A Clinical and Epidemiologic Study of 292 Cases of Lance-Headed Viper Bite in a Brazilian Teaching Hospital

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  • Centro de Ciencias Biomedicas, Universidade Federal de Uberlandia, Uberlandia, Brazil
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The records of 292 patients who were admitted to a teaching hospital from 1984 to 1990 in Uberlandia in southeastern Brazil after being bitten by snakes of the genus Bothrops were retrospectively surveyed. The patients were from 42 municipalities in three states of Brazil. Most (42%) bites occurred between 4:00 pm and 10:00 pm. Fourteen percent of the bites occurred in the month of April. In 54 (18%) of the cases, the snakes were captured and identified as belonging to the following species: B. moojeni (29), B. neuwiedi (18), and Bothrops species (7). A diagnosis was made based on clinical findings in 238 (82%) cases. The lower limbs were the commonest site of bite (74%). The median time interval between bite and admission to the hospital was 3 hr. Fang marks were recorded in 58% of the cases and swelling was recorded in 82%. Clotting time was greater than 15 min in (142 of 264) 54% of the cases. A tourniquet was used on 44 cases. The mean ± SD dose of specific antivenom used was 187.48 ± 93.44 mg. The complications that occurred included abscess formation in 18% of the cases, necrosis in 16%, and renal failure in 5%. Amputation was performed in three (1%) cases. The case fatality rate was also 1% (three cases). When all cases were analyzed, the chi-square test for trend showed an increased susceptibility of renal failure with age (P < 0.04). Clotting time greater than 15 min was associated with the development of abscesses (P < 0.02). The use of a tourniquet, swelling, or site of the bite were not significantly associated with abscesses, necrosis, or renal failure. When only proven cases were analyzed, statistically significant findings were an increased risk of abscess with a longer interval between bite and admission to the hospital (P < 0.02), and when the bite was in the proximal segments of the lower limbs compared with the distal segments (P < 0.04).