Objectives:
Most guidelines recommend pausing chest compressions at 2-min intervals to analyze the cardiac rhythm. We assessed the literature on the optimal interval at which to pause chest compressions in adults for cardiac rhythm analysis in any setting.
Methods:
To conduct this systematic review and meta-analysis, we searched PubMed, Embase, and Cochrane databases through January 2, 2015, including human studies addressing any two different intervals of rhythm analysis. We excluded animal studies, manikin studies, case reports, editorials, and studies published only in abstract form. We assessed for bias per the Cochrane Handbook criteria for randomized controlled trials (RCT) and observational studies, then used GRADE methodology to evaluate the quality of evidence for functional outcome, survival, and return of spontaneous circulation. Two reviewers independently screened titles/abstracts, and resolved disagreement by consensus. We summarized study results using RR for RCTs and OR for observational studies. Meta-analyses were performed with Mantel-Haenszel random effects model.
Results:
Of 1,135 papers identified, 8 were included (3 RCT and 5 observational studies) encompassing 15,242 subjects. Quality of evidence was very low or low (downgraded for risk of bias and indirectness). RCT comparing specific time intervals (3-minutes vs. immediate analysis; 1-minute vs. 2-minutes; 3-minutes vs. 1-minute) demonstrated no benefit in either arm. Meta-analyses of 5 observational studies demonstrated moderate pooled benefit of a bundled ‘minimally interrupted chest compression’ protocol dictating 200-compression intervals over historical controls treated with 1- or 3-minute intervals per the 2000 guidelines (ROSC: OR 1.9, 95% CI 1.3, 2.7; survival to discharge: OR 2.9, 95% CI 2.1, 3.8; good functional outcome: OR 2.9, 95% CI 1.6, 5.4). No pooled estimate had significant heterogeneity.
Conclusion:
We found no quality evidence to support pausing chest compressions at any singular interval to assess the cardiac rhythm in adults in cardiac arrest in any setting. Very low quality evidence suggests improved outcomes in patients receiving a bundled 200-compression interval protocol compared to 1- or 3-minute intervals.
Cardiac rhythm analysis during ongoing cardiopulmonary resuscitation using the Analysis During Compressions with Fast Reconfirmation technology
