Hyperventilation following a large-scale hazardous-materials incident.

Actual or perceived exposure to hazardous materials may result in physiologic and psychological effects. However, hyperventilation following such exposures has not previously been reported. After a large-scale industrial release of oxides of nitrogen, five (29%) of 17 patients evaluated at a major trauma center were hyperventilating, as defined by arterial PCO2 <33 mm Hg, and nine patients (53%) had arterial PCO2 <37 mm Hg. First responders (rescue team members and paramedics) had a higher rate of hyperventilation than other occupational groups. Age, gender, marital status, decontamination, and mode of arrival were not significantly associated with hyperventilation, although marital status approached significance. This study suggests that hyperventilation may be a common reaction after hazardous-materials incidents, and that certain populations may be at increased risk for this condition.