The effect of sodium bicarbonate on OHCA patients: A systematic review and meta-analysis of RCT and propensity score studies

Evidence on the efficacy of sodium bicarbonate (SB) in out-of-hospital cardiac arrest (OHCA) is controversial and generally of low quality. A systematic review and meta-analysis was performed to evaluate the effect of SB in OHCA patients based on randomized controlled trial (RCT) and propensity score matching (PSM) cohort studies.We searched the PubMed, Cochrane, and Embase databases for RCTs and PSM cohort studies from inception to July 15, 2023. We included studies involving adult (>16 years) no-trauma OHCA patients with clear comparisons between the Bicarbonate group and Control group. All studies reported our primary outcome of short-term survival rate included ROSC and survival to emergency department or hospital admission or secondary outcome of long-term survival rate included survival at hospital discharge and good neurologic survival at 1 month. Results were expressed as odds ratio (OR) with accompanying 95% confidence interval (CI). To reduce bias, we performed a subgroup analysis of RCTs and PSM cohort studies. Also, we performed sensitivity analysis to resolve the heterogeneity.Six studies (3 RCTs and 3 PSMs) comprising 21,402 patients were included. The primary outcome of this meta-analysis showed that short-term survival rate between the two groups was no difference (OR = 1.04; 95% CI, 0.98 to 1.12; P = 0.21; χ2 = 6.68; I2 = 25%). Secondary outcome demonstrated that long -term survival rate between the two groups was no difference (OR = 0.82; 95% CI, 0.50 to 1.34; P = 0.43; χ2 = 14.96; I2 = 80%). A sensitive analysis was performed by removing one study showed long-term survival rate of the Bicarbonate group was lower than that of the Control group.In patients with OHCA, sodium bicarbonate administration was associated neither with short-term survival rate nor with long-term survival rate, it may even worsen the long-term survival.