End‐tidal carbon monoxide measurements in infant respiratory distress syndrome

Abstract

RDS involving inflammatory and oxidative processes may lead to increased production of carbon monoxide (CO). The relationship between end-tidal CO, corrected for inhaled CO (ETCOc), and RDS severity was investigated in preterm infants as well as the value of early ETCOc measurements to predict chronic lung disease. 78 infants (30 no RDS, 32 moderate RDS, 16 severe RDS) were included. ETCOc was measured using the CO-Stat End Tidal Breath Analyzer. ETCOc was significantly higher in RDS compared to no RDS during the first week (p<0.05). Severity of RDS was the most significant independent variable in a stepwise regression model related to ETCOc (F-test: 18.17). Negative predictive value of early (within first 12 h of life) ETCOc measurement (<2.5 ppm) for development of chronic lung disease was excellent (100%). During severe RDS, inflammation may contribute to increased lipid peroxidation leading to increased local CO production in the lung, indicated by increased ETCOc. Early ETCOc determinations may be helpful to exclude occurrence of chronic lung disease.