RESUMEN
Effect of infusion and bolus injection of lidocaine on the pressure response to the increased intracranial pressure(ICP) was investigated in urethane-anesthetized rabbits. 1) Arterial blood pressure(BP) and ICP were significantly raised by infusing saline(0.05ml/min) into an epidural balloon. 2) Infusing of lidocaine(0.5mg/kg/min) into an ear vein minutely inhibited the elevation of BP and ICP when infusing saline into an epidural balloon. However, infusion of lidocaine(1.5mg/kg/min) markedly inhibited the elevation of BP and ICP. 3) Repeating the infusion of saline into the epidural balloon with intervals, the duration reached to the level of 80-10 mmHg ICP was gradually shortened. Each depressor response to the first, second and third injection of lidocaine(3 mg/kg) was similar. The first injection transiently reduced the elevated ICP, but the second and third injection reduced that significantly and the reducing effect was gradually prolonged according to repeating the lidocaine injection. These results show that lidocaine could delay the elevation of ICP and reduce the previously increased ICP by infusing saline into an epidural balloon.