Research Projects


Firefighting and On-Scene Rehabilitation on Homeostasis

Summary

Funding provided by: National Institute of Occupational Safety and Health (NIOSH)

It is well recognized that firefighting leads to increased cardiovascular and thermal strain. However, the time course of recovery from this firefighting induced strain is not well documented, despite the fact that a large percentage of firefighting fatalities occur after firefighting activity. Furthermore, on scene rehabilitation has been broadly recommended to mitigate the cardiovascular and thermal strain associated with performing strenuous firefighting activity, yet the efficacy of different rehabilitation interventions has not been well documented.

Therefore, firefighters participated in this study designed to describe the acute effects of fire fighting on a broad array of physiological and psychological measures and several key cardiovascular variables. This study provided the first detailed documentation of the time course of recovery during 2½ hours post-fire fighting. Additionally, we compared two rehab strategies to determine their effectiveness.

As expected, a short term bout (18 minutes) of firefighting activity resulted in significant physiological, psychological, and cardiovascular strain. Immediately post-firefighting, core temperature, heart rate, blood pressure and blood catecholamine levels were significantly elevated from baseline conditions. Platelet function and number, along with coagulatory and fibrinolytic variables, showed significant increases from baseline, suggesting that the hemostatic equilibrium was disrupted. Vascular function was significantly affected, resulting in a reduction in the ability to perfuse myocardial tissue. Importantly, the time rate of recovery from many of these effects appeared to be closer to several hours instead of minutes as is often assumed. After 120 minutes of recovery, it was found that fibrinolytic markers returned to baseline levels, but coagulation remained significantly elevated. As many heart attacks on the fireground occur following fire suppression, these results suggested a possible mechanism for the increased risk. In this study, the active cooling process was no more effective than passive cooling in cool environmental conditions in which rehab was conducted. Furthermore, there was no significant effect on blood pressure, coagulation or fibrinolytic variables or psychological measures as a result of the enhanced rehab protocol.

 

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