Submodule
VTE Risk and Pathobiology
Venous stasis, endothelial disturbance, and hypercoagulability combine across surgery, trauma, immobility, cancer, hormones, pregnancy, inflammation, catheters, inherited factors, and prior thrombosis.
- Virchow triad
- Major reversible factors
- Persistent and unprovoked risk
- Propagation, embolization, and recurrence
Slow flow favors local clot growth
Expose or activate endothelium
Shift thrombin generation
Clot can extend or travel to the lungs
Build risk through the Virchow triad
Immobility and venous obstruction produce stasis. Surgery, trauma, inflammation, and catheters disturb endothelium. Cancer, hormones, pregnancy, inherited thrombophilia, and systemic inflammation can increase coagulation. Multiple moderate risks often combine to create the event.
Define reversible factors precisely
Major surgery or trauma can strongly provoke VTE during a limited interval. Nonsurgical transient exposures vary in strength. Document the exact factor, timing, duration, and resolution rather than assigning a broad label from any recent event.
Identify persistent risk
Active cancer, chronic inflammatory disease, persistent immobility, ongoing hormonal exposure, antiphospholipid syndrome, and recurrent events can sustain thrombosis risk. A first VTE without a major reversible factor also has important implications for extended treatment.
Understand propagation and recurrence
A venous thrombus can extend proximally or embolize to the pulmonary circulation. Anticoagulation prevents new thrombin generation and propagation while endogenous systems remodel clot. It does not immediately dissolve all thrombus, so symptoms and recovery can lag behind anticoagulant onset.
Quick check
Submodule
DVT Diagnosis and Distal Disease
DVT symptoms overlap with cellulitis, venous insufficiency, edema, injury, and ruptured cysts, so pretest probability determines whether D-dimer or venous ultrasound should be used.
- Clinical probability
- D-dimer rule-out
- Compression ultrasonography
- Distal and catheter-associated DVT
Use a validated pathway
Apply only in the eligible low-risk pathway
Identify proximal or distal thrombosis
Use location, symptoms, and extension risk
Estimate probability before testing
Use a validated clinical probability pathway with symptoms, cancer, immobilization, prior VTE, examination findings, and alternative diagnoses. Examination alone cannot reliably confirm or exclude DVT because swelling, pain, tenderness, and erythema are nonspecific.
Use D-dimer to exclude, not confirm
In an eligible low-probability pathway, a negative high-sensitivity D-dimer can exclude DVT. Positive results are common with age, inflammation, cancer, pregnancy, hospitalization, and recent surgery. Age-adjusted thresholds can improve specificity when used in a validated protocol.
Match ultrasound protocol to follow-up
Compression ultrasound identifies noncompressible thrombosed veins. Whole-leg and limited proximal protocols have different coverage. A negative limited study can require repeat imaging when probability persists because distal thrombus may extend.
Individualize distal and catheter disease
Selected isolated distal DVT with mild symptoms and low extension risk can undergo serial ultrasound for two weeks. Severe symptoms or extension risk favors anticoagulation. Upper-extremity disease requires assessment of catheters, cancer, infection, thoracic outlet anatomy, and future access needs.
Quick check
Submodule
PE Diagnosis and 2026 Clinical Categories
Pulmonary embolism evaluation combines probability, D-dimer, imaging, hemodynamics, symptoms, biomarkers, right-ventricular findings, and a new A through E severity framework.
- PE probability and imaging
- Right-heart and biomarker risk
- Categories A through E
- Home, early-discharge, and inpatient pathways
Home or early-discharge pathway when eligible
Hospitalize and optimize therapy
Escalate monitoring and consider advanced care
Immediate rescue strategy
Use a probability-based diagnostic pathway
Validated low-risk pathways may avoid testing or use D-dimer. Higher probability generally proceeds to imaging. CT pulmonary angiography is common, while ventilation-perfusion imaging can be useful when kidney function, contrast reaction, pregnancy, radiation, chest imaging, or local expertise changes the balance.
Measure physiologic impact
Vital signs, oxygen and ventilatory support, perfusion, lactate, troponin, natriuretic peptides, ECG, and right-ventricular imaging reveal cardiopulmonary stress. Normotension does not guarantee low risk when RV dysfunction or biomarkers are abnormal.
Apply categories A through E
Category A is asymptomatic. Category B is symptomatic with low clinical severity. Category C includes elevated clinical severity score, biomarkers, or RV dysfunction. Category D has incipient cardiopulmonary failure. Category E has cardiopulmonary failure with persistent hypotension. Subcategories add further precision.
Match disposition to category and implementation
Category A can be discharged from the emergency setting, and early discharge is generally recommended for eligible category B patients. Categories C, D, and E require hospitalization. Home treatment also requires medication access, low bleeding risk, support, education, and rapid follow-up.
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Submodule
Initial Treatment and PE Escalation
Prompt anticoagulation prevents propagation, while the 2026 PE category, bleeding, organ function, intervention plan, oral eligibility, and local expertise determine drug and rescue strategy.
