Negative-Pressure Pulmonary Edema: A Perioperative Emergency.

Negative-pressure pulmonary edema (NPPE) is a potentially fatal perioperative condition that requires increased awareness. This narrative review highlights the underrecognized aspects of the condition and analyzes the risk factors, diagnosis, management, and prevention of NPPE in the current literature. NPPE most frequently develops in the post-extubation period. It is a non-cardiogenic and non-fluid-overload pulmonary edema that occurs due to the generation of high negative pressure against a closed glottis, hence also termed obstructive pulmonary edema. NPPE is potentially lethal and requires intensive care therapy. Risk factors for developing NPPE include young age, male sex, and upper airway surgery or obstruction. Clinical manifestations include pink frothy sputum and respiratory distress. Chest X-ray and ultrasound reveal diffuse infiltrates and increased B-lines, respectively. NPPE should be differentiated from cardiogenic pulmonary edema, tension pneumothorax, aspiration pneumonia, and fluid overload by history and monitoring. Milder cases of NPPE improve with oxygen therapy and the use of non-invasive ventilation to maintain airway patency. Severe NPPE cases require intubation and invasive ventilation with positive end-expiratory pressure. β-agonist therapy may help by accelerating alveolar fluid clearance. Severe cases of NPPE with persistent hypoxia may require extracorporeal membrane oxygenation support. Preventive measures include suctioning of endotracheal secretions before extubation, limiting the number of laryngoscopy attempts, considering deep or awake extubation, and the use of lidocaine.