Boldt J, Knothe C, Welters I, Dapper F L, Hempelmann G
Department of Anesthesiology, Justus-Liebig-University Giessen, Germany.
Ann Thorac Surg. 1996 Jul;62(1):130-5. doi: 10.1016/0003-4975(96)00239-1.
The differences between hypothermic and normothermic cardiopulmonary bypass (CPB) on platelet function and endothelial-related coagulation (eg, the thrombomodulin/protein C/protein S system) should be investigated.
According to a randomized sequence, 30 patients undergoing aortocoronary bypass grafting underwent either hypothermic (rectal temperature, 27 degrees C to 28 degrees C, n = 15) or normothermic CPB (rectal temperature, more than 35 degrees C, n = 15). Arterial blood samples were taken after induction of anesthesia (baseline values), before, during, and immediately after CPB, 5 hours after CPB, and on the morning of the first postoperative day. Circulating thrombomodulin, (free) protein S, protein C, and thrombin/antithrombin III complex were measured from these samples. Platelet function was assessed by aggregometry (turbidometric technique) induced by adenosine diphosphate (2 mumol/L), collagen (4 micrograms/L), and epinephrine (25 mumol/L).
Hypothermic patients showed a significantly higher blood loss and need for homologous blood than the normothermic patients. Thrombomodulin plasma level increased more in the hypothermic (from 28 +/- 5 ng/mL to 60 +/- 10 ng/mL) than in the normothermic group (from 28 +/- 7 ng/mL to 41 ng/mL); p < 0.05). Both protein C and (free) protein S were reduced significantly in the hypothermic (protein C, from 88% +/- 25% to 60% +/- 11%; protein S, from 71% +/- 10% to 40% +/- 8%) than in the normothermic patients. Platelet aggregation was significantly more decreased in the hypothermic (adenosine diphosphate, maximum decrease by -43% relative to baseline) than in the normothermic patients (adenosine diphosphate, maximum decrease by -22% relative to baseline). In the hypothermic CPB group, platelet aggregation had recovered incompletely, whereas in the normothermic patients platelet aggregation even slightly exceeded baseline values.
Hypothermic CPB resulted in more pronounced alterations of platelet aggregation and endothelial-related coagulation than normothermic CPB. Plasma levels of soluble thrombomodulin were more increased in hypothermic than in normothermic CPB indicating more extensive endothelial damage or activation associated with hypothermic CPB.
应研究低温与常温体外循环（CPB）对血小板功能和内皮相关凝血（如血栓调节蛋白/蛋白C/蛋白S系统）的影响差异。
按照随机序列，30例行主动脉冠状动脉搭桥术的患者接受低温CPB（直肠温度27℃至28℃，n = 15）或常温CPB（直肠温度高于35℃，n = 15）。在麻醉诱导后（基线值）、CPB前、CPB期间、CPB后即刻、CPB后5小时以及术后第一天早晨采集动脉血样本。检测这些样本中的循环血栓调节蛋白、（游离）蛋白S、蛋白C以及凝血酶/抗凝血酶III复合物。通过用二磷酸腺苷（2μmol/L）、胶原（4μg/L）和肾上腺素（25μmol/L）诱导的凝集测定法（比浊法）评估血小板功能。
低温组患者的失血量和对同源血的需求量显著高于常温组患者。低温组血栓调节蛋白血浆水平升高幅度（从28±5 ng/mL升至60±10 ng/mL）大于常温组（从28±7 ng/mL升至41 ng/mL）；p<0.05）。低温组患者的蛋白C和（游离）蛋白S均显著降低（蛋白C，从88%±25%降至60%±11%；蛋白S，从71%±10%降至40%±8%），而常温组患者则无此情况。低温组患者的血小板聚集显著降低（二磷酸腺苷，相对于基线最大降低-43%），而常温组患者（二磷酸腺苷，相对于基线最大降低-22%）则无此情况。在低温CPB组中，血小板聚集未完全恢复，而在常温组患者中血小板聚集甚至略超过基线值。
与常温CPB相比，低温CPB导致血小板聚集和内皮相关凝血的改变更为明显。低温CPB时可溶性血栓调节蛋白的血浆水平升高幅度大于常温CPB，表明与低温CPB相关的内皮损伤或激活更为广泛。
