Abstract
Background and objectives:
Negative pressure pulmonary edema occurs by increased intrathoracic negative pressure following inspiration against obstructed upper airway. The pressure generated is transmitted to the pulmonary capillaries and exceeds the pressure of hydrostatic equilibrium, causing fluid extravasation into the pulmonary parenchyma and alveoli. In anesthesiology, common situations such as laryngospasm and upper airway obstruction can trigger this complication, which presents considerable morbidity and requires immediate diagnosis and propaedeutics. Upper airway patency, noninvasive ventilation with positive pressure, supplemental oxygen and, if necessary, reintubation with mechanical ventilation are the basis of therapy.
Case report:
Case 1: Male, 52 years old, undergoing appendectomy under general anesthesia with orotracheal intubation, non-depolarizing neuromuscular blocker, reversed with anticholinesterase, presented with laryngospasm after extubation, followed by pulmonary edema. Case 2: Female, 23 years old, undergoing breast reduction under general anesthesia with oro-tracheal intubation, non-depolarizing neuromuscular blocker, reversed with anticholinesterase,presented with inspiration against closed glottis after extubation, was treated with non-invasiveventilation with positive pressure; after 1 hour, she had pulmonary edema. Case 3: Male, 44 yearsold, undergoing ureterolithotripsy under general anesthesia, without neuromuscular blocker,presented with laryngospasm after laryngeal mask removal evolving with pulmonary edema. Case 4: Male, 7 years old, undergoing crude fracture reduction under general anesthesia withorotracheal intubation, non-depolarizing neuromuscular blocker, presented with laryngospasmreversed with non-invasive ventilation with positive pressure after extubation, followed bypulmonary edema.
Conclusions:
The anesthesiologists should prevent the patient from perform a forced inspirationagainst closed glottis, in addition to being able to recognize and treat cases of negative pressurepulmonary edema.
KEYWORDS
Pulmonary edema; Negative pressure pulmonary edema; Negative pressure; General anesthesia; Airway obstruction