Optimal effect-site concentration of remifentanil for preventing cough during emergence from sevoflurane-remifentanil anaesthesia

This randomised, double-blinded, controlled trial was designed to identify the optimal dose of remifentanil for cough suppression without adverse effects during emergence from sevoflurane-remifentanil anaesthesia for thyroidectomy. One hundred and four patients were randomly assigned to maintain target effect-site concentrations of remifentanil at 0 (control group), 1.0 (remifentail 1 group), or 1.5 ng.ml(-1) (remifentanil 1.5 group) during emergence. The incidence of coughing was lower in the remifentanil 1.5 group (31%) than in the control group (74%) or remifentanil 1 group (63%) (p = 0.0004). In addition, the severity of coughing during extubation was lower in the remifentanil 1.5 group (median (IQR [range]) 0 (0-1 [0-1]) than in the control group (1 (0-2 [0-3])) and remifentanil 1 group (1 (0-2 [0-3])) (p = 0.004). Haemodynamic changes were reduced, but emergence time and stay in the post-anaesthesia care unit was prolonged in the remifentanil 1.5 group. Maintaining the remifentanil effect-site concentration at 1.5 ng.ml(-1) during emergence from sevoflurane-remifentanil anaesthesia reduces the incidence and severity of coughing without serious adverse events and may provide haemodynamic stability in patients undergoing thyroidectomy. However, awakening may be delayed.