JUI-AN LIN2026-10-162026-10-162005-09-01Pure ID: 14950027Pure UUID: 0a94ec50-c436-4b89-b1bc-9eb8b897808910.1213/01.ANE.0000159161.31276.DBhttps://www.scopus.com/pages/publications/23944509218https://scholars.csmu.edu.tw/handle/123456789/31365We designed this study to evaluate the effect of injection time and smoking on fentanyl-induced cough. Four-hundred-fifty ASA class I-II patients, aged 18-80 yr and weighing 40-90 kg, scheduled for elective surgery were included. All patients received fentanyl (100 μg for patients weighing 40-69 kg and 150 μg for patients weighing 70-90 kg for clinical convenience) via the proximal port of a peripheral IV line on the forearm. Patients were randomly assigned to 3 groups of 150 patients each. Patients in Group I received fentanyl injection over 2 s, whereas for patients in Groups II and III the fentanyl was injected at a constant rate over 15 s and 30 s, respectively. We recorded the number of coughs of each patient during and 30 s after fentanyl injection. The incidence of cough was 18% in group I, 8% in Group II, and 1.3% in Group III, significantly less (P < 0.05) with a longer injection time. Current smokers had a less frequent incidence of cough than nonsmokers; however, this effect was only significant in light smokers (<10 cigarettes per day or <10 smoking years or <10 pack-years). In conclusion, a longer injection time reduces the incidence of fentanyl-induced cough, and light smoking may be a protective factor against fentanyl-induced cough.5enjournal article