Quality of cardiac massage with ratio compression-ventilation 5/1 and 15/2

The aim of this study is to study the quality of chest compressions over a period of 5 min with a compression-ventilation ratio of 5/1 and 15/2.

This prospective study was carried out with an electronic CPR manikin (ResusciAnne with Skillmeter; Laerdal). The participants were 'ambulancier SMUR' (Emergency and Resuscitation Mobil Unit) belonging to a French prehospital emergency team. They all have been trained in cardiopulmonary resuscitation (CPR) and are certified to perform CPR. The quality of chest compression has been evaluated according to the international recommendations. Each participant provided CPR with ratio 5/1 and 15/2.

Twenty-one subjects participated in this experiment. The mean number of attempted compressions per min was 69.24 (S.D.=8.7) for a ratio of 5/1 and 79.26 (S.D.=6.7) for a ratio of 15/2. The rates achieved were similar between the two ratios with, respectively, a mean of 103.5 and 112 per min. The mean correct compression was 56.5 (S.D.=15.7) per min for group 5/1 and 44.16 (S.D.=24.8) for group 15/2. Quality of closed chest compression was very significantly better with a ratio of 5/1 than 15/2 (P=0.0002). A significant decrease in compression quality has been found over the time for a ratio of 15/2 (P=0.011). No correlation between correct compression and duration appeared for group 5/1. Incorrect location on sternum was 24 times most frequent with a ratio of 15/2 than ratio 5/1. Compression of insufficient depth remained the most frequent error both with ratio 5/1 and 15/2 and was 2.2 times more frequent with a ratio of 15/2 than a ratio of 5/1.

Effective closed chest compression was significantly better with a ratio of 5/1 than 15/2. Better management of cardiac arrest suggested by an increase in a number of compressions with a ratio of 15/2 could be attenuated by cardiac compressions of lesser quality.