A modified SCBA facepiece for accurate metabolic data collection from firefighters

Abstract

To better assess the energy expenditure and exertion of firefighters during simulated firefighting activities, a commercial firefighter self-contained breathing apparatus (SCBA) facepiece was modified to interface with a portable metabolic monitoring device (Cosmed K4b²) while still functioning as a positive pressure SCBA air supply. To validate the device, standard National Fire Protection Association 1981 SCBA function tests were conducted and 14 subjects performed variable-workload assessments using all combinations of two test devices (Cosmed K4b² and metabolic cart) and two masks (modified SCBA facepiece and stock manufacturer-supplied breath collection). Metabolic data collected with the Cosmed K4b² via the modified facepiece were found to be accurate when compared to a ParvoMedics Truemax 2400 metabolic cart (average per cent difference: 4.6%). This modified facepiece design is suitable for use in metabolic studies requiring the utilisation of an SCBA system. Furthermore, the well-established overestimation of oxygen consumption from the Cosmed K4b² system was replicated.

Abstract

Practitioner Summary: The nature of a firefighters' self-contained breathing apparatus (SCBA) prevents collection of respiratory metabolic data while the firefighter consumes air from the SCBA. This study introduces and validates a modified SCBA facepiece design integrating metabolic data collection tools with firefighting SCBA allowing for data collection across various firefighting activities.

Keywords::

• oxygen uptake
• gas analysis
• firefighting
• self-contained breathing apparatus
• respiration

Additional information

Funding

This work was supported by the Department of Homeland Security Fire Prevention and Safety [grant number EMW-2010-FP-01606].