The Danish national study in infants with extremely low gestational age and birthweight (the ETFOL study): respiratory morbidity and outcome

Aim: To describe and analyse neonatal care, short and long-term morbidity with special reference to ventilatory support and chronic lung disease (CLD) in a population-based study. Methods: During 1994 and 1995 a prospective, nation-wide, multicentre study was conducted, comprising 477 liveborn infants with gestational age (GA) <28 wk and/or birthweight <1000 g. Of these, 407 infants received active treatment. The ventilatory treatment was based on the principle of permissive hypercapnia and early nasal continuous positive airway pressure (NCPAP) supplemented with surfactant and ventilator therapy in case of CPAP failure. Results: Among actively treated infants 85% received CPAP and 23% mechanical ventilation from the first day of life. A total of 269 infants (56%) survived to discharge. Of these, 195 had a GA <28 wk. One-hundred and five Survivors with GA <28 wk survived with NCPAP as sole respiratory support. In surviving infants, periventricular leucomalacia/intraventricular haemorrhage grade 3-4 was found in 10%, retinopathy of prematurity grade >2 in 4%, and oxygen requirement at 36 and 40 wk of postmenstrual age (CLD) in 16 and 5%, respectively. Three infants either died of CLD (n = 1) or required oxygen therapy beyond 43 wk of postmenstrual age. Logistic regression analysis showed significant associations between oxygen requirement at 40 wk and GA, septicaemia, mechanical ventilation, symptomatic patent ductus arteriosus and Clinical Risk Index for Babies score. Only the two last-mentioned factors proved significant in infants with GA <28 wk. No infant died after discharge and 253 (94%) were followed up at 2 y of corrected age; one or more moderate to severe impairments were found in 66 (26%) of the examined children. Conclusion: Ventilatory treatment in extremely premature and extremely low-birthweight infants based on early NCPAP and permissive hypercapnia may result in comparable survival rates and sensorineural outcome; however, the incidence of CLD seems lower than that reported on conventional treatment.