Physiological responses in female rescuers during 30 minutes sustained CPR with feedback : a comparison between medicine and physical education students

Abstract

Objectives: Since fatigue seems related to poorer physical fitness rather than to gender, we analyzed the physiological responses in female medicine and physical education students during a 30 minutes sustained cardiopulmonary resuscitation (CPR) sequence. Methods: Handgrip strength and maximal aerobic power (VO2 max) determined strength and endurance. Twentythree medicine (M) and 27 physical education (PE) female students performed 30 minutes CPR. Compression quality and ECG were continuously monitored, heart rate and non-invasive blood pressure (NIBP) every 2 minutes. Capillary pH, PcCO2, lactate, potassium and sodium bicarbonate were analyzed every 10 minutes. Results: Handgrip strength (PE 37 kg vs. M 35 kg; p 5 cm was comparable in both groups (PE 80%; M 79%; p=0.67). Mean heart rate during CPR was higher in the M group (148 bpm) compared to the PE group (132 bpm; p<0.05). No intergroup differences in NIBP, pH, PcCO2, potassium and sodium bicarbonate were observed. Mean lactate during CPR was higher in the M group: 3.5 mmol/l (SD 1.4) compared to the PE group: 2.5 mmol/l (SD 0.7) (p<0.05). Conclusion : A high quality sustained CPR effort was well tolerated by all female rescuers. Poorer physical condition (M group) resulted in more drop out after 10 and 20 minutes and in a higher heart rate and blood lactate over time. Improving physical condition may result in less physiological strain and lower perceived exertion