Saf Health Work.  2018 Dec;9(4):468-472. 10.1016/j.shaw.2018.02.002.

Respiratory Responses during Exercise in Self-contained Breathing Apparatus among Firefighters and Nonfirefighters

• Hostler D
• Pendergast DR

• KMID: 2430725
• DOI: http://doi.org/10.1016/j.shaw.2018.02.002

Abstract

BACKGROUND
Firefighters are required to use self-contained breathing apparatus (SCBA), which impairs ventilatory mechanics. We hypothesized that firefighters have elevated arterial COâ‚‚ when using SCBA.
METHODS
Firefighters and controls performed a maximal exercise test on a cycle ergometer and two graded exercise tests (GXTs) at 25%, 50%, and 70% of their maximal aerobic power, once with a SCBA facemask and once with protective clothing and full SCBA.
RESULTS
Respiratory rate increased more in controls than firefighters. Heart rate increased as a function of oxygen consumption (V.(Oâ‚‚)) more in controls than firefighters. End-tidal COâ‚‚ (ETCOâ‚‚) during the GXTs was not affected by work rate in either group for either condition but was higher in firefighters at all work rates in both GXTs. SCBA increased ETCOâ‚‚ in controls but not firefighters.
CONCLUSIONS
The present study showed that when compared to controls, firefighters' hypoventilate during a maximal test and GXT. The hypoventilation resulted in increased ETCOâ‚‚, and presumably increased arterial COâ‚‚, during exertion. It is proposed that firefighters have altered COâ‚‚ sensitivity due to voluntary hypoventilation during training and work. Confirmation of low COâ‚‚ sensitivity and the consequence of this on performance and long-term health remain to be determined.

Keyword

Carbon dioxide retention; Exercise; Protective equipment; Self-contained breathing apparatus

MeSH Terms

Exercise Test
Firefighters*
Heart Rate
Humans
Hypoventilation
Mechanics
Oxygen Consumption
Protective Clothing
Respiration*
Respiratory Rate