Objective: The objective of this study was to determine the time required for equilibration of oxygen saturation (SpO2) and the oxygen flow rate that might predict readiness for oxygen weaning to room air in preterm infants with improving bronchopulmonary dysplasia (BPD).
Study design: This was a prospective longitudinal cohort study, conducted in the neonatal care unit and the neonatal high risk follow-up clinic. Seventeen preterm children with BPD (mean postconceptual age 39.9 [range 31.5 to 43.5] weeks) were enrolled. With the infants breathing room air, the SpO2 pulse and respiratory rates, and clinical status were monitored for 120 minutes. Factors that predicted a successful room air challenge were determined. Children successfully weaned were followed up for 6 months after discontinuation of oxygen therapy.
Results: A total of 20 room air challenges were done in 17 study infants. In most infants the lowest SpO2 value (mean 89.7%) was reached within the first 40 minutes. Infants with an SpO2 > or = 92% at 40 minutes continued to have values > or = 92% at 120 minutes (specificity, 100%; sensitivity, 42%). In all infants receiving oxygen flow rates < or = 20 ml/kg per minute an SpO2 > or = 92% was maintained after 40 and 120 minutes. Infants who were successfully weaned to room air showed maintenance of weight and height percentiles 6 months after discontinuation of oxygen therapy. One child was rehospitalized and oxygen support reinstituted because of viral pneumonia.
Conclusions: An SpO2 value > or = 92% at 40 minutes best predicts readiness for oxygen weaning to room air in infants with improving BPD. Infants requiring oxygen flow rates < or = 20 ml/kg per minute are also likely to be weaned off oxygen support.