Hyperlactatemia is a frequent occurrence in brain tumor surgery. The existing studies, however, are all retrospective, reporting varying effects on clinical outcome. One study reported new neurological deficitis, some found an association with extended hospital stay, while others found no association with outcome. It is therefore important to conduct a prospective study of hyperlactatemia in this patientgroup.
Participants in this study will follow the standard treatment protocol for tumorcraniotomy, aside from 2-3 additional, perioperative blodgas analyses and 2 standardized measurements of neurological disability.

