Outcome after neonatal continuous negative-pressure ventilation: follow-up assessment

A previous randomised trial of continuous negative extrathoracic pressure (CNEP) versus standard treatment for newborn infants with respiratory distress syndrome raised public concerns about mortality and neonatal morbidity. We studied the outcome in late childhood of children entered into the trial to establish whether there were long-term sequelae attributable to either mode of ventilation.

Outpatient assessment of neurological outcome, cognitive function, and disability was done by a paediatrician and a psychologist using standardised tests. 133 of 205 survivors from the original trial were assessed at 9-15 years of age. Of the original pairs randomly assigned to each ventilation mode, the results from 65 complete pairs were available. The primary outcome was death or severe disability.

Primary outcome was equally distributed between groups (odds ratio for the CNEP group 1.0; 95% CI 0.41-2.41). In unpaired analysis there was no significant difference between treatment modalities (1.05; 0.54-2.06). Full IQ did not differ significantly between the groups, but mean performance IQ was 6.8 points higher in the CNEP group than in the conventional-treatment group (95% CI 1.5-12.1). Results of neuropsychological testing were consistent with this finding, with scores on language production and visuospatial skills being significantly higher in the CNEP group.

We saw no evidence of poorer long-term outcome after neonatal CNEP whether analysis was by original pairing or by unpaired comparisons, despite small differences in adverse neonatal outcomes. The experience of our study indicates that future studies of neonatal interventions with the potential to influence later morbidity should be designed with longer-term outcomes in mind.