Use of spontaneous ventilation to monitor the effects of posterior fossa surgery in the sitting position.

We describe the successful excision, guided by spontaneous ventilation, of a cervico-medullary hemangioblastoma in a 22-year-old female in the sitting position. A balanced anesthesia technique comprising an oxygen, nitrous oxide, sevoflurane, fentanyl and vecuronium mixture was used. Apart from routine monitors, electroencephalographic spectral entropy monitoring was used to determine the depth of anesthesia and transesophageal echocardiography for detection of venous air embolism. The patient remained in spontaneous ventilation for 235min during tumor excision. The intraoperative and postoperative course were uneventful. The patient recovered without any major neurological deficit.