Fig. 1.

Biomarkers and variables recorded on ICU admission in patients receiving CPAP. Shaded area denotes normal range. The normal range for C-Reactive Protein (≤ 5 mg/L) is not indicated, FiO₂ fraction of inspired oxygen concentration; PaO₂/FiO₂ ratio of arterial partial pressure to the fraction of inspired oxygen concentration. Shaded area denotes normal range except for PaO₂/FiO₂ where the increasing shades of grey denotes mild, moderate and severe respiratory failure according to the Berlin definition, NT-proBNP N terminal-pro B-type natriuretic peptide