Effects of pretreatment with a small dose of dexmedetomidine on sufentanil-induced cough during anesthetic induction.

We aimed to investigate the effects of pretreatment with a small dose of dexmedetomidine on the cough caused by sufentanil during anesthetic induction. Two hundred and forty patients undergoing elective gynecological surgery under general anesthesia were randomly allocated to 4 groups (n = 60, each group). Dexmedetomidine 0, 0.1, 0.25, and 0.5 μg/kg was administered in 5 min to groups I, II, III, and IV, respectively, followed by the induction of general anesthesia with intravenous propofol, at a target concentration of 5 μg/ml, and sufentanil 0.5 μg/kg. The incidences and severity of cough that occurred within 1 min after the injection of sufentanil were recorded, and the incidences of cardiovascular adverse events that occurred between the administration of the dexmedetomidine infusion and 1 min after tracheal intubation were recorded. The incidences of cough in group II, group III, and group IV were lower than that in group I (6.7, 5.0, and 6.7 vs. 26.7 %, P < 0.01), while there were no significant differences between group II, group III, and group IV. The incidences of severe sinus bradycardia in group III and group IV were higher than that in group I (18.3 and 23.3 vs. 0.0 %, P < 0.01), while there was no significant difference between group I and group II. There was no significant difference in the incidence of low blood pressure among the four groups. Dexmedetomidine at 0.10, 0.25, and 0.50 μg/kg significantly reduced the incidence of sufentanil-induced cough during anesthetic induction, with the effect being most marked for 0.10 μg/kg dexmedetomidine.