Comparison of the incidence and severity of cough induced by sufentanil and fentanyl: a prospective, randomised, double-blind study.

We compared the incidence and severity of cough following a bolus of sufentanil with that following fentanyl in 510 patients, randomly allocated to receive sufentanil 0.3 microg.kg(-1), fentanyl 3 microg.kg(-1) or 5 ml sterile water intravenously over 5 s. Coughing was graded depending on the number of coughs as mild (1-2), moderate (3-5) and severe (> 5). The incidence of coughing was higher after sufentanil (26/165; 15%) and fentanyl (54/169; 32%) than in the control group (0/168; p < 0.001). Sufentanil was also associated with a lesser severity (p = 0.039) of coughing compared with fentanyl. We conclude that equipotent boluses of sufentanil and fentanyl increase the incidence of cough, although the incidence and severity of coughing with sufentanil are less than those with fentanyl.