Fazelat Joyia, Teperman Sheldon H, Touger Michael
Albert Einstein College of Medicine, Bronx, New York 10461, USA.
Clin Toxicol (Phila). 2008 Nov;46(9):823-6. doi: 10.1080/15563650701753849.
Recurrent coagulopathy has been observed in patients after rattlesnake envenomation treated with Crotalidae Polyvalent Immune Fab (ovine) [FabAV]. While recurrent coagulopathy is well documented in the literature, clinically significant sequelae have not been reported. We present a case of recurrent thrombocytopenia after western diamondback envenomation treated with FabAV, resulting in an extensive recurrent local hemorrhage.
A 24-year-old male presented to our emergency department several hours after western diamondback envenomation. He sustained bites to both hands and the right flank by leaning over his pet "snake enclosure." On presentation, the patient was hypotensive, tachycardic, and thrombocytopenic with a platelet count of 17/nl. Antivenom therapy was initiated according to the standard FabAV protocol. However, sixteen hours after completion of the recommended FabAV infusion, the patient experienced a recurrent thrombocytopenia with a dramatic seventeen point drop in hematocrit. The source of bleeding was clinically attributed to an expanding hematoma at the site of envenomation.
FabAV has become the standard treatment for symptomatic crotalid envenomation. However, the pharmacokinetics of this drug predispose it to recurrent coagulopathies. While studies have shown persistent and recurrent coagulopathic derangements after FabAV therapy, no clinically significant sequelae have been reported. This report highlights the potential for recurrent local hemorrhagic complications following rattlesnake envenomation, even after treatment guided by the current FabAV protocol.
Recurrent coagulopathy following FabAV therapy can result in clinically significant hemorrhage, supporting the observation that extended repeat dosing may be necessary to adequately treat subjects of rattlesnake envenomation.
在用抗蛇毒血清（羊）[FabAV]治疗的响尾蛇咬伤患者中观察到复发性凝血病。虽然复发性凝血病在文献中有充分记载，但尚未报道有临床显著后遗症。我们报告一例在用FabAV治疗西部菱斑响尾蛇咬伤后出现复发性血小板减少症的病例，导致广泛的复发性局部出血。
一名24岁男性在被西部菱斑响尾蛇咬伤数小时后到我院急诊科就诊。他因俯身靠近其宠物“蛇笼”而双手和右胁腹被咬伤。就诊时，患者血压低、心率快且血小板减少，血小板计数为17/微升。根据标准的FabAV方案开始抗蛇毒血清治疗。然而，在完成推荐的FabAV输注16小时后，患者出现复发性血小板减少症，血细胞比容急剧下降17个百分点。临床上出血源归因于咬伤部位不断扩大的血肿。
FabAV已成为有症状的响尾蛇咬伤的标准治疗方法。然而，这种药物的药代动力学使其易发生复发性凝血病。虽然研究表明FabAV治疗后存在持续性和复发性凝血病紊乱，但尚未报道有临床显著后遗症。本报告强调了响尾蛇咬伤后即使在当前FabAV方案指导下治疗仍有复发性局部出血并发症的可能性。
FabAV治疗后的复发性凝血病可导致临床上显著的出血，支持这样的观察结果，即可能需要延长重复给药以充分治疗响尾蛇咬伤患者。
