Case Study: Chapter 18

Chapter 18: Venous Thromboembolic Disease

TAKI GALANIS, MD; LUIS H. ERASE, MD, FSVM; ALEJANDRO PEREZ, MD, FSVM; and GENO J. MERLI, MD, FACP, FSVM

CASE STUDY:

A 58-year-old man is scheduled for a hemicolectomy for colon cancer. You are asked to see the patient in preparation for surgery. The patient has a medical history of stable coronary artery disease, hypertension, diabetes mellitus, DVT at age 42 following right femur fracture, and hyperlipidemia.

Medications include simvastatin, 40 mg daily; lisinopril, 20 mg daily; metformin, 500 mg twice each day; and ASA, 81 mg daily.

Physical examination: BP 138/70, P 72, R 12, BMI 40. The heart has regular rhythm. S1 and S2 are normal. There are no carotid bruits. The lungs are clear, without crackles. The abdomen is obese, and bowel sounds are active. There are no masses or organ enlargement. The patient has varicose veins bilaterally, with hemosiderin pigmentation at the distal medial aspect of the extremities.

Case Study: Chapter 18

* 1.) What would be the most effective regimen for venous thromboembolism prophylaxis?
* 2.) The patient does well postprocedure. On the fourth postoperative day, he has left lower extremity pain and swelling. An ultrasound is ordered and reveals the findings depicted in the image below within the left femoral vein. Which of the following venous ultrasound findings for lower extremity DVT is most important for the diagnosis of acute thrombosis?

* 3.) An intravenous unfractionated heparin infu- sion is initiated. The following day, a complete blood count reveals a platelet count of 58,000 and a creatinine clearance of 24 mL/min. On admission, the patient’s platelet count was 272,000 and creatinine clearance was 54 mL/ min. What is the most sensitive and specific test for the laboratory diagnosis of heparin-induced thrombocytopenia?
* 4.) Which of the following medications should be initiated for this patient?