Abstract
Background: The main pathophysiologic characteristic of chronic respiratory disease following extremely premature birth is arrested alveolar growth which translates to a smaller alveolar surface area. We aimed to use non-invasive measurements of gas exchange and volumetric capnography to estimate the alveolar surface area in extremely preterm infants.
Methods: Paired measurements of the fraction of inspired oxygen and transcutaneous oxygen saturation were used to calculate the ventilation/perfusion ratio in extremely preterm infants studied at seven days of life. The ventilation/perfusion ratio was translated to alveolar surface area using Fick’s first law of diffusion and was adjusted using volumetric capnography.
Results: Thirty infants with a median (range) gestational age of 26.3 (22.9-27.9) weeks were studied. The median (range) adjusted alveolar surface area was 647.9 (316.4-902.7) cm2 and was negatively correlated with the duration of in-patient supplemental oxygen (r= - 0.504, p=0.012). The median (range) adjusted alveolar surface area was lower in the infants that required supplemental home oxygen [637.7 (323.5-837.5) cm2] compared to those that did not [799.1 (444.2-902.7) cm2, p=0.016]. In predicting the need for supplemental home oxygen, the adjusted alveolar surface area had an area under the receiver operator characteristic curve of 0.815 (p=0.017). An adjusted alveolar surface area ≥688.6 cm2 had 86% sensitivity and 77% specificity in predicting the need for supplemental home oxygen.
Conclusions: The alveolar surface area can be estimated in extremely preterm infants using non-invasive measurements. The adjusted alveolar surface area has the potential to predict the subsequent need for discharge home on supplemental oxygen.
Methods: Paired measurements of the fraction of inspired oxygen and transcutaneous oxygen saturation were used to calculate the ventilation/perfusion ratio in extremely preterm infants studied at seven days of life. The ventilation/perfusion ratio was translated to alveolar surface area using Fick’s first law of diffusion and was adjusted using volumetric capnography.
Results: Thirty infants with a median (range) gestational age of 26.3 (22.9-27.9) weeks were studied. The median (range) adjusted alveolar surface area was 647.9 (316.4-902.7) cm2 and was negatively correlated with the duration of in-patient supplemental oxygen (r= - 0.504, p=0.012). The median (range) adjusted alveolar surface area was lower in the infants that required supplemental home oxygen [637.7 (323.5-837.5) cm2] compared to those that did not [799.1 (444.2-902.7) cm2, p=0.016]. In predicting the need for supplemental home oxygen, the adjusted alveolar surface area had an area under the receiver operator characteristic curve of 0.815 (p=0.017). An adjusted alveolar surface area ≥688.6 cm2 had 86% sensitivity and 77% specificity in predicting the need for supplemental home oxygen.
Conclusions: The alveolar surface area can be estimated in extremely preterm infants using non-invasive measurements. The adjusted alveolar surface area has the potential to predict the subsequent need for discharge home on supplemental oxygen.
| Original language | English |
|---|---|
| Pages (from-to) | 1707-1713 |
| Number of pages | 7 |
| Journal | Pediatric Research |
| Volume | 94 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - Nov 2023 |
