Background: IV fentanyl en bolus can provoke cough reflex. We evaluated the effects of the IV fentanyl dose on the incidence and onset time of fentanyl-induced cough.
Methods: Tree hundred and eighteen ASA physical status I - II patients scheduled for oral surgery under general anesthesia were randomly assigned to receive 1 microg x kg(-1), 3 microg x kg(-1) or 5 microg x kg(-1) of IV fentanyl (n = 106 for each group). We recorded, in each patient, presence/absence and onset time, if present, of cough reflex for 60 seconds after fentanyl injection.
Results: The incidences of fentanyl-induced cough were 6.6%, 22.5%, and 44.3% in the 1 microg x kg(-1), 3 microg x kg(-1), and 5 microg x kg(-1) groups, respectively. The onset times of fentanyl-induced cough were 29.0 +/- 11.8 seconds, 22.5 +/- 7.9 seconds, and 19.5 +/- 7.0 seconds in the 1 microg x kg(-1), 3 microg x kg(-1), and 5 microg x kg(-1) groups, respectively.
Conclusions: The results indicated that the incidence of fentanyl-induced cough increased, and the onset time decreased, with the increasing dose of fentanyl.