Comparison of the effects of succinylcholine and atracurium on intracranial pressure in monkeys with intracranial hypertension

The effects of succinylcholine (1.5mg·kg^-1 IV) administered five minutes after a defasciculating dose of curare (0.05 mg·kg^-1 IV), were compared with the effects ofatracurium (0.5 mg·kg^-1 IV) on intracranial pressure (ICP) in 13 cynomologus monkeys with intracranial hypertension (ICP· 25 mmHg). Neither succinylcholine nor atracurium increased ICP during general anaesthesia with 60 per cent N₂O/O₂, 0.5-1 per cent halothane. During a rapid sequence induction and intubation with thiopentone 5 mg·kg^-1 IV, ICP increased equally with intubation following both atracurium (25 ± 1 to 32 ± 2 mmHg) and succinylcholine (25 ± 1 to 31 ± 2 mmHg) (p < 0.05). Intubation was also associated with significant increases in PaCO₂, CVP and MAP. We conclude that in this primate model of intracranial hypertension, neither atracurium nor succinylcholine (when given following a defasciculating dose of curare) elevates ICP. In terms of the elevation of ICP associated with intubation, atracurium was found to offer no advantage over succinylcholine.