Does the Choice of the Neuromuscular Blocking Agent Affect the Cardiovascular Response to Intubation

Heart rate and arterial pressure changes induced by tracheal intubation, 3 min after administration of atracurium, vecuronium, tubocurarine, pancuronium or alcuronium, have been studied under thiopentonenitrous oxide-oxygen anaesthesia supplemented by either 0.5% halothane or fentanyl 2 micrograms kg-1. Pancuronium and alcuronium were associated with the greatest increase in heart rate and tubocurarine with the greatest decrease in arterial pressure prior to intubation. Following intubation, all groups, with the exception of tubocurarine showed a similar and significant rise in heart and arterial pressure when compared with control values. The cardiovascular response to intubation, particularly the effect on heart rate, was less marked when fentanyl was given at induction and was short lived with atracurium and vecuronium. Although those patients who received tubocurarine showed no significant rise in arterial pressure following tracheal intubation, this was due to significant hypotension occurring in this group prior to intubation.