von Knobelsdorff G, Hänel F, Werner C, Schulte am Esch J
Department of Anesthesiology, University Hospital Eppendorf, Hamburg, Germany.
J Neurosurg Anesthesiol. 1997 Apr;9(2):128-33. doi: 10.1097/00008506-199704000-00004.
This study investigates changes of jugular bulb oxygen saturation (SjO2) measured by fiberoptic jugular bulb oximetry and changes of intracranial hemodynamics using transcranial Doppler sonography (TCD) during cardiopulmonary bypass (CPB) for coronary artery bypass graft (CABG) in 17 ASA III patients. Anesthesia was maintained with fentanyl, midazolam, and continuous infusion of etomidate. Hypothermic CPB (27 degrees C) was managed according to alpha-stat conditions. SjO2 (%) was measured by a fiberoptic catheter (Opticath F 5.5; Abbott Critical Care Systems) placed in the right jugular bulb via the right internal jugular vein. Mean blood flow velocity (Vmean, cm/s) was measured in the middle cerebral artery using a bidirectional 2-MHz TCD system (Transpect, Medasonics). Data were recorded continuously from the beginning to the end of the CPB. During cooling and hypothermia (27 degrees C); SjO2 and Vmean did not change compared with values at the start of CPB. However, with the beginning of rewarming, Vmean was increased 65% compared with stable hypothermia (27 degrees C). This increase in Vmean was associated with a 25% decrease in SjO2. Maximum desaturation occurred at a 36 degrees C jugular bulb temperature. During cooling and stable hypothermia, global oxygen balance and intracerebral perfusion seemed to be maintained. However, a major alteration in the balance of the cerebral oxygen supply and demand may occur in response to rewarming despite increases in Vmean. Findings suggest inadequate increases in CBF to meet cerebral metabolic demand. Further investigations need to validate these findings with biochemical techniques and neuropsychological tests.
本研究调查了17例美国麻醉医师协会（ASA）Ⅲ级患者在冠状动脉旁路移植术（CABG）体外循环（CPB）期间，通过纤维光学颈静脉球血氧饱和度测定法测量的颈静脉球血氧饱和度（SjO2）的变化，以及使用经颅多普勒超声（TCD）测量的颅内血流动力学变化。麻醉维持采用芬太尼、咪达唑仑和依托咪酯持续输注。低温CPB（27℃）按照α稳态条件进行管理。SjO2（%）通过经右颈内静脉放置在右颈静脉球的纤维光学导管（Opticath F 5.5；雅培重症监护系统）进行测量。使用双向2兆赫TCD系统（Transpect，Medasonics）在大脑中动脉测量平均血流速度（Vmean，厘米/秒）。数据从CPB开始到结束持续记录。在降温及低温（27℃）期间，SjO2和Vmean与CPB开始时的值相比没有变化。然而，随着复温开始，Vmean与稳定低温（27℃）相比增加了65%。Vmean的这种增加与SjO2降低25%相关。最大去饱和发生在颈静脉球温度为36℃时。在降温及稳定低温期间，整体氧平衡和脑灌注似乎得以维持。然而，尽管Vmean增加，但复温可能会导致脑氧供需平衡发生重大改变。研究结果表明脑血流量增加不足，无法满足脑代谢需求。需要进一步的研究用生化技术和神经心理学测试来验证这些发现。
