Venous Thromboembolism Prophylaxis for Medical Inpatients Dennis Whang 4/2/12 DSR2 Mini Lecture

Objectives Recognize the morbidity and mortality with venous thromboembolism of inpatients Determine the risk of VTE for each nonsurgical inpatient admitted Decide the VTE prophylaxis for each nonsurgical inpatient admitted

Background Most medical inpatients are at risk for venous thromboembolism (VTE): Deep venous thrombosis (DVT) Pulmonary embolus (PE) 25% of all VTE cases occur during hospitalization 50-75% of VTE cases occur on medical service 5-10% of inpatient deaths are due to PE Heparin prophylaxis has NOT shown to decrease risk for inpatient mortality However it has shown to decrease the incidence of PE VTE prevention is vital for every inpatient admitted using efficacious and safe modalities Metaanalysis of 10 trials evaluated medical patients wthout stroke Heparin prophy with reduced risk of mortality RR 0.94 [0.84,1.04] Decreased risk for PE with heparin RR 0.69 [0.52,0.90]

Deciding VTE Prophylaxis Must weigh TWO factors before deciding ppx VTE Risk Bleeding risk

VTE Prophylaxis Guideline Patient admitted Determine risk of VTE Low Early ambulation Or High Moderate Determine bleeding risk Anticoagulant prophylaxis High Intermittent pneumatic compression No formal prospective-validated model to determine risk for VTE for hospitalized medical patients ICU patients are automatically considered high risk for VTE Risk of VTE Low risk if all 3: Younger than 40 Mobile No thrombotic risk factors Moderate risk: All other patients High risk: ICU patients High Bleeding Risk Active gastroduodenal bleed Bleeding within 3 months prior to admission Platelet count of < 50

Thrombotic Risk Factors for VTE Obesity: BMI > 30 Smoking Immobility Malignancy Previous VTE Placement of central venous catheter Inherited or acquired hypercoagulable states Oral contraceptives/Hormone replacement therapy/tamoxifen Admission diagnosis of: Congestive heart failure (NYHA III/VI) Acute COPD exacerbation Acute infectious disease or sepsis Acute myocardial infarction Stroke with lower limb paralysis Inflammatory bowel disease VTE risk is 130 times higher in hospitalized patients than community residents, according to study of patients from 1980 to 1990. Elderly hospitalized patients had the highest risk. ICU patients are at the HIGHEST risk for VTE Pregnancy, highest incidence in post-partum period, especially after c-sections. Inherited/Acquired hypercoagulable states include: Factor V Leiden mutation Prothrombin gene mutation Protein S deficiency Protein C deficiency Antithrombin (AT) deficiency Antiphospholipid antibody syndrome Polycythemia vera Essential thrombocythemia Paroxysmal nocturnal hemoglobinuria Nephrotic syndrome

Mechanical VTE Prophylaxis Intermittent pneumatic compression Contraindicated in leg ischemia from peripheral vascular disease Ineffective in prevention of VTE Graduated compression stockings Venous foot pumps Compression prevents venous thrombosis by enhancing blood flow in deep veins of legs to prevent venous stasis. Free of side effects. Should start as soon as patient is admitted, with FEW interruptions. Stockings and foot pumps found no benefit with VTE prophylaxis in one randomized trial, and caused a 4 fold increase of skin ulcers and necrosis. (CLOTS trial, Lancet. 2009;373(9679):1958). Few data supporting venous foot pumps.

Pharmacological VTE Prophylaxis Low dose unfractionated heparin (UFH) 5,000 units SQ TID Low molecular weight heparin (LMWH) Enoxaparin (Lovenox) 40 mg SQ daily Do NOT use if CrCl < 30 ml/min No statistical difference between UFH and LMWH for VTE prevention in 9 trials LMWH are primary cleared by kidneys

What VTE prophylaxis would you use? A 62 yo F is admitted for community acquired pneumonia. No prior history of VTE, bleeding, hepatic, or renal failure. Her platelet count is 200. Moderate risk of VTE Low risk of bleeding VTE ppx: unfractionated heparin or enoxaparin Moderate risk: Not young Thrombotic risk factor: admitted for acute illness of respiratory infection

What VTE prophylaxis would you use? A 35 yo M is admitted for acute gout. He is ambulatory. He has no prior VTE, GI bleed, thrombophilia, or malignancy. BMI 23. His platelet count is 240. Low risk of VTE Low risk of bleeding VTE ppx: early ambulation

What VTE prophylaxis would you use? 21 yo F admitted to ICU for DKA from poor insulin compliance. She is ambulatory. She has no prior VTE, GI bleed, thrombophilia, or malignancy. Platelet count is 300. High risk of VTE Low bleeding risk VTE ppx: unfractionated heparin or enoxaparin ICU admission meets criteria of high risk of VTE

What VTE prophylaxis would you use? A 65 yo F is admitted for treatment of an active malignancy. CrCl is 20 ml/min. She has a history of prior VTE but no history of bleeding, hepatic failure. Her platelet count is 250. Moderate risk for VTE Low bleeding risk VTE ppx: unfractionated heparin Moderate risk due to active malignancy and prior VTE Cannot use lovenox due to renal impairment CrCl < 30 ml/min

VTE Prophylaxis Guideline Patient admitted Determine risk of VTE Low Early ambulation Or High Moderate Determine bleeding risk Anticoagulant prophylaxis High Intermittent pneumatic compression No formal prospective-validated model to determine risk for VTE for hospitalized medical patients ICU patients are automatically considered high risk for VTE Risk of VTE Low risk if all 3: Younger than 40 Mobile No thrombotic risk factors Moderate risk: All other patients High risk: ICU patients High Bleeding Risk Active gastroduodenal bleed Bleeding within 3 months prior to admission Platelet count of < 50

Summary Be aware of VTE in all hospitalized patients Assess risk of VTE with every admission Use pharmacologic prophylaxis with heparin for patients with moderate to high risk of VTE If pharmacologic prophylaxis is contraindicated due to high risk of bleeding, use intermittent pneumatic compression Do not use compression stockings

References Guyatt GH, et al. Executive Summary : Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest 2012;141;7S-47S. Francis, CW. Prophylaxis for Thromboembolism in Hospitalized Medical Patients. N Engl J Med 2007;356:1438-44. Pineo GF. Prevention of venous thromboembolic disease in medical patients. UpToDate, Mar 2012. Qaseem A, et al. Venous Thromboembolism Prophylaxis in Hospitalized Patients: A Clinical Practice Guideline From the American College of Physicians. Ann Intern Med. 2011;155:625-632.