Respiratory Effects of a Single, Moderately Acute, Smoke Inhalation Episode Jairaj Prashad, MD, Roscoe C. Young, Jr., MD, Horace C. Laster, MD, and Robert L. Hackney, Jr., MD Washington, DC
Twenty-three hospital employees who suffered ill effects of smoke inhalation were pulmonary-function tested within 72 hours, after ten weeks, and again after 45 weeks of exposure. Four nonexposed control subjects were selected for comparison of data. Exposed persons commonly had restrictive lung disease which may have resulted from stimulation of irritant receptors in bronchi and/or interstitial edema of chemical injury at the level of the ventilation-perfusion unit. Airways obstruction was infrequent, despite the possibility of inhalation of di-isocyanates, an intermediary product of burning polyurethane foam that may cause chemical asthma. Eye and constitutional symptoms were also frequent. Clinical recovery was as a rule rapid and complete (within a week), but physiologic recovery was protracted (over 45 weeks in some cases). Most surprisingly, cigarette smoking and/or presence of cardiopulmonary disease did not contribute to morbidity. Concern was paid to the respiratory tract in bums for the first time after the Cocoanut Grove fire in Boston on November 29, 1942 in which some of the 498 victims died in the fire not from bums, but from smoke-associated damage to the respiratory tract.1 Since then there has been a plethora of articles dealing with the respiratory tract damage in burns.2-8 About 80 percent of the victims of fire are not touched by flame, but die as a result of exposure to smoke9 which consists of a particulate fraction and gaseous emission. The latter is mainly responsible for injury to the respiratory tract in fire victims. The composition of the gaseous phase de-
From the Harden Pulmonary Laboratory, Pulmonary Disease Division, Howard University Service, District of Columbia General Hospital, and Howard University Hospital. Presented to the 18th Annual Scientific Session of the Maryland Thoracic Society, South Baltimore General Hospital, Respiratory Division, BaltimoreWashington International Airport, February 19, 1978 and to the Section on Internal Medicine of the 83rd Annual Convention of the National Medical Association, Washington, DC, August 1, 1978. Requests for reprints should be addressed to Dr. Roscoe C. Young, Jr., Howard University Hospital, 2041 Georgia Avenue, NW,
Washington, DC 20060.
pends on the materials oxidized and the degree of injury, on the extent to which these oxidized substances are inhaled, the exposure time, and whether or not exposure occurred in a confined space. The unfortunate occurrence of a fire in an unused hospital nursing classroom provided a timely opportunity for a retrospective study of the clinical and physiological effects of smoke inhalation, in which polyvinylchloride, polyurethane foam, wood, and paper were the principal products oxidized. Forty hospital personnel who were part of a fire brigade responded to the fire alarm, helped in evacuating 25 patients from an adjoining ward and extinguishing the fire. Flames quickly gutted the room and sent toxic smoke billowing into the hallways.
Methods Each subject performed three maximum expiratory flow volume curves, and performed a maximum voluntary ventilation (MVV) maneuver and two carbon-monoxide breathholding diffusing capacity (DLco) tests. Testing was
JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 71, NO. 3, 1979
done on an Automated Pulmonary Function Laboratory, the heart of which is a hot-wire anemometer flow sensor.* Calibration was performed daily with an internal Severinghaus syringe, and accuracy was within three percent, in accordance with the Snowbird Workshop recommendations.** Predicted standards used in this study were from the VA-Armed Forces Cooperative Study.10 Data were recorded as age, sex, and height-adjusted percent predicted values. Digital displays, printed outputs, and hard-copy curves were recorded for each test. Spirometry and diffusion studies were repeated at the end of ten weeks in three subjects and at the end of 45 weeks in nine subjects.
Subjects Student's T test was performed on the data and levels of significance were tested. The study population was composed of four healthy, nonexposed controls who were placed in Group 1. Informed consent was obtained from subjects in accordance with National Institutes of Health (NIH) guidelines for human ex-
perimentation. Twenty-three subjects exposed to smoke inhalation were placed in Group 2. These Group 2 subjects were further subdivided into subgroup A, which was composed of 11 healthy nonsmokers and persons who had smoked five pack-years of cigarettes or less, and subgroup B, which was composed of individuals who were symptomatic prior to exposure, had cardiopulmonary disease, or had smoked five pack-years or more of cigarettes. Symptomatic subjects had presmoke exposure cough consistent *M-100B SRL Medical, Inc. Dayton, Ohio. **ATS Snowbird Workshop for Standards for Spirometry, Snowbird, Utah, January 1977.
