Snake bites by the Papuan taipan (Oxyuranus scutellatus canni): paralysis, hemostatic and electrocardiographic abnormalities, and effects of antivenom

Abstract

One hundred sixty-six patients with enzyme immunoassay-proven bites by taipans (Oxyuranus scutellatus canni) were studied in Port Moresby, Papua New Guinea. One hundred thirty-nine (84%) showed clinical evidence of envenoming: local signs were trivial, but most developed hemostatic disorders and neurotoxicity. The blood of 77% of the patients was incoagulable and 35% bled spontaneously, usually from the gums. Fifty-one per cent had microscopic hematuria. Neurotoxic signs (ptosis, ophthalmoplegia, bulbar paralysis, and peripheral muscular weakness) developed in 85%. Endotracheal intubation was required in 42% and mechanical ventilation in 37%. Electrocardiographic abnormalities (sinus bradycardia and septal T wave inversion) were found in 52% of a group of 69 unselected patients. Specific antivenom raised against Australian taipan venom was effective in stopping spontaneous systemic bleeding and restoring blood coagulability but, in most cases, it neither reversed nor prevented the evolution of paralysis even when given within a few hours of the bite. However, early antivenom treatment was associated statistically with decreased incidence and severity of neurotoxic signs. The low case fatality rate of 4.3% is attributable mainly to the use of mechanical ventilation, a technique rarely available in Papua New Guinea. Earlier use of increased doses of antivenoms of improved specificity might prove more effective.