Berling Ingrid, Isbister Geoffrey K
Department of Clinical Toxicology and Pharmacology, Calvary Mater Newcastle, Newcastle, NSW, Australia; School of Medicine and Public Health, University of Newcastle, Newcastle, NSW, Australia.
Department of Clinical Toxicology and Pharmacology, Calvary Mater Newcastle, Newcastle, NSW, Australia; School of Medicine and Public Health, University of Newcastle, Newcastle, NSW, Australia.
Transfus Med Rev. 2015 Apr;29(2):82-9. doi: 10.1016/j.tmrv.2014.09.005. Epub 2014 Dec 18.
Hematologic abnormalities are the most common effects of snake envenoming globally. Venom-induced consumption coagulopathy (VICC) is the commonest and most important. Other hematologic abnormalities are an anticoagulant coagulopathy and thrombotic microangiopathy. Venom-induced consumption coagulopathy is a venom-induced activation of the clotting pathway by procoagulant toxins, resulting in clotting factor consumption and coagulopathy. The type of procoagulant toxin differs between snakes and can activate prothrombin, factor X, and factor V or consume fibrinogen. The most useful investigation in VICC is a prothrombin time/international normalized ratio. The d-dimer may assist in early diagnosis, but fibrinogen levels often add little in the clinical setting. Bedside investigations would be ideal, but point-of-care testing international normalized ratio and whole blood clotting tests have been shown to be unreliable in VICC. The major complication of VICC is hemorrhage, including intracranial hemorrhage which is often fatal. The role of antivenom in VICC is controversial and may only be beneficial for some types of snakes including Echis spp where the duration of abnormal clotting is reduced from more than a week to 24 to 48 hours. In contrast, antivenom does not appear to speed the recovery of VICC in Australian snake envenoming. Other treatments for VICC include factor replacement, observation and prevention of trauma, and heparin. An Australian study showed that fresh-frozen plasma speeds recovery of VICC, but early use may increase consumption. There is no evidence to support heparin.
血液学异常是全球蛇咬伤最常见的影响。毒液诱导的消耗性凝血病（VICC）是最常见且最重要的。其他血液学异常包括抗凝性凝血病和血栓性微血管病。毒液诱导的消耗性凝血病是由促凝血毒素导致的毒液诱导的凝血途径激活，从而引起凝血因子消耗和凝血病。不同蛇类的促凝血毒素类型不同，可激活凝血酶原、因子X和因子V或消耗纤维蛋白原。VICC最有用的检查是凝血酶原时间/国际标准化比值。D-二聚体可能有助于早期诊断，但在临床环境中纤维蛋白原水平往往作用不大。床边检查是理想的，但即时检验国际标准化比值和全血凝血试验在VICC中已被证明不可靠。VICC的主要并发症是出血，包括颅内出血，颅内出血往往是致命的。抗蛇毒血清在VICC中的作用存在争议，可能仅对某些蛇类有益，包括锯鳞蝰属，在这种情况下，异常凝血的持续时间从超过一周缩短至24至48小时。相比之下，抗蛇毒血清似乎并不能加快澳大利亚蛇咬伤所致VICC的恢复。VICC的其他治疗方法包括因子替代、观察和预防创伤以及使用肝素。一项澳大利亚研究表明，新鲜冷冻血浆可加快VICC的恢复，但早期使用可能会增加消耗。没有证据支持使用肝素。
