Effects of Counting Chest Compressions on the Performance of Cardiopulmonary Resuscitation: Prospective Randomized Pilot Study Using Manikin Simulation Trial

ABSTRACT

PURPOSE: This study compared the effects of counting chest compressions verbally and silently on the performance of cardiopulmonary resuscitation (CPR). METHODS: Forty-six medical students were enrolled in this study. After the participants performed a two-min CPR (Test 1), during which they counted each compression silently, they were divided randomly into Groups A and B. After a 30-min rest, the participants took Test 2. In Test 2, Group A performed two-min CPR, during which the participants counted the number of chest compressions verbally (Test 2A), and in Group B, CPR was performed using the same methods as detailed for Test 1 (i.e., with silent enumeration; Test 2B). Each student counted the number of chest compressions aloud from one to 30 in Test 2A. RESULTS: No significant differences were observed for either test (Tests 1 and 2) between Groups A and B. Although the mean compression rate (MCR) was increased significantly from 107.2+/-15.4 to 116.3+/-15.9/min between Tests 1 and 2B in Group B (p<0.01), a similar result was also obtained in Group A. In the individual interviews conducted with the Group A participants, all members reported having difficulty breathing while counting the number of chest compressions verbally when compared with silent enumeration. CONCLUSION: Tallying the numbers of chest compressions verbally did not significantly alter the performance of CPR.