Anesthesia for patients with a cerebral aneurysm who showed hypoxemia during surgery]

Two patients showed hypoxia and brain swelling during craniotomy under the diagnosis of ruptured cerebral aneurysm. It was not possible to continue the operation due to brain swelling. Postoperatively, they were diagnosed as pulmonary embolism by Tc-scintigraphy. Re-operation was carried out after the improvement of the condition and fortunately they were discharged with minor neurological complications. According to the references, cerebral blood flow increases with PaO2 of less than 50 mmHg, but it is possible that brain swelling may occur with PaO2 of about 60 mmHg in the presence of brain ischemia. These cases suggest that, during the craniotomy, operation should be stopped when good operative field is not obtained because of brain swelling, and that a better outcome can be anticipated when re-operation is scheduled after an improvement of the condition.