Management of snakebite and systemic envenomation in rural Ecuador using the 20-minute whole blood clotting test.

OBJECTIVES: In low-income countries, snakebites are frequently managed in rural areas in health centers with severely constrained resources. Many healthcare providers in these settings have limited access to the numerous and relatively expensive laboratory studies used to diagnose envenomation. The relatively simple and inexpensive 20-minute whole blood clotting test (WBCT) has been recommended by several international organizations for the diagnosis of certain venomous snakebites. This study proposes to confirm the utility of the WBCT as the sole laboratory diagnostic tool to determine systemic envenomation in hematotoxic snakebite management in severely resource-constrained areas of the world.
METHODS: The authors reviewed all 110 cases of snakebite during a 6-year period in a small hospital in rural Ecuador using the WBCT.
RESULTS: All cases presented within 24 hours of snakebite. Twenty cases revealed normal coagulation with no clinical evidence of systemic envenomation. Ninety cases had no evidence of clot formation (positive WBCT) at 20 minutes, suggesting systemic envenomation. Of these 90 cases, according to a classification scale, 54 were mild, 26 were moderate, and 10 were severe envenomations requiring transfer to tertiary care. All mild and moderate systemic envenomations were successfully treated at the rural hospital. All severe envenomations were treated initially with antivenom before transfer to tertiary care. One patient with severe envenomation died in tertiary care.
CONCLUSIONS: The WBCT was predictive of the presence or absence of systemic envenomation from snakebite in our region. The WBCT guided the successful management of mild and moderate systemic envenomation, and spared patients with no evidence of systemic envenomation from potential side effects of antivenom.