No relationship between the incidence of fentanyl-induced cough and smoking

Abstract

The purpose of the study was to investigate whether or not the incidence of cough after intra-venous fentanyl depends on the patient’s smoking state and the speed of injection. 530 ASA class I-III patients free of bronchial hyperreactivity and res-piratory tract infection undergoing general anes-thesia for elective surgery were randomized to 1.5 g.kg-1 fentanyl injected over 2, 5 or 10 sec or pla-cebo via a peripheral intravenous cannula. The endpoint was cough within 5 min after completion of injection. Statistical evaluation was performed by factorial ANOVA and chi-square-test. Assuming around 25% smokers in our patient population calculated patient sample size was 340 per group. The study was terminated for futility after enrol-ment of 530 patients since an interims analysis yielded an incidence of cough of 2 % both in smokers (n=174) and nonsmokers (n=356, p= 0,970), which was unrelated to the speed of injec-tion and not different from placebo.