What are the treatment guidelines for patients with a medium risk Pulmonary Embolism Severity Index (PESI) score?

Treatment Guidelines for Medium Risk PESI Score Pulmonary Embolism

Patients with intermediate-risk PE (medium PESI score) should be treated with immediate anticoagulation using LMWH or fondaparinux, followed by a direct oral anticoagulant (DOAC) rather than a vitamin K antagonist, and should NOT receive routine thrombolysis. 1

Initial Anticoagulation Strategy

Start anticoagulation immediately without waiting for complete diagnostic confirmation:

• LMWH or fondaparinux is preferred over unfractionated heparin for most intermediate-risk patients 1
• Initiate treatment while diagnostic workup is still in progress if clinical probability is high or intermediate 1
• Unfractionated heparin should be reserved for patients at high bleeding risk or those with severe renal dysfunction 1

Transition to Oral Anticoagulation

DOACs are strongly preferred over vitamin K antagonists:

• When eligible for a DOAC (apixaban, dabigatran, edoxaban, or rivaroxaban), this is the recommended form of anticoagulant treatment 1
• Apixaban and rivaroxaban offer the advantage of single-drug regimens without requiring LMWH lead-in 1
• Dabigatran and edoxaban require initial parenteral anticoagulation before transitioning 1
• If VKA is used, overlap with parenteral anticoagulation until INR reaches 2.5 (range 2.0-3.0) 1

DOACs are contraindicated in:

• Severe renal impairment (creatinine clearance <30 mL/min) 1
• Pregnancy and lactation 1
• Antiphospholipid antibody syndrome 1

Thrombolysis Decision-Making

Routine primary thrombolysis is NOT recommended for intermediate-risk PE 1

However, rescue thrombolytic therapy is strongly recommended if the patient develops hemodynamic deterioration despite anticoagulation 1. This represents an upgrade from previous guidelines, reflecting the importance of early intervention when patients decompensate 1.

Alternative interventions if thrombolysis is contraindicated or fails:

• Surgical embolectomy should be considered 1
• Percutaneous catheter-directed treatment should be considered 1

Risk Reassessment and Early Discharge Considerations

For patients initially admitted with PESI class III (intermediate risk), reassessment at 48 hours can identify candidates for early discharge:

• Recalculate PESI at 48 hours (PESI-48) 1
• Patients reclassified as PESI class I/II or sPESI score 0 at 48 hours can be considered for early discharge 1
• Those remaining PESI class III or higher require senior review and continued monitoring 1
• Consider repeating RV function assessment (echocardiography or biomarkers) in those with initial RV dysfunction 1

Monitoring and Hemodynamic Support

Close monitoring is essential for intermediate-risk patients:

• Assessment of RV function by imaging or biomarkers should be considered even with low PESI or sPESI of 0 1
• Multidisciplinary team involvement should be considered for selected intermediate-risk cases 1

If hypoxemia develops (SaO2 <90%):

• Administer supplemental oxygen 2
• Escalate oxygen delivery as needed (high-flow nasal cannula, then non-invasive ventilation) 2
• Avoid aggressive fluid challenges, which may worsen RV failure 2, 3

If hemodynamic compromise develops:

• Vasopressor support with norepinephrine and/or dobutamine should be considered 1, 2, 3
• This signals need for rescue thrombolysis 1

Common Pitfalls to Avoid

• Do not use routine thrombolysis in stable intermediate-risk patients, as bleeding risk outweighs benefit 1
• Do not delay anticoagulation while awaiting complete diagnostic confirmation 1
• Do not use aggressive fluid resuscitation in patients with RV dysfunction 2, 3
• Do not miss the window for rescue thrombolysis in patients showing hemodynamic deterioration 1
• Do not prescribe DOACs to patients with severe renal impairment, pregnancy, or antiphospholipid syndrome 1