Extracorporeal membrane oxygenation in refractory negative pressure pulmonary edema: A case report and literature review

Background Negative pressure pulmonary edema (NPPE) is a rare, life-threatening complication of acute upper airway obstruction, typically managed with supportive care including positive pressure ventilation and diuresis. Although most cases are resolved via conventional treatment, patients with refractory NPPE developing into severe acute respiratory distress syndrome and experiencing concomitant hypovolemic shock may require advanced interventions such as venovenous extracorporeal membrane oxygenation (VV-ECMO).Case presentation A 71-year-old obese male with hypertension, coronary heart disease, and type 2 diabetes, but preserved cardiac function, presented with acute respiratory failure following nocturnal episodes of chest tightness, dyspnea, and cough. Initial assessment excluded cardiogenic, infectious, or thromboembolic causes. Chest CT revealed bilateral ground-glass opacities, septal thickening, and pleural effusions. Despite maximal conventional therapy including high-flow nasal oxygen, invasive mechanical ventilation, prone positioning, and CRRT for anuria, he developed refractory hypoxemia with hemodynamic instability 19 h post-ICU admission. VV-ECMO was initiated as salvage therapy, and ECMO support enabled lung-protective ventilation. Serial imaging showed a gradual improvement over 8 days. ECMO was discontinued on day 8, and mechanical ventilation was weaned by day 10. Subsequent polysomnography confirmed mild obstructive sleep apnea (OSA), identified as the likely trigger. The patient was discharged home on day 20 with complete resolution on follow-up CT and no relapse at 3 months.Conclusions This case demonstrated that VV-ECMO support is a feasible approach in patients with life-threatening NPPE. NPPE should be considered in the differential diagnosis of acute pulmonary edema, particularly in patients with risk factors such as OSA.