Effect of dexamethasone on tracheobronchial aspirate fluid cytology and pulmonary mechanics in preterm infants.

The changes induced on respiratory mechanics and on tracheobronchial aspirate fluid (TAF) cytology by dexamethasone courses started at two different postnatal ages in preterm infants at risk of chronic lung disease (CLD) were reported in this clinical trial designed in two phases. The first phase of the study included 20 neonates with birth weight < or = 1,250 g and gestational age < or = 32 weeks, who were oxygen and ventilator dependent on the 10th day of life. They were randomly assigned to the moderately early dexamethasone (MED) group or to the control group. The second phase of the study included 20 neonates with the same characteristics, oxygen and ventilator dependent on the 4th day of life, randomly assigned to the early dexamethasone (ED) group or to the control group. Both treated groups received dexamethasone intravenously for 7 days (0.5 mg/kg/day for the first 3 days, 0.25 mg/kg/day for the next 3 days, and 0.125 mg/kg/day for the last day of treatment). The control groups received no steroid treatment. A significantly lower absolute cell count and percentage of neutrophils (PMN) in the TAF and significantly higher dynamic lung compliance (Cdyn) values were observed in both the MED treated compared to the untreated infants and the ED treated infants compared to the control group. Moreover these changes were more precocious in the ED Group compared to the MED Group. Our study suggests that dexamethasone could be more efficacious in reducing effects of ventilator-induced lung injury in preterm infants at high risk of CLD when started earlier.