Mahadev Dixit

A comparative clinical study of dexmedetomidine versus placebo to attenuate hemodynamic response to endotracheal intubation in patients undergoing off pump coronary arterial bypass grafting

Context: Direct laryngoscopy and endotracheal intubation are the most stressful periods during induction of anesthesia. These events can lead to hypertension, tachycardia, arrhythmias and myocardial ischaemia. Aims: (1) To evaluate the haemodynamic response to laryngoscopy and endotracheal intubation with a single preinduction infusion of dexmedetomidine (DEX) 1 μg/kg over a 10 min period, (2) To assess the incidence of side effects, that is, rebound hypertension, bradycardia and hypotension etc., associated with the use of DEX. Settings and Design: This was a prospective, double-blind, parallel group randomized clinical trial of DEX (1 μg/kg) before anesthetic induction to study the attenuation of hemodynamic response to endotracheal intubation in 60 adult patients undergoing elective off pump coronary arterial bypass grafting. Materials and Methods: Patients were randomly allocated to receive either DEX (DEX group, n = 30) or 0.9% normal saline (PLA group, n = 30). Hemodynamic variables were recorded at baseline (Abbreviated as TB), after completion of drug infusion (Abbreviated as TC), 3 min after induction and immediately before intubation (T0), at the 1 st (T1), 3 rd (T3) and 5 th (T5) min after intubation. Statistical Analysis Used: The data are presented as mean ± standard deviation. Demographic data were analysed by Student′s t-test between the two groups. Analysis of variance for repeated measures f-test was used to analyze changes over time. A P < 0.05 was considered as significant and P < 0.01 or 0.001 was considered as highly significant. Results: All the hemodynamic variables were comparable in both groups at baseline. Heart rate values were statistically significantly lower in the DEX group at TC and highly statistically significantly lower at T1, T3 and T5 values. Systolic blood pressure values were statistically significantly lower in the DEX group at T0 and highly statistically significantly lower at T1, T3 and T5. Diastolic blood pressure and mean blood pressure values and systolic pulmonary artery pressure values were highly statistically significantly lower in the DEX group at T1, T3 and T5. Diastolic pulmonary artery pressure were statistically significantly lower in the DEX group at TC, T0 and T1 and highly statistically significantly lower at T3. Mean pulmonary artery pressure were statistically significantly lower in the DEX group at T0 and highly statistically significantly lower at TC, T1 and T3. Arterial oxygen saturation was statistically significantly lower in the DEX group at TC. There was no case of hypotension or bradycardia in our case series. Conclusions: Dexmedetomeditine (1 μg/kg) attenuates hemodynamic response to laryngoscopy and intubation in elective surgery for off pump coronary artery bypass grafting.