Following approval from the Research Ethics Committee of the Medical Faculty of Uludağ University, (the date and protocol number assigned by this ethics committee were March 4, 2008 and 5/30, respectively),written informed consent was obtained from patients undergoing elective scheduled operations involving craniotomy during anaesthesia consultations. Ninety American Society of Anesthesiologists (ASA) Physical Status classification system I or II patients of either sex between 18-85 years of age were allocated to this randomised, prospective, placebo-controlled, double-blind study. The patients were randomly divided into three groups using a sealed-enveloped technique to receive either 20 ml of 0.5% bupivacaine (Group B (n=30)), 20 ml of 0.5% levobupivacaine (Group L (n=30)) or saline as a placebo (Group C (n=30)). Twenty-millilitre syringes for the block were prepared and numbered by a blinded assistant.
Ninety American Society of Anesthesiologists (ASA) Physical Status classification system I-II patients were recruited for a randomised, placebo-controlled, double-blind study and were randomly divided into three groups to receive either 20 ml of 0.5% bupivacaine (Group B; n=30), 20 ml of 0.5% levobupivacaine (Group L; n=30) or saline as a placebo (Group C; n=30). Scalp block was performed 5 min before head pinning. The primary outcome of the study was mean arterial pressure (MAP) and secondary outcomes were heart rate (HR), visual analogue scale (VAS) scores, additional intraoperative and postoperative drug use. Postoperative pain was evaluated using a 10-cm visual analogue scale (VAS).