Mechanical Pulmonary Edema


Acute Upper Airway Obstruction-Associated Pulmonary Edema (Negative Pressure Pulmonary Edema) (see Obstructive Lung Disease)

  • Bilateral Vocal Fold Immobility (BVFI) (see Bilateral Vocal Fold Immobility)
  • Other Upper Airway Disease
    • Infection
    • Neurologic
    • Miscellaneous
      • Anaphylaxis (see Anaphylaxis)
      • Laryngeal Mask Airway (LMA): improper placement may result in upper airway obstruction
      • Post-Relief of Upper Airway Obstruction [MEDLINE]
      • Strangulation/Near Hanging (see Near Hanging): non-judicial hangings (where drop is <6.5-7.5 ft) do not fracture dens off, they result in death most commonly due to pulmonary complications
      • Thermal Injury/Burns of Upper Airway (see Smoke Inhalation): thermal injury is usually supraglottic (typically, laryngeal injury): may be acute
      • Upper Airway Foreign Body (see Foreign Body)
      • Upper Airway Tumor
      • Urticaria-Angioedema Syndrome (see Urticaria-Angioedema): typically acute

Acute Tracheal Obstruction-Associated Pulmonary Edema (Negative Pressure Pulmonary Edema)

  • Tracheal Foreign Body (see Foreign Body)
  • Tracheal Stent Placement [MEDLINE]: stent obstruction may result in airway obstruction
  • Tracheal Tumor

Overdistention Pulmonary Edema

  • Occurs with use of excessively large tidal volumes on mechanical ventilation

Post-Pneumonectomy Pulmonary Edema

  • Occurs post-pneumonectomy (especially with use of excessively large tidal volumes on mechanical ventilation)

Re-Expansion Pulmonary Edema

  • Occurs after rapid evacuation of air or fluid from pleural space

Clinical Presentations

Upper Airway Obstruction-Associated Pulmonary Edema

  • Physiology: generation of large neagtive airway pressures against an obstructed upper airway
  • Clinical

Overdistention Pulmonary Edema

  • Physiology: mechanical ventilation with excessive tidal volumes
  • Clinical
    • Acute Lung Injury-ARDS Due to Overdistention (see Acute Lung Injury-ARDS, [[Acute Lung Injury-ARDS]]): typically unilateral in post-pneumonectomy cases

Post-Pneumonectomy Pulmonary Edema

  • Physiology: mechanical ventilation with excessive tidal volume following pneumonectomy
  • Clinical:

Re-Expansion Pulmonary Edema

  • Risk Factors Associated with Re-Expansion Pulmonary Edema
    • Young Age
    • Extent of Lung Collapse: drainage of larger amount of fluid increases risk
      • ATS Recommendation: remove <1.5 L of fluid at one time (provided that patient does not have severe cough, dyspnea, or chest pain)
      • Removal of more fluid may be safe if patient has contralateral shift and is tolerating the procedure well
    • Collapse for >3 Days: possible risk factor
    • Rapid Drainage
  • Factors Not Associated with Increased Risk of Re-Expansion Pulmonary Edema
    • Use of Intrapleural Suction
  • Physiology
    • Mechanical Injury to Lung
    • Oxygen Free Radical Generation
    • Increased Vascular Permeability
  • Diagnosis
    • Pleural Manometry
      • Large negative pleural pressure during thoracentesis may indicate the presence of a trapped lung
      • It is safe to remove fluid with pressure no greater than -20 cm H2O
      • However, rapid drainage may increase risk of reexpansion pulmonary edema, even without a fall in pressure or less than -20 cm H2O
    • CXR
      • Typically unilateral pulmonary edema on side of re-expansion
      • However, in some cases, edema may also involve the contralateral side
  • Clinical
    • Dyspnea
  • Treatment
    • Supportive care