Department of Anaesthesiology, Munich University Hospital, Ludwig-Maximilians-University Munich, Nussbaumstrasse 20, 80336 Munich, Germany.
Br J Anaesth. 2010 Oct;105(4):429-36. doi: 10.1093/bja/aeq199. Epub 2010 Aug 6.
Plasma-free volume replacement in haemorrhage often results in dilutional coagulopathy. Prothrombin time index (PTI) and activated partial thromboplastin time (aPTT) are used for monitoring haemostasis but have not yet been clinically evaluated. Our aim was to investigate the effects of haemodilution on the course of global coagulation tests and clotting factors (CFs).
Blood samples from each of 10 volunteers were diluted with sodium chloride 0.9% (saline) or 6% hydroxyethyl starch 130/0.4 (HAES) by 30-80%. PTI, aPTT, CF, and the thrombelastometric parameters (ROTEM(®)) coagulation time (CT) and maximum clot firmness (MCF) were determined.
Dilution-dependent CF decreased in an almost linear manner and was not influenced by the diluent. Critically low activities for CF of ∼30% and a fibrinogen concentration <100 mg dl(-1) were measured at dilutions of between 60% and 75%. Critically low CF activities of about 30% were indicated by a PTI of 35-40%. PTI and MCF decreased continuously, demonstrating a good correlation with CF activities and fibrinogen. aPTT and CT showed a linear course up to a dilution of 65-75% corresponding to CF activities of 30-40%. Thereafter, values became pathological. PTI and aPTT were not influenced by the type of diluent, whereas the diluents had profound differences on results of thromboelastometry.
PTI and MCF are useful for monitoring dilution and intervention points. aPTT and CT reflect intervention points when showing pathological values. The type of diluents does not seem to interfere with PTI and aPTT, but HAES impairs haemostasis in ROTEM(®) more profoundly than saline.
出血患者常进行血浆无蛋白容积置换，从而导致稀释性凝血障碍。凝血酶原时间指数（PTI）和活化部分凝血活酶时间（aPTT）常用于监测止血情况，但尚未在临床上进行评估。我们的目的是研究血液稀释对整体凝血试验和凝血因子（CFs）的影响。
对 10 名志愿者的血液样本分别用 0.9%氯化钠（盐水）或 6%羟乙基淀粉 130/0.4（HAES）稀释 30-80%。测定 PTI、aPTT、CF 和血栓弹性描记法参数（ROTEM®）凝血时间（CT）和最大凝块硬度（MCF）。
CF 呈稀释依赖性，几乎呈线性下降，且不受稀释剂的影响。在 60%-75%的稀释度下，CF 活性降至临界低值约 30%，纤维蛋白原浓度＜100mg/dl。PTI 为 35-40%时，CF 活性临界低值约为 30%。PTI 和 MCF 持续下降，与 CF 活性和纤维蛋白原呈良好相关性。aPTT 和 CT 呈线性变化，直至稀释度为 65-75%，对应 CF 活性为 30-40%。此后，值变得异常。PTI 和 aPTT 不受稀释剂类型的影响，而血栓弹性描记法的稀释剂有显著差异。
PTI 和 MCF 可用于监测稀释和干预点。当 aPTT 和 CT 出现异常值时，可反映干预点。稀释剂的类型似乎不会影响 PTI 和 aPTT，但与盐水相比，HAES 更严重地影响 ROTEM®的止血功能。
