Clinical and laboratory features distinguishing between Deinagkistrodon acutus and Daboia siamensis envenomation

Abstract

BackgroundThere are 6 species of venomous snakes in Taiwan. Two of them, Deinagkistrodon acutus (D. acutus) and Daboia siamensis (D. siamensis), can cause significant coagulopathy. However, a significant proportion of patients with snakebites cannot identify the correct snake species after envenomation, which hampers the application of antivenom. Hence, the differential diagnosis between the two snakebites by clinical presentations is important. This study aims to compare their clinical and laboratory features for the purpose of differential diagnosis between the two snakebites.MethodsWe retrospectively reviewed the medical records of patients who arrived at the emergency department due to D. acutus or D. siamensis envenomation, between 2003 and 2016, in one medical center in eastern Taiwan. Since these snakebites are rare, we also included 3 cases reported from another hospital in central Taiwan.ResultsIn total, 15 patients bitten by D. acutus and 12 patients by D. siamensis were analyzed. Hemorrhagic bulla formation and the need for surgical intervention only presented for D. acutus envenomation cases (Both 53.3% vs. 0.0%, P = 0.003). As to laboratory features, lower platelet counts (20.0 × 103/μL [interquartile range, 14–66 × 103/μL] vs. 149.0 × 103/μL [102.3–274.3 × 103/μL], P = 0.001), lower D-dimer level (1423.4 μg/L [713.4–4212.3 μg/L] vs. 12,500.0 μg/L [2351.4–200,000 μg/L], P = 0.008), higher proportion of patients with moderate-to-severe thrombocytopenia (platelet count < 100 × 103/μL) (80% vs. 16.7%, odds ratio (OR) = 20.0, 95% CI, 2.77–144.31; P = 0.002), and lower proportion of patients with extremely high D-dimer (> 5000 ng/mL) (16.7% vs. 66.7%, adjusted OR = 0.1 (95% CI, 0.01–0.69; P = 0.036) were found among cases of D. acutus envenomation compared to D. siamensis envenomation. The combination of hemorrhagic bulla, thrombocytopenia, and a lack of extremely high D-dimer had good discriminatory power (area under the curve (AUC) = 0.965; 95% CI, 0.904–1.00) for distinguishing D. acutus from D. siamensis envenomation.ConclusionsThe presentation of moderate to severe thrombocytopenia (platelet count < 100 × 103/μL) and hemorrhagic bulla formation may indicate D. acutus envenomation. However, the envenomed patient with extremely high D-dimer levels may indicate a D. siamensis envenomation. These findings may help diagnose and select the right antivenom in patients with unknown snakebites who present significant coagulopathy.

Personal Experience of Daboia siamensis Envenomation

“…However, the subsequent redness and swelling continued to worsen, extending over the wrist joint, and therefore, another 4 vials were administered. Compared with previous studies, the overall amount of antivenom administered to this patient was more than the average dose, and there were no blisters or hemorrhagic bullae, and surgical intervention was not required [3]. e weak neurotoxic manifestations observed in this patient were numbness and pain at the ankles, general weakness, and difficulty in walking at the initial stage after the snakebite.…”

“…Although early antivenom administration would benefit wound recovery and reduce pain in affected patients [7,8], the optimal antivenom administration strategy for D. siamensis envenomation remains unclear. Compared to a recent study [3], most patients with D. siamensis envenomation were administered 4-6 vials of antivenom. e patient in this case was initially administered 4 vials of antivenom.…”

“…Patients who experience the bite of Daboia siamensis, a medically important venomous snake in Taiwan, are mainly resident in the southern and eastern areas of Taiwan [1] e major symptoms of D. siamensis bites in envenomed patients include local effects, varying degrees of acute kidney injury, incoagulable blood with bleeding tendency, and hemolysis [2,3]. Before the availability of a specific antivenom in Taiwan in August 2008, the bite of D. siamensis species induced more serious kidney injury than that of other Russell's vipers in Southeast Asia [4][5][6].…”

A Biochemical and Pharmacological Characterization of Phospholipase A2 and Metalloproteinase Fractions from Eastern Russell’s Viper (Daboia siamensis) Venom: Two Major Components Associated with Acute Kidney Injury

“…Myotoxicity with a significant increase in creatine kinase (CK) is a common clinical observation following envenoming by myotoxic snake species including sea snakes (e.g., Hydrophiinae ), some elapids (e.g., Pseudechis australis and Bungarus candidus ) [ 34 , 35 ] and some vipers (e.g., Daboia russelii and Bothrops asper ) [ 9 , 36 ]. Systemic myotoxicity, which causes rhabdomyolysis, is induced by systemic myotoxins that cause widespread muscle injury resulting in elevation of CK, hyperkalaemia, and AKI with myoglobinuria.…”

“…envenoming displays remarkable geographical variation. According to the available clinical data, hematotoxicity and nephrotoxicity are prominently observed following D. siamensis envenoming in Taiwan and Myanmar [ 9 , 10 ]. Whereas, envenoming by the Sri Lankan and South Indian population of D. russelii causes significant skeletal muscle paralysis and myoglobinuria [ 11 , 12 , 13 ].…”