Pre-emptive small dose of fentanyl suppresses fentanyl-induced cough: a meta-analysis of randomized controlled trials

Fentanyl-induced cough (FIC) should be effectively prevented in patients requiring stable induction of general anesthesia. We reviewed available randomized-controlled trials (RCTs) that focused on the pre-emptive fentanyl to prevent FIC, and preformed this meta-analysis to clarify the efficacy and to recommend a specific application. The PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Chinese BioMedical Literature Database were searched for relevant RCTs without restriction on the year or language of the publications. All of the published RCTs that assessed the efficacy of pre-emptive fentanyl on preventing FIC were selected. A total of seven studies were identified for inclusion. Meta-analysis showed that a priming fentanyl dose of 0.5 μg/kg decreased the FIC incidence (RR = 0.29, 95% CI: 0.17-0.49) and severity (WMD = -0.46, 95% CI -0.70 - -0.23) of FIC; however, a priming fentanyl dose of 1.0 μg/kg (RR = 0.26, 95% CI 0.04-1.70; WMD = -0.60, 95% CI -1.33-0.14) or 1.5 μg/kg (RR = 0.94; 95% CI: 0.77-1.15; WMD = -0.08, 95% CI -0.33-0.17) had no effect on FIC. Our meta-analysis demonstrated that pre-emptive low dose of fentanyl could effectively prevent FIC, and the dose of 0.5 μg/kg was recommended.