Evaluation of Oral Clonidine as a Premedicant in Attenuating Hemodynamic Stress Response to Laryngoscopy and Intubation ‑ A Clinical Study

Context: Endotracheal intubation constitutes a period of extreme hemodynamic stress. The search for an ideal agent to attenuate this pressor response still continues. Clonidine, α2 adrenergic agonist, slows down the heart rate and leads to a dose‑dependent decrease in systolic and diastolic blood pressure. It has 100% bioavailability following oral administration. Aims: To evaluate the efficacy of oral clonidine in attenuating the hemodynamic responses to laryngoscopy and endotracheal intubation and to study associated side effects. Setting and Design: This was a prospective, randomized controlled, double‑blind study. Materials and Methods: Fifty patients of either sex, aged 20‑60 years, ASA grade I/II undergoing elective surgeries under general anesthesia were included. Group A received Clonidine 3 mcg/kg orally 90 min before induction and group B received 5 ml distilled water. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure, and rate pressure product were noted at baseline, preinduction, postinduction, intubation and thereafter, 1, 3 and 5 min following intubation. Statistical Methods: Student’s t‑test was used to find the significance of study parameters on a continuous scale. A Chi‑square and the Fisher exact test has been used to find the homogeneity of samples on categorical scale. Results: There was a statistically significant difference in heart rate, systolic, diastolic, mean arterial pressure and rate pressure product between two groups during laryngoscopy and the difference in parameters persisted for 5 minutes. Clonidine group had more stable hemodynamic parameters throughout. Conclusion: Oral clonidine premedication in the dose of 3 mcg/kg can effectively attenuate the hemodynamic stress response to laryngoscopy and intubation with minimal side effects.