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Taiwan cobra envenoming: serum venom concentration before and after specific treatment and relationship with debridement of necrotic wound tissue

Chia-Cheng Wang1,2,Chun-Hsiang Ou Yang1,2, Chih-Po Hsu1,2, Chien-Chun Liu3, Jau-Song Yu3,4,5,6, Chih-Hong Lo7, Wen-Chih Fann8,Yen-Chia Chen9,10, Chih-Chuan Lin2,11 [ + show more ]

J Venom Anim Toxins incl Trop Dis, 2023, 29:e20220077
Received: 16 June 2022 | Accepted: 01 December 2022 | Published online: 13 January 2023


Background: Bivalent freeze-dried neurotoxic (FN) antivenom has been the primary treatment since the 1980s for Taiwan cobra (Naja atra) envenomation in Taiwan. However, envenomation-related wound necrosis is a significant problem after cobra snakebites. In the present study, we analyzed the changes in serum venom concentration before and after antivenom administration to discover their clinical implications and the surgical treatment options for wound necrosis. Methods: The patients were divided into limb swelling and wound necrosis groups. The clinical outcome was that swelling started to subside 12 hours after antivenom treatment in the first group. Serum venom concentrations before and after using antivenoms were measured to assess the antivenom's ability to neutralize the circulating cobra venom. The venom levels in wound wet dressing gauzes, blister fluids, and debrided tissues were also investigated to determine their clinical significance. We also observed the evolutional changes of wound necrosis and chose a better wound debridement timing. Results: We prospectively enrolled 15 Taiwan cobra snakebite patients. Males accounted for most of this study population (n = 11, 73%). The wound necrosis group received more antivenom doses than the limb swelling group (4; IQR:2-6 vs 1; IQR:1-2, p = 0.05), and less records of serum venom concentrations changed before/after antivenom use (p = 0.0079). The necrotic wound site may release venom into circulation and cause more severe envenomation symptoms. Antivenom can efficiently diminish limb swelling in cobra bite patients. However, antivenom cannot reduce wound necrosis. Patients with early debridement of wound necrosis had a better limb outcome, while late or without debridement may have long-term hospital stay and distal limb morbidity. Conclusions: Antivenom can efficiently eliminate the circulating cobra venom in limb swelling patients without wound necrosis. Early debridement of the bite site wound and wet dressing management are suggestions for preventing extended tissue necrosis and hospital stay.


Keywords: Taiwan cobra; Naja atra; Venom concentration; Wound necrosis; Wound debridement.

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