Anesthésie et hypertension intracrânienne sur œdème cérébral

Abstract

The main objective for anaesthesia in patients with intracranial hypertension (ICH) is to maintain the cerebral perfusion pressure (CPP). Before the operation, the assessment of the level of intracranial pressure relies on the Glasgow coma score and the signs of ICH on the CT-scan. In the perioperative period, repeated transcranial Doppler examinations may help in determining the adequate CPP. Haemodynamic and respiratory complications are common after subarachnoid haemorrhage or head injury. Careful preoperative screening of the cardiovascular and respiratory system is mandatory before anaesthesia. There is no recommended anaesthetic technique for patients with ICH. Nitrous oxide should be avoided in patients with severe ICH or during emergency surgery. Theoretically, intravenous anaesthesia is a better choice than inhalation anesthesia because of the cerebral vasodilatation induced by inhalation agents. In the most severe cases thiopental is the only anaesthetic agent to consider. Treatment of hypovolaemia with fluid loading and the early use of vasoactive agents can be recommended to maintain CPP. Before intracranial surgery, large doses of mannitol have been demonstrated to improve neurological recovery in brain injured patients. The urinary losses due to the infusion of mannitol should be replaced with isotonic saline. Emergence and extubation are best performed in the intensive care unit under close systemic and cerebral haemodynamic control.