Medline ® Abstracts for References 1,7,8

of 'Reactive airways dysfunction syndrome and irritant-induced asthma'

1
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Reactive airways dysfunction syndrome (RADS). Persistent asthma syndrome after high level irritant exposures.
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Brooks SM, Weiss MA, Bernstein IL
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Chest. 1985;88(3):376.
 
Ten individuals developed an asthma-like illness after a single exposure to high levels of an irritating vapor, fume, or smoke. In most instances, the high level exposure was the result of an accident occurring in the workplace or a situation where there was poor ventilation and limited air exchange in the area. In all cases, symptoms developed within a few hours and often minutes after exposure. We have designated the illness as reactive airway dysfunction syndrome (RADS) because a consistent physiologic accompaniment was airways hyperreactivity. When tested, all subjects showed positive methacholine challenge tests. No documented preexisting respiratory illness was identified nor did subjects relate past respiratory complaints. In two subjects, atopy was documented, but in all others, no evidence of allergy was identified. In the majority of the cases, there was persistence of respiratory symptoms and continuation of airways hyperreactivity for more than one year and often several years after the incident. The incriminated etiologic agent varied, but all shared a common characteristic of being irritant in nature. In two cases, bronchial biopsy specimens were available, and an airways inflammatory response was noted. This investigation suggests acute high level, uncontrolled irritant exposures may cause an asthma-like syndrome in some individuals which is different from typical occupational asthma. It can lead to long-term sequelae and chronic airways disease. Nonimmunologic mechanisms seem operative in the pathogenesis of this syndrome.
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PMID
7
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Cough and bronchial responsiveness in firefighters at the World Trade Center site.
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Prezant DJ, Weiden M, Banauch GI, McGuinness G, Rom WN, Aldrich TK, Kelly KJ
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N Engl J Med. 2002;347(11):806.
 
BACKGROUND: Workers from the Fire Department of New York City were exposed to a variety of inhaled materials during and after the collapse of the World Trade Center. We evaluated clinical features in a series of 332 firefighters in whom severe cough developed after exposure and the prevalence and severity of bronchial hyperreactivity in firefighters without severe cough classified according to the level of exposure.
METHODS: "World Trade Center cough" was defined as a persistent cough that developed after exposure to the site and was accompanied by respiratory symptoms severe enough to require medical leave for at least four weeks. Evaluation of exposed firefighters included completion of a standard questionnaire, spirometry, airway-responsiveness testing, and chest imaging.
RESULTS: In the first six months after September 11, 2001, World Trade Center cough occurred in 128 of 1636 firefighters with a high level of exposure (8 percent), 187 of 6958 with a moderate level of exposure (3 percent), and 17 of 1320 with a low level of exposure (1 percent). In addition, 95 percent had symptoms of dyspnea, 87 percent hadgastroesophageal reflux disease, and 54 percent had nasal congestion. Of those tested before treatment of World Trade Center cough, 63 percent of firefighters (149 of 237) had a response to a bronchodilator and 24 percent (9 of 37) had bronchial hyperreactivity. Chest radiographs were unchanged from precollapse findings in 319 of the 332 with World Trade Center cough. Among the cohort without severe cough, bronchial hyperreactivity was present in 77 firefighters with a high level of exposure (23 percent) and 26 with a moderate level of exposure (8 percent).
CONCLUSIONS: Intense, short-term exposure to materials generated during the collapse of the World Trade Center was associated with bronchial responsiveness and the development of cough. Clinical and physiological severity was related to the intensity of exposure.
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Bureau of Health Services, Fire Department of New York City, New York, USA. prezand@fdny.nyc.gov
PMID
8
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Persistent hyperreactivity and reactive airway dysfunction in firefighters at the World Trade Center.
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Banauch GI, Alleyne D, Sanchez R, Olender K, Cohen HW, Weiden M, Kelly KJ, Prezant DJ
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Am J Respir Crit Care Med. 2003;168(1):54.
 
New York City Fire Department rescue workers experienced massive exposure to airborne particulates at the World Trade Center site. Aims of this longitudinal study were to (1) determine if bronchial hyperreactivity was present, persistent, and independently associated with exposure intensity, (2) identify objective measures shortly after the collapse that would predict persistent hyperreactivity and a diagnosis of reactive airways dysfunction 6 months post-collapse. A representative sample of 179 rescue workers stratified by exposure intensity (high, moderate, and control) without current smoking or prior respiratory disease was enrolled. Highly exposed workers arrived within 2 hours of collapse, moderately exposed workers arrived later on Days 1-2; control subjects were not exposed. Hyperreactivity at 1, 3, and 6 months post-collapse was associated with exposure intensity, independent of ex-smoking and airflow obstruction. Six months post-collapse, highly exposed workers were 6.8 times more likely than moderately exposed workers and control subjects to be hyperreactive (95% confidence interval, 1.8-25.2; p = 0.004), and hyperreactivity persisted in 55% of those hyperreactive at 1 and/or 3 months. In highly exposed subjects, hyperreactivity 1 or 3 months post-collapse was the sole predictor for reactive airways dysfunction (p = 0.021). In conclusion, development and persistence of hyperreactivity and reactive airways dysfunction were strongly and independently associated with exposure intensity. Hyperreactivity shortly post-collapse predicted reactive airways dysfunction at 6 months in highly exposed workers; this has important implications for disaster management.
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Professor of Medicine, Montefiore Medical Center, Pulmonary Division, Centennial 423, Bronx, NY 10467, USA. Prezd@dnamail.com
PMID