Dexmedetomidine reduces the incidence of fentanyl-induced cough: A double-blind, randomized, and placebo-controlled study

Objectives. The incidence of fentanyl-induced cough (FIC) during induction of general anesthesia varies around 40% and is undesirable. It increases intracranial, intraocular, and intra-abdominal pressures. This prospective, randomized, double-blind, placebo-controlled study evaluated the effect of dexmedetomidine (DEX) pretreatment on the incidence and severity of FIC. Methods. Altogether 300 patients undergoing elective surgical procedures were randomly allocated into three groups (I, II, III; n = 100) and administered intravenously, over 10 min, 10 mL isotonic saline, DEX 0.5 mu g/kg in 10 mL isotonic saline, or DEX 1 mu g/kg in 10 mL isotonic saline, respectively. All groups subsequently received a fentanyl (4.0 mu g/kg) intravenous push. The incidence and severity of cough were recorded for 1 min after fentanyl administration. Results. The incidence of FIC was 61%, 40%, and 18% in groups I, II, and III, respectively (P < 0.05 for treatment groups II and III versus control group I). There was no significant difference in the severity or onset time of cough, or hemodynamic variables, among the three groups. Conclusions. Intravenous DEX (0.5 mu g/kg or 1 mu g/kg) immediately before the administration of intravenous fentanyl (4.0 mu g/kg) significantly reduced the incidence of FIC.