Emergency Department Management Of Pulmonary Embolism

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Emergency Department Management Of Pulmonary
Embolism

• Emergency Medicine Clinics Of North America
• Vol.19, Nov,2001

91-09-14 ??? ???
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Frameworks

• 1. Introductions
• 2. Natural history of pulmonary embolism
• 3. Risk stratification
• 4. Goals of therapy
• 5. Unfractionated heparin (UFH)
• 6. LMWH
• 7. Thrombolytic therapy
• 8. IVC filter
• 9. Transvenous catheter embolectomy
• 10.Surgical embolectomy

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Introduction (1)

• Greatest threat to patient with PE is failure to
  be diagnosed.
• Correct decision regarding therapy can be made
  only after a correct diagnosis

4
Introduction (2)

• The physician must know
• 1. Natural course of events without
  treatment
• 2. How are these events improved by therapy
• 3. To which extent are these improvements
  mitigatated by adverse effects of this therapy

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Introduction (3)

• 1960s, anticoagulant therapy ? mainstay for PE
• 1970s, thrombolytic therapy began to use in PE (
  esp. presenting in shock)
• 1990s, focused on risk stratification, extension
  of indication for thrombolytic therapy, use of
  LMWH, newer mechanical methods of therapy, and
  surgical embolectomy.

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Introduction (4)

• The differential diagnosis is important since the
  treatment for PE is contraindicated in some of
  these conditions, such as pericarditis and aortic
  dissection.

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Natural history of pulmonary embolism

• Clots fron veins in legs, pelvis, and arm
  ?embolize to the lung?pulmonary vascular
  obstruction release vasoactive agents? increase
  pulmonary resistance?right ventricular
  dysfunction(hypertension, ischemia, and
  hypokinesis)? inadequate C.O. and death

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Natural history of pulmonary embolism (2)

• Approximately 10 patients die within the first
  hour of PE ( diagnosis and therapy unfeasible)
• Survive within first hours and remain untreated,
  approximately 30 will die of PE, usually from
  recurrent embolism and right heart failure.
• changes in position of the clots or endogenous
  fibrinolysis ? favorable outcome?less mortality

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Risk Stratification

• Treatment must be tailored to the individual
  patient, a one-size-fits-all policy does not
  make pathophysiologic sense.
• Prognostic factors
• 1. Embolic load
• 2. Underlying cardiopulmonary reserve
• 3. Status of the right ventricle

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Risk Stratification (2)

• In a multicenter study (2500 Pt of PE)
• RV dysfunction is an independent predictor of
  mortality.

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Goals of therapy

• 1. Immediate goals of therapy
• ?normalize pulm. vascular resistance
• ? reduce recurrent embolism
• 2. long term goals
• ? reduce the frequency of chronic
  pulmonary hypertension

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Unfractionated Heparin (NFH)

• For decades, unfractionated heparin ? cornerstone
  of therapy for PE
• Unless contraindicated, heparin is used in
  high-likelihood patients
• Heparin? accelerating the action of
• AT-III? prevent further clot formation

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Unfractionated Heparin (2)

• Several points bear emphasis
• 1. UFH, IV customarily, can be SC
• 2. Adequate initial anticoagulation is
  important to reduce the likelihood of recurrent
  venous thromboembolism

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Unfractionated Heparin(3)

• Recommended dose of heparin
• Initial 80 IU/kg, iv, bolus
• Maintain 18 IU/kg/hr, infusion
• ( P/s once fully heparinization, a first dose of
  warfarin can be administered )

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Low molecular weight heparin

• Multiple studies have shown that LMWH are equal
  in efficacy to UFH in the treatment of venous
  thromboembolic disease
• Enoxaparin and tinzaparin FDA approved on Nov,
  2000

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Low molecular weight heparin(2)

• Venous thromboembolic disease? primary
  manifestation is DVT, with or without PE, can be
  treated as out-patient ( carefully selected
  patient hemodynamic stable and normal RV
  function)
• If primary manifestation is PE? out-patient
  therapy is not recommended
• Admitted Pt with PE ( LMWH is used)
• 1.shorten the length of stay
• 2.not costly than using UFH

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Thrombolytic Therapy

• Advantages of thrombolytic therapy
• 1. Rapid clots lysis ? reduce pulm.
• hypertension
• 2. Reduce recurrent rate ? reduce
• mortality rate

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Thrombolytic Therapy (2)

• Risk stratification and individualization of
  therapy are important

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Thrombolytic Therapy (3)

• Bleeding risk 13
• Bleeding complication
• major bleeding ( 510 )
• ICH ( 12 )

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Inferior Vena Cava Interruption

• Placement of IVC filter increasing? long term
  outcome (?)
• Indications
• 1. Contraindication to anticoagulant
• 2. Failure of anticoagulation

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Transvenous Catheter Embolectomy

• In whom thrombolysis fails or is contraindicated
• Very ill and require a rapid approach

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Surgical Embolectomy

• Indications
• 1.massive PE with shock and too ill for
• thrombolytic therapy
• 2. Contraindication to or failure of
• thrombolytic therapy
• Mortality still high 2040
• Worse in those pre-op cardiac arrest

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Summary

• 1. Chest pain, dyspnea, syncope, oxygen
  desaturation, or unexplained hypotension
  ?consider the diagnosis of PE evaluate
  rationally
• Develop algorithms ?both diagnostics
  therapeutics flow smoothly and rapidly
• Concept of risk stratification and
  individualization of therapy is important.