465 - Nasal Cannula or Incubator Oxygen in Preterm Infants with Bronchopulmonary Dysplasia: A Randomized Crossover Trial

Poster Number: 465
Publication Number: 465.229

Colm P. Travers, University of Alabama at Birmingham, Birmingham, AL, United States; Waldemar A. Carlo, University of Alabama at Birmingham, Birmingham, AL, United States; Arie Nakhmani, University of Alabama at Birmingham, Birmingham, AL, United States; Rouba A. Chahine, The University of Alabama at Bimringham, Birmingham, AL, United States; inmaculada Aban, University of Alabama at Birmingham, School of Public Health, Birmingham, AL, United States; Namasivayam Ambalavanan, University of Alabama School of Medicine, Birmingham, AL, United States

Background: Incubator oxygen may reduce intermittent hypoxemia by maintaining a more stable pharyngeal effective fraction of inspired oxygen compared with low-flow nasal cannula oxygen.

Objective: Test the hypothesis that digitally-set servo-controlled incubator oxygen compared with low-flow (≤0.5L/min) nasal cannula oxygen improves respiratory stability among preterm infants on supplemental oxygen.

Design/Methods: This trial was conducted at the University of Alabama at Birmingham (NCT03333174). Infants < 29 weeks’ gestation on supplemental oxygen ≥ 32 weeks’ postmenstrual age (PMA) were randomized to 2 modes of oxygen delivery in one of two sequences with four sessions lasting 24 hours or 96 hours total: baseline-incubator-cannula-incubator or baseline-cannula-incubator-cannula. We collected cardiorespiratory data directly from patient monitors. The primary outcome was episodes of intermittent hypoxemia (oxygen saturations (SpO2) < 85% for ≥10 sec). Secondary outcomes included severe intermittent hypoxemia (SpO2 < 80% for 10 sec), bradycardia (heart rate < 100 bpm for ≥10 sec), cerebral ( < 55%) and abdominal hypoxemia ( < 40%) on near-infrared spectroscopy, and end-tidal PCO2 measured using an additional nasal cannula. Results were analyzed for each 24 hour intervention period using generalized linear mixed models to account for repeated measurements.

Results: We enrolled 25 infants with a gestational age of 26w 4d ± 14d (mean+SD) and birth weight 805±202 grams at 33w 0d ± 12d PMA. There were no differences in episodes of intermittent hypoxemia (106±68 vs 96±61 per 24 hours; p=0.38), severe intermittent hypoxemia (34±26 vs 36±32; p=0.83), cerebral hypoxemia (162±182 vs 163±164; p=0.16), or bradycardia (4±5 vs 5±7; p=0.28) between incubator and nasal-cannula oxygen treatments. There was a higher rate of episodes of abdominal hypoxemia with incubator oxygen compared with nasal cannula oxygen (158±125 vs 132±130; p< 0.01). The proportion of time with SpO2 < 85% (5.3±3.6% vs. 4.2±2.5%; p=0.04) and abdominal hypoxemia (17.2±20.5% vs 16.4±20.6%; p=0.04) was higher among infants while on incubator oxygen. The proportion of time with SpO2 < 80% or cerebral hypoxemia did not differ. PCO2 values were lower while on incubator oxygen compared with low-flow nasal cannula (36±10mmHg versus 41±11mmHg; p=0.02).Conclusion(s): There was no difference in intermittent hypoxemia between incubator and nasal cannula oxygen among preterm infants on supplemental oxygen. Infants had higher levels of PCO2 while on nasal-cannula treatment suggesting PCO2 retention, which may have improved some measures of respiratory stability in this study.