What are the guidelines for treating pulmonary embolism?

Pulmonary Embolism Treatment Guidelines

Initiate anticoagulation immediately without delay in all patients with suspected PE while diagnostic workup is in progress, unless absolute contraindications exist. 1

Risk Stratification Framework

Risk stratification based on hemodynamic stability is the critical first step that determines treatment intensity 1:

• High-risk PE: Hemodynamic instability (systolic BP <90 mmHg, need for vasopressors, or shock) 1
• Intermediate-risk PE: Hemodynamically stable but with evidence of right ventricular dysfunction or myocardial injury 1
• Low-risk PE: Hemodynamically stable without RV dysfunction 1

Treatment Algorithm by Risk Category

High-Risk PE (Hemodynamically Unstable)

Systemic thrombolytic therapy is the recommended first-line treatment for high-risk PE (Class I, Level B recommendation). 1

Immediate management steps:

• Unfractionated heparin (UFH) with weight-adjusted bolus should be initiated immediately (Class I, Level C). 1
• Norepinephrine and/or dobutamine should be considered for hemodynamic support (Class IIa, Level C). 1
• Avoid fluid boluses in hypotensive patients with RV overload, as this worsens RV function; consider preload reduction or gentle diuresis instead. 2

If thrombolysis is contraindicated or fails:

• Surgical pulmonary embolectomy is recommended (Class I, Level C). 1
• Percutaneous catheter-directed treatment should be considered as an alternative (Class IIa, Level C). 1
• ECMO may be considered in combination with surgical embolectomy or catheter-directed treatment for refractory circulatory collapse or cardiac arrest (Class IIb, Level C). 1

Intermediate-Risk and Low-Risk PE (Hemodynamically Stable)

For parenteral anticoagulation, LMWH or fondaparinux is recommended over UFH (Class I, Level A). 1

For oral anticoagulation, a direct oral anticoagulant (NOAC) is recommended in preference to a vitamin K antagonist (VKA) (Class I, Level A). 1, 3, 4

Specific NOAC options include:

• Apixaban 4
• Rivaroxaban 3
• Dabigatran 1
• Edoxaban 1

If VKA is used instead:

• Overlap with parenteral anticoagulation until INR reaches 2.5 (range 2.0-3.0) (Class I, Level A). 1

Rescue thrombolytic therapy is recommended if hemodynamic deterioration occurs despite anticoagulation (Class I, Level B). 1, 5

Routine systemic thrombolysis is NOT recommended in intermediate- or low-risk PE (Class III, Level B). 1

Special Populations and Contraindications

NOACs are contraindicated in:

• Severe renal impairment (CrCl <15-30 mL/min depending on agent) 1, 3
• Pregnancy and lactation 1
• Antiphospholipid antibody syndrome 1

For antiphospholipid syndrome patients:

• Continue VKA indefinitely (Class I recommendation). 1

For pregnant patients:

• Use therapeutic fixed doses of LMWH based on early pregnancy weight 1
• Avoid spinal/epidural procedures within 24 hours of last LMWH dose 1
• Do not administer LMWH within 4 hours of epidural catheter removal 1

Duration of Anticoagulation

All patients require therapeutic anticoagulation for >3 months minimum (Class I recommendation). 1

Discontinue after 3 months if:

• First PE secondary to a major transient/reversible risk factor (e.g., surgery, trauma) 1

Continue indefinitely if:

• Recurrent VTE (at least one previous episode of PE or DVT) not related to a major transient risk factor 1, 5
• Antiphospholipid antibody syndrome 1

For patients on extended anticoagulation:

• Reassess drug tolerance, adherence, hepatic/renal function, and bleeding risk at regular intervals 1

Inferior Vena Cava Filters

IVC filters should be considered in:

• Acute PE with absolute contraindications to anticoagulation (Class IIa, Level C) 1
• Recurrent PE despite therapeutic anticoagulation (Class IIa, Level C) 1, 5

Routine use of IVC filters is NOT recommended (Class III, Level A). 1

Discharge Planning

Carefully selected low-risk PE patients should be considered for early discharge and home treatment if proper outpatient care and anticoagulation can be provided (Class IIa, Level A). 1

All patients should be routinely re-evaluated 3-6 months after acute PE to assess for chronic thromboembolic pulmonary hypertension and persistent symptoms. 1

Critical Pitfalls to Avoid

• Never delay anticoagulation while awaiting confirmatory diagnostic tests unless absolute contraindications exist 5
• Do not use fluid boluses in hypotensive high-risk PE patients, as this worsens RV function 2
• Do not routinely use thrombolysis in intermediate- or low-risk PE, as bleeding risks outweigh benefits 1, 6
• Do not use NOACs in severe renal impairment, pregnancy, or antiphospholipid syndrome 1
• Standard CPR is ineffective when pulmonary circulation is obstructed; consider emergency thoracotomy or cardiopulmonary bypass for cardiac arrest from PE 2

Multidisciplinary Pulmonary Embolism Response Teams (PERT)

Consider establishing or consulting a PERT for high-risk and selected intermediate-risk PE cases, bringing together specialists from cardiology, pulmonology, interventional radiology, cardiothoracic surgery, and intensive care to formulate real-time treatment plans. 1