While hiking, Paul Sawyer, age 31, is bitten twice on the right hand by a rattlesnake. When he arrives at the emergency department (ED), the team obtains STAT laboratory tests, including a complete blood count, prothrombin time, partial thromboplastin time, fibrinogen, fibrin, chemistry panel, blood typing and crossmatch, urinalysis, and urine myoglobin. Nurse Lauren Groves inserts two large-bore peripheral I.V. lines as ordered and gives a 500-mL bolus of normal saline solution followed by a continuous infusion. She inserts a urinary catheter, assesses the patient’s wounds, and checks his vital signs every 15 minutes. She also gives a tetanus injection.
History and assessment hints
Noting swelling and discoloration of the patient’s right hand and arm, Lauren marks the affected area with an indelible-ink pen to monitor for changes. After assessing the puncture wounds for drainage, she evaluates capillary refill, pulse quality, edema, and discoloration, looking for signs and symptoms of infection, tissue necrosis, and compartment syndrome.
Mr. Sawyer’s puncture wounds are ecchymotic and edematous but don’t extend beyond the wrist. He’s experiencing nausea and vomiting, oral paresthesia, mild hypotension, mild tachycardia, and tachypnea, but no clinical evidence of bleeding exists.
The snake, which a friend had photographed with his cell phone, is identified as a Northern Pacific rattlesnake. Its venom can lead to tissue necrosis, hemolysis, and neurotoxicity.
On the scene
After consulting the poison control center, the ED physician prescribes Crotalidae Polyvalent Immune Fab (Ovine) (CroFab), two vials I.V. every 6 hours for 18 hours. Lauren notes Mr. Sawyer’s blood pressure is 140/80 mm/Hg; pulse, 120 to 140 beats/minute; respirations, 20 breaths/minute and unlabored; and oxygen saturation, 98% on room air. Urine output is adequate; his urine tests negative for myoglobin. He’s transferred to the intensive care unit (ICU) for observation and further CroFab administration.
Call for help
Late on day 1, the ICU nurse notes a rising creatinine level—a possible sign of early rhabdomyolysis. The next morning, Mr. Sawyer complains of severe pain in his right arm despite hydromorphone administration. The nurse observes increased swelling and redness spreading up the arm, suggesting compartment syndrome. The attending physician (a trauma surgeon) orders another CroFab dose.
The redness and swelling continue to progress, capillary refill is delayed, and the nail beds are dusky. The physician orders a third CroFab dose.
The next day, the patient has an elevated white blood cell count and markedly elevated creatine kinase, indicating rhabdomyolysis. His arm is demarcated to the axilla; the skin is red, ecchymotic, edematous, and taut when elevated. He complains of severe pain.
The trauma surgeon quickly assesses the patient and consults an orthopedic surgeon. Direct pressure measurements reveal elevated intracompartmental pressure. The patient immediately undergoes a fasciotomy of the right arm. A negative-pressure wound therapy apparatus is applied to the surgical site.
Education and follow-up
Two weeks after his admission, the patient is ready for discharge, with his right arm intact. The nurse teaches him how to use the portable negative-pressure wound therapy apparatus and tells him the dressing changes will be done by a home health nurse.
First aid for snakebites focuses on reducing venom spread and obtaining medical attention as soon as possible. Fortunately for Mr. Sawyer, the snake was identified promptly and healthcare providers took quick action. Close monitoring for compartment syndrome and other complications helped save his arm.
Sharon Lee Savinsky is a registered nurse in critical care at Winchester Medical Center in Winchester, Virginia.