field, because it’s now possible to quantify cigarette smoke exposure," coinvestigator Dr. Michael A. Matthay said at the annual meeting of the American College of Chest Physicians.

The researchers set out to investigate if exposure to cigarette smoke increases susceptibility to acute lung injury among trauma patients. They used serum cotinine testing because obtaining a reliable smoking history in the ICU "is difficult," said Dr. Matthay, professor of medicine and anesthesia at UCSF. "The patients are ventilated and there is a high mortality rate, and the family may not be able to give you a good smoking history. Therefore, Dr. Calfee is using biomarkers to measure both active and passive cigarette smoke exposure."

Serum cotinine has been shown in several studies to accurately identify both active and passive exposure to cigarette smoke. "These levels are very well validated, so now you can not only know if they’ve been exposed to cigarette smoke but you can put them in the category of secondhand or primary smoke exposure," Dr. Matthay said.

Earlier this year, researchers including Dr. Calfee reported that serum cotinine levels reflect active smoking and secondhand smoke exposure in nonsmokers in the ICU (Crit. Care Med. 2011;39:40-5). "We also found that if you use the urine for NNAL, a metabolite of nitrosamines produced in the tobacco-curing process, you can quantify the amount of cigarette smoke exposure in patients over several weeks," Dr. Matthay said.

For the ongoing cohort study, the researchers collected blood from 144 patients who presented to emergency department of San Francisco General Hospital with severe trauma caused by events that included motor vehicle accidents, falls, and assaults. They had blood drawn via waiver of consent within 5 minutes of arrival to the ED. Serum cotinine was measured from this sample. Follow-up consent was obtained from the patient or surrogate.

Active smokers were defined as those having a serum cotinine level of 3.08 ng/mL or greater, whereas passive smokers were defined as those with a cotinine level greater than zero but less than 3.08 ng/mL.

Of the 144 patients, 62 had acute lung injury (43%) and 82 (57%) did not. Patients in the acute lung injury group were significantly younger than their counterparts in the nonacute lung injury group (mean age, 44 vs. 52 years) but otherwise shared similar characteristics, including injury severity and history of alcohol abuse.

According to results from the serum cotinine testing, 44% of patients were categorized as active smokers, 37% were categorized as passive smokers, and only 19% were categorized as unexposed to smoke. "Imagine this in San Francisco, where only about 15%" of the population smoke, Dr. Matthay commented. In the ED, however, "in patients with blunt trauma, it’s the reverse: We have 81% who are exposed to some level of smoke."

"Now you can not only know if [patients] have been exposed to cigarette smoke but you can put them in the category of secondhand or primary smoke exposure."

The researchers observed that increased serum cotinine levels were associated with the development of acute lung injury. "This includes the patients with passive secondhand smoke exposure above the median level in the cohort, not just active exposure," Dr. Matthay said. "The relationship between cotinine levels and acute lung injury persisted after multivariate analysis."

He noted that the patients’ serum cotinine levels showed the inadequacy of the chart history. For example, 53 patients were defined as nonsmokers based on chart history, but many "had plasma cotinine levels that were elevated."

Dr. Matthay emphasized that many questions about the relationship between serum cotinine levels and acute lung injury remain. "The mechanism of association between exposure and acute lung injury in blunt trauma is still unknown," he said.

Dr. Calfee is currently carrying out an analysis of cigarette smoke exposure and acute lung injury in mixed medical-surgical patients in collaboration with Dr. Lorraine Ware at Vanderbilt University in Nashville, Tenn., he said. In addition, Dr. Calfee and colleagues are measuring NNAL in 489 patients enrolled in trials being conducted by the National Heart, Lung, and Blood Institute’s Acute Respiratory Distress Syndrome Network.

"Biomarkers of endothelial and epithelial injury are also being studied in patients with acute lung injury, to determine if differences exist between smokers and nonsmokers," Dr. Matthay said.

Dr. Matthay disclosed that this research, led by Dr. Calfee, is supported by the NHLBI and the Flight Attendant Medical Research Institute.

HONOLULU – Both active smoking and secondhand smoke exposure are associated with increased susceptibility to acute lung injury in patients following blunt trauma, results from an ongoing cohort study demonstrated.

