A 56-year-old man comes to the emergency department with left hand pain that started 2 hours ago. He was reaching into some grass to move a large pipe on his ranch when he felt a sharp bite to his left hand. He did not see what bit him. Medical history includes hypertension. Upon arrival, his blood pressure is 88/60 mm Hg, pulse is 118/min, and respirations are 22/min. Examination of the left hand reveals 2 puncture wounds just distal to his left wrist. Persistent oozing is noted from the wound. There is pronounced swelling and ecchymosis present to the middle of his upper arm. There is significant pain with passive movement of the left wrist and elbow. Sensation is intact in the left arm. Capillary refill is decreased in all 4 extremities equally. Which of the following is the best initial treatment for this patient?

Question

A 56-year-old man comes to the emergency department with left hand pain that started 2 hours ago.  He was reaching into some grass to move a large pipe on his ranch when he felt a sharp bite to his left hand.  He did not see what bit him.  Medical history includes hypertension.  Upon arrival, his blood pressure is 88/60 mm Hg, pulse is 118/min, and respirations are 22/min.  Examination of the left hand reveals 2 puncture wounds just distal to his left wrist.  Persistent oozing is noted from the wound.  There is pronounced swelling and ecchymosis present to the middle of his upper arm.  There is significant pain with passive movement of the left wrist and elbow.  Sensation is intact in the left arm.  Capillary refill is decreased in all 4 extremities equally.  Which of the following is the best initial treatment for this patient?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d852_4632_bc81_b1e21d496479_MD0003_00 This patient likely suffered a venomous snakebite (eg, puncture wounds from 2 fangs, swelling, ecchymosis) and should be treated with antivenom immediately due to signs of shock (eg, hypotension) and coagulation abnormalities (eg, persistent oozing). Venom from North American snakes contains toxins that can cause local tissue toxicity (eg, swelling), coagulation abnormalities (eg, oozing, ecchymosis), neuro/myotoxicity, and cardiovascular collapse (eg, hypotension, delayed capillary refill). Some effects may be delayed by several hours. Complete blood count, creatine kinase, prothrombin/partial thromboplastin time, INR, and fibrinogen should be obtained. Frequent wound examinations should assess for swelling, ecchymosis, and symptom progression. A decision should be made regarding antivenom administration. There are 2 types of antivenom for North American snake bites: Crotalidae polyvalent immune Fab (ovine), brand name CroFab (FabAV), which can be used for all North American snake bites, and Crotalidae Immune F(ab')₂ (equine), brand name Anavip (Fab2AV), which can be used only for confirmed rattlesnake bites. Treatment with either carries a risk of anaphylaxis and should be done in consultation with a toxicologist or snake bite expert. ₂ Given the risk of anaphylaxis, patients with mild envenomation (eg, mild, localized swelling; normal laboratory studies) should not receive antivenom but should be observed for 12-24 hours because delayed toxicity can occur. Patients with progressing or pronounced symptoms (eg, pronounced swelling and ecchymosis), abnormal coagulation (eg, oozing), or cardiovascular compromise (eg, hypotension) should receive antivenom and be admitted to the intensive care unit. (Choice B) Prophylactic antibiotics are sometimes indicated in animal and human bites, deep puncture wounds, or bites to high-risk areas (eg, hands). Infections related to snake bites are uncommon, and prophylactic antibiotics are not recommended. (Choice C) Snake bites can cause symptoms mimicking compartment syndrome (eg, pronounced swelling, pain with passive movement, decreased capillary refill). However, most swelling occurs outside the muscular compartment and does not affect intracompartmental perfusion pressure. Fasciotomies should involve expert consultation and should not proceed without intracompartmental pressure measurement. (Choices D and E) Tourniquets or pressure immobilization techniques are not recommended because they trap the venom in the involved extremity and can potentially cause ischemia. Suctioning (eg, local suction devices) only minimally reduces total body venom amount and may actually increase venom absorption by causing local tissue damage. Although these techniques were previously used, they should be avoided. Educational objective: Venomous snake bites should be managed with close observation and frequent coagulation studies and wound evaluations. Patients with mild envenomation and normal laboratory studies can be observed for 12-24 hours. Patients with abnormal laboratory results, progressing symptoms, or signs of systemic toxicity should receive antivenom.

A 56-Year-Old Man Comes to the Emergency Department with Left