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

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 (V02 max) determined strength and endurance. Twenty-three 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<0.05) and V02 max (PE 50 ml/kg/min vs. M 44 ml/ kg/min; p<0.05) revealed a better strength and endurance in PE students. Six medicine and 1 PE student did not complete the entire 30 minutes of CPR. Percentage compressions >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/I (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.