The researchers, led by Dr. Carolyn S. Calfee of the pulmonary and critical care division at the University of California, San Francisco, measured serum cotinine to quantify exposure to cigarette smoke, an approach that "transforms the field, because it’s now possible to quantify cigarette smoke exposure," coinvestigator Dr. Michael A. Matthay said at the annual meeting of the American College of Chest Physicians.

The researchers set out to investigate if exposure to cigarette smoke increases susceptibility to acute lung injury among trauma patients. They used serum cotinine testing because obtaining a reliable smoking history in the ICU "is difficult," said Dr. Matthay, professor of medicine and anesthesia at UCSF. "The patients are ventilated and there is a high mortality rate, and the family may not be able to give you a good smoking history. Therefore, Dr. Calfee is using biomarkers to measure both active and passive cigarette smoke exposure."

Serum cotinine has been shown in several studies to accurately identify both active and passive exposure to cigarette smoke. "These levels are very well validated, so now you can not only know if they’ve been exposed to cigarette smoke but you can put them in the category of secondhand or primary smoke exposure," Dr. Matthay said.

Earlier this year, researchers including Dr. Calfee reported that serum cotinine levels reflect active smoking and secondhand smoke exposure in nonsmokers in the ICU (Crit. Care Med. 2011;39:40-5). "We also found that if you use the urine for NNAL, a metabolite of nitrosamines produced in the tobacco-curing process, you can quantify the amount of cigarette smoke exposure in patients over several weeks," Dr. Matthay said.

For the ongoing cohort study, the researchers collected blood from 144 patients who presented to emergency department of San Francisco General Hospital with severe trauma caused by events that included motor vehicle accidents, falls, and assaults. They had blood drawn via waiver of consent within 5 minutes of arrival to the ED. Serum cotinine was measured from this sample. Follow-up consent was obtained from the patient or surrogate.

Active smokers were defined as those having a serum cotinine level of 3.08 ng/mL or greater, whereas passive smokers were defined as those with a cotinine level greater than zero but less than 3.08 ng/mL.

Of the 144 patients, 62 had acute lung injury (43%) and 82 (57%) did not. Patients in the acute lung injury group were significantly younger than their counterparts in the nonacute lung injury group (mean age, 44 vs. 52 years) but otherwise shared similar characteristics, including injury severity and history of alcohol abuse.

According to results from the serum cotinine testing, 44% of patients were categorized as active smokers, 37% were categorized as passive smokers, and only 19% were categorized as unexposed to smoke. "Imagine this in San Francisco, where only about 15%" of the population smoke, Dr. Matthay commented. In the ED, however, "in patients with blunt trauma, it’s the reverse: We have 81% who are exposed to some level of smoke."

"Now you can not only know if [patients] have been exposed to cigarette smoke but you can put them in the category of secondhand or primary smoke exposure."

The researchers observed that increased serum cotinine levels were associated with the development of acute lung injury. "This includes the patients with passive secondhand smoke exposure above the median level in the cohort, not just active exposure," Dr. Matthay said. "The relationship between cotinine levels and acute lung injury persisted after multivariate analysis."

He noted that the patients’ serum cotinine levels showed the inadequacy of the chart history. For example, 53 patients were defined as nonsmokers based on chart history, but many "had plasma cotinine levels that were elevated."

Dr. Matthay emphasized that many questions about the relationship between serum cotinine levels and acute lung injury remain. "The mechanism of association between exposure and acute lung injury in blunt trauma is still unknown," he said.

Dr. Calfee is currently carrying out an analysis of cigarette smoke exposure and acute lung injury in mixed medical-surgical patients in collaboration with Dr. Lorraine Ware at Vanderbilt University in Nashville, Tenn., he said. In addition, Dr. Calfee and colleagues are measuring NNAL in 489 patients enrolled in trials being conducted by the National Heart, Lung, and Blood Institute’s Acute Respiratory Distress Syndrome Network.

"Biomarkers of endothelial and epithelial injury are also being studied in patients with acute lung injury, to determine if differences exist between smokers and nonsmokers," Dr. Matthay said.

Dr. Matthay disclosed that this research, led by Dr. Calfee, is supported by the NHLBI and the Flight Attendant Medical Research Institute.

HONOLULU – Both active smoking and secondhand smoke exposure are associated with increased susceptibility to acute lung injury in patients following blunt trauma, results from an ongoing cohort study demonstrated.

