Chowdhury A, et al. – Researchers performed a comprehensive and thorough analysis of current literature reporting the efficacy of antiarrhythmics in advanced life support. They found that efficacy of any antiarrhythmic agents for improving rates of return of spontaneous circulation (ROSC), survival to admission, survival to discharge or neurological outcomes, was not conclusively evident in the current literature and data. Given the side effects of some of these agents, further research into their utility in current cardiopulmonary resuscitation guidelines was recommended.

Methods

• Two authors performed a systematic search through multiple bibliographic databases including CINAHL, SCOPUS, PubMed, Web of Science, Medline(Ovid) and the Cochrane Clinical Trials Registry.
• The studies were included if they compared an antiarrhythmic to either a control group, placebo or another antiarrhythmic in adult cardiac arrests.
• These studies were independently screened for outcomes in cardiac arrest assessing the effect of antiarrhythmics on return of spontaneous circulation (ROSC), survival and neurological outcomes.
• Data was extracted independently, compared for homogeneity and level of evidence was evaluated using the Cochrane Collaboration’s tool for assessing the risk of bias.
• Researchers used the Mantel-Haenszel (M-H) random effects model and assessed heterogeneity using the I² statistic.

Results

• Overall, 30 studies, including 39,914 patients, were identified.
• Researchers identified 8 antiarrhythmic agents.
• They noted that amiodarone and lidocaine, the two most commonly used agents, demonstrated no significant impact on any outcome either against placebo or each other.
• Furthermore, small low quality studies revealed benefits in isolated outcomes with esmolol and bretylium against placebo.
• Data showed that the only significant benefit of one antiarrhythmic over another was demonstrated with nifekalant over lidocaine for survival to admission (p = 0.003).
• On sensitivity analysis of a small number of high quality level one RCTs, it was found that both amiodarone and lidocaine had a significant increase in survival to admission, with no effect on survival to discharge.