Unfavorable Neurological Outcomes with Incremental Cardiopulmonary Resuscitation Duration in Cardiac Arrest Brain Injury: A Systematic Review and Meta-Analysis

Abstract

The duration of cardiopulmonary resuscitation (CPR) affects neurological outcomes. Conclusive data on its decremental effect on neurological outcomes have not been explored before in a quantitative review. PubMed and Google Scholar were searched for relevant studies from 2015 up to May 2023 using relevant keywords. The odds of good neurological outcomes were studied. Binary random effects were used to estimate pooled odds ratios (OR) and 95% confidence intervals (CI). A leave-one-out sensitivity analysis was performed. Heterogeneity was assessed using I2 statistics. For outcomes showing moderate to high heterogeneity, subgroup analysis was performed for follow-up duration or type of study. A p value of < 0.05 was considered statistically significant. A total of 349,027 cardiac arrest patients (mean age, 70.2 years; males, 56.6%) from four studies were included in the meta-analysis. Of them, the initial rhythm was shockable in 11% (38,465/349,027) and non-shockable in 88.97% (310,562/349,027) of the population. Odds of having favorable neurological outcomes were 0.32 (95% CI 0.10–1.01, p = 0.05) for 6–10 min (n = 14,118), 0.10 (95% CI 0.02–0.64, p = 0.02) for 11–15 min (n = 43,885), 0.05 (95% CI 0.01–0.36, p 0.01) for 16–20 min (n = 66,174), 0.04 (95% CI 0.01–0.21, p < 0.01) for > 20 min (n = 181,262), and 0.03 (95% CI 0.00–1.55, p = 0.08) for > 30 min (n = 66,461) when compared to patients receiving CPR for < 5 min (n = 6420). Steady decremental odds of favorable neurological outcomes were seen with every 5 min of increased CPR duration, with a statistically significant decline seen in CPR duration from 11 to 15 min onwards.