General anaesthesia for supratentorial neurosurgery

Anaesthesia for the surgical treatment of supratentorial tumours requires a n understanding of: the pathophysiology of a localised or generalised incre ase in intracranial pressure (ICP), the regulation and maintenance of intra cerebral perfusion, avoidance of secondary systemic insults to the brain, a nd the effects of anaesthetic drugs on ICP, cerebral perfusion and cerebral metabolism. Knowledge of the therapeutic options available for decreasing ICP, brain bulk and brain tension perioperatively is also essential. Potential complications which may present during supratentorial neurosurger y include massive intraoperative haemorrhage and seizures. The fact that th e surgeon is operating on a tensed brain is also a potential source of diff iculty. The need to monitor brain function and environment during surgery p oses a challenge to the anaesthesiologist, as does the acheivement of rapid emergence from anaesthesia with the adequate use of anaesthetic drugs. The aim of this article is to provide recommendations and guidelines to ass ist in choosing the most appropriate anaesthetic procedures and agents (inc luding induction and maintenance anaesthetics, and muscle relaxants) in pat ients who are undergoing anaesthesia for the surgical removal of supratento rial tumours. Complex physiological processes within the brain can impact o n treatment choices (both pharmacological and procedural). As back-around, section I provides an overview of the most relevant of these processes.