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

Background: 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.

Methods: 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.

Results: 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; I = 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; I = 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.

Conclusions: 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.