RESUMO
PURPOSE: The aim of this study was to estimate the effect of counting numbers out for giving breaths on the interruption time (IT) of chest compressions (CCs) and chest compression fraction (CCF) in the 2-rescuer cardiopulmonary resuscitation (CPR). METHODS: Thirty medical students were enrolled in this randomized control simulation study, and were randomly divided into the control group and the study group. Both groups performed 2-rescuer CPR for 5-cycles with giving breaths using a bag-mask. Only participants in the study group were instructed to count numbers out for each breath verbally ("one, two") at the end point of each inspiration period and immediately perform CCs at the point of counting "two". RESULTS: However, no differences in terms of depth, rate, incorrect location, and duty cycle of CCs, as well as ventilation volume of each breath, time to delivery of two breaths, and counts of breathing during 1 minute were observed between the two groups. CONCLUSION: The study group had significantly shorter IT and higher CCF compared with the control group. And no significant differences in the other measured parameters of CPR quality were observed between the two groups.