[Nitrous oxide in neurosurgery].

Nitrous oxide (N2O) is far from inert in terms of its cerebral effects. It can increase the cerebral blood flow (CBF) and the cerebral metabolic rate for oxygen in animals and in man. In poor risks patients, the N2O may increase the intracranial pressure (ICP) but these effects are blocked by hyperventilation, benzodiazepines, barbiturates and narcotics. N2O is not epileptogenic but modifies evoked potentials. Because of its greater solubility than Nitrogen it can increase ICP, in case of pneumoencephalus and the size and consequences of gazous embolism. In neurosurgical patients, nitrous oxide should be used cautiously in regards of its neurological effects.