The relationship between rate of chest compression and compression:relaxation ratio.

One of the arguments put forward in support of a relatively fast rate of chest compression during CPR, is that it facilitates the achievement of a high compression:relaxation ratio. This has been shown to increase blood flow. In this study a group of volunteers carried out chest compression at the rate that each felt was correct and comfortable. There was no significant relationship between compression rate and compression:relaxation ratio. In a second study volunteers carried out chest compression on a manikin at rates of 40/min; 60/min; 80/min and 100/min. There was no significant rate related difference in the compression:relaxation ratios recorded. The ability to achieve a high compression duration is not related to compression rate, and should not be a consideration when guidelines on CPR are revised.