Using lung ultrasonography scores to estimate respiratory outcomes at 2 years of age

Using lung ultrasonography scores to estimate respiratory outcomes at 2 years of age | Image Credit: © Elena Medoks - © Elena Medoks - stock.adobe.com.

Authors of a research letter published in JAMA Network Open stated that the lung ultrasonography score (LUS) in very preterm neonates is a "promising tool" for estimating respiratory outcomes in the first 2 years of life.

Though evidence supporting the use of LUS to estimate bronchopulmonary dysplasia (BPD) is growing, the association between LUS and later respiratory outcomes is unknown.

As a result, the investigators enrolled preterm infants (< 30 weeks' gestation) between September 2019 and November 2022 to investigate LUS within the first 3, 7, and 14 days of life (DOL) and its associated respiratory outcomes at 2 years' corrected age. Respiratory outcomes consisted of respiratory exacerbations, physician-diagnosed wheezing episodes, and respiratory medication use.

Respiratory morbidity scores and clinical data were collected and investigators evaluated LUS as a risk factor for respiratory outcomes, "applying area under the receiver operating characteristic curve (AUC) analysis," they wrote. Two-sided P < .05 indicated statistical significance.

Fifty-one patients were enrolled with a mean gestational age (GA) of 27.3 (1.7) weeks and 20 were females. Mean birth weight was 947 (301) grams. Among the 51 patients, 31% developed moderate to severe BPD and 8 (16%) developed mild BPD. Thirty-two infants (63%) received at least 1 respiratory drug of bronchodilators, corticosteroids, and/or antibiotics, 16 (31%) were hospitalized for respiratory problems, and 3 (3%) needed to be admitted to the pediatric intensive care unit (ICU). The mean respiratory morbidity score at 2 years was 0.51 (0.76), according to the authors.

Compared with infants not receiving drugs or hospitalization, infants needing respiratory drugs had higher median LUS at:

- DOL 3 (1 [0-3] vs 6 [3-10]; P = .02)

- DOL 7 (0 [0-1] vs 5 [2-10]; P < .001)

- DOL 14 (1 [0-2] vs 6 [1-11]; P < .001)

Among infants needing hospitalization, LUS was higher at:

- DOL 3 (3 [0-7] vs 4 [3-12]; P < .001)

- DOL 7 (1 [0-4] vs 10 [5-12]; P < .001)

- DOL 14 (2 [0-3] vs 8 [7-12]; P < .001)

Infants needing ICE always had LUS over 8, the study authors noted.

At DOL 3, 7, and 14, LUS correlated with the number of respiratory exacerbations needing drugs (P = 0.762) or hospitalization (P = 0.663), and respiratory morbidity score (P = 0.714). "LUS was associated with respiratory outcomes (eg, DOL 7 AUC, 0.838 [needing drugs] and 0.868 [needing hospitalizations])," stated the authors.

"Our findings suggest that infants with later respiratory problems show signs of worse lung aeration measured by LUS in the first 14 DOL," they added. After GA corrections, significant correlation results have been obtained as early as DOL 7, suggesting a higher LUS at that time is a risk factor for more frequent respiratory episodes. The presence of an active evolving disease in the lungs is also suggested based on different cutoff values, which were higher at later time points.

"Lung ultrasonography performed at DOL 3 may not be associated with long-term outcomes because LUS could be altered by other pathological processes, such as respiratory distress syndrome and patent ductus arteriosus. Good timing to estimate respiratory outcomes seems to be the second week of life, although the ideal DOL remains unknown," said the investigators.

Small sample and inclusion of infants born at 28 to 29 weeks' gestation, with potentially lower risk for respiratory complications were study limitations. In very preterm neonates, the authors concluded the association of LUS with the number of respiratory episodes needing medication and/or hospitalization, and with respiratory morbidity score "suggests that LUS is a promising tool for estimating respiratory outcomes in the first 2 years of life."

Reference:

Bonadies L, De Luca D, Auciello M, et al. Lung ultrasonography scores in preterm infants and respiratory outcomes at age 2 Years. JAMA Netw Open. 2024;7(6):e2415513. doi:10.1001/jamanetworkopen.2024.15513