Negative pressure pulmonary edema
Revision as of 05:16, 25 July 2016 by Neil.m.young (talk | contribs) (Text replacement - "==Diagnosis==" to "==Evaluation==")
Background
- Also known as post-obstructive pulmonary edema
- Forced inspiration against obstructed airway causes large negative intrathoracic pressure, leading to pulmonary edema[1]
- Mostly due to postoperative laryngospasm, sudden drops in PEEP (high PEEP to manual BVM), trauma such as hanging, strangulation, foreign bodies, etc.
Clinical Features
- Hypoxemia (may be sudden and large - beware "fake" or "not real" SpO2), stridor, retractions, accessory muscle use, crackles/wheezes
- CXR shows diffuse interstitial and alveolar infiltrates
- CT shows preferential central/nondependent distribution of edema (as opposed to other forms of pulmonary edema)
Differential Diagnosis
Pulmonary Edema Types
Pulmonary capillary wedge pressure <18 mmHg differentiates noncardiogenic from cardiogenic pulmonary edema[2]
- Cardiogenic pulmonary edema
- Noncardiogenic pulmonary edema
- Negative pressure pulmonary edema
- Upper airway obstruction
- Reexpansion pulmonary edema
- Strangulation
- Neurogenic causes
- Iatrogenic fluid overload
- Multiple blood transfusions
- IV fluid
- Inhalation injury
- Pulmonary contusion
- Aspiration pneumonia and pneumonitis
- Other
- High altitude pulmonary edema
- Hypertensive emergency
- ARDS
- Flash pulmonary edema
- Immersion pulmonary edema
- Hantavirus pulmonary syndrome
- Missed dialysis in kidney failure
- Naloxone reversal
- Negative pressure pulmonary edema
Evaluation
Management
- Relieve airway obstruction
- Vent with generous PEEP and diuretics