[Effect of local anesthetics on hemodynamic effects during Mayfield skull clamp fixation in neurosurgery using total intravenous anesthesia].

Abstract

For neurosurgical procedures, the association between insertion of the Mayfield skull clamp and haemodynamic changes is generally recognized. We investigated the protective effect of two local anaesthetic substances (lidocaine and bupivacaine) under the conditions of total intravenous anaesthesia (TIVA) with propofol and alfentanil. Forty-two patients undergoing an elective craniotomy (tumor resection) were included in the study and randomly divided into three groups. All patients were given a total intravenous anaesthesia with propofol and aflfentanil. After induction, the skin areas for the pin were infiltrated with 0.9% sodium chloride (n = 14, control group 1), 1% lidocain (n = 14, group 2) or 0.5% bupivacaine (n = 14, group 3). After an interval of 1 to 2 minutes the pins were inserted. The intra-arterial line was inserted before induction. The haemodynamic parameters heart rate (HR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP) and mean arterial pressure (MAP) were monitored continuously. The haemodynamic parameters were recorded at four set times: (1) after induction of anaesthesia, (2) at the onset of the local anaesthesia, (3) at the insertion of the pin-holder, (4) five minutes after insertion. Insertion of the pins led to a significant increase in HR, SAP, MAP and DAP in the control group. These haemodynamic changes can be reduced by local infiltration with lidocaine or bupivacaine. The effect of both substances was the same in our study. Our results suggest that a significant reduction of the haemodynamic effects caused by insertion of the Mayfield skull clamp can be achieved by the use of local anaesthesia. Total intravenous anaesthesia alone with propofol and alfentanil cannot protect against these haemodynamic stimuli.