Melbourne, Australia

Author Affiliations: Department of Pediatrics, Ritchie Centre for Baby Health Research, Monash University, Monash Medical Centre, Australia (Yu V); Newborn Services, Monash Medical Centre, Australia (Tan JB)

Corresponding Author: Victor Yu, MD MSc (Oxon) FRACP FRCP (Lond Edin & Glasg) FRCPCH, Professor of Neonatology, Department of Paediatrics, Monash University, Monash Medical Centre, 246 Clayton Road, Clayton, Victoria 3168, Australia (Tel: 61 3 9595 5191; Fax: 61 3 9594 6115; Email: victor.yu@med.monash.edu.au)

Background:  With advances in neonatal intensive care, increasing numbers of preterm neonates are now surviving. In the past they would have died before there was time to develop chronic lung disease (CLD). Based on the definition of a neonate requiring any form of respiratory therapy (oxygen or assisted ventilation) at 36 weeks' post-menstrual age, the CLD rate in Australia is 52% in those <28 weeks and 12% in those 28-32 weeks gestation. The high CLD rate in the former group is due to their improved survival rates (one-year survival rate of infants born in the State of Victoria is 41% at 23 and 24 weeks, 73% at 25 weeks, and 88% at 26 weeks).

Data sources:  Randomized controlled trials (RCTs), including meta-analyses and Cochrane reviews on the prevention and treatment of CLD were identified in the published literature.

Results: The following perinatal strategies were found to be effective in preventing or minimizing CLD: antenatal corticosteroids, postnatal surfactant, reduced oxygen saturation targeting at 89%-94%, early use of continuous positive airway pressure, synchronized ventilation, permissive hypercapnia ventilation strategy, high frequency oscillatory ventilation, closure of symptomatic patent ductus arteriosus with indomethacin, reduced fluid intake, and inhaled nitric oxide. Several anti-inflammatory and anti-oxidant agents have been found in RCTs to be effective, including vitamin A and recombinant human superoxide dismutase. Clinical management after the development of CLD includes appropriate oxygen and ventilation strategies, fluid restriction, and diuretic and bronchodilator therapy. Postnatal corticosteroid therapy is efficacious but its side-effect is increasing. The risk of cerebral palsy outweighs the benefit of therapy. Only in severe CLD, low-dose and short-course dexamethasone should be used.

Conclusion: Ongoing basic and clinical research is required to identify perinatal and neonatal interventions that are effective in either preventing or treating CLD in preterm neonates.

Key words: chronic lung disease; bronchopulmonary dysplasia; respiratory failure; prematurity; neonatal intensive care