Aphasia in a farmer after viper bite.

Sir—J M Polo and colleagues (June 22, p 2164) report aphasia in a farmer after he was bitten on the left thumb by a viper. He developed swelling and ecchymosis of the corresponding limb. He reported to hospital within 2 h of being bitten, and his status was an absolute indication for immediate administration of polyvalent antivenom, according to WHO recommendations, to avoid the systemic effects of venom. However, delayed administration of antivenom or waiting until he had systemic manifestations—ie, a 6 h wait—resulted in systemic envenoming. We work in a rural area and have reported various poisonous snake bites. Between June, 2001, and May, 2002, six people were admitted to hospital for viper bite (four Echis carinatus, one Pit viper, one Russell’s viper). The time lapse between bite and admission was 2·5, 1·0, 1·25, 4·5, 1·5, and 1·5 h, respectively. All patients brought the killed snakes to the hospital for identification. Every patient developed progressive local oedema extending beyond the bitten segment of the limb, with ecchymosis. All were given polyvalent antivenom without test dose, preceded by subcutaneous adrenalin as prophylaxis against anaphylaxis to the antivenom. Each patient recovered within 48 h without development of systemic manifestations. A male farmer aged 32 years was bitten on the dorsum of his right hand by a Russell’s viper while harvesting grass. He felt giddy and experienced severe pain at the site of the bite. Swelling developed rapidly with bleeding from the fang marks. He reported to hospital within 1·5 h. On arrival, his blood pressure was 80/60 mm Hg. He developed rapid progressive swelling with ecchymosis over the bitten limb, and enlarged tender lymph nodes in right axilla. His head was placed in a low position, intravenous crystalloid solution was administered, and 4 mL blood was drawn into a clean glass test tube for coagulation testing. His blood did not clot for 20 min and remained incoagulable. We gave the patient ten vials of polyvalent antivenom in 200 mL dextrose over 60 min. Oedema lessened gradually over 48 h. His blood clotted within 10 min after 6 h of administration of antivenom. We gave him penicillin for wound infection and tetanus immunisation; he did not have diabetes. Early administration of antivenom if the indication is clear can prevent development of venom-induced thrombus and subsequent development of disseminated intravascular coagulation. The delayed administration of antivenom to Polo and colleagues’ patient resulted in systemic envenoming; the patient kept his head turned to the left, which suggests that he was pointing the lesion at left cerebral cortex. Timely administration of appropriate and adequate quantity of polyvalent antivenom is more beneficial than waiting. *H S Bawaskar, P H Bawaskar