Low-Dose Naloxone for Prophylaxis of Postoperative Nausea and Vomiting: A Systematic Review and Meta-analysis.

STUDY OBJECTIVE: To determine whether postoperative administration of low-dose intravenous naloxone decreases the incidence of postoperative nausea and vomiting (PONV) and its impact on postoperative opioid requirements and pain scores.

DESIGN: Meta-analysis of nine randomized controlled trials.

PATIENTS: A total of 946 adult and pediatric patients who received low-dose intravenous naloxone for 24 hours after various surgeries.

MEASUREMENTS AND MAIN RESULTS: Systemic literature searches of the Cochrane Central Register of Controlled Trials, Evidence-Based Medicine Reviews, PubMed, and Ovid MEDLINE databases were conducted. Among the relevant studies, data extraction and bias assessment determined the trials for inclusion in this meta-analysis. Nine randomized controlled trials met inclusion criteria. Naloxone demonstrated a reduced risk of postoperative nausea (risk ratio [RR] 0.80, 95% confidence interval [CI] 0.67-0.95, p=0.01) in a pooled analysis of eight of the nine studies. However, naloxone did not decrease the risk of postoperative vomiting in a collective assessment of all nine trials (RR 0.83, 95% CI 0.63-1.09, p=0.18). Subgroup analysis of continuous-infusion naloxone found further reductions in nausea and vomiting, but these findings were limited to 186 of the 946 patients. Three studies recorded antiemetic doses and found an overall dose reduction (RR 0.64, 95% CI 0.42-0.96, p=0.03). Compared with controls, naloxone prophylaxis of PONV did not significantly change cumulative postoperative opioid needs (mean difference 0.29 mg, 95% CI -3.55 to 4.13 mg, p=0.88) among five trials, nor visual analog scale pain scores (mean difference -0.11, 95% CI -0.26 to 0.05, p=0.18) in six studies.

CONCLUSION: This pooled analysis of data suggests that low-dose naloxone plays no role in preventing PONV, while exhibiting no significant effects on postoperative opioid needs and pain scores. The reduction demonstrated in postoperative nausea did not translate into decreases in postoperative vomiting.