Anesthesia techniques that minimize anesthetic requirements and their effects may be beneficial. Esmolol, a short acting hyperselective β-adrenergic blocker is effective in blunting adrenergic response to several perioperative stimuli and so it might interfere in the effect of the anesthetic drugs on the brain. This study was designed to investigate the effect of esmolol on the consumption of propofol and sevoflurane in patients undergoing craniotomy.

Patients undergoing elective craniotomy for aneurysm clipping or tumor dissection were randomly divided in two groups (four subgroups). Anesthesia was induced with propofol, fentanyl and a single dose of cis-atracurium, followed by continuous infusion of remifentanil and either propofol or sevoflurane. Patients in the esmolol group received 500 mcg/kg of esmolol bolus 10 min before induction of anesthesia, followed by additional 200 mcg/kg/min of esmolol. Monitoring of the depth of anesthesia was also performed using the Bispectral Index-BIS. It was also performed monitoring of the cardiac output in order to evaluate the effect of esmolol on cardiac output.

The inspired concentration of sevoflurane and the infusion rate of propofol were adjusted in order to maintain a BIS value between 40-50.

Intraoperative emergence was detected by the elevation of BIS value, HR or MAP.

It was recorded intraoperative fluctuations of propofol and sevoflurane in both groups. Data were expressed as mean ± SD. Differences in categorical data were evaluated using the student t test.

Inclusion Criteria:

• Patients with ASA physical status 1-3
• Glasgow Coma Scale:15

Exclusion Criteria:

• Patients with ASA physical status >3,
• Body Mass Index (BMI) over 30,
• indication for rapid sequence induction,
• any contraindication for receiving b-blocker,
• chronic use of b-blocker,
• Glasgow Coma Scale (GCS) <15,
• history of drug abuse,
• severe mental impairment,
• preoperative aphasia,
• neurologic deficit or preoperatively foreseen delayed extubation.