Abstract
Aims and objectives: Extremely preterm infants are born prior to the alveolar stage of lung development and often exhibit histopathological features of alveolar simplification. Knowledge of the alveolar surface area may allow for characterisation of short- and long-term pulmonary morbidity and enable the development of therapies targeted at the optimisation of alveolar growth.
Methods: Preterm infants born at less than 28 weeks of gestation were studied at one week after birth. Paired measurements of the fraction of inspired oxygen (FiO2) and peripheral oxygen saturation (SpO2) were obtained, and using the non-invasive oxyhaemoglobin dissociation curve method, values of ventilation-perfusion (VA/Q) ratio and right-to-left shunt were calculated. Estimation of the alveolar surface area was achieved utilising a validated regression model based on functional morphometric values.
Results: Thirty infants were studied with a mean (SD) gestational age of 26.0 (1.4) weeks and a birthweight of 834 (188) grams. All infants received postnatal surfactant. The infants were studied at a mean postnatal age of 7 days. The mean (SD) VA/Q was 0.51 (0.06) with a shunt of 8.0 (7.2) %. The average SA was 1,019 (129.2) cm2. Furthermore, the SA was related to the FiO2 [r=-0.45, p=0.012] and arterial carbon dioxide level [r=-0.39, p=0.03] at one week of age.
Conclusions: Non-invasive measurements of ventilation-perfusion relationships can be utilised to estimate the alveolar surface area (SA) in infants born extremely prematurely. Knowledge of the SA may reflect initial respiratory status and be predictive of long-term pulmonary morbidity.
Footnotes
Cite this article as Eur Respir J 2022; 60: Suppl. 66, 567.
This article was presented at the 2022 ERS International Congress, in session “-”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
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