The Role of Point-of-Care Ultrasound (POCUS) in Envenomation by a Desert Viper

Patient: Male, 53-year-old Final Diagnosis: Snakebite envenomation Symptoms: Pain • swelling Medication: — Clinical Procedure: Antivenom administration • Point of care ultrasound (POCUS) Specialty: Critical Care Medicine • Radiology • Toxicology OBJECTIVE: Challenging differential diagnosis BACKGROUND: There are few reports of crotaline envenomation in Qatar, where clinically significant snakebite is infrequently encountered. This report presents a case that resulted in significant hematotoxicity. The report introduces the concept that there may be a role for point-of-care ultrasound (POCUS) as an Emergency Department (ED) bedside imaging tool in the early evaluation of crotaline snakebites. CASE REPORT: A 53-year-old Bangladeshi male without any prior medical history or allergies presented to the ED at the Hamad General Hospital stating that a sand-colored snake with a large head had bitten him on an uncovered part of his distal right leg leading to moderate swelling. Baseline laboratory testing showed a single laboratory suggestion of hematotoxicity (borderline elevation in prothrombin time) and moderately elevated lactate, indicating the potential for localized tissue destruction. POCUS demonstration of subcutaneous edema extending proximal to the knee was interpreted as suggesting the bite may be sufficiently serious to warrant administration of antivenom as the swelling crosses a major joint. CONCLUSIONS: The presentation of the current case provides useful information for crotaline envenomation evaluation and management in Qatar and surrounding Middle Eastern countries. The mainstays of therapy are early suspicion of hematotoxicity, close observation for soft tissue, and timely treatment with appropriate antivenom. The case presented also provides a suggestion that ED ultrasound (POCUS) may be of assistance in assessing and predicting subcutaneous edema extent in patients with crotaline envenomation.