Outcomes in Extremely Preterm Neonates After the Introduction of Early Low-Dose Hydrocortisone Treatment: A Retrospective Case-Control Study

Objective Assess the association between use of early low-dose hydrocortisone (ELDH) in extremely preterm neonates, and bronchopulmonary dysplasia (BPD)-free survival at 36 weeks completed gestational age (CGA), as well as additional secondary outcomes. Design Retrospective, matched, case-control study. Setting Tertiary neonatal intensive care units in Nottingham University Hospitals NHS Trust (Queens Medical Centre and Nottingham City Hospital). Patients 188 extremely preterm neonates. 94 historical controls born between 1 October 2017 and 30 September 2019. 94 cases born between 1 January 2020 and 31 December 2022. Interventions ELDH using the published PREMILOC study protocol (total dose of 8.5mg/kg over 10 days) initiated within the first 24 hours of life. Primary outcome measure Survival without BPD at 36 weeks CGA. Results There were no statistically significant associations between the sex, gestational age or birthweight of the groups. There was no significant association between use of ELDH and increased survival without BPD at 36 weeks CGA (p= 0.152) or reduction in mortality (p=1.000). Using ELDH significantly increased the incidence of culture positive late-onset sepsis (p=0.006), median CPAP days (p=0.033) and median total length of stay (p=0.004). The incidence of BPD was higher in the cases if their mother received a full course of antenatal steroids. Conclusions ELDH use was not associated with an improvement in BPD free survival in extremely preterm neonates. The cases had a higher incidence of culture positive late-onset sepsis and longer duration of respiratory support. Further research exploring stratification of preterm neonates that will benefit from ELDH is needed.