Postobstructive pulmonary edema (POPE) also known as negative pressure pulmonary edema (NPPE) is an underdiagnosed entity in clinical practice and can lead to life-threatening hypoxemia. A 64-year-old male patient’s perioperative course was complicated by acute hypoxemic respiratory failure, after extubation following general anesthesia, following the excision of the right vocal cord papilloma. His chest X-ray showed features of pulmonary edema, EKG showed dynamic ST-T changes in the lateral leads, and echocardiography showed evidence of regional motion abnormalities. His coronaries were normal on the immediate angiogram. He was managed with lung protective mechanical ventilation strategy, diuretics, and fluid restriction. His respiratory status improved, and trachea was extubated after 10 hours of intensive care unit (ICU) stay. The case illustrates the various differentials of immediate postoperative flash pulmonary edema and ensuing appropriate management strategy.
Negative pressure pulmonary edema (NPPE), a form of noncardiogenic pulmonary edema, results from marked inspiratory effort against a closed airway [
A 64-year-old male underwent surgical excision of a vocal cord papilloma, under general anesthesia, and received approximately one liter of crystalloid during the procedure. His medical history was significant for compensated liver cirrhosis secondary to Hepatitis C infection, hepatocellular carcinoma, and peripheral neuropathy. His perioperative course was complicated by acute hypoxemic respiratory failure immediately following extubation. He was reintubated in the operating room, given intravenous furosemide, and transferred to the ICU for further care.
Upon ICU arrival, he was sedated with propofol and mechanically ventilated on volume control mode, with tidal volume 6ml/kg, PEEP 7cm of H2O, and FiO2 70%. Physical exam revealed bilateral lung crepitus and normal heart sounds, with pink frothy sputum in the endotracheal tube. His chest radiograph (Figure
Chest X-ray showing features of pulmonary edema.
NPPE was suspected in this patient due to the absence of preexisting heart disease, negative cardiac workup, and recent papilloma resection. He was managed with protective mechanical ventilator support, diuretics, and fluid restriction. His respiratory status improved with resolution of the pulmonary edema (Figure
Postextubation chest x- ray showing resolution of the edema.
This case illustrates a common clinical dilemma and frequently missed differentials of pulmonary edema in the immediate perioperative period. NPPE is estimated to occur in 1 of every 1000 postanesthesia patients, and laryngospasm is the culprit in the majority of the cases involving adults [
The pathogenesis of NPPE is mainly attributed to the generation of marked negative intrapleural pressure [
Typical signs and symptoms of NPPE include respiratory distress, hypoxia, cyanosis, frothy pink sputum, and hemoptysis [
NPPE itself can promote cardiac depression in consequence to hypoxia and the subsequent acidotic state, which may make the diagnostic workup misleading [
The treatment of NPPE includes careful monitoring, maintenance of a patent airway, oxygen supplementation, and positive end-expiratory pressure via endotracheal intubation or noninvasive ventilation [
This work was previously presented as an abstract in SCCM 2018.
As the primary and corresponding author of this paper, I wish to declare on behalf of all the authors of the article that our original work and the report have not been published previously in whole or part, except in abstract form in
All authors were involved in the care of the patient and planning of the manuscript. The final manuscript has been seen and approved by the authors.