Investigation of informative value of NO metabolite measurement in the exhaled breath condensate (EBC) has been performed. NO metabolites were considered as a biochemical marker for detection and monitoring of course of the acute respiratory distress syndrome (ARDS) in newborns. Measurement of NO metabolites in EBC was performed using spectrophotometry with Grace`s reagent in 80 newborns with different stages of ARDS. Two-fold increase in NO metabolite concentration was found in early stage ARDS (the acute lung injury syndrome) and 3- to 4-fold increase was found in advanced ARDS. In the terminal stage of ARDS, NO synthesis decreased to the level measured in controls. Multifactoral nitroxide changes in the lungs depending on activity of pulmonary proteolysis and fibrinolysis and functional activity of blood neutrophils were describes. Measurement of NO metabolites in EBC is a sensitive and informative test to diagnose ARDS in newborns and could be used for diagnosis of parenchymal type respiratory failure and evaluation of its clinical course in newborns.
Exhaled breath condensate acidification in acute lung injury