Attenuation of hemodynamic response to laryngoscopy and orotracheal intubation using intravenous clonidine

BACKGROUND AND AIMS: Alpha-2 agonists are being increasingly used as adjuncts in general anesthesia and the present study was carried out to study the effect of clonidine as an adjuvant to low dose fentanyl in attenuating the hemodynamic response to laryngoscopy and orotracheal intubation. MATERIALS AND METHODS: Ninety female patients belonging to American Society of Anesthesiologists (ASA) physical status I, II, and III in age group 25-65 years, body mass index (BMI) 21-26 kg/m(2), and diagnosed as carcinoma breast scheduled for breast surgery were included in this Prospective, randomized, placebo-controlled study. One-way analysis of variance (ANOVA), paired t-test, and chi-square test was applied where deemed appropriate. P-value at or below the level of 0.05 was considered as statistically significant. RESULTS: Intravenous (IV) clonidine 1.0 μg kg(-1) and clonidine 2.0 μg kg(-1) significantly attenuated the hyperdynamic response to laryngoscopy and intubation. Clonidine 2.0 μg kg(-1) was associated with adverse effects like hypotension at the time of induction and postoperative sedation which was not observed with clonidine 1.0 μg kg(-1). CONCLUSIONS: A single intravenous low dose clonidine (1.0 μg kg(-1)) when combined with low dose fentanyl (2 μg kg(-1)) is a practical, pharmacological and safe method with minimal side effects to attenuate the hyperdynamic response to laryngoscopy and intubation.