Massive Pulmonary Air Embolism To Air is Humoral

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Massive Pulmonary (Air) EmbolismTo Air is
Humoral

• Greg Stratmann

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Definition

• Varies
• PE causing systemic hypotension or shock
• gt 100 ml of air
• gt 50 of pulmonary vasculature occluded

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Incidence / Natural History of thromboembolic
PE

• 40- 80 of PEs are massive
• Up to 30 of patients die
• 75 of those who die do so in 1st hr
• Of those who live 40 will have a
  recurrence within 2 - 4 weeks without
  therapy

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Intraoperative presentation

• Sudden ? EtCO2
• ? PaO2/FiO2
• ? Aa-gradient
• Tachycardia (42)
• Anterior T-inversions (82), A-fib, ST
• ? BP, ? PaCO2, mixed acidosis, arrest

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Immediate Management

• CPR, flood field
• 100 O2, Epi or Norepi, ABG, TEE
• Streptokinase 1,500,000 U iv push if clot
  visible
• Pulmonary vasodilators

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Mechanical obstruction
Dead space
PAP
shunt
RV-afterload
Vasoconstriction
Bronchoconstriction
RV dilation/dysfunction
RV O2 supply/demand
Hypoventilation
Pulmonary embolism
RV-output septal shift
Coronary perfusion
Hypoxia
LV-preload
cardiac-output
FRC - CC
Neural
Capillary leak
Platelets
Neutrophils
Endothelium
Activation
Humoral
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Shunt ?CO ? PaO2

• Insert the two figures from Benumofs
  textbook

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Effect of pressors / inotropes on PVR depends
on PAP
Anesth Analg 2003, 97 341-54
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Effect of pressors / inotropes on PVR depends
on PAP
Anesth Analg 2003, 97 341-54
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Effect of pressors / inotropes on PVR depends
on PAP
Anesth Analg 2003, 97 341-54
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Effect of pressors / inotropes on PVR depends
on PAP
Anesth Analg 2003, 97 341-54
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Other pulmonary vasodilators

• Inhaled PGI-2 (c-AMP)
• Inhaled NO (c-GMP)
• Sildenafil (c-GMP)
• Nebulized nitrite (is converted to NO)

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Secondary management

• Aimed at prevention of recurrence
• Anticoagulation 8 recur within 1 mo
• IVC filter 1 recur within 1 month but risk
  of thrombosis / PE from filter itself
  thereafter.

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Paradoxical gas embolism Transpulmonary
passage of air

• Pulmonary filter can be exhausted by
  0.3ml/kg/min or 20 ml total (dogs)
• ? PAP ? intrapulmonary AV-shunts ? passage of
  bubbles as big as 0.5 mm
• Aminophylline (and other inotropes / pulmonary
  vasodilators) completely abolishes pulmonary
  filter function ? systemic gas embolizes
  freely

Anesth Analg 2004 ---------------
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Systemic gas embolismTreatment

• Right-side-down, Trendelenburg may work (does
  work in dogs)
• Air will rise to right coronary ostium
• ? ABP may push air through coronary
  circulation (unproven)
• Hyperbaric chamber

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Summary

• Presentation, natural history, immediate,
  secondary management of massive PE
• Treatment goals ? RCA perfusion pressure, ?
  PVR, ? embolic burden, ? PaO2
• Systemic air embolism
• Questions / Comments?
• Thank you!