Hess John R
1University of Maryland School of Medicine, Baltimore, MD.
Hematology Am Soc Hematol Educ Program. 2013;2013:664-7. doi: 10.1182/asheducation-2013.1.664.
For 30 years, the Advanced Trauma Life Support course of the American College of Surgeons taught that coagulopathy was a late consequence of resuscitation of injury. The recognition of trauma-induced coagulopathy overturns that medical myth and creates a rationale for procoagulant resuscitation. Analysis of the composition of currently available blood components allows prediction of the upper limits of achievable coagulation activity, keeping in mind that oxygen transport must be maintained simultaneously. RBCs, plasma, and platelets given in a 1:1:1 unit ratio results in a hematocrit of 29%, plasma concentration of 62%, and platelet count of 90,000 in the administered resuscitation fluid. Additional amounts of any 1 component dilute the other 2 and any other fluids given dilute all 3. In vivo recovery of stored RBCs is ∼90% and that of platelets ∼60% at the mean age at which such products are given to trauma patients. This means that useful concentrations of the administered products are a hematocrit of 26%, a plasma coagulation factor activity of 62% equivalent to an international normalized ratio of ∼1.2, and a platelet count of 54,000. This means there is essentially no good way to give blood products for resuscitation of trauma-induced coagulopathy other than 1:1:1. Because 50% of trauma patients admitted alive to an academic-level 1 trauma center who will die of uncontrolled hemorrhage will be dead in 2 hours, the trauma system must be prepared to deliver plasma- and platelet-based resuscitation at all times.
30年来,美国外科医师学会的高级创伤生命支持课程一直教导说,凝血病是创伤复苏的晚期后果。创伤性凝血病的认识推翻了这一医学误区,并为促凝复苏创造了理论依据。分析目前可用血液成分的组成,可以预测可实现的凝血活性上限,同时要记住必须维持氧输送。按1:1:1的单位比例给予红细胞、血浆和血小板,在输注的复苏液中会产生29%的血细胞比容、62%的血浆浓度和90,000的血小板计数。任何一种成分的额外用量都会稀释其他两种成分,而给予的任何其他液体都会稀释所有三种成分。在将这些产品给予创伤患者的平均年龄时,储存红细胞的体内回收率约为90%,血小板约为60%。这意味着所输注产品的有效浓度为26%的血细胞比容、62%的血浆凝血因子活性(相当于国际标准化比值约为1.2)和54,000的血小板计数。这意味着除了1:1:1的比例外,基本上没有其他好的方法来给予血液制品用于创伤性凝血病的复苏。因为在学术水平的一级创伤中心,50%因无法控制的出血而死亡的存活入院创伤患者将在2小时内死亡,创伤系统必须随时准备进行基于血浆和血小板的复苏。