Associations Between Snakebite Severity Scores and Antivenin Administration

In the United States, thousands of crotalid envenomations are reported annually, with incidence varying significantly by region. Crotalid envenomation in North America lacks a standardized treatment protocol. We evaluated Snakebite Severity Scores (SSSs) calculated by health care providers and their association with aspects of care.

Retrospective review of venomous snakebites (VSB) at a level I trauma center, March 2017-September 2023. Data included SSS documented by clinicians (CSSS), retrospectively calculated SSS from clinical documentation (RSSS), injury details, antivenin administration, patient response, and SSS classification (mild, moderate, and severe). Discrepant scores were further analyzed. Statistical analysis was performed using SPSS v28.

N = 134 patients (age 46.5 ± 17.6 y; 64.9% male; 67.9% referral hospital transfer). Copperhead bites predominated (76.9%). The mean CSSS was 3.09 ± 1.64, while RSSS was 3.59 ± 2.42 (r = 0.889, P < 0.001). Categorically, 70 patients (60.3%) were classified as mild, 25 (21.6%) moderate, and 3 (2.6%) severe. CSSS/RSSS differed in 47 patients (40.5%), with 40 RSSS > CSSS. Eighteen discrepancies (13.4%) suggested potential variation in treatment classification. CSSS aligned with the eventual clinical course in 10 patients: eight required no antivenin and two received antivenin consistent with their CSSS category. RSSS aligned more closely in seven patients: three improved with antivenin despite CSSS suggesting otherwise; two required additional antivenin; one received antivenin that may not have been clinically necessary; one had delayed intensive care unit admission. One patient's antivenin requirement appeared underestimated by both CSSS and RSSS.

Inconsistent use of institutional protocol for VSBs highlights educational needs. Miscalculated SSS values were associated with potential delays in treatment. Patients with an SSS of four did not receive antivenin, indicating variability in decision-making. Computer-based electronic medical record checklists may aid calculations and improve protocol adherence.