Conclusions
Mechanically ventilated neonates born at <30 week GA, with evidence of BPD requiring dexamethasone to facilitate extubation, had a lower likelihood of successful extubation by day 14 if at the time of commencing steroids they were less mature at birth, had higher MAPs and higher oxygen requirements.
INTRODUCTION
Most extremely preterm neonates require mechanical ventilation.1 Once they are intubated, the aim is to extubate as soon as possible to minimise time spent mechanically ventilated. The desired outcome is to reduce the risk of the development of chronic lung disease, aka bronchopulmonary dysplasia (BPD), and associated adverse outcomes.2-4
The chronic lung disease, which often requires further prolonged periods of intubation, involves inflammatory parenchymal change with incremental increases in inspired oxygen, inflation pressures and tidal volume to achieve adequate gas exchange.5 BPD is still common; occurring in 80% of neonates less than 25 weeks gestational age (GA).6 The risk is higher in very low birthweight neonates who remain intubated after 1-2 weeks of age.3Systemic dexamethasone facilitates weaning of invasive ventilatory support by suppressing inflammation, improving lung compliance, and decreasing airway resistance.5-8 There are well documented complications of systemic steroids: gastric perforation and bleeding, hypertension, hyperglycaemia, poor growth and worse neurodevelopmental outcome.8-11 Therefore, steroids are often reserved for neonates who are difficult to extubate from mechanical ventilation, who exhibit clinical evidence of BPD and are greater than 7 days of age; and where the risk of BPD is >50%.12 Clinicians should also aim to give with the lowest cumulative dose of steroids.9,13,14
Responses to the initial dexamethasone courses are variable, at times resulting in dexamethasone treatment that does not facilitate extubation. There may be factors present at the time of considering treating the neonate with steroids that are associated with a lesser or greater chance of successful extubation. If factors are identified that are associated with a reduction in successful extubation, it may well be worth electing to wait until circumstances are more favourable. Given the paucity of research investigating these potential factors, the aim of our study was to identify, in mechanically ventilated neonates less than 30 weeks GA with clinical evidence of BPD, predictors that are associated with a first course of systemic dexamethasone leading to extubation within 14 days and remaining extubated for at least 7 days.