Influences on respiratory outcomes in preterm adolescents

Student thesis: Doctoral ThesisDoctor of Philosophy


Introduction: In a randomised trial (United Kingdom Oscillation Study, UKOS), high frequency oscillatory ventilation (HFOV) compared to conventional mechanical ventilation (CMV) from birth in infants born less than 29 weeks of gestation conferred benefits in lung function and school performance at 11 to 14 years of age.

Aims: To investigate in vitro responses in A549 cells to cyclical mechanical stretch mimicking those modes of ventilation. To re-examine the UKOS cohort when aged 16-19 years to determine if the benefits previously seen were present after puberty.

Methods: An in-vitro model of ventilation was used to assess the level of interleukin 6 and 8 release from A549 cells during stretching mimicking CMV and HFOV. Participants enrolled in UKOS had their lung function assessed (spirometry, plethysmography, helium dilution, diffusion capacity for carbon monoxide, lung clearance index, impulse oscillometry) and exercise capacity assessed by a shuttle sprint test. Participants completed a questionnaire about their school performance, health and exercise habits.

Results: Inflammation from A549 cells was increased with increasing tidal stretch, that is greater in
the CMV model.

There were no significant overall differences in lung function or other outcomes according to neonatal mode of ventilation. Male sex, BPD, IUGR and postnatal steroid exposure were associated with poorer lung function. Exercise capacity was reduced at in those with the poorest lung

Discussion: These data highlight that factors affecting prematurely born infants continue to influence lung function through puberty. Those with the poorest lung function also had a functional deficit and may be at risk of developing adult lung disease.
Date of Award1 Mar 2022
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorAnne Greenough (Supervisor) & Janet Peacock (Supervisor)

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