2.1 Study design
All inpatient children under 18 years of age with a admission diagnosis of ELP and a confirmed history of exogenous oily materials aspiration were retrospectively reviewed from June 2012 to December 2021 from the medical records at First Affiliated Hospital of Guangzhou Medical University, a tertiary care, free-standing public hospital. Medical records were retrospectively reviewed by using a standardized form to collect demographic data, clinical manifestations, laboratory test results and radiological findings. All patients with established ELP were evaluated by the senior attending pediatrician at the inpatient units on the basis of signs, symptoms, and laboratory/imaging findings during hospital stay. The exclusion criterion was suspected with a history of or no evidence of exogenous substances inhalation. A total of 17 children patients was included in the final analysis. CT scans of all children found diffuse pulmonary lesion at admission. Supporative measures, such as oxygen therapy, emprical antibiotic therapy, local or systematic corticosteriods use to slow the inflammatory response, were performed in children with clinical symptoms or severe lung damage. The number of bronchoscopic lung lavage was carried out in terms of the severity of clinical symptoms/signs and radiological findings.