Fischer M, Hossmann K A
Clinic of Anesthesiology and Intensive Care Medicine, Bonn, Germany.
Resuscitation. 1996 Oct;32(3):227-40. doi: 10.1016/0300-9572(96)00953-7.
Resuscitation of the brain after cardiac arrest requires homogeneous blood recirculation which, however, may be impaired by low reperfusion pressure, intravascular coagulation, increased blood viscosity and endothelial cell swelling. Intravascular volume expansion induced by intravenous infusion of a small volume of hypertonic solution has previously been shown to improve nutritional flow to the brain after severe hemorrhage shock. We therefore investigated whether this therapy also improves cerebral reperfusion after cardiopulmonary resuscitation. Fourteen adult normothermic cats were resuscitated after 15 min of ventricular fibrillation by closed-chest cardiac massage in combination with epinephrine, bicarbonate and DC-defibrillations. Eight animals were submitted to the standard resuscitation protocol. Six cats received additionally 2 ml/kg/10 min 7.5% NaCl/6% hydroxyethyl starch solution for post-ischemic volume expansion. EEG, ECG, CBF, and the aortic, left ventricular, central venous and intracranial pressures were monitored. Reperfusion of the brain was visualized 30 min after cardiac resuscitation by labelling the circulating blood with fluorescein isothiocyanate albumin. Areas of impaired brain reperfusion (no-reflow)-defined by the absence of microvascular filling-were identified by fluorescence microscopy at eight standard coronal levels of the forebrain, and expressed as percent of total sectional area. All animals were successfully resuscitated although volume expansion decreased myocardial and cerebral reperfusion pressure during cardiopulmonary resuscitation. Treatment with hypertonic solution increased serum osmolality transiently and prevented hemoconcentration throughout the experiment. Cerebral no-reflow was significantly reduced from 28 +/- 13% to 15 +/- 6% of total forebrain sectional area. Volume expansion by small volume hypertonic solutions may, therefore, improve recovery of brain function following cardiac arrest.
心脏骤停后脑复苏需要均匀的血液再循环，然而，低再灌注压力、血管内凝血、血液粘度增加和内皮细胞肿胀可能会损害这种再循环。先前已证明，静脉输注少量高渗溶液引起的血管内容量扩张可改善严重失血性休克后脑的营养血流。因此，我们研究了这种疗法是否也能改善心肺复苏后的脑再灌注。14只成年体温正常的猫在心室颤动15分钟后，通过闭胸心脏按摩联合肾上腺素、碳酸氢盐和直流电除颤进行复苏。8只动物接受标准复苏方案。6只猫额外接受2 ml/kg/10 min的7.5%氯化钠/6%羟乙基淀粉溶液用于缺血后容量扩张。监测脑电图、心电图、脑血流量以及主动脉、左心室、中心静脉和颅内压。在心脏复苏30分钟后，通过用异硫氰酸荧光素白蛋白标记循环血液来观察脑再灌注情况。通过荧光显微镜在前脑的八个标准冠状层面确定脑再灌注受损区域（无复流），该区域由微血管充盈缺失定义，并表示为总横截面积的百分比。所有动物均成功复苏，尽管容量扩张在心肺复苏期间降低了心肌和脑再灌注压力。高渗溶液治疗可使血清渗透压短暂升高，并在整个实验过程中防止血液浓缩。脑无复流从总前脑横截面积的28±13%显著降低至15±6%。因此，小容量高渗溶液进行容量扩张可能会改善心脏骤停后脑功能的恢复。
