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

1. Pt w/ massive PE
2. Pt w/ submassive PE w/ e/o adverse prognosis + low risk of bleeding complications
   1. Hemodynamic instability
   2. Worsening resp insufficiency
   3. Severe RV dysfunction
   4. Major myocardial necrosis

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)

Algorithm

1. Clinical features suggestive of PE
   1. Bilateral LE Ultrasound
      1. Positive-->LMWH
      2. Negative-->CTA

Source

Tintinalli

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