Objective: To evaluate the minimal dose of intravenous lidocaine (0.25 mg/kg) administered before extubation to prevent post-operative cough and sore throat.

Materials and Methods: The present study employed a prospective double-blinded randomized, control trial. Eighty-five patients scheduled for elective surgery were randomized to receive an intravenous lidocaine bolus of 0.25 mg/kg (treatment group), or 0.5 mg/kg (control group) at the end of anesthesia. The severity of cough and post-operative sore throat were evaluated by a blinded anesthesiologist.

Results: Forty-two patients were assigned to the treatment group and 43 patients to the control group. According to the noninferiority margin in the present study of 10% compared with the high-dose group, the coughing rate after extubation in the 0.25 mg/kg group was 42.9%, and in the 0.5 mg/kg group was 23.3%, a difference of coughing rate between both groups of 19.6% (95% CI 3.17% to 36.03%, p-value for non-inferiority=0.998).

Conclusion: The treatment group (0.25 mg/kg of lidocaine) had less effective medicine than the control group (0.5 mg/kg of lidocaine) for preventing cough after extubation as well as the severity of cough.

Keywords: Fentanyl, Lidocaine, Cough, Post-operative sore throat, General anesthesia

Received 26 Mar 2019 | Revised 10 Jul 2019 | Accepted 12 Jul 2019