Influential Factors of Local Tissue Necrosis after Taiwan Cobra Bites: A Secondary Analysis of the Clinical Significance of Venom Detection in Patients of Cobra Snakebites

Abstract

Local tissue swelling, inflammation, and wound necrosis are observed in Taiwan cobra bites. Knowledge of the factors influencing local tissue necrosis after cobra bites might improve the cobra bite treatment strategy. Therefore, we aimed to explore the factors influencing local tissue necrosis after cobra bites. This was a retrospective observational cohort study. All patients clinical presentations including serum venom levels for determining the influential factors in this study were obtained from Hung et al.’s previous study. Clinical features, such as bite information, initial swelling, patient presentation time, serum venom levels, and antivenom, use were extracted. The measurement outcome was the development of wound necrosis. The factors influencing wound necrosis were investigated using univariate and logistic regression analyses. The influential factors of local tissue necrosis and their areas under the curve were: initial limb swelling, 0.88; presentation time × serum level, 0.80; initial necrosis, 0.75; patient presentation time, 0.70. Serum venom level alone cannot be used as a predictive factor. The development of tissue necrosis might be associated with the venom factor, time factor, and their interaction. These influential factors can be used in future studies to evaluate antivenom efficacy.

Clinical study of anti-snake venom blockade in the treatment of local tissue necrosis caused by Chinese cobra (Naja atra) bites

“…Therefore, cobra bites should immediately be cleaned, debrided, and dressed as soon as possible, and given antibiotics to reduce the incidence of infection [42,43]. Additionally, some reports have shown that wound necrosis is related to the patient's treatment time, the concentration of toxin, and the dose of anti-snake venom; the less toxin secreted by the cobra, the earlier the patient visits the medical practitioner, and the higher the dose of anti-snake venom used, the lower the probability of wound necrosis [44,45]. Pharmacokinetics indicated that higher doses of anti-snake venom administered for cobra envenoming facilitate the neutralization of venom antigens [46], but still can't completely neutralize the residual venom depot at the site of wound [47], which may remain active and slowly lead to local tissue necrosis.…”

Characteristic Cases of Snake Bite in Sanjiwani Hospital

“…Studies by Lin and Alcoba found only (29,6%) and (5%) of the sample that presented with cell necrotic. [22], [23] Most snake venom contains hydro lithic enzymes such as Metallo Proteinase, PLA2, and 3-Finger Toxin that are responsible for cell necrotic. These components cause the destruction of local tissue by inducing Neutrophil Extracellular Traps (NETs), that blockade the blood flow and fill the site of the bite with venom, which later on increases the cytotoxicity.…”

Dermonecrosis caused by spitting cobra snakebite results from toxin potentiation and is prevented by the repurposed drug varespladib

“…The need to deliver antivenom intravenously by a medical professional in a clinical environment prolongs the time from bite to treatment by an average of five to nine hours due to poor hospital-accessibility in the remote, rural tropical regions where most snakebites occur ( 22, 25, 26 ). Furthermore, intravenous antivenom antibodies are too large (typically ∼110 or ∼150 kDa) to rapidly penetrate the envenomed peripheral tissue and neutralise the aetiological cytotoxins – rendering antivenom treatment largely ineffective in reversing the swelling, blistering and necrotic outcomes of local envenoming ( 1, 22, 23, 27, 28 ). Collectively, these limitations highlight why the development of effective therapeutics is one of the core goals of the WHO’s roadmap to reduce the impact of snakebite envenoming ( 2 ).…”