251
Table 2. Characteristics of Population
Table 1. Partition of Study Population
1*
Group 1 Healthy Nonexposed Controls Group 2 Exposed Subjects A. Healthy Nonsmokers and
Twenty-three hospital employees who suffered ill effects of smoke inhalation were pulmonary-function tested within 72 hours, after ten weeks, and again after 45 weeks of exposure. Four nonexposed control subjects were selected for comparison of data. Exposed persons commonly had restrictive lung disease which may have resulted from stimulation of irritant receptors in bronchi and/or interstitial edema of chemical injury at the level of the ventilation-perfusion unit. Airways obstruction was infrequent, despite the possibility of inhalation of di-isocyanates, an intermediary product of burning polyurethane foam that may cause chemical asthma. Eye and constitutional symptoms were also frequent. Clinical recovery was as a rule rapid and complete (within a week), but physiologic recovery was protracted (over 45 weeks in some cases). Most surprisingly, cigarette smoking and/or presence of cardiopulmonary disease did not contribute to morbidity. Concern was paid to the respiratory tract in bums for the first time after the Cocoanut Grove fire in Boston on November 29, 1942 in which some of the 498 victims died in the fire not from bums, but from smoke-associated damage to the respiratory tract.1 Since then there has been a plethora of articles dealing with the respiratory tract damage in burns.2-8 About 80 percent of the victims of fire are not touched by flame, but die as a result of exposure to smoke9 which consists of a particulate fraction and gaseous emission. The latter is mainly responsible for injury to the respiratory tract in fire victims. The composition of the gaseous phase de-
From the Harden Pulmonary Laboratory, Pulmonary Disease Division, Howard University Service, District of Columbia General Hospital, and Howard University Hospital. Presented to the 18th Annual Scientific Session of the Maryland Thoracic Society, South Baltimore General Hospital, Respiratory Division, BaltimoreWashington International Airport, February 19, 1978 and to the Section on Internal Medicine of the 83rd Annual Convention of the National Medical Association, Washington, DC, August 1, 1978. Requests for reprints should be addressed to Dr. Roscoe C. Young, Jr., Howard University Hospital, 2041 Georgia Avenue, NW,
Washington, DC 20060.
pends on the materials oxidized and the degree of injury, on the extent to which these oxidized substances are inhaled, the exposure time, and whether or not exposure occurred in a confined space. The unfortunate occurrence of a fire in an unused hospital nursing classroom provided a timely opportunity for a retrospective study of the clinical and physiological effects of smoke inhalation, in which polyvinylchloride, polyurethane foam, wood, and paper were the principal products oxidized. Forty hospital personnel who were part of a fire brigade responded to the fire alarm, helped in evacuating 25 patients from an adjoining ward and extinguishing the fire. Flames quickly gutted the room and sent toxic smoke billowing into the hallways.
Methods Each subject performed three maximum expiratory flow volume curves, and performed a maximum voluntary ventilation (MVV) maneuver and two carbon-monoxide breathholding diffusing capacity (DLco) tests. Testing was
JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 71, NO. 3, 1979
done on an Automated Pulmonary Function Laboratory, the heart of which is a hot-wire anemometer flow sensor.* Calibration was performed daily with an internal Severinghaus syringe, and accuracy was within three percent, in accordance with the Snowbird Workshop recommendations.** Predicted standards used in this study were from the VA-Armed Forces Cooperative Study.10 Data were recorded as age, sex, and height-adjusted percent predicted values. Digital displays, printed outputs, and hard-copy curves were recorded for each test. Spirometry and diffusion studies were repeated at the end of ten weeks in three subjects and at the end of 45 weeks in nine subjects.
Subjects Student's T test was performed on the data and levels of significance were tested. The study population was composed of four healthy, nonexposed controls who were placed in Group 1. Informed consent was obtained from subjects in accordance with National Institutes of Health (NIH) guidelines for human ex-
perimentation. Twenty-three subjects exposed to smoke inhalation were placed in Group 2. These Group 2 subjects were further subdivided into subgroup A, which was composed of 11 healthy nonsmokers and persons who had smoked five pack-years of cigarettes or less, and subgroup B, which was composed of individuals who were symptomatic prior to exposure, had cardiopulmonary disease, or had smoked five pack-years or more of cigarettes. Symptomatic subjects had presmoke exposure cough consistent *M-100B SRL Medical, Inc. Dayton, Ohio. **ATS Snowbird Workshop for Standards for Spirometry, Snowbird, Utah, January 1977.
251
Table 2. Characteristics of Population
Table 1. Partition of Study Population
1*
Group 1 Healthy Nonexposed Controls Group 2 Exposed Subjects A. Healthy Nonsmokers and
