Abstract 234: Quantifying the Effect of CPR Quality on Cardiac Arrest Outcome: A Meta-analysis
Objective: While evidence has accrued that CPR quality impacts cardiac arrest outcome, the effect size of variation in CPR quality remains poorly characterized. Furthermore, the relative contributions of chest compression (CC) components (such as rate and depth) to successful resuscitation remain unclear. We sought to measure the effect of CPR quality on cardiac arrest outcome through systematic review and meta-analysis.
Methods: A comprehensive search was performed for English-language articles using PubMed, MEDLINE, Cochrane Library, and direct author contact. We included any clinical study assessing CPR performance on adult cardiac arrest patients where survival was a reported outcome, either return of spontaneous circulation (ROSC) or survival to admission or discharge. Effect sizes were reported as mean differences. Missing data were resolved by author contact. Estimates were segregated by CPR metric (CC rate, depth, no-flow fraction, and ventilation rate), and a random-effects model was applied to estimate an overall pooled effect. Evidence for statistical heterogeneity between studies was tested via goodness of fit (X2).
Results: Of 603 abstracts evaluated, 8 studies published between 2005 and 2012 met inclusion criteria. These 8 studies included 2113 unique arrest cases (1937 out-of-hospital, 176 in-hospital). Mean age was 68.0 years, 64.1% of the cohort was male, overall ROSC was 31.2%, and survival to discharge was 4.9%. Arrest survivors were significantly more likely to have received deeper CCs than non-survivors (mean difference 2.44 mm, 95% CI 1.19 to 3.69 [p<0.001], n=6 studies, p for heterogeneity=0.9). Survivors were also significantly more likely to have received CC rates closer to 85-100 cpm than non-survivors (absolute mean difference from 100 cpm -5.04 cpm, 95% CI -8.44 to -1.65 cpm [p=0.004], n=6 studies, p for heterogeneity=0.2). Findings for depth and rate did not vary by arrest location, CPR performer, study quality, or outcome type. No significant difference in no-flow fraction (n=5 studies) or ventilation rate (n=3 studies) between survivors and non-survivors was observed.
Conclusions: Deeper chest compressions and rates closer to 85-100 cpm are significantly associated with improved survival from cardiac arrest.
- © 2012 by American Heart Association, Inc.