Efficacy and safety of epidural clonidine by continuous infusion or patient-controlled analgesia in labor: A meta-analysis of randomized controlled trials.

Background: Epidural clonidine improves analgesia but may induce adverse effects in labor.
Objective: To evaluate the efficacy and safety of epidural clonidine as local anesthetics (LA) adjuvant by continuous infusion or patient-controlled epidural analgesia (PCEA) in labor.
Search Strategy: PubMed, Embase, Web of Science, and CENTRAL were searched from inception to May 10, 2022 without language restriction; references of the retrieved studies were hand searched.
Selection Criteria: Randomized controlled trials (RCTs) comparing epidural LA with and without clonidine using continuous infusion or PCEA in labor were included.
Data Collection and Analysis: A random effects model was used to pool the data on analgesia and adverse effects.
Main Results: Eight RCTs were included. Clonidine did not reduce the incidence of parturients requiring additional epidural boluses but reduced LA consumption and pain scores without increasing adverse effects, except for a higher incidence of instrumental delivery when clonidine was combined with LA and opioid (risk ratio 2.38, 95% confidence interval 1.26-4.50). Clonidine offered similar analgesia to opioids but had reduced opioid-related adverse effects. Trial sequential analysis showed that the evidence was insufficient.
Conclusions: Epidural clonidine by continuous infusion or PCEA does not increase significant adverse effects and offers similar analgesia to opioids in labor. PROSPERO registration no. CRD42022306565.
(© 2022 International Federation of Gynecology and Obstetrics.)