Influence of chest compression rate guidance on the quality of cardiopulmonary resuscitation performed on manikins

Abstract

Aims The adequate chest compression rate during CPR is associated with improved haemodynamics and primary survival. To explore whether the use of a metronome would affect also chest compression depth beside the rate, we evaluated CPR quality using a metronome in a simulated CPR scenario. Methods Forty-four experienced intensive care unit nurses participated in two-rescuer basic life support given to manikins in 10 min scenarios. The target chest compression to ventilation ratio was 30:2 performed with bag and mask ventilation. The rescuer performing the compressions was changed every 2 min. CPR was performed first without and then with a metronome that beeped 100 times per minute. The quality of CPR was analysed with manikin software. The effect of rescuer fatigue on CPR quality was analysed separately. Results The mean compression rate between ventilation pauses was 137 ± 18 compressions per minute (cpm) without and 98 ± 2 cpm with metronome guidance ( p < 0.001). The mean number of chest compressions actually performed was 104 ± 12 cpm without and 79 ± 3 cpm with the metronome ( p < 0.001). The mean compression depth during the scenario was 46.9 ± 7.7 mm without and 43.2 ± 6.3 mm with metronome guidance ( p = 0.09). The total number of chest compressions performed was 1022 without metronome guidance, 42% at the correct depth; and 780 with metronome guidance, 61% at the correct depth ( p = 0.09 for difference for percentage of compression with correct depth). Conclusions Metronome guidance corrected chest compression rates for each compression cycle to within guideline recommendations, but did not affect chest compression quality or rescuer fatigue.