[When and how to start sedation in a neuro-intensive care patient?]

Sedatives drugs are part of the everyday care in the neuro-ICU. Reasons to sedate patients in neuro-ICU are as usual to ensure the comfort and to secure the patients, to permit nursing as well as to permit adaptation to the ventilator. But some objectives are specific in neuro-ICU as optimisation of cerebral haemodynamics and oxygenation, and to avoid a convulsive state or a dysautonomic syndrome. Starting the sedation usually necessitate a tracheal intubation and mechanical ventilation. Patients presenting with intracranial hypertension are at risk of developing cerebral ischaemia in case of cerebral haemodynamics alteration associated with anaesthetic drugs injection. Morphinomimetics increase intracranial pressure (ICP), but cerebral perfusion pressure and oxygenation (CPP) remain usually unaltered. Injection of an intravenous bolus of thiopental or propofol lowers ICP and CPP, but also the cerebral tissular oxygen consumption: the cerebral oxygenation seems therefore protected. The succinylcholine used for emergency tracheal intubation has no effect on the cerebral haemodynamic. Some more studies are needed to better understand the cerebral oxygenation at the local level when sedative drugs are injected or perfused in patients with intracranial hypertension.