The researchers, led by Dr. Carolyn S. Calfee of the pulmonary and critical care division at the University of California, San Francisco, measured serum cotinine to quantify exposure to cigarette smoke, an approach that "transforms the field, because it’s now possible to quantify cigarette smoke exposure," coinvestigator Dr. Michael A. Matthay said at the annual meeting of the American College of Chest Physicians.

The researchers set out to investigate if exposure to cigarette smoke increases susceptibility to acute lung injury among trauma patients. They used serum cotinine testing because obtaining a reliable smoking history in the ICU "is difficult," said Dr. Matthay, professor of medicine and anesthesia at UCSF. "The patients are ventilated and there is a high mortality rate, and the family may not be able to give you a good smoking history. Therefore, Dr. Calfee is using biomarkers to measure both active and passive cigarette smoke exposure."

Serum cotinine has been shown in several studies to accurately identify both active and passive exposure to cigarette smoke. "These levels are very well validated, so now you can not only know if they’ve been exposed to cigarette smoke but you can put them in the category of secondhand or primary smoke exposure," Dr. Matthay said.

Earlier this year, researchers including Dr. Calfee reported that serum cotinine levels reflect active smoking and secondhand smoke exposure in nonsmokers in the ICU (Crit. Care Med. 2011;39:40-5). "We also found that if you use the urine for NNAL, a metabolite of nitrosamines produced in the tobacco-curing process, you can quantify the amount of cigarette smoke exposure in patients over several weeks," Dr. Matthay said.

For the ongoing cohort study, the researchers collected blood from 144 patients who presented to emergency department of San Francisco General Hospital with severe trauma caused by events that included motor vehicle accidents, falls, and assaults. They had blood drawn via waiver of consent within 5 minutes of arrival to the ED. Serum cotinine was measured from this sample. Follow-up consent was obtained from the patient or surrogate.

Active smokers were defined as those having a serum cotinine level of 3.08 ng/mL or greater, whereas passive smokers were defined as those with a cotinine level greater than zero but less than 3.08 ng/mL.

Of the 144 patients, 62 had acute lung injury (43%) and 82 (57%) did not. Patients in the acute lung injury group were significantly younger than their counterparts in the nonacute lung injury group (mean age, 44 vs. 52 years) but otherwise shared similar characteristics, including injury severity and history of alcohol abuse.

According to results from the serum cotinine testing, 44% of patients were categorized as active smokers, 37% were categorized as passive smokers, and only 19% were categorized as unexposed to smoke. "Imagine this in San Francisco, where only about 15%" of the population smoke, Dr. Matthay commented. In the ED, however, "in patients with blunt trauma, it’s the reverse: We have 81% who are exposed to some level of smoke."

"Now you can not only know if [patients] have been exposed to cigarette smoke but you can put them in the category of secondhand or primary smoke exposure."

The researchers observed that increased serum cotinine levels were associated with the development of acute lung injury. "This includes the patients with passive secondhand smoke exposure above the median level in the cohort, not just active exposure," Dr. Matthay said. "The relationship between cotinine levels and acute lung injury persisted after multivariate analysis."

He noted that the patients’ serum cotinine levels showed the inadequacy of the chart history. For example, 53 patients were defined as nonsmokers based on chart history, but many "had plasma cotinine levels that were elevated."

Dr. Matthay emphasized that many questions about the relationship between serum cotinine levels and acute lung injury remain. "The mechanism of association between exposure and acute lung injury in blunt trauma is still unknown," he said.

Dr. Calfee is currently carrying out an analysis of cigarette smoke exposure and acute lung injury in mixed medical-surgical patients in collaboration with Dr. Lorraine Ware at Vanderbilt University in Nashville, Tenn., he said. In addition, Dr. Calfee and colleagues are measuring NNAL in 489 patients enrolled in trials being conducted by the National Heart, Lung, and Blood Institute’s Acute Respiratory Distress Syndrome Network.

"Biomarkers of endothelial and epithelial injury are also being studied in patients with acute lung injury, to determine if differences exist between smokers and nonsmokers," Dr. Matthay said.

Dr. Matthay disclosed that this research, led by Dr. Calfee, is supported by the NHLBI and the Flight Attendant Medical Research Institute.