Propofol-dexmedetomidine Versus Propofol-remifentanil Conscious Sedation for Awake Craniotomy During Epilepsy Surgery

After approval from the ethics committee of Menoufia University Hospitals and informed written consent, the present study was conducted on sixty patients of both sexes. Patients' age was between 18-50 years, American society of anesthesiologists (ASA) I and II and scheduled for awake craniotomy for treatment of epilepsy. Exclusion criteria included patients with history of allergy to any of the drugs used for the study, patients with alcohol or substance abuse, pregnant females, patients with mental instability, morbid obese patients, and patients with liver, kidney, or cardiac comorbidities.

Patients were randomly allocated using computerized software into two groups, thirty patients in each group to receive intra-operative either propofol-dexmedetomidine (PD group) or propofol-remifentanil (PR group) intravenous infusion. All patients received their routine treatment for epilepsy at their scheduled time before surgery. All patients were fully monitored intra-operatively for heart rate, non-invasive blood pressure, oxygen saturation, respiratory rate, and bi-spectral index (BIS). Oxygen was supplied to all patients via nasal cannula peri-operatively.

Anaesthesia was achieved by regional scalp block and IV sedation. Regional blockade of the scalp was performed using bupivacaine 0.5% and 2% lidocaine with epinephrine 1/200.000. The branches of the cranial nerves blocked were supratrochlear, supraorbital, auriculotemporal, greater and lesser occipital, great auricular, zygomatic, and infraorbital nerves. Supplemental local anesthetic solution was used to infiltrate along the incision lines prior to skin incision. During craniotomy, a mixture of 0.25% bupivacaine and lidocaine1% without epinephrine was used to anesthetize the dura mater. The maximum dose of lidocaine used did not exceed 4.5 mg kg -1 and for bupivacaine 3 mg kg -1.

All patients received propofol 1% with a starting intravenous infusion dose of 250 μg kg-1 min-1 for 15 min and then basal infusion dose at 50 μg kg-1min-1. Sedation was achieved for group PD by a combination of propofol and dexmedetomidine with a starting infusion dose of 1ug kg-1 hr -1 for 15 min, and then titrated down to 0.2μ g kg-1 hr-1.

In PR group, IV sedation was achieved by a combination of propofol and remifentanil at an initial bolus dose of 0.5 μg.kg-1 over 60 seconds and then a basal infusion of 0.1μg kg-1 min1. Insufficient sedation in both groups was treated with boluses of 250 μg kg-1 propofol. The total amount of propofol used in both groups was recorded.