Pre-induction fentanyl dose-finding study for controlled hypotension during functional endoscopic sinus surgery

BACKGROUND AND AIMS: Fentanyl can facilitate controlled intraoperative hypotension by its sympatholytic effect in patients undergoing functional endoscopic sinus surgery (FESS). We investigated the effects of different doses of pre-induction fentanyl on controlled hypotension profile during FESS. METHODS: This prospective, randomised study included 120 patients randomly allocated to three groups (40 each) based on administration of pre-induction fentanyl; 2 μg/kg group, 3 μg/kg group and 4 μg/kg group. The primary objective was to assess effect on intraoperative heart rate and mean arterial pressure. Use of additional hypotensive agents, surgical field condition and surgeon satisfaction were also analysed. RESULTS: Controlled hypotension was achieved adequately in all participants. Patients belonging to fentanyl 4 μg/kg group had significantly lower heart rate for the duration of controlled hypotension intraoperatively versus fentanyl 2 μg/kg group (P < 0.05). Trinitroglycerin [TNG] and metoprolol were administered to 3 [7.5%] and 9 [22.5%] patients respectively in the fentanyl 3 μg/kg group, and to 3 [7.5%] and 5 [12.5%] patients respectively in the 4 μg/kg group, compared to 14 [35%] and 20 [50%] in the fentanyl 2 μg/kg group, respectively (TNG, P < 0.001). Surgical field conditions and surgeon satisfaction scores were significantly superior in fentanyl 3 μg/kg and 4 μg/kg groups than in fentanyl 2 μg/kg group. CONCLUSION: Pre-induction fentanyl 3 μg/kg and 4 μg/kg group showed superior controlled hypotension facilitation than 2 μg/kg fentanyl during FESS in terms of measurable haemodynamic endpoints and favourable operative conditions, surgeon's satisfaction and sparing of additional hypotensive agents.