Pulmonary antioxidant concentrations and oxidative damage in ventilated premature babies

Abstract

Objective: To determine the relation between lipid peroxidation and the antioxidants ascorbate, urate, and glutathione in epithelial lining fluid in ventilated premature babies, and to relate the biochemical findings to clinical outcome.

Design: A cohort study conducted between January 1999 and June 2001.

Setting: A NHS neonatal intensive care unit.

Patients: An opportunity sample of 43 ventilated babies of less than 32 weeks gestation.

Main outcome measures: The duration of supplementary oxygen according to the definition of bronchopulmonary dysplasia (BPD; oxygen dependency at 36 weeks gestational age).

Methods: Epithelial lining fluid was sampled by bronchoalveolar lavage. Ascorbate, urate, glutathione, and malondialdehyde (a marker of lipid peroxidation) were measured.

Results: Babies who developed BPD had significantly lower initial glutathione concentrations (mean (SEM) 1.89 (0.62) v 10.76 (2.79) μM; p  =  0.043) and higher malondialdehyde concentrations (mean (SEM) 1.3 (0.31) v 0.345 (0.09) μM; p < 0.05) in the epithelial lining fluid than those who were not oxygen dependent. These variables were poor predictors of the development of BPD. Gestational age, endotracheal infection, and septicaemia had good predictive power. The level of oxidative damage was associated with the presence of endotracheal infection/septicaemia rather than inspired oxygen concentration.

Conclusions: Endotracheal infection, septicaemia, and gestational age, rather than antioxidant concentrations, are the most powerful predictors of the development of BPD.