PE Management Decision Tree

First split: hemodynamically unstable vs stable. That single branch changes urgency, imaging tolerance, and reperfusion decisions.

High-yield: Massive PE = obstructive shock until proven otherwise

Suspected / confirmed pulmonary embolismGive oxygen if hypoxemic, monitor vitals, IV access, consider anticoagulation while workup proceeds if probability is high and bleeding risk acceptable.

↓

Is the patient hemodynamically unstable?

Immediate resuscitation

ABC + circulatory support

Oxygen, IV access, fluids cautiously, vasopressors if needed. Avoid overloading the right ventricle.

Confirm fast if feasible

Bedside echo ± CTPA

If too unstable for CT, bedside echo showing RV strain can support urgent reperfusion decisions.

Anticoagulate

Start unfractionated heparin

UFH is preferred when rapid reversal or procedures may be needed, unless contraindicated.

Reperfusion

Systemic thrombolysis if no contraindication

Massive PE with shock/hypotension → thrombolysis is the classic exam answer.

If lysis contraindicated/fails

Catheter-directed therapy or surgical embolectomy

Use when bleeding risk blocks thrombolysis or the patient remains unstable despite treatment.

Probability first

Use Wells / Geneva or clinical probability

Do not jump blindly to imaging in low-risk patients.

Low/intermediate probability

D-dimer

Negative D-dimer can rule out PE in appropriate low-risk settings. Positive → imaging.

High probability or positive D-dimer

CT pulmonary angiography

CTPA is the usual confirmatory test. Consider V/Q scan if contrast is unsuitable.

Confirmed PE

Anticoagulation

DOAC/LMWH/UFH depending on renal function, pregnancy, cancer, procedures, and bleeding risk.

Intermediate-risk check

RV strain + troponin/BNP

RV dysfunction or positive biomarkers → monitor closely; thrombolysis is not routine unless deterioration occurs.

Low-risk stable

Ward or outpatient pathway

Selected low-risk patients may be managed as outpatient if reliable follow-up and low bleeding risk.

Unstable clues

SBP < 90 mmHgShockSyncopeCardiac arrestSevere RV strain

Stable workup trap

In low probability PE, a negative D-dimer rules out. In high probability PE, go to imaging rather than relying on D-dimer.

Tap a complication / special situation

If anticoagulation is contraindicated or PE recurs despite adequate anticoagulation, consider an IVC filter.

PE Decision Tree