Envenoming by the Common Krait ( Bungarus caeruleus) and Asian Cobra ( Naja naja): Clinical Manifestations and Their Management in a Rural Setting

Abstract

Villagers are commonly poisoned by kraits and cobras in India, and resulting deaths are common. An inadequate understanding of appropriate snakebite treatment often delays proper treatment of those who are bitten. A lack of simple airway management equipment such as resuscitation bags and laryngoscopes compounds the difficulty in treating many patients and increases mortality in neurotoxic (elapid) venom poisoning. This article discusses the clinical signs and symptoms of krait and cobra envenoming and medical intervention in a rural setting. We enrolled 30 subjects of presumed snake envenoming (krait = 23 cases, cobra = 7 cases). Details of the bite site, the subject's activities at the time of the bite, local manifestations, systemic involvement, progress of venom poisoning, and subsequent response to treatment were collected on a standard data form. The type of snake was confirmed either by analyzing the killed specimen or by combining clinical findings and identification by the subject or bystanders when presented with preserved specimens. Of 23 subjects (11 male, 12 female) bitten by kraits, 2 were deceased upon arrival, 7 died in the hospital, and 14 recovered. Of the 14 survivors, 4 required artificial respirations with a resuscitation bag, antivenom, and anticholinesterase drugs. One had a dry bite. The remaining 9 recovered with supportive treatment only. Of 7 subjects (5 male; 2 female) encountering cobras, 2 who had been bitten were deceased upon arrival at the hospital, and 1 died suddenly of an apparent cardiac arrest after seeing a hooded cobra on a road (there was no evidence of a bite site on this individual). Four subjects recovered with antivenon, anticholinesterase drugs, and/or artificial respiration. Early administration of antivenom prevents respiratory paralysis after elapid snake bite. Patients with evidence of respiratory insufficiency after neurotoxic venom poisoning require rapid intubation and artificial ventilation. Anticholinestrase agents may help reverse neuromuscular dysfunction caused by elapid envenoming and may accelerate recovery.