Sevoflurane provides faster recovery and postoperative neurological assessment than isoflurane in long-duration neurosurgical cases

Sevoflurane (SEVO) provides faster emergence than isoflurane (ISO). This advantage is thought to magnify with increased duration of exposure. In addition, SEVO has several of the characteristics of an ideal neuroanesthetic. We designed a prospective, randomized, double-blinded study to compare the recovery profile of SEVO versus ISO in neurosurgery. Sixty patients undergoing intracranial surgery were enrolled. They were randomized to receive SEVO or ISO in 40% oxygen as part of a balanced anesthetic regimen. The anesthetic concentration (0.5 to 1.0 minimum alveolar anesthetic concentration [MAC]) was adjusted to maintain mean arterial blood pressure within 20% of the preinduction baseline. At the end of the surgery, neuromuscular blockade was reversed, anesthetics were discontinued without prior tapering, and fresh gas flow was increased to 10 L/min. Recovery end-points were measured as the time from closure of the anesthetic vaporizer. Mean MAC-hours were identical in both groups (4.7). Patients in the SEVO group demonstrated a shorter time to emergence (P = 0.02) and for response to command (squeeze hand, P = 0.03; move feet, P = 0.01). Patients in the SEVO group obtained a Glasgow coma scale score of greater than or equal to105 min before patients in the ISO group (P = 0.04). Obtaining an early neurological examination can be critical in neurosurgical patients. The observed difference in emergence between SEVO and ISO could therefore be of clinical importance.