Venous thromboembolism (VTE)





This chapter will review the pharmacotherapy for prevention and treatment of venous thromboembolism according to the American College of Chest Physicians evidence-based clinical practice guidelines on antithrombotic therapy and prevention of thrombosis.


Introduction


The threat of pulmonary embolism (PE) is a daily concern for patients in the intensive care unit (ICU), who typically have one or more risk factors for venous thromboembolism (VTE), the precursor of pulmonary embolism.


Risk factors for VTE


See Table 24.1 .



Table 24.1

Risk Factors for VTE in Hospitalized Patients

Data from Goldhaber SZ. Risk factors for venous thromboembolism. J Am Coll Cardiol . 2010;56(1):1–7; and Lijfering WM, Rosendaal FR, Cannegieter SC. Risk factors for venous thrombosis—current understanding from an epidemiological point of view. Br J Haematol . 2010;149(6):824–833.
























Surgery Major surgery, especially cancer-related surgery, hip and knee surgery
Trauma Multisystem trauma, especially spinal cord injury and fractures of the spine
Malignancy Any malignancy, active or occult chemotherapy and radiotherapy
Acute medical illness Stroke, right-sided heart failure, sepsis, inflammatory bowel disease, nephrotic syndrome, myeloproliferative disorders
Drugs Erythropoiesis-stimulating drugs, estrogen-containing compounds
Patient-specific factors Prior thromboembolism, obesity, increasing age, pregnancy
ICU-related factors Prolonged mechanical ventilation, neuromuscular paralysis, severe sepsis, vasopressors, platelet transfusions, immobility

ICU, Intensive care unit; VTE, Venous thromboembolism


Prevalence of VTE


See Fig. 24.1 .




Figure 24.1


Prevalence of Venous Thromboembolism (VTE) in Hospitalized Patients. *

In the past 3 months.

From Spencer FA, Emery C, Lessard D, et al. The Worcester Venous Thromboembolism Study: a population-based study of the clinical epidemiology of venous thromboembolism. J Gen Intern Med. 2006;21:722–727.


Thromboprophylaxis





  • Thromboprophylaxis for specific conditions ( Table 24.2 )



    Table 24.2

    Thromboprophylaxis for Specific Conditions

    Data from Falck-Ytter Y, Francis CW, Johanson NA, et al. Prevention of VTE in orthopedic surgery patients. Chest . 2012;141(2 suppl):e278S–e325S; and Gould MK, Garcia DA, Wren SM, et al. Prevention of VTE in nonorthopedic surgical patients. Chest . 2012;141(2 suppl):e227S–e277S.






















































































































































    CONDITIONS REGIMENS (ANY DRUG OR MECHANICAL DEVICE)
    UFH LMWH FONDAPARINUX ASA APIXABAN DABIGATRAN RIVAROXABAN WARFARIN IPC



    • Acute medical illness




    • +




    • +




    • +




    • General and abdominal-pelvic surgery




      • Low risk



      • Moderate risk



      • High risk





    • +



    • +




    • +



    • +







    • Abdominal-pelvic surgery for cancer




    • +




    • Thoracic Surgery




      • Moderate risk



      • High risk





    • +



    • +




    • +



    • +





    • Cardiac surgery with complications




    • +




    • +





    • Craniotomy




    • +




    • Spinal surgery




    • +




    • +




    • +




    • Hip or knee surgery





    • +











    • Major orthopedic surgery




    • +




    • +







    • Major trauma




    • +




    • +




    • +




    • Head or spinal cord injury




    • +




    • +





    • Any of the above + active bleeding or high risk of bleeding




    • +


    ASA , Aspirin; IPC , Intermittent pneumatic compression; LMWH , Low-molecular-weight heparin; UFH , Unfractionated heparin

    a If contraindicated to UFH or LMWH


    b Combined with UFH or LMWH


    c Alternative ( LMWH , Preferred)


    d Second-line agent


    e Combined with apixaban or dabigatran




  • Pharmacotherapy according to specific conditions ( Table 24.3 )



    Table 24.3

    Pharmacotherapy for Thromboprophylaxis According to Specific Conditions a

    From Guyatt GH, Akl EA, Crowther M, 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(2 suppl):7S–47S.




































































    ANTICOAGULANT USUAL DOSE DOSE ADJUSTMENT COMMENTS
    Unfractionated Heparin



    • UFH




    • 5000 units SubQ q8–12h




    • BMI ≥50: 7000 units q8h




    • LWMH has a lower risk of HIT compared to UFH



    • LMWH is equivalent to UFH for most conditions in ICU except for orthopedic procedures involving the hip and knee (LMWH is superior to UFH)



    • First dose of LMWH should not be given <12 h after surgery

    Low-Molecular-Weight Heparins



    • Enoxaparin




    • 40 mg SubQ q24h



    • or



    • 30 mg SubQ q12h




    • BMI >40: 0.5 mg/kg q24h



    • CrCl <30: 30 mg q24h




    • Dalteparin




    • 2500–5000 units SubQ q24h




    • No adjustment

    Factor Xa Inhibitors



    • Fondaparinux




    • 2.5 mg SubQ q24h




    • CI: <50 kg or CrCl <30: avoid




    • Useful for patients with history of HIT




    • Betrixaban (Bevyxxa)




    • 160 mg ×1 then 80 mg PO daily with food ×35–42 days




    • CrCl 15–29 or strong P-gp inhibitors (e.g., amiodarone, azithromycin, clarithromycin, ketoconazole, verapamil): 80 mg ×1 then 40 mg PO daily with food ×35–42 days



    • CrCl <15 or dialysis: not studied




    • New prophylactic anticoagulant for acute medical illness

    Antiplatelet



    • Aspirin




    • 160 mg PO daily




    • Caution in CrCl <10




    • N/A

    Direct Oral Anticoagulants



    • Apixaban




    • 2.5 mg PO BID




    • CrCl <30: excluded from studies




    • Apixaban, dabigatran, and rivaroxaban can elevate the INR




    • Dabigatran




    • 150 mg–220 mg PO daily




    • CrCl ≤30: excluded from studies




    • Rivaroxaban




    • 10 mg PO daily




    • CrCl <30: avoid

    Vitamin K Antagonist



    • Warfarin




    • 5–10 mg PO daily for 2 days, then titrate to INR 2–3




    • Monitor INR closely




    • Monitor INR closely


    BID , Twice daily; BMI , Body mass index; CI , Contraindicated; CrCl , Creatinine clearance; HIT , Heparin-induced thrombocytopenia; ICU , Intensive care unit; INR , International normalized ratio; LMWH , Low-molecular-weight heparin; P-gp , P-glycoprotein; PO , Orally; SubQ , Subcutaneous; UFH, Unfractionated heparin

    a Refer to specific conditions in Table 24.2

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Feb 28, 2021 | Posted by in EMERGENCY MEDICINE | Comments Off on Venous thromboembolism (VTE)

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