Air management and physiological responses during simulated firefighting tasks in a high-rise structure

Air consumption, oxygen uptake (VO2), carbon dioxide output (VCO2) and respiratory exchange ratio (RER = VCO2/VO2) were measured directly from the self-contained breathing apparatus (SCBA) as 36 professional firefighters (three women) completed scenarios of high-rise stair climbing and fifth floor search and rescue. During stair climbing VO2 was 75 ± 8% VO2max (mean ± SD), RER = 1.10 ± 0.10, and heart rate = 91 ± 3% maximum (based on maximum treadmill data). Firefighters stopped climbing on consuming 55% of the air cylinder then descended. In the fifth floor search and rescue VO2 was slightly lower than stair climbing but RER remained elevated (1.13 ± 0.12) reflecting high anaerobic metabolism. The first low air alarm sounded, indicating 25% of the air remaining in a “30-min cylinder”, during the stair climb at 8 min with 19 of 36 sounding before 12 min. Aggressive air management strategies are required for safety in high-rise firefighting.