234 - The respiratory trajectory of extremely preterm infants from birth to discharge

Publication Number: 234.6866

Tugba Alarcon-Martinez, The Royal Women's Hospital, CAULFIELD NORTH, Victoria, Australia; Kate L. Francis, Murdoch Children's Research Institute, Melbourne, Victoria, Australia; Peter A. Dargaville, Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia; Kate Hodgson, Royal Women’s Hospital, Parkville, Victoria, Australia; C. Omar kamlin, Royal Women's Hospital, Melbourne, London, England, United Kingdom; Wissam Shalish, McGill University Faculty of Medicine and Health Sciences, Montreal, PQ, Canada; Guilherme Sant'Anna, McGill University, Montreal, PQ, Canada; Susan Jacobs, Royal Women's Hospital, Parkville, Victoria, Australia; Georg Schmölzer, University of Alberta Faculty of Medicine and Dentistry, Edmonton, AB, Canada; Brenda H. Law, University of Alberta Faculty of Medicine and Dentistry, Edmonton, AB, Canada; Kei Lui, University of New South Wales, Sydney, New South Wales, Australia; Jeanie Cheong, Murdoch Children's Research Institute, Melbourne, Victoria, Australia; Lex W. Doyle, The Royal Women's Hospital, Melbourne, Carlton North, Victoria, Australia; Peter Davis, Royal Women's Hospital, Melbourne, Victoria, Australia; Christopher McKinlay, University of Auckland, Auckland, Auckland, New Zealand; Brett J. Manley, Mercy Hospital for Women, Melbourne, Melbourne, Victoria, Australia

Background: To survive, most extremely preterm infants (EPI; born < 28 weeks’ gestation) receive respiratory assistance soon after birth. However, the type of respiratory support required throughout the neonatal admission has not been well delineated, particularly for those born at < 25 weeks.

Objective: To describe the trajectory of respiratory support of infants born < 28 weeks’ gestation during the primary hospital admission.

Design/Methods: Secondary analysis of the PLUSS Trial, a multicenter, randomized trial (Australia, New Zealand, Canada, and Singapore, 2018 to 2023) of intratracheal budesonide mixed with surfactant for infants < 28 weeks’ gestation, with a primary outcome of survival free of bronchopulmonary dysplasia (BPD) at 36 weeks’ postmenstrual age (PMA). Infants were eligible if < 48h and: 1) mechanically ventilated, or 2) receiving non-invasive respiratory support with a clinical decision to treat with surfactant. Perinatal and respiratory support data in the first two weeks, and respiratory outcomes at 36 weeks’ PMA and discharge were collected prospectively. Descriptive analysis was performed by week of gestation.

Results: 1059 EPI were enrolled, with mean (SD) gestational age 25.6 (1.3) weeks (355 infants born < 25 weeks) and median (IQR) birth weight 750 (630,905) g. 97% of infants born at 22-23 weeks were intubated at birth, compared with 40% at 27 weeks (Table). During the first 2 weeks, oxygen requirements and mean airway pressure increased for all infants, especially those born < 25 weeks (Figure 1). At day 14, 86% of infants born at 22-23 weeks and 70% at 24 weeks were mechanically ventilated (Figure 2). Postnatal age at first extubation for those intubated primarily varied from 15 (7.4-25.7) days at 22–23 weeks to 1.3 (0.6-4.7) days at 27 weeks. At 22-23-weeks, 70% had an unsuccessful first extubation attempt, in contrast to 22% at 27 weeks. The median (IQR) duration of mechanical ventilation was 23.9 (7.3-43.8) days for infants born at 22-23 weeks. At 36 weeks’ PMA, the proportion of infants receiving mechanical ventilation, non-invasive support, and supplemental oxygen was 7%, 75%, and 90% at 22–23 weeks, decreasing to 2%, 48%, and 77% at 27 weeks, respectively (Table). Thirty-five (10%) newborns born < 25 weeks survived without BPD, compared with 30% at ≥25 weeks. Moreover, 50% of infants born < 25 weeks were discharged home on oxygen.

Conclusion(s): Among extremely preterm infants, trajectories of respiratory support vary by each week of gestation at birth and postnatal age. For those born at < 25 weeks, respiratory support requirements remain high until discharge and beyond.

Table- Respiratory support and respiratory outcomes by gestation
*Excludes single intubations who died by 36 weeks’ PMA (n=827)

Figure 1- Oxygen requirement in first 14 postnatal days by gestation


Figure 2- Respiratory support mode in first 14 postnatal days by gestation
NHF, nasal high flow; CPAP, continuous positive airway pressures; MV, mechanical ventilation
Cohort represents infants who survived to 14 days