Benjamin Jordan Max, Chippaux Jean-Philippe, Sambo Bio Tamou, Massougbodji Achille
Center for the Study and Research of Malaria Associated with Pregnancy and Childhood (CERPAGE), 08 BP 841 Cotonou, Bénin.
2Whitman College, Department of Biology, Walla Walla, WA 99362 USA.
J Venom Anim Toxins Incl Trop Dis. 2018 May 16;24:14. doi: 10.1186/s40409-018-0151-1. eCollection 2018.
The whole blood clotting test (WBCT) is a simple test of coagulation that is often used in the assessment, diagnosis, and therapeutic monitoring of snakebite patients in sub-Saharan Africa. WBCT requires only a clean glass tube and several milliliters of venous blood and is ideal for use in poorly equipped health centers throughout the rural areas where 95% of snakebites occur. However, questions surrounding the accuracy and reliability of the test remain unanswered due to variations in testing conditions and a lack of comparative research with which to validate them. This is the first study to evaluate WBCT results at both 20-min (WBCT20) and 30-min (WBCT30) reading times in the same group of snakebite patients.
In order to define the best reading time, the authors compared the results of serial WBCT evaluation at both 20 and 30 min after collection in 23 patients treated for snake envenomation in Bembèrèkè, northern Benin.
WBCT results were identical at both reading times in patients without coagulopathy or when coagulation was restored permanently following a single dose of antivenom. Out of 17 patients with coagulopathy, 14 showed discrepancies between WBCT20 and WBCT30 results in at least one pair of serial evaluations. These could be completely contradictory results (e.g. normal clot at WBCT20 and no clot at WBCT30) or a marked difference in the quality of the clot (e.g. no clotting activity at WBCT20 and an unstable partial clot at WBCT30). WBCT discrepancies were encountered most frequently in three situations: initial normalization of hemostasis following antivenom therapy, detection of a secondary resumption of coagulopathy, or final restoration of hemostasis after a secondary resumption had occurred.
This study suggests that the WBCT is robust and that a sequential reading should improve the diagnosis and monitoring of venom-induced coagulopathies. It also indicates the possibility of discrepancies in the sensitivity of WBCT20 and WBCT30 for detecting the resolution or reoccurrence of coagulopathy and identifies how these findings, if confirmed, may be used to increase the efficacy and efficiency of antivenom treatment in the field.
全血凝血试验（WBCT）是一种简单的凝血试验，常用于撒哈拉以南非洲地区蛇咬伤患者的评估、诊断和治疗监测。WBCT仅需要一个干净的玻璃管和几毫升静脉血，非常适合在95%的蛇咬伤事件发生的农村地区设备简陋的卫生中心使用。然而，由于检测条件的差异以及缺乏用于验证的对比研究，围绕该试验准确性和可靠性的问题仍未得到解答。这是第一项在同一组蛇咬伤患者中评估20分钟（WBCT20）和30分钟（WBCT30）读数时间的WBCT结果的研究。
为了确定最佳读数时间，作者比较了在贝宁北部Bembèrèkè接受蛇毒中毒治疗的23例患者采集血液后20分钟和30分钟时连续WBCT评估的结果。
在没有凝血病的患者中，或者在单次注射抗蛇毒血清后凝血功能永久恢复的患者中，两个读数时间的WBCT结果相同。在17例凝血病患者中，14例在至少一组连续评估中显示WBCT20和WBCT30结果存在差异。这些差异可能是完全矛盾的结果（例如，WBCT20时血凝块正常，而WBCT30时无血凝块），或者是血凝块质量的显著差异（例如，WBCT20时无凝血活性，而WBCT30时有不稳定的部分血凝块）。WBCT差异最常出现在三种情况下：抗蛇毒血清治疗后止血功能初步恢复正常、检测到凝血病再次出现、或再次出现后止血功能最终恢复。
本研究表明WBCT是可靠的，连续读数应能改善对毒液诱导的凝血病的诊断和监测。它还指出了WBCT20和WBCT30在检测凝血病缓解或复发的敏感性方面存在差异的可能性，并确定了如果这些发现得到证实，如何可用于提高现场抗蛇毒血清治疗的疗效和效率。
