TERBUTALINE INHALATION SUPPRESSES FENTANYL-INDUCED COUGHING

Purpose: To study the suppressive effect of inhalation of a selective beta(2)-adrenergic bronchodilator terbutaline, and the effect of an in travenous anticholinergic, atropine, on fentanyl-induced coughing. Met hods: We studied 131 ASA class I patients, aged 16-45 yr, scheduled fo r elective surgery, randomized into Soar groups. Fifteen minutes befor e bolus fentanyl (5 mu g . kg(-1), iv), patients inhaled either normal saline (4 ml; Group I, n = 30) or terbutaline (5 mg in 2 mi normal sa line; Group 2, n = 34) via a jet nebulizer. After inhalation of normal saline, patients in Group 3 (n = 32) received sterile water iv instea d of fentanyl. Patients in Group 4 (n = 35) were pretreated with atrop ine (0.01 mg . kg(-1), iv) 10 min before iv fentanyl bolus. The onset, frequency and intensity of cough were observed immediately by an anae sthetist blinded to the study. Results: The cough frequency was higher in Groups 1 (43%) and 4 (46%) than in Groups 2 (3%) and 3 (0%) (P < 0 .05). The onset time and intensity of cough showed no difference among groups. No truncal rigidity was observed in patients receiving fentan yl bolus iv. The blood pressure, heart rate, and peripheral oxygen sat uration did nor change in Groups I, 2, and 3, while patients in Group 4 showed an increase in heart rate (25.5 +/- 15.2%). Conclusions: The inhalation of a selective beta(2)-adrenergic bronchodilator, terbutali ne, effectively inhibited fentanyl-induced cough, whereas atropine, an antimuscarinic vagolytic, had no efficacy. Our results suggest that b ronchoconstriction may underlie the mechanism on fentanyl-induced coug h.