Pulmonary embolism

DIAGNOSIS

What is the clinical probability of PE?

Pulmonary Embolism Wells Score

- Symptoms of DVT (3 points)

- No alternative diagnosis better explains the illness (3 points)

- Pulse > 100 (1.5 points)

- Immobilization (>= 3 days) or surgery in the previous four weeks (1.5 points)

- Prior history of DVT or pulmonary embolism (1.5 points)

- Presence of hemoptysis (1 point)

- Presence of malignancy (1 point)

Wells Criteria:

0-1 point: Low probability

2-6 points: Moderate probability

7-12 points: High probability

Modified Wells criteria:

0-4 points: PE unlikely

4-12 points: PE likely

Do I need imaging?

PE unlikely + negative D-dimer = no imaging

PE unlikely + positive D-dimer = imaging required

PE likely = imaging required (even if D-dimer is negative)

TREATMENT

• 1. Hemodynamic support as needed
• Oxygen
• IVF (give cautiously as incr. RV wall stress may lead to ischemia)
• Pressors (norepi, epi, or dopa if 1L NS fails to raise BP)
• 2. 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
• 3. 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

    A. Alt diag as/more likely-->low

    B. Alt diag less likely

         i. No RF --> low

         ii. +RF --> intrmte

2) Typical

    A. Alt diag as/more likely

         i. No RF --> low

         ii. +RF --> mod

    B. Alt diag less likely

         i. No RF --> mod

         ii. +RF --> high

3) Severe

    A. Alt diag as/more likely->mod

    B. Alt diag less likely --> high

PROBABILITY --> W/O

I. Low

    1) No sx DVT --> d-dimer

         A. neg --> R/O

         B. pos --> spiral CT

    2) sx DVT --> US

         A. neg --> go to I.1

         B. pos --> R/I

II. Mod/high

    1) no sx DVT --> spiral CT

    2) sx DVT --> US

         A. neg --> go to II.1

         B. 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)

(>=2 of A plus >=1 of B)

A

    1. dyspnea

    2. pleuritic CP

    3. hemoptysis

    4. rub

    5. PaO2 <92%

B

    1. HR >90

    2. low grade fever (<101)

    3. leg sx

    4. CXR c/w PE

• Does not apply to pregnant women*

S1Q3T3

Source

UpToDate

2/8/06 DONALDSON (from 'the board')