Cardiopulmonary outcomes in school age children born extremely prematurely

    Student thesis: Doctoral ThesisDoctor of Philosophy


    Background: The incidence of bronchopulmonary dysplasia, the main respiratory complication of preterm birth, has remained unchanged, despite improved survival. Small airway function appears to decline in infancy, in infants conventionally ventilated at birth. Pulmonary hypertension has been described in babies born extremely preterm. Methods: In a randomized controlled multi-center study, high frequency oscillation (HFO) was compared to conventional ventilation (CV) in 797 extremely preterm babies immediately after birth (UKOS). There were no significant differences in mortality or the incidence of BPD. Comprehensive lung function assessments and an echocardiogram were undertaken and respiratory, health related quality of life and functional assessment questionnaires were completed when the UKOS children were 11-14 years old. The results were compared to those of children born at term. Results: 318 children from the UKOS cohort completed the study. The HFO group had superior small airway function (z score FEF75, mean difference 0.23 SD (95%CI 0.02,0.45), p = 0.04), superior large airway function (FEV1 z score mean difference 0.35 SD (95% CI 0.02, 0.45), p=0.008) and diffusion capacity of the alveo-capillary membrane (DLCO z score mean difference 0.31 SD (95% CI 0.04, 0.58), p=0.02), without poorer functional outcomes. Prematurely born children had significantly worse lung function than term born children: z FEV1 mean difference 0.62 SD (95%CI -0.85, -0.38), p<0.001, z FEF75 mean difference 0.55 SD (95%CI -0.77, -0.33), p<0.001 , z DLCO mean difference 0.78 SD (95%CI 0.53, 1.02), p<0.001, and higher pulmonary pressures (mean MAP 24.6 vs 20.5 mmHg, p<0.001). Conclusions: HFOV used immediately after birth in extremely premature babies was associated with better lung function outcomes without evidence of poorer functional outcomes. Airway obstruction is significantly worse in preterm children at school age than in term born children. Children born very prematurely have significantly higher pulmonary pressures at school age, with potential cardiovascular implications in later life.
    Date of Award2017
    Original languageEnglish
    Awarding Institution
    • King's College London
    SupervisorJanet Peacock (Supervisor) & Anne Greenough (Supervisor)

    Cite this