Lower cardiopulmonary resuscitation quality after pre-resuscitation physical exertion and stress exposure in active firefighters: a within-subject field study in a standardized operational setting.

Introduction: Cardiopulmonary resuscitation is a physically demanding intervention critical for survival in sudden cardiac arrest. While most studies focus on fatigue developing during resuscitation, emergency responders often initiate cardiopulmonary resuscitation after physically and psychologically demanding events. This study investigated changes in cardiopulmonary resuscitation performance following pre-exposure to physical and psychological stress in active firefighters. Methods: 23 Caucasian firefighters (18 male, 5 female; body mass index = 25.4 ± 3.86; body fat = 19.7% ± 8.98) participated in a within-subject field design. Each participant performed a standardized two-minute cardiopulmonary resuscitation on a manikin before and after a fire service-typical operational task involving a self-contained breathing apparatus. Cardiopulmonary resuscitation performance was assessed using the SimPad Plus by Leardal Medical. Secondary outcomes included heart rate, salivary cortisol (nmol/L), alpha-amylase (U/mL), self-reported affect and anxiety. Results: Physiological markers indicated an acute stress response, with cortisol increasing by 236% (95% CI: 56-416%) and alpha-amylase by 60% (95% CI: 35-84%) (both Discussion: These findings suggest that pre-resuscitation exertion may be associated with reduced CPR quality, which could be relevant for physically demanding emergency settings. They may therefore have implications for workload management and physical preparedness in emergency personnel.