ABSTRACT
PURPOSE: The aim of this study was to help set the domestic guidelines for administration of antivenom to envenomated patients with snake. METHODS: This retrospective observation case series comprised 128 patients with a snake envenomation. The patients were divided into two groups according to the need for additional antivenom after the initial treatment strategy based on the traditional snakebite severity grading scale; one group recovered successfully with the initial treatment decision and did not require an additional antivenom (N=85) and the other group required an additional administration of antivenom later (N=43). RESULTS: The group requiring additional administration of antivenom showed a higher local effect score and traditional snakebite severity grading at presentation, a shorter prothrombin and activated partial prothrombin time, a higher frequency of rhabdomyolysis and disseminated intravascular coagulopathy, and longer hospitalization than the group that did not require an antivenom later. The most common cause of additional administration was the progression of local symptoms. The independent factor associated with the need for additional antivenom administration was a local effect scoring of pain score (odds ratio, 2.477; 95% confidence interval, 1.309 to 4.689). The optimal cut off value of local effect scoring of pain was 1.5 with 62.8% sensitivity and 71.8% specificity. CONCLUSION: The local effect scoring of pain should be considered when treating patients who are envenomated with a snake using the traditional snakebite severity scale. If the local effect scoring of pain is more than 2, an increase of antivenom should be considered and the patients should be assessed frequently.