Role of d-tubocurarine in suppression of cardiovascular responses following endotracheal intubation.

ABSTRACT

The role of d-tubocurarine in blocking the hypertensive tachycardiac response following laryngoscopy and endotracheal intubation was evaluated in 45 female patients aged 20-40 yr. The patients belonging to grade I (of American Society of Anaesthesiologists) and undergoing elective surgical procedures under general anaesthesia were allocated in 3 equal groups. Patients in the 3 groups received 1.5 mg/kg succinylcholine, 0.6 mg/kg d-tubocurarine and 0.12 mg/kg pancuronium bromide, respectively for intubation. There were no dysrhythmias in any of the groups following endotracheal intubation. There was significant (P less than 0.01) fall in blood pressure following induction prior to intubation in all the three groups. Maximum fall was noted in group II (23.53 +/- 7.21 mmHg in mean arterial pressure). Following endotracheal intubation, blood pressure and heart rate increased significantly (P less than 0.01) in all 3 groups. Maximum increase was observed in group I (26.4 +/- 4.95 mmHg in mean arterial pressure and 19.07 +/- 6.54 beats/min in heart rate). Blood pressure and heart rate increases in groups II and III were comparable. Our findings indicate that hypotension produced by d-tubocurarine through ganglion blockade is not effective in attenuating the cardiovascular responses following endotracheal intubation. It is also possible that increased cardiovascular response following endotracheal intubation may not be due to sympathetic ganglion stimulation.