Differential Diagnosis of Negative Pressure Pulmonary Edema During COVID-19 Pandemic

Negative pressure pulmonary edema (NPPE) is a form of noncardiogenic pulmonary edema that typically occurs in response to an upper airway obstruction, where patients generate high negative intrathoracic pressures, leading to a pulmonary edema especially in the postoperative period. Here, we report a case of NPPE following general anesthesia that can easily be misdiagnosed as COVID-19 both radiologically and clinically during this pandemic. Twenty-year-old male was presented with sudden onset respiratory distress, tachypnea, and cyanosis just after the rhinoplasty surgery under general anesthesia. Chest radiography and thoracic computed tomography scans revealed the bilateral patchy alveolar opacities with decreased vascular clarity that looks similar to COVID-19 radiology. Negative pressure pulmonary edema is a sudden onset and life-threatening complication following general anesthesia particularly after head and neck surgery in young healthy individuals. It is a clinical condition that cannot be diagnosed unless it comes to mind. While both NPPE and COVID-19 cause hypoxemia and respiratory distress, as well as ground-glass opacities in the chest computed tomography, those opacities in NPPE appear mostly in central areas, whereas those opacities are mostly seen in peripheral areas in COVID-19. Furthermore, while NPPE cause decreased vascular clarity, COVID-19 causes vascular dilatations in the areas of opacities. Those differences together with medical history of the patient is crucial to differentiate these 2 similar identities. Negative pressure pulmonary edema requires an immediate recognition and intervention, therefore, we would like to raise the awareness of clinicians for such condition to avoid possible mistakes during the pandemic situation.