Comparative study of intravenous clonidine versus fentanyl in attenuating hemodynamic response to laryngoscopy and tracheal intubation

Abstract

Background: Laryngoscopy and tracheal intubation trigger a transient sympathetic surge causing tachycardia and hypertension, which can be harmful in patients with comorbidities. Clonidine and fentanyl are used to attenuate this response, but comparative evidence on their effectiveness is limited. Aims and Objectives: The aim of the study is to evaluate and compare the effectiveness of intravenous (IV) clonidine and fentanyl in attenuating the hemodynamic response to laryngoscopy and tracheal intubation. Materials and Methods: A prospective, randomized study was conducted over 6 months involving 80 adult patients (American Society of Anaesthesiologists physical status I and II), aged 18–65 years, scheduled for non-cardiovascular elective surgeries under general anesthesia. Patients were randomly assigned to two groups: Group C received IV clonidine (4 μg/kg) and Group F received IV fentanyl (2 μg/kg) approximately 5 min before intubation. Hemodynamic parameters – systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), and oxygen saturation (SpO2) – were recorded at baseline, pre-intubation, during intubation, and at 1, 3, and 5 min post-intubation. Statistical analysis was performed using independent t-tests and one-way analysis of variance. Results: Both groups exhibited attenuation of hemodynamic responses. SBP at 5-min post-intubation was significantly lower in the fentanyl group (P=0.037). However, inter-group differences in DBP, MAP, HR and SpO2 were not statistically significant. Intra-group analysis revealed transient fluctuations in SBP, DBP, and MAP post-intubation, with HR and SpO2 remaining stable. Conclusion: Both IV clonidine and fentanyl are effective in blunting the hemodynamic response to laryngoscopy and intubation. The choice between the two may be guided by patient profile, comorbidities, and anesthetic context.