Brain protection during neurosurgery: an update from the anaesthetist's perspective

Brain protection is defined as measures instituted before a potential insult to prevent or ameliorate brain damage, or measures undertaken after an insult to protect the brain from secondary damage. Potential brain protection modalities during neurosurgery include hypothermia, anaesthetic agents, specific inhibitors of peri-ischemic events, induced hypertension and haemodilution. Available evidence suggests that we should induce mild hypothermia ( approximately 34 degrees C), as it has proven benefit in animal studies, and may have fewer side-effects than high doses of anaesthetic agents. Well conducted anaesthesia with any of a variety of agents probably affords similar protection. Experimental agents now in development may provide specific protective effects in the future, but have the disadvantage that most affect only one factor in a complex sequence of neurochemical and ionic events during ischaemia.