Enrolled subjects will have nasal brushings collected at days 1, 3, 7, and 14 of intubation with collection of serum at these same time points. Brushing RNA will be processed by mRNA-Seq for gene expression analysis and compared to previously published serum biomarkers (interleukin-8, advanced glycosylation end-product specific receptor, and angiopoietin-2) to assess correlation and ability to discriminate PARDS endotypes. Changes in gene expression over time will be assessed to define a PARDS recovery gene expression signature, and correlation between bronchial and nasal gene expression will be determined.