Noninvasive Fireground Assessment Of Carboxyhemoglobin Levels in Firefighters

OBJECTIVES: Carboxyhemoglobin (COHb) levels can be estimated by chemical analysis of exhaled breath. Such noninvasive measurement would allow operational EMS personnel to screen firefighters (FFs) and victims for carbon monoxide (CO) toxicity on the fireground. The purpose of this IRB-approved study was to assess the feasibility of using a hand-held, battery-powered CO monitoring device to screen for CO toxicity in FFs under field conditions. METHODS: Using an FDA-approved hand-held breath CO detection device (CO Sniffer, Scott/Bacharach Instruments, Exton PA), COHb readings were collected from FFs wearing self-contained breathing apparatus (SCBA) and performing interior fire attack and overhaul during live-fire training exercises. Ambient CO levels were periodically measured in interior areas where the FFs were working to assess the degree of CO exposure. Data were collected by 5 EMS physicians or PA's who are cross-trained as FFs, qualified to wear SCBA for interior ambient measurements. Baseline COHb levels were obtained from all participating FF's during the informed consent process. COHb levels were obtained from FFs as they exited burn buildings following training evolutions. Data were entered into a computer spreadsheet, and simple, descriptive statistics were obtained. RESULTS: Baseline COHb readings of 64 FF's ranged from 0% to 3% (mean 2%, median 1%). A total of 184 COHb readings were collected during 5 training exercises. The mean COHb was 2%; the median was 1%. The maximum value with SCBA was 3%; a value of 14% was measured on an instructor who removed his SCBA mask during a fire attack evolution. Each reading was also compared to the FF's baseline: the mean and median changes were both 0%. Ambient CO readings for fire attack ranged from 75 to 1290 ppm, and for overhaul from 0 to 130 ppm. CONCLUSIONS: The 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.