Abstract: Objective: To investigate the efficacy of remifentanil inducing controlled hypotension in functional endoscopic sinus surgery. Methods: Sixty patients with ASA class I orⅡsubjected to general anesthesia were divided into three groups: the sodium nitroprusside group(N), the remifentanil group(R) and the remifentanil-sodium nitroprusside group(RN). A deliberate hypotension was induced to retain the MAP at 60-70 mmHg by SNP, remifentanil or remifentanil combined with SNP. MAP and HR were determined before hypotension(T0), during hypotension(T1) and after stopping hypotension(T2). The duration of operation and hypotension, the time from the end of the operation to extubation of the tracheas, and the dose of SNP and remifentanil were also determinded. Quality of the surgical field and the consciousness of patients were assessed. Results: MAP could be retained at 60-70 mmHg by remifentanil in 28 patients of group R（70%). The hypotensive ceiling-effect of remifentanil was produced in 12 patients of group RN (30%). After the addition of a small dosage of sodium nitroprosside, target MAP was easily achieved and the dosage of remifentanil was decreased. During induced hypotension, HR was significantly increased in group N (P＜0.05). However, HR was significantly decreased in groups R and RN (P＜0.05). Rebound hypertension only occurred in group N. Quality of the surgical field was better in groups R and RN than in group N. There were no significant differences of the time from the end of the operation to extubation of the tracheas and the patients′ consciousness from anesthesia among the three groups. Conclusion： Induced hypotension by remifentanil combined with a balanced anesthesia is feasible and safe for functional endoscopic sinus surgery. In the operation, the quality of the surgical field and the consciousness from anesthesia are good.

Key words: Remifentanil, Controlled hypotension, Sodium nitroprusside, Functional endoscopic sinus surgery