The effects of up-down hand position switch on the quality of external chest compression and fatigue during cardiopulmonary resuscitation

Abstract

Objective To investigate the effects of up-down hand position switch on the quality of external chest compression and the fatigue of rescuers during cardiopulmonary resuscitation (CPR). Methods Two methods of external chest compression were compared in the experiment. One method was a chest compression by alternating two oberlapped hans up-and-down compressing directly on the chest wall, and the other was the chest compression without alternating hand positions. A total of 177 medical students trained by standard basic life support course were randomly assigned to the sequences of those two methods by drawing lots. Two different methods of chest compression were separately performed at 7 days interval. Each time, 10 cycles of standard adult CPR were made on the manikin. The data including CPR quality, physiological variables and subjective fatigue feeling of the rescuers before and after CPR were recorded. The results were expressed as mean±SD. The t test was used to compare the means of two groups, and χ2 test was used to compare the frequency between groups. The probability of event-free(no fatigue appearance) was estimated by Kaplan-Meier. The statistical significance was defined as P<0.05. Results Among the rescuers, those used the dominant hand in contact with the sternum firstly, there were no significant differences in chest compression quality (P>0.05), Borg scores after CPR(13.17±1.62 vs.13.41±2.11, P=0.437), or cycle number of fatigue appearance (P=0.127) between the alternating compressing hand position group and the conventional compressing without alternating hand position group. While among the rescuers, those used the non-dominant hand in contact with the sternum firstly, compression depth was deeper [（39±10)mm vs.（38±9)mm,P=0.015], Borg score after CPR was lower(12.67±2.03 vs.13.33±1.95, P=0.011), and the appearance of fatigue appeared later(P=0.041) in the compression with alternating hand positions group, compared with the conventional compression without alternating hand positions group. Conclusion The up-down hand position alternate during CPR may delay the fatiguewhich appeared earlier in non-dominant hand position rescuers and improve the quality of external chest compressions. Key words: Cardiopulmonary resuscitation; External chest compression; Compressing hand; Fatigue; Quality