Differential effects of lidocaine and remifentanil on response to the tracheal tube during emergence from general anaesthesia

Abstract

Background: I.V. lidocaine administration and target-controlled infusion (TCI) of remifentanil may each be used to reduce cough and haemodynamic stimulation during emergence from general anaesthesia. We therefore compared the effects of these two treatments on patients' responses to the tracheal tube during recovery from general anaesthesia after thyroid surgery.

Methods: Seventy female patients undergoing thyroidectomy under general anaesthesia using sevoflurane and remifentanil were randomly assigned to i.v. lidocaine (Group L, n=35) or remifentanil by TCI (Group R, n=35). At the end of surgery, sevoflurane was turned off, and the remifentanil infusion was stopped in Group L and maintained in Group R at an effect-site concentration of 2.0 ng ml(-1) until extubation. At the same time, i.v. lidocaine 1.5 mg ml(-1) was administered in Group L. The incidence and severity of cough, haemodynamic parameters, and recovery profiles were evaluated during the emergence.

Results: The incidence of cough during the emergence was significantly higher in Group L than in Group R (72.7% vs 20.6%, P<0.001) and so was the grade of cough (P<0.001). The mean arterial pressure and heart rate were significantly lower in the R group than in the L group during the emergence period (P<0.05), although the two groups showed comparable recovery profiles.

Conclusions: TCI of remifentanil reduces responsiveness to the tracheal tube during emergence from general anaesthesia more effectively than does i.v. lidocaine in female patients undergoing thyroid surgery.