Comparison of dexmedetomidine and fentanyl for attenuation of the hemodynamic response to laryngoscopy and tracheal intubation

Background The pressor response, which is part of a huge spectrum of stress responses, results from the increase in sympathetic and sympathoadrenal activity. This study was conducted to compare the efficacy of dexmedetomidine and fentanyl for attenuation of largyngoscopic pressor response. Patients and methods Sixty patients of ASA I and II were randomly divided into two groups. Group D patients received an injection of dexmedetomidine at a dose of 1 μg/kg, whereas group F patients received an injection of fentanyl at a dose of 2 μg/kg preoperatively over 10 min before induction of anesthesia with an injection of thiopentone and vecuronium. After laryngoscopy, anesthesia was maintained with isoflurane (0.6% v/v)+N ₂ O (50%)+O ₂ (50%). Intraoperatively, heart rate, systolic blood pressure, diastolic blood pressure, mean arterial pressure (MBP), SpO ₂ , and ECG were recorded at the following intervals: at baseline, after drug administration (at 2, 5, and 8 min), before induction, after induction, and after laryngoscopy. Results Dexmedetomidine significantly attenuated the sympathetic response to laryngoscopy and intubation in terms of heart rate, systolic blood pressure, and diastolic blood pressure compared with fentanyl. The total dose of thiopentone for induction of general anesthesia was significantly less in the dexmedetomidine group as compared with the fentanyl group. Incidence of bradycardia and hypotension was higher in patients of the dexmedetomidine group when compared with the fentanyl group. Conclusion An intravenous infusion of dexmedetomidine at 1 μg/kg administered 10 min before laryngoscopy and endotracheal intubation can be recommended over fentanyl at 2 μg/kg to attenuate the sympathetic response to laryngoscopy and endotracheal intubation with minimal side effects.