[ report of three cases with negative pressure pulmonary edema]

ABSTRACT

Negative pressure pulmonary edema [NPPE] is a relatively rare event complicating GA which occurs following airway obstruction despite the patient's effective attempt to inspire and ultimately high negative pressure inside airways. This results in fluid transudation into the interstitial tissue and alveoles. The prevalence of NPPE is less than 0.1%. This article aims to give more information about NPPE as a leading cause of pulmonary edema following airway obstruction after GA. Also discussed in this article are diagnosis and how to differentiate it from aspiration pneumonia as well as the appropriate treatment. Three patients were evaluated. The mild form presented with hypoxia who had findings at the auscultation of lungs; the severe form manfiested with symptoms and signs characteristic of pulmonary edema. Airway obstruction and laryngospasm was due to the irritation secondary to the tracheal tube in the first case, post-tonsillectomy bleeding in the second case and increased secretions in the third one. Patients were treated with oxygen, mechanical ventilation, steroids, diuretics and aminophylline. They experienced no complications thereafter. The most important point in diagnosing NPPE is to hold it in mind when encountering such a problem. NPPE is seen more in healthy athletic young patients. Care must be given to the patients at risk. Rapid relief of upper airway obstruction, restoring of patient's ventilation, FiO2 increment and the application of CPAP- PEEP are the cornerstones of treatment