Pulmonary embolism

Background

• Suspect in pt w/ dyspnea, tachypnea, or pleuritic pain
• Only 40% of ambulatory ED pts w/ PE have concomitant DVT

Diagnosis

Wells

Wells Criteria

1. Symptoms of DVT - 3pts
2. No alternative diagnosis better explains the illness - 3pts
3. HR > 100 - 1.5 pts
4. Immobilization within prior 4wks - 1.5pts
5. Prior history of DVT or PE - 1.5pts
6. Active malignancy - 1pt
7. Hemoptysis - 1pt

Wells Score

1. 0-1 point: Low probability (3.4%)
2. 2-6 points: Moderate probability (27.8%)
3. 7-12 points: High probability (78.4%)

Workup by Probability

Low Probability

• If low prob and PERC Rule neg then d/c
• If low prob and PERC Rule pos then d-dimer

Moderate Probability

• Obtain d-dimer

High Probability

• Consider anticoagulation before imaging!
• CTPA if GFR >60
• V/Q if GFR <60

Treatment

Anticoagulation

• Indicated for all patients with confirmed PE or high clinical suspicion
• Treatment options:
  • LMWH SC
    • 1st line for most hemodynamically stable pts
  • UFH
    • Consider in pts w/:
      • Persistent hypotension
      • Increased risk of bleeding
      • Recent sx/trauma
      • Renal failure (GFR <30)
      • Morbid obesity or anasarca (poor sc absorption)
      • Thrombolysis is being considered

Thrombolysis

Indications

• Consider for pt with confirmed PE and hemodynamic instability
  • For example:
    • Cardiac arrest
    • Hypotension
    • Severe hypoxemia (SpO2<90% despite O2)
    • Elevated troponin

Instructions

1. Review contraindications
2. Discontinue heparin during infusion
3. tPA 100mg over 2hr OR 0.6 mg/kg over 2min
4. After infusion complete measure PTT
   1. Once value is <2x upper limit restart anticoagulation

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

PE in Pregnancy

• Heparin and Enoxaparin are safe (coumadin is not)
• Consider utz as initial test
• CT (with sheild) vs. V/Q is roughly equilivalent radiation exposure
• D-Dimer can still be used with following limits:
  • 1st trimester: <750 (+50% increase from normal lab threshold)
  • 2nd trimester: <1000 (+100% from normal)
  • 3rd trimester: <1250 (+150% from normal)

Source

Tintinalli

UpToDate