Key Points
- Use the highest‑yield diagnostic test early; do not let testing delay time‑critical therapy.
- Set objective targets and reassess frequently.
- Plan definitive source control or disease‑specific therapy when indicated; document follow‑up and patient education.
Algorithm
- Assess pretest probability → D-dimer vs direct imaging.
- If high probability and low bleed risk, start anticoagulation before imaging if delays expected.
- Identify massive vs submassive vs low-risk; consider thrombolysis/catheter therapy when indicated; arrange follow-up for provoked/unprovoked PE and cancer screening.
Clinical Synopsis & Reasoning
Suspect PE with unexplained dyspnea, pleuritic pain, or syncope. Use Wells/Geneva and D-dimer to select imaging. Start anticoagulation when probability is high and bleeding risk acceptable. Thrombolysis or catheter therapy is reserved for massive PE (shock) and selected submassive cases with RV dysfunction and clinical deterioration.
Treatment Strategy & Disposition
Stabilize ABCs. Initiate guideline‑concordant first‑line therapy with precise dosing and continuous monitoring. Escalate to advanced/procedural interventions based on explicit failure criteria. Define ICU, step‑down, and ward disposition triggers; involve specialty teams early.
Epidemiology / Risk Factors
- Risk varies by comorbidity and precipitants; see citations for condition‑specific data.
Investigations
| Test | Role / Rationale | Typical Findings | Notes |
|---|
| Wells/Rev Geneva + D-dimer | Pretest probability | Rule-out strategy in low/moderate risk | Avoid unnecessary CTPA |
| CTPA (first-line) or V/Q (if contrast contraindicated) | Diagnosis | Filling defects or mismatched perfusion defect | — |
| Troponin/BNP and echocardiography | Risk | RV strain identifies submassive PE | Guides disposition |
High-Risk & Disposition Triggers
| Trigger | Why it matters | Action |
|---|
| Hypotension (SBP <90) or shock | Massive PE | Activate PE team; thrombolysis or thrombectomy; ICU |
| RV strain (echo/CT) with elevated troponin/BNP | Submassive PE | Consider catheter-directed therapy |
| Active bleeding/high bleed risk | Thrombolysis hazard | Heparin only; consider IVC filter if anticoagulation contraindicated |
| Pregnancy or cancer | Complex course | Specialist input; LMWH preferred |
| Severe hypoxemia or recurrent syncope | Instability | ICU monitoring |
Pharmacology
| Medication/Intervention | Mechanism | Onset | Role in Therapy | Limitations |
|---|
| UFH/LMWH or DOACs (apixaban/rivaroxaban) | Anticoagulation | Hours | First-line therapy | LMWH preferred in cancer/pregnancy |
| Systemic thrombolysis (e.g., alteplase 100 mg over 2 h) for massive PE | Fibrinolysis | Hours | Hemodynamic rescue | Bleeding risk high |
| Catheter-directed thrombolysis/thrombectomy | Interventional | Hours | Selected submassive/massive | PE response team decision |
Prognosis / Complications
- Outcome depends on timeliness of diagnosis and definitive therapy; monitor for complications.
Patient Education / Counseling
- Provide red‑flag education, adherence guidance, and explicit return precautions; arrange timely specialty follow‑up.
References
- ESC/ACCP PE guidelines — Link