Department of Intensive Care, Medical Academy, Lithuanian University of Health Sciences, Eivenių 2, 50028 Kaunas, Lithuania.
Medicina (Kaunas). 2011;47(8):461-7. Epub 2011 Nov 18.
More than 5 million people are bitten by venomous snakes annually and more than 100,000 of them die. In Europe, one person dies due to envenomation every 3 years. There is only one venomous snake species in Lithuania--the common adder (Vipera berus)--which belongs to the Viperidae family; however, there are some exotic poisonous snakes in the zoos and private collections, such as those belonging to the Elapidae family (cobras, mambas, coral snakes, etc.) and the Crotalidae subfamily of the Viperidae family (pit vipers, such as rattlesnakes). Snake venom can be classified into hemotoxic, neurotoxic, necrotoxic, cardiotoxic, and nephrotoxic according to the different predominant effects depending on the family (i.e., venom of Crotalidae and Viperidae snakes is more hemotoxic and necrotoxic, whereas venom of Elapidae family is mainly neurotoxic). The intoxication degree is estimated according to the appearance of these symptoms: 1) no intoxication ("dry" bite); 2) mild intoxication (local edema and pain); 3) moderate intoxication (pain, edema spreading out of the bite zone, and systemic signs); 4) severe intoxication (shock, severe coagulopathy, and massive edemas). This topic is relevant because people tend to make major mistakes providing first aid (e.g., mouth suction, wound incision, and application of ice or heat). Therefore, this article presents the essential tips on how first aid should be performed properly according to the "Guidelines for the Management of Snake-Bites" by the World Health Organization (2010). Firstly, the victim should be reassured. Rings or other things must be removed preventing constriction of the swelling limb. Airway/breathing must be maintained. The bitten limb should be immobilized and kept below heart level to prevent venom absorption and systemic spread. Usage of pressure bandage is controversial since people usually apply it improperly. Incision, mouth suction, or excision should not be performed; neither a tourniquet nor ice or heat should be applied. A doctor must monitor respiratory rate, blood pressure, heart rate, renal function, fluid balance, and coagulation status. The only specific treatment method is antivenin--serum with antibodies against antigens of snake venom. Antivenins against pit vipers used in the United States are Antivenin Crotalidae Polyvalent (ACP) and a more purified and hence causing less adverse reactions--Crotalidae Polyvalent Immune Fab (CroFab). In Europe, a polyvalent antiserum against Viperidae family snakes (including the common adder) can be used. Antivenins often may cause severe hypersensitivity reactions because of their protein nature. The bite of the common adder (the only poisonous snake in such countries as Lithuania and Great Britain) relatively rarely results in death; thus, considering the risk of dangerous reactions the antivenin causes itself, the usage of it is recommended to be limited only to life-threatening conditions.
每年有超过 500 万人被毒蛇咬伤，其中超过 10 万人死亡。在欧洲，每 3 年就有 1 人因蛇咬伤而死亡。立陶宛只有一种毒蛇——普通蝰蛇（Vipera berus）——属于蝰蛇科；然而，动物园和私人收藏中也有一些外来的毒蛇，如眼镜蛇科（眼镜蛇、曼巴蛇、珊瑚蛇等）和蝰蛇科的响尾蛇亚科（响尾蛇，如响尾蛇）。根据不同的家族（即，响尾蛇科和蝰蛇科的蛇毒更具血液毒性和坏死毒性，而眼镜蛇科家族的蛇毒主要是神经毒性），蛇毒可分为血液毒性、神经毒性、坏死毒性、心脏毒性和肾毒性。根据这些症状的出现程度来估计中毒程度：1）无中毒（“干”咬伤）；2）轻度中毒（局部肿胀和疼痛）；3）中度中毒（疼痛、肿胀超出咬伤区域，并出现全身症状）；4）重度中毒（休克、严重凝血障碍和大量肿胀）。这是一个相关的话题，因为人们在提供急救时往往会犯严重的错误（例如，口腔抽吸、伤口切开和冰敷或热敷）。因此，本文根据世界卫生组织（2010 年）的《蛇咬伤管理指南》，介绍了如何正确进行急救的基本要点。首先，应使伤者安心。必须去除戒指或其他物品，以防止肿胀肢体的收缩。必须保持气道/呼吸畅通。应固定被咬伤的肢体，并使其低于心脏水平，以防止毒液吸收和全身扩散。压力绷带的使用存在争议，因为人们通常使用不当。不应进行切开、抽吸或切除；也不应使用止血带、冰敷或热敷。医生必须监测呼吸频率、血压、心率、肾功能、液体平衡和凝血状态。唯一的特殊治疗方法是抗蛇毒血清——一种含有蛇毒抗原抗体的血清。在美国使用的响尾蛇科抗蛇毒血清有抗蛇毒 Crotalidae 多价（ACP）和更纯化的，因此引起的不良反应更少——响尾蛇科多价免疫 Fab（CroFab）。在欧洲，可以使用针对蝰蛇科（包括普通蝰蛇）蛇的多价抗血清。抗蛇毒血清由于其蛋白质性质，往往会引起严重的过敏反应。普通蝰蛇（立陶宛和英国等国家唯一的毒蛇）的咬伤相对较少导致死亡；因此，考虑到其自身引起危险反应的风险，建议仅在危及生命的情况下使用抗蛇毒血清。
