Tussive effect of a fentanyl bolus administered through a central venous catheter.

One hundred and ten male patients scheduled for coronary artery bypass grafting were allocated randomly into one of three groups. Patients in group A received fentanyl 7 micrograms/kg via a central venous catheter, those in group B were given fentanyl 7 micrograms/kg through a peripheral venous cannula, and patients in group C received sterile water via a central venous catheter. In group A, 45.9% of patients coughed after injection of fentanyl; the mean onset time from the end of fentanyl administration to the beginning of coughing was 10.6 seconds. Only one patient in group B and no patient in the control group exhibited a cough response (p less than 0.0001). We hypothesise that fentanyl can evoke the pulmonary chemoreflex.