Chapter 37: Venous Thromboembolism

KEY CONCEPTS

• VTE is often associated with identifiable risk factors.

• The diagnosis of suspected VTE should be confirmed by objective testing.

• During hospitalization, patients should receive VTE prophylaxis based on the risk factors present and the anticipated duration of risk.

• Initial VTE treatment should include a rapid-acting anticoagulant.

• For VTE treatment, injectable anticoagulants should be overlapped with warfarin for at least 5 days and until the patient's international normalized ratio is ≥2.0 for at least 24 hours.

• Direct oral anticoagulants (DOACs) such as rivaroxaban, apixaban, dabigatran, edoxaban, and betrixaban are a significant advancement in VTE treatment.

• Most patients with uncomplicated DVT or PE can be safely treated as outpatients.

• Most patients with VTE should receive 3 months of anticoagulation therapy; treatment beyond 3 months should be based on the risk of VTE recurrence and bleeding as well as patient preferences.

• Optimal anticoagulant therapy management requires knowledge of pharmacologic and pharmacokinetic characteristics as well as systematic management approach with ongoing patient education.

Patient Care Process for the Treatment of Venous Thromboembolism

Collect

• Patient characteristics (eg, age, sex, pregnant)

• Patient history (past medical, family, social—dietary habits including intake of vitamin K containing foods (see Table 37-13), tobacco/ethanol use)

• Current medications including aspirin/OTC NSAID use and prior anticoagulant medication use

• Objective data

  • Blood pressure (BP), heart rate (HR), respiratory rate (RR), O₂-saturation, height, weight

  • Labs (eg, Hgb, Scr, platelets, aPTT, PT)

  • Do NOT order hypercoagulability tests

  • Objective confirmation of VTE (see Figs. 37-6 and 37-7)

Assess

• Hemodynamic stability (eg, SBP<90 mm="" hg,="" hr="">110 bpm, O₂-sat<90%[0.90], RR), evidence of limb ischemia

• Presence of active bleeding and/or bleeding risk factors (see Table 37-10)

• Presence of VTE provoking factors (eg, recent surgery, plaster casting of lower extremity, indwelling catheter, cancer, pregnancy, estrogen use, prolonged immobility, recent hospitalization)

• Ability/willingness to self-inject LMWH/fondaparinux

• Ability/willingness to pay for various anticoagulation therapy options

• Ability/willingness to obtain appropriate laboratory monitoring (eg, INR for warfarin)

• Emotional status (eg, presence of anxiety, depression)

Plan^*

• Drug therapy regimen including specific anticoagulant(s), dose, route, frequency, and duration; (see Figs. 37-8 and 37-9, Tables 37-3, 37-4, 37-6, 37-8, and 37-9)

• Monitoring parameters including efficacy (eg, INR results, pain control, limb swelling, shortness of breath), safety (bleeding, VTE recurrence), and timing of assessments

• Patient education (eg, purpose of treatment, dietary and lifestyle modification, invasive procedures, drug therapy; see Table 37-5)

• Self-monitoring for resolution of VTE symptoms, occurrence of bleeding, when to seek emergency medical attention

• Referrals to other providers when appropriate (eg, thrombosis specialist, behavioral health, dietician)

Implement

• Provide patient education regarding all elements of the treatment plan

• Use motivational interviewing and coaching strategies to maximize adherence

• Schedule follow-up (eg, INR tests [warfarin], Scr [DOACs], adherence assessment, bleeding risk assessment, duration of therapy assessment)

Follow-up: Monitor and Evaluate

• Resolution of VTE symptoms (eg, shortness of breath, chest pain, swelling, redness, pain)

• Presence of adverse effects (eg, bleeding, GI upset [dabigatran])

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