- Immediate anticoagulation
- LMWH and UFH selection
- DOAC oral pathways
- Thrombolysis, intervention, surgery, and PERT
Act promptly when diagnosis is established
Match indication and patient eligibility
Reserve for severe PE categories
Coordinate high-risk decisions
Start therapeutic anticoagulation promptly
Once VTE is confirmed, or when probability is sufficiently high and delay is unsafe, begin therapeutic anticoagulation if bleeding risk permits. Obtain baseline hemoglobin, platelets, kidney and liver function, weight, pregnancy status when relevant, and a complete antithrombotic history.
Prefer LMWH when parenteral PE therapy is needed
The 2026 acute PE guideline recommends LMWH over UFH for patients who need initial parenteral anticoagulation. UFH can remain useful when severe kidney impairment, rapid titration or offset, an imminent intervention, or another patient-specific factor makes it preferable.
Prefer a DOAC when eligible
For acute PE patients eligible for oral therapy, DOACs are recommended over vitamin K antagonists unless contraindicated. Apixaban and rivaroxaban begin with intensified oral regimens. Dabigatran and edoxaban require an initial parenteral treatment period. Verify exact product and phase.
Escalate severe PE through a PERT
Systemic thrombolysis, catheter-based thrombolysis, mechanical thrombectomy, or surgical embolectomy is reasonable for category E1 and can be considered for category D1 or D2. Activate a PE response team early, support perfusion, and balance bleeding, anatomy, trajectory, expertise, and delay.
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Submodule
Duration and Special Populations
Initial, primary, and extended treatment phases serve different goals, while provoking factors, recurrence, bleeding, cancer, pregnancy, unusual anatomy, and patient priorities determine duration and regimen.
- Treatment phases
- Reversible and persistent risk
- Cancer-associated VTE
- Pregnancy and individualized populations
Estimate recurrence after stopping
Avoid premature discontinuation
Reassess rather than set and forget
Use population-specific evidence
Name the phase
Initial management begins at diagnosis and covers the early weeks. Primary treatment usually continues for at least three months. Extended therapy continues beyond primary treatment when recurrence prevention remains more valuable than the bleeding and treatment burden.
Connect duration to causal persistence
A VTE provoked by a resolved major reversible factor often has lower recurrence risk after primary treatment. The 2026 PE guideline recommends extended therapy after a first PE without a major reversible factor and after PE with a persistent factor. Reassess the balance over time.
Adapt to cancer
Cancer-associated VTE selection depends on cancer site and activity, GI or GU lesions, systemic therapy, thrombocytopenia, kidney and liver function, interactions, vomiting or absorption, procedures, prognosis, access, and preference. The plan can change with the cancer course.
Coordinate pregnancy and other complex groups
Pregnancy requires maternal-fetal assessment, trimester-aware care, delivery and neuraxial timing, postpartum duration, and lactation planning. Antiphospholipid syndrome, severe organ disease, extreme weight, unusual thrombosis sites, and recurrent VTE also require population-specific evidence rather than a default drug.
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Submodule
Follow-Up, Recovery, and Recurrence Prevention
Recovery requires medication implementation, symptom and function review, bleeding and recurrence surveillance, post-thrombotic care, and structured screening for chronic thromboembolic disease after PE.
- Medication acquisition and adherence
- Bleeding and recurrent VTE
- Post-thrombotic symptoms
- CTEPD surveillance for at least one year
Verify acquisition, adherence, and interactions
Support mobility and individualized rehabilitation
Assess at every visit for at least one year
Update the extended-treatment plan
Close medication gaps
Reconcile the exact product, indication, treatment phase, dose, interval, first outpatient dose, duration, refill access, cost, interactions, missed-dose instructions, and procedure contacts. Use teach-back and verify acquisition before the initial supply runs out.
Monitor bleeding and recurrence
Teach urgent evaluation for hemodynamic symptoms, severe headache or neurologic change, major trauma, black stool, vomiting blood, heavy bleeding, recurrent unilateral swelling, sudden dyspnea, chest pain, syncope, or hemoptysis. Review all antiplatelet and NSAID exposure.
Support venous recovery
Persistent swelling, discomfort, skin change, and venous ulceration can follow DVT. Encourage safe mobility and individualized symptom management. Compression can help selected symptoms but should not be promised as universal prevention of post-thrombotic syndrome.
Screen for chronic thromboembolic disease
Ask about PE-related dyspnea and functional limitation at every visit for at least one year. Persistent symptoms require evaluation for recurrent VTE, anemia, heart or lung disease, deconditioning, and chronic thromboembolic pulmonary disease, with specialist referral when indicated.
Quick check
Module test
Check the connections.
Each attempt draws 10 questions from the complete 100 question bank.
Each attempt draws a fresh set and rearranges the answer choices.
References
Current clinical foundation.
Lecture material was synthesized with the following contemporary guidance. Verify local policy and current guidance before applying clinical information.