693 - Respiratory Support After 36 Weeks Postmenstrual Age Among Infants Without Bronchopulmonary Dysplasia

Publication Number: 4677.693

Neil Rowen, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, CA, United States; Susana Camacho Plascencia, Kaiser Permanente Bernard J. Tyson School of Medicine, Arcadia, CA, United States; Ashwini Lakshmanan, Kaiser Permanente Bernard J. Tyson School of Medicine, Pasadena, CA, United States; Fu-Sheng Chou, Southern California Permanente Medical Group, Riverside, CA, United States

Background: Very preterm infants (VPIs) born before gestational age (GA) 32 weeks have a higher risk of respiratory support needs in the NICU. In modern neonatal practice, infants are given an operationally defined diagnosis of bronchopulmonary dysplasia (BPD) at 36 weeks postmenstrual age (PMA) if they continue to require respiratory support. For those who do not, it is unclear whether they remain free of support until reaching their original due date or not, and if needing respiratory support again puts them at a higher risk of adverse childhood outcomes.

Objective: This study aims to describe respiratory trajectories of infants without BPD and correlate with early childhood outcomes.

Design/Methods: In this retrospective cohort study, we used multi-center data from Kaiser Permanente Southern California. Inclusion/exclusion criteria are listed in Fig 1A. Clinical data were extracted from an EHR database. Charts were manually reviewed to determine clinical reasons for respiratory support after 36 weeks PMA, and inductive coding was used to group participants. Mixed-effects logistic regression modeling was used to describe the association between perinatal morbidities and respiratory support needs. Early childhood outcomes were compared between infants who remained in room air (RA) and those who required respiratory support again.

Results: Out of 5116 infants, 3879 (76%) had no BPD, and of these, 210 (5%) required respiratory support after 36 weeks PMA. Reasons for respiratory support are listed in the flowchart in Fig 1A. VPIs without BPD requiring respiratory support for respiratory issues later were younger [28w0d (IQR: 25w6d-29w6d) in support group vs. 30w1d (IQR: 28w4d-31w1d) in RA group] and smaller (BW z-score -0.22±1 in support group vs. 0.11±0.83 in RA group) (Fig 1B). These infants had significantly higher odds of NEC or intestinal perforation, late-onset sepsis, and grade 3/4 IVH after adjusting for GA, BW z-score, and placental abruption (Fig 1C). In the cohort, 2914 (79%) infants remained at KPSC at 3 years of corrected age. Infants without BPD who required respiratory support again due to respiratory issues had significantly higher rates of ED visits, re-hospitalization, unfavorable respiratory outcomes, and unfavorable motor function outcomes at 3 years (Fig 1D).

Conclusion(s): Operationally defined BPD may underestimate adverse early childhood outcomes associated with the subgroup of infants without BPD who require respiratory support again for respiratory issues after 36 weeks PMA. These infants are younger, smaller, and more likely to have neonatal morbidities.

Figure 1. Describing neonatal respiratory and early childhood outcomes in infants without BPD.
Figure1_PAS.jpeg(A) Inclusion and exclusion criteria with characterization of reasons for respiratory support after 36 weeks PMA among VPIs without BPD. (B) Neonatal and maternal characteristics of infants remained on room air versus those needing respiratory support after 36 weeks PMA. (C) Mixed-effects logistic regression model for the association between demographics/morbidities and respiratory support need after 36 weeks PMA. (D) Early childhood outcomes in VPIs who remained on room air versus those with respiratory support after 36 weeks due to respiratory issues. Overall health: all-cause ED visits, all-cause hospital re-admission, and post-NICU discharge mortality. Respiratory health: Wheezing requiring pharmacological therapy (steroids or bronchodilators), home oxygen support, ED visits due to respiratory problems, hospital readmission due to respiratory problems, tracheostomy. Motor function outcome: hypotonia, developmental delay in motor function, cerebral palsy.