Dx: Snake Bite Patient Returns Within 24 Hours
Unfortunately, the patient returned within 24 hours with abdominal pain, increased leg swelling. Her vital signs were as follows: pulse, 140 and regular; and blood pressure 82/45 mm Hg. Pulse oximetry on room air showed 100% saturation. Her abdominal examination revealed diffuse tenderness with bilateral flank eccymosis. Her left foot revealed 2 puncture marks at the left lateral mid foot with moderate swelling to the groin with severe inguinal lymph node tenderness. Her hemoglobin was 6.4 gm/dl; fibrinogen 10 mg/dL; platelet count 2 per μl; prothrombin time > 60 seconds was. She was resuscitated and given 6 vials of Crofab Antivenin emergently and another 18 vials during her hospital course. An abdominal cat scan revealed retroperitoneal bleeding and underwent interventional radiological embolization. Because of active bleeding, she was transfused 8 units of PRBC’s over the next 8 hours. Her 10-day hospital course was complicated by a transfusion reaction, MRSA central line infection and healthcare associated pneumonia.
The patient was discharged with antibiotics. Although these wounds may appear frightening, acute infection is exceedingly rare.
Beyond the Bite:
The literature reports dry bites following rattlesnake envenomation as high as 20%. To call someone a dry bite, laboratory data (PT, Fibrinogen and platelets) should be normal or not trending worse 6-8 hours after envenomation.
Most rattlesnakes result in coagulopathy, thrombocytopenia and soft tissue swelling. The lower extremity can hide mild to moderate swelling and consideration should be given to observe all lower extremity envenomations for 12-24 hours.
Although mortality is rare from rattlesnake envenomation in the USA, the patient suffered significant morbidity by not being observed after the initial ED encounter. Her typical course had she been admitted after the first encounter would have likely been to receive Crofab Antivenin and be discharged within 1-2 days with repeat laboratory parameters and physical examination in 2-5 days after discharge.