Physiologic Definition of Bronchopulmonary Dysplasia
Physiologic Definition of Bronchopulmonary Dysplasia
This observational study was conducted to design and test a physiologic definition for
 bronchopulmonary dysplasia at 36 weeks of life. Infants were studied in a supine position
 with the pulse oximeter in position with good signal prior to collecting baseline data.
 Feedings and medications were given 30 minutes before the evaluation. Baseline data was
 collected on infant's current oxygen. Then, the infants were weaned to room air for 30
 minutes. If saturations remain ≥90%, the infant was considered to have passed the oxygen
 reduction challenge (to NOT have BPD). The infant should then be placed back in his/her
 baseline oxygen. If the infant has saturations <90% for 5 continuous minutes or <80% for 15
 seconds, the infant should be immediately placed back in his/her baseline oxygen, and the
 infant was considered to have NOT passed the challenge (to have BPD).
One of the confounders to any study that looks at bronchopulmonary dysplasia (BPD) is the
 lack of a precise definition. Most neonates with BPD do not undergo lung biopsy or any
 physiologic test; thus, their pulmonary disease is defined clinically, on the basis of the
 sustained need for supplemental oxygen at 36 weeks postmenstrual age. The validity of this
 definition is supported by evidence that oxygen dependence at 36 weeks is predictive of
 long-term impairment in pulmonary function. An inherent limitation of defining BPD by the
 need for supplemental oxygen is that the need for oxygen is determined by individual
 physicians, rather than on the basis of a physiologic assessment. Published literature cites
 acceptable saturation ranges from 88-98%.

 This observational study was conducted to design and test a physiologic definition for
 bronchopulmonary dysplasia at 36 weeks of life.

 Infants were studied in a supine position with the pulse oximeter in position with good
 signal prior to collecting baseline data. Feedings and medications were given 30 minutes
 before the evaluation. Baseline data was collected on infant's current oxygen. Then, the
 infants were weaned to room air for 30 minutes. If saturations remain ≥90%, the infant was
 considered to have passed the oxygen reduction challenge (to NOT have BPD). The infant should
 then be placed back in his/her baseline oxygen. If the infant has saturations <90% for 5
 continuous minutes or <80% for 15 seconds, the infant should be immediately placed back in
 his/her baseline oxygen, and the infant was considered to have NOT passed the challenge (to
 have BPD).
Inclusion Criteria:

 -  Infant with birthweight 401-1500 grams

 -  Alive at 36+1 week corrected age

 -  On supplemental oxygen as follows:

 -  A. Infants receiving oxygen by hood at rest:

 -  A1. Oxygen by hood <27% with majority* of saturations ≥ 90% in prior 24 hours.

 -  A2. Oxygen by hood 27-30% with majority* of saturations ≥ 96% in prior 24 hours

 -  B. Infants receiving oxygen by nasal cannula at restΔ:

 -  B1. Oxygen by nasal cannula <27% EFFECTIVE** oxygen and majority* of saturations ≥90%
 in prior 24 hours.

 -  B2. Oxygen by nasal cannula 27-30% EFFECTIVE** oxygen and majority* saturations ≥96%
 on prior 24 hours.

 -  C. Infants receiving room air by nasal cannula at ANY liter per minute (lpm) flow.

 Exclusion Criteria:

 -  Need for mechanical ventilation or continuous positive airway pressure (CPAP)

 -  Oxygen by hood >30%

 -  Oxygen by nasal cannula >30% effective oxygen