Pulmonary Embolism Consultant Guide

Comprehensive Clinical Guide: Pulmonary Embolism (PE) This document is a detailed, up-to-date, consultant-level guide on Pulmonary Embolism (PE), incorporating the latest evidence-based recommendations for diagnosis, management, risk stratification, pharmacological and supportive therapy, and prophylaxis. I. Overview Pulmonary embolism (PE) is a potentially life-threatening condition resulting from embolic obstruction of pulmonary arteries, most commonly due to thrombi originating in deep veins of the legs. It ranges in severity from asymptomatic to causing sudden cardiac arrest. II. Etiology & Risk Factors - Deep Vein Thrombosis (DVT) – >90% of cases - Virchow’s triad: • Venous stasis (immobility, surgery) • Hypercoagulability (e.g., malignancy, thrombophilia, pregnancy) • Endothelial injury (trauma, surgery) - Others: Estrogen use, obesity, prior VTE, nephrotic syndrome, antiphospholipid syndrome III. Classification 1. Massive PE: Hypotension (SBP < 90 mmHg or drop ? 40 mmHg for >15 mins), or cardiac arrest 2. Submassive (intermediate-high risk): Normotensive but with RV dysfunction and/or raised troponin 3. Low-risk PE: No RV strain, normal biomarkers, and hemodynamic stability IV. Clinical Features - Dyspnea, pleuritic chest pain, cough, hemoptysis - Tachypnea, tachycardia, hypotension, hypoxia - Signs of DVT: unilateral leg swelling/pain - Syncope, shock, or cardiac arrest (massive PE) V. Investigations 1. ECG: Sinus tachycardia, S1Q3T3, new RBBB, RV strain pattern 2. CXR: Usually normal or nonspecific (e.g., Westermark sign, Hampton’s hump) 3. Labs: - D-dimer: Sensitive but nonspecific - Troponin, BNP: Risk stratification - ABG: Hypoxia, hypocapnia 4. Imaging: - CTPA: Gold standard - V/Q scan: Use in renal impairment or contrast allergy - Doppler USG of leg veins - Echocardiogram: RV strain in massive/submassive PE VI. Risk Stratification - Wells Score - Revised Geneva Score - PESI or sPESI (Pulmonary Embolism Severity Index) - RV dysfunction on ECHO or CT - Troponin and BNP VII. Management Overview A. Supportive Management: - Oxygen if SpO? < 90% - IV fluids: cautious use - Vasopressors (Norepinephrine) in shock - Mechanical ventilation in respiratory failure B. Anticoagulation (cornerstone therapy): Start anticoagulation immediately unless contraindicated. 1. LMWH: - Enoxaparin: 1 mg/kg SC q12h or 1.5 mg/kg SC q24h - Dalteparin: 200 IU/kg SC daily 2. UFH: - Bolus 80 U/kg IV ? infusion 18 U/kg/hr (titrate to aPTT) 3. DOACs: - Apixaban: 10 mg BD × 7d ? 5 mg BD - Rivaroxaban: 15 mg BD × 21d ? 20 mg OD 4. Warfarin: Start with LMWH bridge; INR goal 2–3 C. Thrombolysis: - Indication: Massive PE or clinical decompensation - Alteplase: 100 mg IV over 2 hours - Contraindications: Recent bleed, surgery, ICH D. Embolectomy/Catheter-based therapy: - For thrombolysis failure or contraindication E. Duration of anticoagulation: - Provoked: 3 months - Unprovoked: ?6–12 months - Recurrent or thrombophilia: lifelong - Cancer: LMWH or DOAC × 6–12 months - Pregnancy: LMWH during pregnancy + 6 weeks postpartum VIII. VTE Prophylaxis Indicated in all hospitalized patients with risk factors. 1. LMWH: - Enoxaparin 40 mg SC OD (CrCl >30) - Reduce dose in renal impairment 2. UFH: - 5000 units SC q8–12h 3. Mechanical prophylaxis: - Intermittent pneumatic compression in bleeding risk Special populations: - Post-op ortho: consider DOAC or LMWH × 10–35 days - Pregnancy: LMWH (avoid DOACs and warfarin) IX. Outpatient Management (Low-Risk PE) Criteria: Hemodynamic stability, no oxygen need, no bleeding risk, good support. - Start DOAC (Apixaban/Rivaroxaban) - Ensure follow-up in 48–72 hrs X. Follow-Up and Long-Term Management - Thrombophilia testing: after 3 months off anticoagulation - Cancer screening in unprovoked PE - Lifestyle: Avoid estrogen, smoking, immobility - Travel precautions: LMWH/DOACs in high-risk flyers