The Effects of Epinephrine, as a Supplement for Epidural and Spinal Anesthesia, on the Duration of Analgesia during Childbirth and Apgar Score: A Systematic Review and Meta‑Analysis

Background: Labor pain is one of the most severe pains that woman may experience during their lifetime. Objectives: This study aimed to systematically review and meta‑analyze studies into the effects of epinephrine on the duration of analgesia during childbirth and Apgar score. Methods: This systematic review was conducted in 2018. Data were collected through searching online databases, namely the PubMed, Scopus, Google scholar, SID, Medlib, Magiran, and Iranmedex. Inclusion criteria were an interventional design, comparison of the effects of epinephrine with other modalities on the duration of analgesia and Apgar score, and publication from January 1990 to October 2018 in English or Persian in peer‑reviewed journals. Meta‑analysis was performed using the fixed and the random effects models with a 95% confidence interval (CI). The Q and the I2 statistics were used to assess heterogeneity, while the funnel plot and the Egger’s test were used to evaluate the possibility of publication bias. Results: The standardized mean difference between the epinephrine and the comparison groups respecting the duration of analgesia was 0.65 (95% CI: 0.32–0.98). This difference was statistically significant (P < 0.05). The between‑group standardized mean differences respecting the total, 1 min, and 5‑min Apgar scores were −0.33 (95% CI: −0.97–0.30), −0.26 (95% CI: −1–0.47), and −0.54 (95% CI: −1.79–0.70), respectively. None of these differences was statistically significant (P > 0.05). Conclusion: Epinephrine increases the duration of analgesia without causing serious side effects.