system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Five days after undergoing an open colectomy and temporary colostomy for colon cancer, a 73-year-old man develops severe pain and swelling of the left calf. He was diagnosed with colon cancer 3 months ago. He has hypothyroidism and hypertension. His father died of colon cancer at the age of 68. He does not smoke. Prior to admission, his medications included levothyroxine, amlodipine, and carvedilol. Since the surgery, he has also been receiving unfractionated heparin, morphine, and piperacillin-tazobactam. He is 172 cm (5 ft 8 in) tall and weighs 101 kg (223 lb); BMI is 34.1 kg/m2. He appears uncomfortable. His temperature is 38.1°C (100.6°F), pulse is 103/min, and blood pressure is 128/92 mm Hg. Examination shows multiple necrotic lesions over bilateral thighs. The left calf is erythematous, tender, and swollen. Dorsiflexion of the left foot elicits pain behind the knee. The abdomen is soft and nontender. There is a healing midline incision and the colostomy is healthy and functioning. The remainder of the examination shows no abnormalities. Laboratory studies show:
Hemoglobin 13.6 g/dL
Leukocyte count 12,100/mm3
Platelet count 78,000/mm3
Prothrombin time 18 seconds (INR = 1.1)
Activated partial thromboplastin time 46 seconds
Serum
Na+ 138 mEq/L
Cl- 103 mEq/L
K+ 4.1 mEq/L
Urea nitrogen 18 mg/dL
Glucose 101 mg/dL
Creatinine 1.1 mg/dL
Which of the following is the most appropriate next step in management?"
assistant
Switch from unfractionated heparin to argatroban therapy