Medications for the prevention of pruritus in women undergoing cesarean delivery with Intrathecal morphine: A systematic review and bayesian network meta-analysis of randomized controlled trials

Abstract

PurposeIntrathecal morphine-induced pruritus can cause significant discomfort in parturients and is refractory to conventional antipruritic treatment. This systematic review and network meta-analysis evaluates the effectiveness of the medications used for prevention of intrathecal (IT) morphine-induced pruritus after cesarean delivery under spinal anesthesia. MethodsA literature search was conducted from 1946 up to October 2019. We included all randomized controlled trials (RCTs) that compared medications used for prevention of pruritus with a control group in women undergoing cesarean delivery under spinal anesthesia with IT morphine. The primary outcome examined was the incidence of pruritus up to 24 h after cesarean delivery. Dichotomous data were extracted and summarized using odds ratios (OR) and 95% credible intervals (CrI) with Bayesian random effects network meta-analysis model. The GRADE approach was used to evaluate quality of the studies and effect evidence. ResultsOf the 26 studies included in the systematic review, 21 studies with a total of 2594 patients were included in the network meta-analysis [prophylaxis, n = 1603 (62%) vs. control, n = 991 (38%)]. These studies investigated seven classes of drugs including serotonin-receptor antagonists, dopamine-receptor antagonists, opioid agonist-antagonists, opioid-receptor antagonists, histamine-receptor antagonists, propofol and celecoxib. The network meta-analysis showed that serotonin-receptor antagonists' prophylaxis [control vs. prophylaxis: 60% vs. 47%; OR (95% CrI): 2.69 (1.43–5.36)] and opioid agonist-antagonists prophylaxis [control vs. prophylaxis: 72% vs. 47%; OR (95% CrI): 4.57 (1.67–12.91)] decreased the incidence of pruritus compared to the control group. Although all included studies were at low risk of bias, the quality of the overall network meta-analysis pooled estimates was low. ConclusionThis bayesian network meta-analysis of RCTs demonstrates serotonin-receptor antagonists and opioid agonist-antagonists may prevent pruritus in women undergoing cesarean delivery with intrathecal morphine compared to control group. However, further RCTs of adequate power and clearly defined end points are warranted.