Mechanical Pulmonary Edema

Etiology

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)
- Cricoarytenoid Arthritis (see Cricoarytenoid Arthritis)
- Inflammation of Larynx
- Laryngospasm (see Laryngospasm)
  - Aspiration Event (see Aspiration Pneumonia)
  - Gastroesophageal Reflux Disease (GERD) (see Gastroesophageal Reflux Disease)
  - Chlorine Gas (see Chlorine)
  - General Anesthesia (see General Anesthesia)
  - Post-Extubation
  - Organophosphates (see Organophosphates): nicotinic effects cause laryngospasm
- Neurologic Disease/Dysfunction Involving the Vocal Folds
  - Dystonic Reaction of Pharyngeal+Laryngeal Muscles (see Dystonic Reaction of Pharyngeal+Laryngeal Muscles): typically acute
  - Idiopathic Bilateral Vocal Cord Paralysis
  - Vocal Cord Dysfunction (see Vocal Cord Dysfunction): typically acute
- Developmental Abnormality or Neoplasm the Involving Vocal Folds
- Intubation Injury to Vocal Folds
- Mechanical/Iatrogenic Injury to Vocal Folds
- Surgical Injury to Vocal Folds
Other Upper Airway Disease
- Infection
  - Epiglottitis (see Epiglottitis)
- Neurologic
  - Parkinson’s Disease (see Parkinson’s Disease): may be acute (particularly in post-op setting)
- 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
- Acute Lung Injury-ARDS (see Acute Lung Injury-ARDS)

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

Treatment

Acute Lung Injury-ARDS (see Acute Lung Injury-ARDS): supportive care

References

Pulmonary edema following relief of acute upper airway obstruction. Ann Otol Rhinol Laryngol. 1980 Mar-Apr;89(2 Pt 1):124-8 [MEDLINE]
Negative pressure pulmonary edema during tracheal Dumon stent implantation. J Bronchology Interv Pulmonol. 2012 Oct;19(4):345-8 [MEDLINE]
Negative Pressure Pulmonary Edema. Am J Med Sci. 2012 Oct 30 [MEDLINE]
Negative pressure pulmonary oedema following use of ProSeal LMA. Indian J Anaesth. 2013 Mar;57(2):188-90. doi: 10.4103/0019-5049.111854 [MEDLINE]