Lung volumes in infants who had mild to moderate bronchopulmonary dysplasia

Abstract

"New" bronchopulmonary dysplasia (BPD) has been suggested to be a maldevelopment sequence with reduced alveolarisation of the lungs; affected infants then would be predicted to have low lung volumes. The aim of this study was to test that hypothesis by comparing the lung volumes of infants who had had mild-moderate BPD with those without BPD of similar postmenstrual age. Lung volumes of 17 infants who had mild-moderate BPD (oxygen dependent beyond 28 days, but not past term) (BPD infants) were compared to those of 17 infants without BPD (non-BPD infants). All were born at less than 33 weeks of gestation and studied at postmenstrual ages of 33 to 39 weeks. Lung volume was assessed by measurement of functional residual capacity (FRC). The BPD infants had lower lung volumes (median 19.1 ml/kg) than the non-BPD infants (median 26.5 ml/kg) (p = 0.0001). The BPD compared to the non-BPD infants were of greater postnatal age (p = 0.0003), born at a lower gestational age (p = 0.0001) and of lighter birthweight (p = 0.0001). Regression analysis, however, demonstrated that lung volume was significantly related to BPD status (p = 0.005), independently of postnatal age, birthweight and gestational age. It is concluded that the lower lung volumes of the infants who had had mild-moderate BPD support the hypothesis that new BPD is associated with poor alveolarisation.

Chest radiograph thoracic areas and lung volumes in infants developing bronchopulmonary dysplasia

“…We have previously demonstrated a low FRC in the perinatal period is predictive of BPD development 31 and confirm those findings in this study. The CXR thoracic areas were less predictive of BPD development and regression analysis demonstrated that FRCs, but not CXR thoracic areas, were significantly associated with BPD development after accounting for gestational age, birthweight, growth retardation and gender.…”

“…The present results do not exclude abnormal lung growth contributing to the low FRC results in the infants developing BPD and at 36 weeks PMA, we previously highlighted that infants with BPD compared to those without BPD had lower FRC results. 31 It is possible, however, at that postmenstrual age the lower FRCs in the BPD infants reflect gas trapping. 32,33 At 36 weeks PMA, FRC measured using a nitrogen washout technique was significantly lower in BPD infants compared to controls, but FRC pleth was significantly higher.…”

Relationship Between Functional Residual Capacity and Oxygen Desaturation During Short Central Apneic Events During Sleep in “Late Preterm” Infants

“…Part of the difference with previous studies may result from different techniques and populations. Although we took care to limit variability, the intrasubject coefficient of variation for FRC was 13.7 Ϯ 11.1%, which corresponds to somewhat lower reproducibility than previously reported with the He technique (8%) (4 ). We failed to observe a sleep state effect on FRC values as previously reported (7,11,23,24), probably because we only measured FRC during regular breathing pattern.…”

“…In the adult, the FRC is determined by the elastic recoil forces of the lungs and the chest wall. In the neonate, the end-expiratory lung volume is actively determined by the breathing pattern (1)(2)(3)(4). During apnea, very frequent at this age, the ability to maintain an oxygen supply from the existing reserves will be determined by the size of the FRC, the existence of any underlying disorders affecting lung growth and ongoing changes in lung volume and mechanics.…”

Fatores associados à morbidade respiratória entre 12 e 36 meses de vida de crianças nascidas de muito baixo peso oriundas de uma UTI neonatal pública

“…O nascimento prematuro pode estar associado com a interrupção do desenvolvimento pulmonar normal que pode resultar em anormalidades na mecânica pulmonar 22 .…”