Sodium Lactate and Brain Relaxation (LSD)

It's a prospective, comparative, randomised, double blinded study. It will enroll 50 patients undergoing resection surgery of supratentorial brain tumor. They will be randomly divided in 2 groups of 25 patients each : Mannitol 20% and molar Sodium Lactate. The only difference between the 2 groups is the drug used for brain relaxation at the surgical incision : Mannitol or Sodium lactate. The outcome measures include quality of brain relaxation, need of "rescue" therapy to get an adequate brain relaxation, electrolytes alterations, change in lactate serum level, quantification of post operative brain swelling by MRI, time of extubation, Glasgow Coma Scale, neuropsychological evaluation, blood levels of Protein S100-β, NSE (Neuron-Specific Enolase) and GFAP Glial Fibrillary Acid Protein), morbidity and mortality during 30 days after surgery.