What is the treatment for pulmonary embolism in an inpatient setting?

Inpatient Management of Pulmonary Embolism

For inpatient management of pulmonary embolism (PE), patients should receive low molecular weight heparin (LMWH), fondaparinux, or direct oral anticoagulants (DOACs) such as apixaban or rivaroxaban as first-line therapy, with treatment selection based on hemodynamic stability, risk stratification, and patient-specific factors. 1, 2

Initial Assessment and Risk Stratification

Initial management of PE in the inpatient setting requires prompt risk stratification to guide treatment decisions:

• High-risk PE (massive PE with hemodynamic instability):

  • Systolic BP <90 mmHg or drop of ≥40 mmHg for >15 minutes
  • Signs of shock or end-organ hypoperfusion
  • Consider thrombolysis, surgical or mechanical embolectomy 2

• Intermediate-risk PE:

  • Hemodynamically stable but with right ventricular (RV) dysfunction on imaging
  • Elevated cardiac biomarkers (troponin, BNP, NT-proBNP)
  • Requires close monitoring for clinical deterioration 1, 2

• Low-risk PE:

  • Hemodynamically stable without RV dysfunction
  • Normal cardiac biomarkers
  • Consider for early discharge when appropriate 1

Anticoagulation Therapy

Initial Anticoagulation

1. Hemodynamically unstable patients:

   • Unfractionated heparin (UFH) IV: 80 units/kg bolus followed by 18 units/kg/hour infusion
   • Target aPTT 1.5-2.5 times control value 2
   • Preferred in massive PE due to shorter half-life and reversibility if thrombolysis becomes necessary

2. Hemodynamically stable patients:

   • LMWH: Weight-based dosing (preferred over UFH due to lower bleeding risk) 1, 3
   • Fondaparinux: 5 mg (weight <50 kg), 7.5 mg (weight 50-100 kg), or 10 mg (weight >100 kg) SC once daily 4
   • DOACs: Apixaban or rivaroxaban can be started immediately without parenteral anticoagulation lead-in 1, 2, 3

Transition to Oral Anticoagulation

• DOACs (apixaban, rivaroxaban, edoxaban, dabigatran) are now preferred over vitamin K antagonists (VKAs) for most patients 1, 2, 3

• Specific DOAC regimens:

  • Apixaban: 10 mg BID for 7 days, then 5 mg BID
  • Rivaroxaban: 15 mg BID for 21 days, then 20 mg daily
  • Edoxaban: After 5-10 days of parenteral anticoagulation, 60 mg daily (30 mg if CrCl 30-50 mL/min or weight ≤60 kg)
  • Dabigatran: After 5-10 days of parenteral anticoagulation, 150 mg BID 1, 2

• VKA (warfarin): If DOACs are contraindicated, overlap with parenteral anticoagulation until INR 2.0-3.0 for at least 24 hours 2

Special Situations

Massive PE with Hemodynamic Instability

• Systemic thrombolysis: Alteplase (tPA) 100 mg over 2 hours or accelerated regimen of 50 mg IV bolus with option for repeat bolus in 15 minutes 2
• Surgical embolectomy: Consider for patients with contraindications to thrombolysis or failed thrombolysis 2
• Mechanical thrombectomy: Option when thrombolysis is contraindicated 2

Renal Impairment

• For severe renal impairment (CrCl <30 mL/min):
  • Avoid DOACs
  • Use UFH with careful monitoring or adjusted-dose LMWH 1, 2

Pregnancy

• LMWH is the anticoagulant of choice
• DOACs are contraindicated 1, 2

Cancer-Associated PE

• LMWH has traditionally been preferred for at least 6 months
• Recent evidence supports DOACs (apixaban, edoxaban, rivaroxaban) as effective alternatives 2, 3

Duration of Anticoagulation

• Provoked PE with transient risk factor: 3 months 2, 3
• Unprovoked PE or persistent risk factors: Extended anticoagulation (>3 months) 2, 3
• Recurrent PE: Indefinite anticoagulation 2

Monitoring During Hospitalization

• Continuous assessment of hemodynamic parameters
• Serial evaluation of RV function if initially abnormal
• Monitor for bleeding complications
• For patients on UFH, check aPTT every 6 hours until therapeutic, then daily 5
• For patients on LMWH or fondaparinux, routine coagulation monitoring is not required 4

Common Pitfalls and Considerations

• UFH dosing challenges: Studies show that with standard UFH dosing, only 26-28% of patients achieve therapeutic aPTT within 24 hours, potentially increasing risk of recurrent VTE 5
• Early discharge considerations: Patients initially admitted with intermediate risk PE (PESI class III) can be considered for early discharge when they meet criteria for low risk (PESI class I/II or sPESI score 0) 1
• Inferior vena cava filters: Should not be used routinely; consider only when anticoagulation is contraindicated 2
• Antiphospholipid syndrome: DOACs should not be used; VKA is preferred 2

Follow-up Planning Before Discharge

• Arrange follow-up with clinicians experienced in VTE management
• Consider screening for underlying malignancy in unprovoked PE
• Plan for reassessment at 3-6 months to evaluate for post-thrombotic syndrome and chronic thromboembolic pulmonary hypertension 1
• For patients on extended anticoagulation, schedule periodic reassessment of drug tolerance, adherence, renal/liver function, and bleeding risk 2