[Deaths caused by venomous snakes in the State of São Paulo: evaluation of 43 cases from 1988 to 1993].

UNLABELLED

The prognostic factors and the causes for obit occurrence in ophidian envenoming are yet not completely clear.

PURPOSE

To determine the prognostic factors and the most probable causes for obit occurrence in ophidian envenoming.

METHODS

In the State of São Paulo were notified 12,639 cases of accidents by venomous snakes from 1988 to 1993. There were 43 deaths (0.34%). The variables from the accident notification reports were compared with the promptuary notes and/or with the death records (in lethal cases).

RESULTS

The snake genus was classified in 11,297 accidents and in 41 from the lethal ones. Bothrops was responsible for 9,828 (87%) accidents and 28 (68.3%) deaths, Crotalus for 1,359 (12.0%) accidents and 13 deaths (31.7%) and Micrurus for 110 (1%) accidents and no death (p < 0.05). The information regarding to sex and age of the patients was available, respectively, in 12,620 and 12,527 accidents and in all lethal ones. There were 9,783 (77.5%) male patients in the accidents and 35 (81.4%) in the lethal cases (p > 0.05). Regarding to age, 15.9% of the patients and 41.8% of the ones who died were 50 years-old or more (p < 0.05). The most frequently bitten anatomic regions were: foot (42.2%), hand (20.6%), leg (17.6%), and ankle (13.1%) in the accidents, and foot (35.7%) and leg (35.7%) in the lethal cases (p < 0.05). Coagulation disorders occurred in 34 (91.9%) from 37 patients who died (those where this datum was available). The information above was not available in non lethal cases. The most common manifestations and complications implicated as possible death causes were: acute renal failure (34-79.1%), acute respiratory failure (28-65.1%), shock (18-41.9%), and sepsis (18-41.9%). Among all lethal cases but one without information, 29.4% of the patients died within the first two days after bite and 67.6% within the first 5 days. Acute respiratory failure was most common among the patients who died owing to crotalic envenoming, and sepsis was only seen in bothropic envenoming.

CONCLUSION

Most of the accidents and obits are caused by Bothrops; Crotalus envenoming, leg bites, and accidents in 50 year-old patients (or more) are frequently lethal; the most common complication in lethal cases is acute renal failure.