Comparison of the recovery from isoflurane anesthesia with or without fentanyl infusion in patients undergoing elective supratentorial craniotomy.

BACKGROUND Several anesthetic agents have been used successfully to provide optimal anesthetic maintenance in neurosurgery for supratentorial tumors. Due to longer surgical time that these procedures demand and thoughout avoidance of intracranial bleeding from a hastened emergence of anesthesia in the operating room, the neurosurgeons in our hospital favor a placid late emergence from anesthesia in the neurosurgical intensive care unit (NCU). Accordingly, we designed this clinical trial to compare the effects of volatile general anesthesia with or without fentanyl infusion on postoperative hemodynamics, Glasgow coma scale (GCS) score, extubation time, as well as neurological outcome in patients after craniotomy. METHODS Forty-two patients undergoing elective surgery for supratentorial lesions were randomly divided into two anesthetic groups. In isoflurane group, after induction, anesthesia was maintained with isoflurane up to 1.2% end-tidal concentration. In fentanyl-isoflurane group, an infusion of fentanyl was started at a rate of 3 micrograms/kg/h after induction, and anesthesia was maintained with isoflurane up to 0.6% end-tidal concentration. All the anesthetics were discontinued once the surgical wound was dressed. We studied the postoperative hemodynamics and several recovery variables for 48 h after completion of anesthesia. RESULTS The time from completion of surgery to extubation was shorter in isoflurane group (9.3 +/- 6.6 h) as compared with fentanyl-isoflurane group (14 +/- 3.5 h, P < 0.05). Better GCS score was seen in isoflurane group in the early recovery period. However, both groups did not differ in both average postoperative blood pressure and heart rate and there was no significant difference between 2 groups in total duration of the postoperative NCU stay. CONCLUSIONS In pursuance of the policy of late emergence, we are of the opinion that isoflurane anesthesia offers an earlier recovery than fentanyl-isoflurane anesthesia in patients undergoing supratentorial craniotomy.