Effects of suxamethonium on the cerebrum following disruption of the blood-brain barrier in dogs.

We have studied the effects of suxamethonium 1.0 mg kg-1 i.v. on cerebral blood flow (CBF), cerebral metabolic rate (CMRO2), and the electroencephalogram (EEG) in dogs anaesthetized with halothane (1.0 MAC) following blood-brain barrier (BBB) disruption with intracarotid (i.c.) mannitol. The combination produced a transient increase in CBF, while CMRO2 did not change. These responses were similar to those produced by i.c. mannitol plus i.v. saline. Suxamethonium produced desynchronization of the EEG that persisted longer than that produced by saline. In only one of the six animals was the desynchronization sustained (90 min) beyond that found in dogs with a normal BBB. We conclude that disruption of the BBB did not enhance the cerebral stimulating effects of i.v. suxamethonium, and did not increase the likelihood of seizure activity following suxamethonium.