Choi JY, et al. - By performing this retrospective review, researchers examined the link between a combination of two markers, peripheral and bronchoalveolar lavage (BAL) eosinophil percentage (BEP), and oxygen demand among patients suffering from acute eosinophilic pneumonia (AEP). The data for patients managed for AEP at the Armed Forces Capital Hospital between May 2012 and May 2017 were analyzed. There were 338 patients in total, with a mean age of 20.4 ± 1.4 years, and 99.7% were male. In correlation analyses, the link of both the PaO₂ (arterial oxygen tension)/FiO₂ (inspiratory oxygen fraction) ratio and duration of oxygen supply with BEP was shown. A cut-off level of 41.5% was suggested in ROC curve analyses. In AEP patients, favourable outcomes were reported in relation to both peripheral and BAL eosinophilia.