Pulmonary embolism

DIAGNOSIS

• What is the clinical probability of PE?

• Pulmonary Embolism Wells Score

1. Symptoms of DVT (3 points)
2. No alternative diagnosis better explains the illness (3 points)
3. Pulse > 100 (1.5 points)
4. Immobilization (>= 3 days) or surgery in the previous four weeks (1.5 points)
5. Prior history of DVT or pulmonary embolism (1.5 points)
6. Presence of hemoptysis (1 point)
7. Presence of malignancy (1 point)

• Wells Criteria:

1. 0-1 point: Low probability
2. 2-6 points: Moderate probability
3. 7-12 points: High probability

• Modified Wells criteria:

1. 0-4 points: PE unlikely
2. 4-12 points: PE likely

• Do I need imaging?

1. PE unlikely + negative D-dimer = no imaging
2. PE unlikely + positive D-dimer = imaging required
3. PE likely = imaging required (even if D-dimer is negative)

TREATMENT

• Oxygen
• IVF
  • Give cautiously as incr. RV wall stress may lead to ischemia
• Pressors
  • Nnorepi, epi, or dopa if 1L NS fails to raise BP
• Anticoagulation
  • Indicated for all patients with confirmed PE or high clinical suspicion
  • Risk-benefit: (untreated PE = 30% mortality, major bleeding <3%)
  • Treatment options:
    • SC LMWH - First-line agent for most hemodynamically stable patients
    • IV/SC UFH - Consider only in pts with:
      • Persistent hypotension
      • Increased risk of bleeding
      • Recent sx/trauma
      • Age > 70yrs
      • Concurrent ASA use
      • Renal failure
      • Morbid obesity or anasarca
      • Thrombolysis is being considered
      • Cr clearance < 30ml/min
• Thrombolysis
  • Consider for patients with confirmed PE and shock
  • Can also consider, although controversial, for:
    • Severe hypoxemia
    • Massive embolic burden on CT
    • RV dysfunction
    • Free-floating RA or RV thrombus
    • Patent foramen ovale
  • Absolute contraindications:
    • History of hemorrhagic stroke
    • Active intracranial neoplasm
    • Recent (<2 months) intracranial sx or trauma
    • Active or recent internal bleeding in prior 6 months
  • Relative contraindications:
    • Bleeding diathesis
    • Uncontrolled severe HTN (sys BP >200 or dia BP >110)
    • Nonhemorrhagic stroke within prior 2 months
    • Surgery within the previous 10 days
    • Plt < 100K
    • Associated with intracranial hemorrhage in 3% of patients
    • Mortality benefit has never been shown
    • Consider embolectomy if thrombolytics are contraindicated

• PROB DETERMINATION (BY SX)

1. Atypical
   1. Alt diag as/more likely-->low
   2. Alt diag less likely
      1. No RF --> low
      2. +RF --> intrmte
2. Typical
   1. Alt diag as/more likely
      1. No RF --> low
      2. +RF --> mod
   2. Alt diag less likely
      1. No RF --> mod
      2. +RF --> high
3. Severe
   1. Alt diag as/more likely->mod
   2. Alt diag less likely --> high

• PROBABILITY --> W/O

1. Low
   1. No sx DVT --> d-dimer
   2. Neg --> R/O
   3. Pos --> CT
   4. sx DVT --> US
      1. neg --> go to I.1
      2. pos --> R/I
2. Mod/high
   1. no sx DVT --> spiral CT
   2. sx DVT --> US
      1. neg --> go to II.1
      2. pos --> R/I

RISK FACTORS

1. Prior DVT/PE (or FHx >2 people)
2. CA (within 6mo)
3. Paralyisis
4. Bed rest (3dys in last mo)
5. Plaster imob (<12wk)
6. Surg (<12wk)
7. OB deivery (<12wk)

SEVERE (DEFINITION)

1. Syncope
2. BP <90 with HR >100
3. Requires O2
4. New onet R heart failue

TYPICAL (DEFINITION)

1. (>=2 of A plus >=1 of B)
   1. A
      1. dyspnea
      2. pleuritic CP
      3. hemoptysis
      4. rub
      5. PaO2 <92%
   2. B
      1. HR >90
      2. low grade fever (<101)
      3. leg sx
      4. CXR c/w PE

• Does not apply to pregnant women*

Source

Tintinalli UpToDate