Abstract
Aim
External cardiac compressions (ECC) are a critical component in determining the effectiveness of cardiopulmonary resuscitation (CPR). Guidelines prior to the 2010 International Liaison Committee on Resuscitation directed rescuers to place the heel of the dominant hand directly on the chest when performing ECC, however current guidelines are silent on this issue. Existing research is inconsistent in findings, and heterogeneous in design and participants. The aims of this pilot study were to: 1) investigate the impact of hand dominance on effectiveness of ECC; and 2) generate outcome data to inform sample size calculations for a larger future study.
Methods
This study utilised a single blinded, prospective randomised crossover trial design. Each participant was allocated to a ‘dominant hand on chest’ (DHOC) or ‘non-dominant hand on chest’ (NDHOC) group. On a simulation manikin, participants in the DHOC group performed 3 minutes of ECC with dominant hand on the chest and non-dominant hand supporting, followed by a ‘rest and recovery’ period and then a second 3-minute period of ECC with the hand reversed such that the non-dominant hand was on the chest. The NDHOC group performed the same series of compressions but in reverse order. The primary outcome measure was effectiveness of ECC, determined by a percentage-based ‘CPR score’ (‘CS’). Secondary outcomes were compression depth, rate and release. The Wilcoxon rank-sum (Mann-Whitney) test was used due to the non-normal distribution of the data. Due to the crossover design, hierarchical linear regression was used to assess for a period or cross over effect.
Results
For the primary outcome of this study, we have found no significant difference in CS between DHOC and NDHOC (69.9% (SD=29.9) vs. 69.1% (SD=34.1); p=0.92), respectively. There were no differences in the secondary outcomes of compression rate and depth, though compression release was improved in the DHOC group (53% vs. 42%; p=0.02).
Conclusion
In this randomised crossover study conducted in a simulation context there was no difference in ECC effectiveness measured by an overall effectiveness outcome according to placement of the dominant or non-dominant hand on the chest during compressions. A modest improvement in ECC release was seen in the dominant hand on chest group. While the study was underpowered, the results support an approach involving rescuers placing whichever hand they are most comfortable with on the chest irrespective of handedness.