Thrombotic Microangiopathy Following Arabian Saw-Scaled Viper (Echis coloratus) Bite: Case Report

Strikes and stripes of the Saw-scaled Viper in the Western Ghats-A case series

We describe 5 cases of envenomation and complications related to saw scaled viper (Echis carinatus) bites from the Western Ghats region of Karnataka over a period of 5 years (December 2019-May 2023). Although the smallest member of the Big Four, Saw Scaled viper envenomation is associated with significant morbidity. In our region, envenomation appears to be rare. The careful review of all these cases has suggested VICC with one patient having persistent coagulopathy despite adequate ASV administration, and three patients developing anaphylaxis. It needs to be brought to notice that the complications due to envenoming run high, despite timely administration of ASV. Through these cases, we want to contribute evidence suggesting variable efficacy of Indian polyvalent ASV for Echis carinatus bites and the need for updating protocols for the same.

Snakebite Associated Thrombotic Microangiopathy and Recommendations for Clinical Practice

Snakebite is a significant and under-resourced global public health issue. Snake venoms cause a variety of potentially fatal clinical toxin syndromes, including venom-induced consumption coagulopathy (VICC) which is associated with major haemorrhage. A subset of patients with VICC develop a thrombotic microangiopathy (TMA). This article reviews recent evidence regarding snakebite-associated TMA and its epidemiology, diagnosis, outcomes, and effectiveness of interventions including antivenom and therapeutic plasma-exchange. Snakebite-associated TMA presents with microangiopathic haemolytic anaemia (evidenced by schistocytes on the blood film), thrombocytopenia in almost all cases, and a spectrum of acute kidney injury (AKI). A proportion of patients require dialysis, most survive and achieve dialysis free survival. There is no evidence that antivenom prevents TMA specifically, but early antivenom remains the mainstay of treatment for snake envenoming. There is no evidence for therapeutic plasma-exchange being effective. We propose diagnostic criteria for snakebite-associated TMA as anaemia with >1.0% schistocytes on blood film examination, together with absolute thrombocytopenia (<150 × 10⁹/L) or a relative decrease in platelet count of >25% from baseline. Patients are at risk of long-term chronic kidney disease and long term follow up is recommended.

Atypical Hemolytic Uremic Syndrome in a Patient With Bothrops asper Envenomation

Bothrops asper envenomation is common in Colombia and is characterized by local tissue injury and venom-induced consumption coagulopathy (VICC). Rarely, thrombotic microangiopathy is associated with envenomation by this species. The case of a 57-y-old man with B asper bite and envenomation on the left foot is presented. The patient was admitted 8 h after the event and progressively developed edema, hemorrhage at the site of the bite, and hemorrhagic blisters. His coagulation test results (prothrombin and partial thromboplastin times) were prolonged, and his fibrinogen levels were severely reduced. The diagnosis of VICC was made. Administration of Colombian polyvalent viper antivenom controlled the VICC within a few hours. Subsequently, the patient developed severe microangiopathic anemia, thrombocytopenia, and acute kidney injury. A diagnosis of thrombotic microangiopathy was made, and the patient met the criteria for hemolytic uremic syndrome. Management with hemodialysis in addition to therapeutic plasma exchange and replacement with fresh frozen plasma was indicated. The patient's condition resolved 14 d later. To the best of our knowledge, this is the first case of B asper envenomation in which the patient presented with hemolytic uremic syndrome after VICC. A proposal is made regarding the pathogenesis of this chain of events.

Thrombotic microangiopathy following saw-scaled viper (Echis carinatus) envenoming in Sri Lanka

The saw-scaled viper (Echis carinatus) is considered as a highly venomous snake in Sri Lanka. The clinical manifestations are localized pain and swelling, coagulopathy and renal impairment. Thrombotic microangiopathy is rarely reported as a complication of saw-scaled viper envenoming. The clinical manifestations of thrombotic microangiopathy include thrombocytopenia, microangiopathic haemolytic anaemia and acute kidney injury. The consumption coagulopathy of post-envenoming could be followed by a syndrome consistent with thrombotic microangiopathy. We describe a patient with thrombotic microangiopathy following saw-scaled viper systemic envenoming which was managed with antivenom and supportive therapy. The dead snake which was brought by patient was identified by medical professional as saw-scaled viper (E. carinatus) based on morphological features. This case illustrates a rare manifestation thrombotic microangiopathy following saw-scaled viper envenoming.

Challenges in the Management of an Echis coloratus Adult Snakebite Victim at a Tertiary Care Hospital: A Case Report

Patient: Male, 18-year-old

Final Diagnosis: Snakebite envenomation

Symptoms: Coagulopathy

Medication:—

Clinical Procedure: Anti snake venom

Specialty: General and Internal Medicine • Toxicology • Tropical Medicine