Intravenous Anesthesia Versus Anesthesia With Volatile Agents in Elective Craniotomy for Tumors

This is a randomized blinded clinical trial. Patients will be randomized into one of two groups. One group will receive a volatile anesthetic (sevoflurane)while the other group will receive intravenous anesthetics (propofol + remifentanil) for maintenance of General Anesthesia. The anesthesia team will know the result of randomization at induction. Postoperative data will be gathered by research personnel who will be blinded to the anesthetic method used. Patients will be blinded to the anesthetic they receive until after the 4-week outcomes are collected, when they will have the option to be unblinded. Peripheral blood samples will be taken a total of 7 times; pre-induction to anesthesia, 15 minutes after surgical positioning, after the tumor is extracted, and at 6,12,18, and 24 hours after emergence from anesthesia. Patients will be called for follow up every week for 4 weeks following discharge.