OBJECTIVETo investigate the influence of sex on the cough-preventing effect of target-controlled infusion(TCI)of remifentanil during anesthetic emergence.

METHODSA total of 25 female(group F)and 25 male(group M)patients undergoing thyroidectomy were recruited in the current study. Anesthesia was maintained with sevoflurane and remifentanil TCI.At the end of the surgery,inhalational anesthetics were discontinued,and remifentanil TCI at an effect-site concentration(Ce)of 2.0 ng/ml was maintained during emergence until extubation. The cough score,blood pressure,and heart rate(HR)during peri-extubation period as well as the respiratory rate,calm score,and sore throat score after extubation were evaluated.

RESULTSDuring extubation,the proportion of patients with no cough or just a single cough was significantly higher in group F than in group M(88% vs. 64%,P=0.047). Mean arterial pressure(P=0.025,P=0.037)and HR(P=0.035)were significantly increased during extubation compared with preoperative levels in group M.

CONCLUSIONSSex may influence the cough-preventing effect of remifentanil TCI during anesthetic emergence. At a Ce of 2.0 ng/ml,remifentanil has better cough-preventing effect and more stable hemodynamic status in females than in males.