Use of sodium bicarbonate in out-of-hospital cardiac arrest: a systematic review and meta-analysis

Background Out-of-hospital cardiac arrest (OHCA) is a common cause of death worldwide (Neumar et al., Circulation 122:S729-S767, 2010), affecting about 300,000 persons in the USA on an annual basis; 92% of them die (Roger et al., Circulation 123:e18-e209, 2011). The existing evidence about the use of sodium bicarbonate (SB) for the treatment of cardiac arrest is controversial. We performed this study to summarize the evidence about the use of SB in patients with out-of-hospital cardiac arrest (OHCA). Methods We searched PubMed, Scopus, EBSCO, Web of Science, and Cochrane Library, until June 2019, for randomized controlled trials (RCTs) and observational studies that used SB in patients with OHCA. Outcomes of interest were the rate of survival to discharge, return of spontaneous circulation (ROSC), sustained ROSC, and good neurological outcomes at discharge. Odds ratio (OR) with their 95% confidence interval (CI) were pooled in a random or fixed meta-analysis model. Results A total of 14 studies (four RCTs and 10 observational studies) enrolling 28,412 patients were included; of them, eight studies were included in the meta-analysis. The overall pooled estimate did not favor SB or control in terms of survival rate at discharge (OR= 0.66, 95% CI [0.18, 2.44], p=0.53) and ROSC rate (OR= 1.54, 95% CI [0.38, 6.27], p=0.54), while the pooled estimate of two studies showed that SB was associated with less sustained ROSC (OR= 0.27, 95% CI [0.07, 0.98], p=0.045) and good neurological outcomes at discharge (OR= 0.12, 95% CI [0.09, 0.15], p<0.01). Conclusion The current evidence demonstrated that SB was not superior to the control group in terms of survival to discharge and return of spontaneous circulation. Further, SB was associated with lower rates of sustained ROSC and good neurological outcomes.