NPPB and acute respiratory distress syndrome: In a study of 81 ICU patients, Karmpaliotis and colleagues reported a median BNP level in patients with cardiogenic pulmonary oedema of 1260 pg/ml (interquartile range (IQR), 540 to 2020 pg/ml) vs. 325 pg/ml (IQR, 82 to 767 pg/ml) in those with ALI/ARDS, and Levitt and colleagues reported mean values in these groups of 747 ± 476 pg/ml and 496 ± 439 pg/ml, respectively, in a study of 54 critically ill patients [23,24].