Muscle Activity during the Performance of CPR in Simulated Microgravity and Hypogravity

Abstract

Cardiopulmonary resuscitation (CPR) is a series of resuscitation actions that improve the survival chances after a cardiac arrest, maintaining tissue perfusion through sternal compressions. This study aimed to clarify potential differences in upper-body muscle activity during CPR in microgravity and hypogravity (Mars’ gravitational field). Thirty healthy male volunteers each performed three sessions of 30 external chest compressions (ECCs) on a mannequin. During that time, the muscle activity of the pectoralis major, triceps brachii, and rectus abdominis was recorded via superficial electromyography. Hypogravity and microgravity were simulated using a body suspension device and a counterweight system, to which the volunteer was connected via a harness. The standard terrestrial (1G) CPR position was adopted in simulated hypogravity, and the Evetts–Russomano method was used in simulated microgravity. Heart rate and perceived exertion were also measured via the Borg scale. No significant difference was found between ECCs performed per minute and per set of compressions at 1G and in simulated hypogravity. However, the mean depth achieved during compressions differed significantly with hipogravity. After three sets of 30 ECCs, the mean heart rate showed an increase from rest values to those obtained from the three gravitational fields, and also from 1G to microgravity, but not from 1G to hypogravity. Mean perceived exertion increased significantly from 1G to hypogravity and to microgravity. Muscle activation during CPR at 1G and in hypogravity was markedly higher in the rectus abdominis. All muscles were more active during CPR in microgravity when compared with 1G. These findings suggest that the rescuer should be physically well-trained to deliver adequate CPR in extraterrestrial environments. Physical training should aim to improve muscular endurance and cardiorespiratory capacity to enhance the effectiveness of the rescuer’s emergency assistance.

BibTeX

@article{baptista2015muscle,
  title={Muscle activity during the performance of CPR in simulated microgravity and hypogravity},
  author={Baptista, Rafael Reimann and SUSIN, Thiago B and Dias, Mariana Kloeckner Pires and Corr{\^e}a, Nicholas and Cardoso, Ricardo Bertoglio and Russomano, Thais},
  journal={American Journal of Medical and Biological Research},
  year={2015}
}