What is the workup for a patient with pulmonary embolism (PE) in all 5 segments of their lungs?

Workup for Inpatient with Pulmonary Embolism in All 5 Lung Segments

Immediately initiate weight-adjusted unfractionated heparin (UFH) bolus and infusion while simultaneously performing risk stratification to determine if this patient requires systemic thrombolysis or other reperfusion therapy. 1

Immediate Risk Stratification (Within Minutes)

The presence of PE in all 5 lung lobes suggests high clot burden, making risk assessment critical for determining treatment intensity:

Assess for High-Risk PE (Hemodynamic Instability)

• Check vital signs immediately: Look for systolic blood pressure <90 mmHg, drop of ≥40 mmHg for >15 minutes, or need for vasopressors 1
• Perform bedside echocardiography if hemodynamically unstable to assess right ventricular dysfunction and guide immediate management decisions 1
• If high-risk PE is confirmed: Proceed directly to systemic thrombolytic therapy (Class I, Level B recommendation) unless contraindications exist 1

If Hemodynamically Stable: Assess for Intermediate-Risk PE

• Obtain cardiac biomarkers: Troponin and BNP/NT-proBNP to detect myocardial injury 1
• Perform echocardiography or review CTPA findings for right ventricular dysfunction (RV/LV ratio >0.9 suggests RV strain) 1
• Calculate PE Severity Index (PESI) or simplified PESI score to stratify mortality risk 1

Essential Laboratory Workup

Baseline Coagulation and Hematology

• Complete blood count to assess baseline hemoglobin and platelet count before anticoagulation 1
• PT/INR and aPTT for baseline coagulation status 1
• Renal function (creatinine/eGFR) to guide anticoagulant selection, as NOACs are contraindicated in severe renal impairment 1
• Liver function tests to assess bleeding risk and drug metabolism 1

Thrombophilia Testing (If Indicated)

• Draw blood for Factor V Leiden and Prothrombin G20210A mutation testing immediately, as these genetic tests remain unaffected by acute thrombosis or anticoagulation 2
• Consider antiphospholipid antibody panel (lupus anticoagulant, anticardiolipin antibodies, anti-β2-glycoprotein I antibodies) if clinically indicated, understanding confirmation requires repeat testing at 12 weeks off anticoagulation 2
• Defer Protein C and Protein S testing until at least 2-4 weeks after completing anticoagulation, as levels are falsely decreased during acute thrombosis and further suppressed by warfarin 2

Critical caveat: Routine thrombophilia testing has limited clinical utility, as indefinite anticoagulation is recommended for unprovoked PE regardless of test results 2

Cancer Screening

Given the extensive clot burden, assess for occult malignancy:

• Careful history and physical examination focusing on constitutional symptoms, weight loss, and cancer risk factors 1
• Basic laboratory tests: Complete metabolic panel, LDH 1
• Review chest imaging (CTPA already performed for PE diagnosis) for incidental findings 1
• Do not perform comprehensive CT abdomen or PET scanning routinely, as randomized trials showed no benefit over limited screening 1

Lower Extremity Evaluation

• Perform compression ultrasound of bilateral lower extremities to identify deep vein thrombosis, which would confirm venous thromboembolism and may influence IVC filter consideration if anticoagulation becomes contraindicated 1

Monitoring During Hospitalization

For High-Risk PE Patients

• Continuous cardiac monitoring and frequent vital sign assessment 1
• Serial troponin and BNP measurements if intermediate-risk to detect deterioration 1
• Repeat echocardiography if clinical deterioration occurs to guide escalation to rescue thrombolysis 1

For All PE Patients

• Monitor aPTT every 4-6 hours initially if on UFH infusion, targeting therapeutic range (1.5-2.5 times control) 1
• Daily hemoglobin to detect occult bleeding 1
• Monitor for signs of hemodynamic deterioration requiring rescue thrombolysis 1

Common Pitfalls to Avoid

• Do not delay anticoagulation while awaiting thrombophilia test results, as these do not change acute management 2
• Do not routinely order comprehensive thrombophilia panels, as results rarely alter treatment duration for extensive PE 2
• Do not perform routine IVC filter placement, as filters are only indicated for absolute contraindications to anticoagulation or recurrent PE despite adequate anticoagulation 1
• Do not discharge patients with extensive PE involving all lung lobes without careful risk stratification, as these patients warrant close monitoring even if initially stable 1