364 - Timing of Surfactant Treatment in Very Preterm Outborn Infants – a Population Outcome Evaluation in Neonatal Intensive Care and Retrieval Services in 2017 to 2022

Publication Number: 364.6857

Giannina Tinoco Mendoza, University of New South Wales, Royal Hospital for Women, Sydney, Sydney, New South Wales, Australia; Temesgen Molla, UNSW, SYDNEY, New South Wales, Australia; Tim Schindler, Royal Hospital for Women, Sydney, New South Wales, Australia; Srinivas Bolisetty, Royal Hospital for Women, Randwick, New South Wales, Australia; Trisha Parmar, Royal Hospital for Women, Sydney, New South Wales, Australia; Rahul Prasad, Royal Hospital for Women , Randwick NSW Australia, Randwick, New South Wales, Australia; Kenneth Tan, Monash University, Melbourne, Victoria, Australia; Kathryn A. Carmo, Sydney Children's Hospitals Network, BANKSTOWN AERODROME, New South Wales, Australia; Lucy Cooke, Queensland Health, Brisbane, Queensland, Australia; Jonathan W. Davis, University of Western Australia, Perth, Western Australia, Australia; Michael J. Stewart, Royal Children's Hospital, Parkville, Victoria, Australia; Amy Keir, University of Adelaide, Adelaide, South Australia, Australia; Prudence Creighton, University of New South Wales, SYDNEY, New South Wales, Australia; Kei Lui, University of New South Wales, Sydney, New South Wales, Australia

Background: Very preterm infants born outside perinatal centres (outborns) without on-site neonatal intensive care units (NICU) have higher rates of mortality and morbidities than inborns. Advances in respiratory care and coordinated regional retrieval services have likely contributed to improved outborn outcomes.

Objective: To explore the performance of timely surfactant administration and clinical outcomes in very preterm (VPT) outborn infants cared for in Australian and New Zealand NICUs from 2017 to 2022.

Design/Methods: A retrospective cohort study utilising data from the Australian and New Zealand Neonatal Network. NICU infants born at 23 to 31 weeks gestational age (GA) were included. Mortality, composite outcome (mortality/intraventricular hemorrhage Grade III/IV) and bronchopulmonary dysplasia (BPD) at 36 weeks GA relating to early management of timely surfactant treatments for infants born at 23-27 weeks and 28-31 weeks GA were evaluated.

Results: Clinical characteristics and outcomes of 19,466 VPT infants, including 2133 outborn (11%) are summarised (Table 1). While GA and birthweights were similar, fewer outborns received a completed antenatal steroid course (17% v 71%) than inborns, and more outborns received surfactant treatment (66% v 53%). The timing of first surfactant dose for outborns at 23-27 weeks GA closely matched that of inborn counterparts (median 1 hr, IQR 2 hrs for both) but it was delayed for 28-31 weeks GA outborns (median 3 hrs, IQR 5 hrs) compared to inborns (median 2 hrs, IQR 5 hrs). Outborns had significantly higher rates of mortality and composite outcome than their inborns counterparts. Outcome disparities were greatest at lower GA (Figure 1). Outborns did not have more BPD among survivors. Management and outcome changes between Epoch 1 (2017-19) to Epoch 2 (2020-22) are summarised (Table 2). Emerging use of minimal invasive surfactant treatment by catheters and a small decrease in early surfactant administration before 2 hours were seen in both inborns and outborns. Evidence based practices of delayed cord clamping, antenatal steroids, magnesium sulphate in outborns remained low. There were no significant outcome changes between the epochs for both inborn and outborn infants.

Conclusion(s): There are high rates of surfactant administration in outborns and its timely use in low gestation infants approached that of inborns. Mortality and IVH rates continued to be high. There are areas for improvement such as earlier antenatal steroids, magnesium sulphate and delayed cord clamping as well as earlier surfactant doses to improve outborn outcomes.

Table 1: Comparison of Clinical Characteristics and Outcomes Between Outborns and Inborns in Australian and New Zealand Neonatal Intensive Units
* denotes statistical significance between outborns and inborn GA counterparts (inborn as reference group)

Figure 1: Comparison of Gestation-specific Mortality and Composite Outcomes Between Outborn and Inborn Infants
Composite Outcome as Death or Grade III/IV Intraventricular Hemorrhage.

Table 2: Comparison of Clinical Characteristics and Outcomes Between Epoch 1 (2017 –2019) and Epoch 2 (2020 – 2022) for Outborn and Inborn Infants
* denotes statistical significance between Epoch 1 and Epoch 2 (Epoch 1 as reference group) for inborns and outborns. The surfactant treatment timing changes in outborn corresponded parallel to that of inborn infants.