The 2005 compression-ventilation ratio in practice: cycles or time?

The purpose of this study was to determine how long it takes rescuers to complete five cycles of cardiopulmonary resuscitation (CPR) using a compression-ventilation (CV) ratio of 30:2.

Twenty subjects, who were all members of the medical service at a motor racing circuit and trained in basic life support (BLS), were instructed to provide five cycles of CPR with a CV ratio of 30:2 using a manikin (Little Anne Adult CPR Manikin, Laerdal, Stavanger, Norway). The time taken to deliver the first two breaths and to complete all five cycles was recorded.

The median time to deliver the first two breaths was 7.3 s (IQR 6.5-9.6 s) and the median time to complete five cycles with a CV ratio of 30:2 was 105.0 s (IQR 92.0-112 s). Many of the subjects found it difficult to count five cycles when using this CV ratio.

Five cycles of CPR using a CV ratio of 30:2 takes approximately 1 min 45 s to complete. Using this CV ratio, trained individuals find it difficult to count out five cycles of CPR. It may be simpler to train individuals to give CPR for a specified time (2 min) instead of a specific number of cycles.