Continuous postoperative infusion of remifentanil inhibits the stress responses to tracheal extubation of patients under general anesthesia

Purpose: The study aimed to assess the combined effects of parecoxib with three different doses of remifentanil and its effect on the stress and cough responses following tracheal extubation under general anesthesia. Methods: A total of 120 patients with American Society of Anesthesiologists (ASA) scores of I or II, undergoing selective thyroidectomy with total intravenous anesthesia (propofol-remifentanil) and tracheal intubation, were randomly allocated to be treated with an intravenous injection of parecoxib and a continuous infusion of remifentanil at 0.1 μg/kg/min (R1), 0.2 μg/kg/min (R2), 0.3 μg/kg/min (R3), or an isotonic saline injection (the control group). Hemodynamic vital signs, emergence time, extubation time, sedation-agitation scale (SAS) score, pain visual analog scale (VAS) score, occurrence of coughing, and side effects were recorded before surgery and during the peri-extubation period. The vital signs included blood pressure (BP), heart rate (HR), respiratory rate (R), and peripheral arterial oxygen saturation (SPO 2 ). Results: BP, HR, the occurrence rate of coughing, and extubation awareness decreased with the dose of remifentanil, and the differences among the groups were significant ( P < 0.05). Emergence and extubation time increased with the dose of remifentanil, and the differences among the groups were significant ( P < 0.05). The occurrence rates of respiratory depression and bradycardia in group R3 were significantly higher than those in other groups ( P < 0.05). SAS and VAS were lowest in group R3, and the differences among the groups were significant ( P < 0.05). BP, HR, SAS, and VAS increased with time in the remifentanil groups. Conclusion: The combined use of parecoxib and a moderate dose of remifentanil can effectively suppress the stress and coughing responses during the peri-extubation period. The appropriate quantity of remifentanil was found to be 0.2 μg/kg/min, as this dosage caused no side effects. Keywords: remifentanil, continuous infusion, stress response, coughing, tracheal extubation, anesthesia