The Effects of Ketamine on Hemodynamics and Intracranial Pressure during O2-N2O-Isoflurane Anesthesia in Rabbits

Abstract

Background : The potential adverse effects of ketamine in neurosurgical anesthesia have been well established. However, the effects of ketamine on intracranial pressure(ICP) and hemodynamics during general anesthesia remain unclear. The purpose of this study was to assess the effects of ketamine on hemodynamics and ICP in anesthetized, ventilated rabbits. Methods : Thirty rabbits were divided into three groups: Group 1(n=10) received 1 ml/kg normal saline iv; Group 2(n=10) received 0.5 mg/kg ketamine iv; Group 3(n=10) received 1.0 mg/kg ketamine iv. After induction with thiopental, anesthesia was maintained with isoflurane and nitrous oxide in oxygen. During controlled ventilation, ICP, mean arterial pressure(MAP), cerebral perfusion pressure(CPP) and heart rate(HR) were measured. The ICP was measured using Ladd ICP monitoring system. All variables were evaluated at baseline and for 30 min following ketamine. Results : In group 1, ICP, MAP, CPP and HR were unchanged over the course of the study. In group 2, ICP, MAP and CPP were unchanged. HR increased at 1, 3 and 5 min(P＜0.01), 10 and 20 min(P＜0.05) after injection. In group 3, ICP, MAP and CPP increased at 1 and 3 min(P＜0.01) after injection. HR increased at 1, 3 and 10 min(P＜0.01), 5 min(P＜0.05) after injection. Conclusions : These results suggest that 0.5 and 1.0 mg/kg of ketamine don''t significantly affect the hemodynamics and ICP in anesthetized, mechanically ventilated rabbits.(Korean J Anesthesiol 1997; 33: 804∼810)