Second course of systemic dexamethasone: efficacy and respiratory function changes

Abstract

Background

There is a paucity of data concerning the efficacy of a second course of systemic postnatal corticosteroids resulting in a successful extubation of prematurely-born, ventilated infants and its effect on their respiratory function.

Objectives

To determine the efficacy of a second course of systemic dexamethasone in successful extubation of prematurely-born infants and to describe the respiratory function changes that occur following the administration of the second course

Methods

Retrospective cohort study of ventilated infants less than 30 weeks of gestation who received a nine-day second course of intravenous dexamethasone in a tertiary neonatal unit. Extubation was deemed successful if the infants were not re-intubated within 72 h of the extubation attempt. We calculated the ventilation perfusion ratio (V_A/Q) and the fraction of required oxygen (F_IO₂) requirement expressed as a percentage before and after the course.

Results

Fifteen (10 male) infants with a median (IQR) gestational age (GA) of 25.7 (24.7–26.6) weeks and a birth weight of 0.79 (0.67–0.93) kg were studied at a postnatal age of 60 (48–73) days. Fourteen of fifteen infants (93%) were successfully extubated. The V_A/Q before the course was 0.13 (0.11–0.16) and significantly higher at 72 h after starting the course [0.26 (0.19–0.36), p = 0.001]. The F_IO₂ requirement decreased from 0.70 (0.59–0.79) to 0.34 (0.28–0.52) nine days after starting the course (p < .001).

Conclusions

A second course of systemic dexamethasone appears efficient in weaning premature infants off invasive ventilation and is associated with a significant improvement in oxygenation.

Keywords:

• Prematurely born infants
• dexamethasone
• respiratory function

Acknowledgments

The secretarial assistance of Mrs Deirdre Gibbons is gratefully acknowledged.

Ethical approval

The study was registered with the Clinical Governance Department of KCH. The Health Research Authority Toolkit of the National Health System, United Kingdom confirmed that the study was not considered as research and hence would not need regulatory approval by a research ethics committee.

Author contributions

TD conceived the study, analyzed the data and wrote the first version of the manuscript. OK participated in the design of the study, collected the data and approved the final version of the manuscript. AG supervised the project, contributed to the interpretation of the results and critically revised the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The research was supported by the National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy’s and St Thomas’ NHS Foundation Trust and King’s College London. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.