Attenuation of cardiovascular responses to tracheal extubation with labetalol

Background Stress response to tracheal extubation causes autonomic or endocrine disturbances such as hypertension, tachycardia, and arrhythmias that may be potentially dangerous in patients with cardiovascular disease. It is better to avoid the occurrence of stress response by preemptive therapy. Various pharmacological methods are used to suppress this response, but none of them is 100% effective. So, it is desirable to use a drug with rapidly recognizable and easily treatable adverse effects. Aim The aim of this study was to compare the effects of labetalol, fentanyl, and lidocaine in suppressing hemodynamic stress response to tracheal extubation. Patients and methods This prospective, randomized, controlled, double-blinded study was conducted in multicenter Fakhry Hospital, Al Hussain University hospital and Al Zahra University hospital on 80 patients classified as American Society of Anesthesiologists physical status I or II who were undergoing elective general surgery under general anesthesia between January 2017 and June 2017. These 80 patients were randomized through computer-generated and sealed opaque envelope method into four equal groups, each of them with 20 patients. All patients received a standardized anesthetic protocol. Fifteen minutes before extubation, patients received either labetalol 0.25 mg/kg or fentanyl 2.0 µg/kg or lidocaine 2% 1.5 mg/kg or isotonic saline. All patients were extubated by anesthesiologists who were blinded to the studied drugs, and all were continuously monitored for 20 min after extubation. The primary outcome was hemodynamic changes, heart rate (HR) and mean arterial blood pressure (MAP), which were recorded before and after extubation. The secondary outcomes were respiratory rate and oxygen saturation (SpO2), which were recorded after extubation on room air, and the degree of sedation after extubation, as assessed by Ramsay sedation score. Results The results of our study reveal that HR and MAP were comparable in all the groups until 10 min before extubation. Later, there was an increase in HR and MAP in lidocaine and saline groups. There was statistically significant decrease in HR and MAP in labetalol and fentanyl groups at 5 min before extubation, at extubation, and 5 and 10 min after extubation, in comparison with lidocaine and saline groups. Moreover, there was a statistically significant decrease in HR and MAP in labetalol group at 5 min before extubation, at extubation, and 5 and 10 min after extubation, in comparison with fentanyl group. Conclusion We conclude that both labetalol and fentanyl effectively blunt hemodynamic response to tracheal extubation in patients undergoing elective surgeries under general anesthesia and can be safely used. Labetalol at dose of 0.25 mg/kg is a better agent than fentanyl (2.0 µg/kg) and lidocaine (1.5 mg/kg) in attenuating the sympathetic response to tracheal extubation. However, patients in the fentanyl group showed greater degree of sedation without any deleterious effects.