Meta-analysis of neostigmine injections given at the Zusanli (ST 36) acupoint in the treatment of postpartum urinary retention

Objective: We aimed to determine the effect of neostigmine injections given at the Zusanli (ST 36) acupoint when treating postpartum urinary retention. Methods: We conducted a systematic review to identify randomized controlled trials (RCTs) involving neostigmine injections given at the Zusanli (ST 36) acupoint for treating postpartum urinary retention. We searched the Cochrane Library, Pubmed, Web of Science, Chinese National Knowledge Infrastructure, Vip Database, and Chinese Biomedical Literature Database from the creation of the database to December 30, 2016. Bias risk assessment was performed using Revman 5.3 software from Cochrane based on the criteria set out in the Cochrane Handbook for Systematic Reviews of Interventions, version 5.1.0. Results: Thirteen studies were included with 627 participants in the treatment group and 584 participants in the control group. (1) Overall response rate: neostigmine injections given at the Zusanli (ST 36) acupoint have a better curative effect than injections given in muscle, odds ratio (OR) = 8.74, 95% confidence interval (CI) [5.83, 13.10], Z = 10.49 (P < 0.001); (2) Comparison of effects at different dosages: (i) 0.5 mg of neostigmine Zusanli (ST 36) acupoint injection group has better effect than 1 mg of neostigmine intramuscular injection group, OR = 15.84, 95% CI [5.74, 43.72], Z = 5.34 (P < 0.001), (ii) 0.5 mg of neostigmine injection given at the Zusanli acupoint has a better curative effect than 0.5 mg of neostigmine injection given in muscle, OR = 7.30, 95% CI [3.47, 15.34], Z = 5.24 (P < 0.001); (iii) 1 mg of neostigmine injection at the Zusanli (ST 36) acupoint has better efficacy than 1 mg of neostigmine injection in muscle, OR = 7.76, 95% CI [4.46, 13.52], Z = 7.25 (P < 0.001). Conclusion: Neostigmine injections at the Zusanli (ST 36) acupoint have beneficial effects in treating postpartum urinary retention. However, the low quality of the studies included in the meta-analysis raises questions over the reliability of the results. Further studies are still needed.