Noninvasive fireground assessment of carboxyhemoglobin levels in firefighters.

Objectives: Carboxyhemoglobin (COHb) levels can be estimated by chemical analysis of exhaled alveolar breath. Such noninvasive measurement could be used on the fireground to screen both firefighters (FFs) and victims. The purpose of this study was to assess the feasibility of using a hand-held carbon monoxide (CO) monitoring device to screen for CO toxicity in FFs under field conditions.

Methods: Informed consent was obtained from all participants. Using a hand-held breath CO detection device, COHb readings were collected at baseline, and then as FFs exited burning buildings after performing interior fire attack and overhaul with self-contained breathing apparatus (SCBA) during live-fire training. Ambient CO levels were occasionally measured in interior areas where the FFs were working to assess the degree of CO exposure.

Results: Baseline COHb readings of 64 FFs ranged from 0% to 3% (mean 1%, median 1%). One hundred eighty-four COHb readings were collected during training exercises. The mean and median COHb levels were 1%. The maximum value in a FF wearing SCBA was 3%; values of 14%, 5%, and 4% were measured in instructors who were not properly wearing SCBA. Ambient CO readings during fire attack ranged from 75 to 1,290 ppm, and the ambient CO reading for overhaul ranged from 0 to 130 ppm. When the device was used for interior CO monitoring, washout time limited its utility for COHb monitoring in FFs.

Conclusions: A hand-held CO monitoring device adapted for estimation of COHb levels by exhaled breath analysis can feasibly be deployed on the fireground to assess CO exposure in FFs.