氯胺酮对兔脑微循环的影响

应用微循环闭路电视显微系统对１２只兔行颅骨开窗法对软脑膜微循环进行录像。通过直接动态观察发现氯胺酮可显著扩张脑微血管。同时使血流加快，网状毛细血管明显充盈，增多，微血管数目增加，由此引起脑脊液动力学和颅压增高。因此提出，对脑损伤，颅内出血，颅内高压或脑脊液压力异常者应慎用氯胺酮。

Effects of Ketamine on Cerebral Microcirculation in Rabbits

Video-record of microcirculation of cerebral pia mater via microscope system of closed-circut TV was carriedout in 12 rabbits anesthetized with 5%amobarbital sodium (50mg/kg). The calibres,blood flow rate and state of3, 4th order arterioles and 4, 5th order venules video-records were taken. Ketamine, 5mg/kg, was injected intra-venously. Rectal temperature and artery gas were kept within the preset limits. Results : 3,4th order arterioles and4,5th order venules were significantly dilated after ketamine and remained within 15min(P<0. 01). At 15min,mi-crovessls delated 18.9%, 24.3%, 15.6%, 20% respectively. At the same time,CBF was increased significantly.Capillary nets were dilated. The number of microvessls was increased. It is conclucled that ketamine has a direct dilating effect on cerebral microvessels,resulting in an increase inCBF and intracranial pressure, Ketamine,therefore,should probably be avoided in patients with abnormal CSFflow dynamics or intracranial pathology.