Gravity-induced loss of aeration and atelectasis development in the preterm lung: a serial sonographic assessment

Lung Ultrasound Assessment of Regional Distribution of Pulmonary Edema and Atelectasis in Infants with Evolving Bronchopulmonary Dysplasia

Background: Preterm infants are at risk for bronchopulmonary dysplasia (BPD) due to prolonged respiratory support. Studies have described differences in the regional distribution of lung ventilation (non-dependent (NDL) vs. dependent (DL)). The aim of this study was to use LUS to compare regional distribution of pulmonary edema and atelectasis in infants with evolving BPD. Methods: We prospectively performed LUS in premature infants with evolving BPD. On each side, three lung areas (NDL/anterior, lateral, and DL/posterior) were examined for the presence of pulmonary edema and atelectasis. Pulmonary edema scores were assigned based on the number of B-lines, and atelectasis scores were assigned based on the presence/absence of atelectasis. Results: 38 premature infants were enrolled. The NDL showed more pulmonary edema and atelectasis compared to the DL (p = 0.003, p = 0.049, respectively) and compared to the lateral lung (p =< 0.001, p = 0.004, respectively). There was no difference between the lateral and DL (p = 0.188, p = 0.156, respectively). There was no difference between the right and the left lung (p = 0.223, p = 0.656, respectively). Conclusions: In this cohort of preterm infants with evolving BPD, lung disease was unevenly distributed, with more pulmonary edema and atelectasis in the NDL regions compared to the DL or lateral regions.

Lung ultrasound detects regional aeration inhomogeneity in ventilated preterm lambs

BACKGROUND

Inhomogeneous lung aeration is a significant contributor to preterm lung injury. EIT detects inhomogeneous aeration in the research setting. Whether LUS detects inhomogeneous aeration is unknown. The aim was to determine whether LUS detects regional inhomogeneity identified by EIT in preterm lambs.

METHODS

LUS and EIT were simultaneously performed on mechanically ventilated preterm lambs. LUS images from non-dependent and dependent regions were acquired and reported using a validated scoring system and computer-assisted quantitative LUS greyscale analysis (Q-LUSMGV). Regional inhomogeneity was calculated by observed over predicted aeration ratio from the EIT reconstructive model. LUS scores and Q-LUSMGV were compared with EIT aeration ratios using one-way ANOVA.

RESULTS

LUS was performed in 32 lambs (~125d gestation, 128 images). LUS scores were greater in upper anterior (non-dependent) compared to lower lateral (dependent) regions of the left (3.4 vs 2.9, p = 0.1) and right (3.4 vs 2.7, p < 0.0087). The left and right upper regions also had greater LUS scores compared to right lower (3.4 vs 2.7, p < 0.0087) and left lower (3.7 vs 2.9, p = 0.1). Q-LUSMGV yielded similar results. All LUS findings corresponded with EIT regional differences.

CONCLUSION

LUS may have potential in measuring regional aeration, which should be further explored in human studies.

IMPACT

Inhomogeneous lung aeration is an important contributor to preterm lung injury, however, tools detecting inhomogeneous aeration at the bedside are limited. Currently, the only tool clinically available to detect this is electrical impedance tomography (EIT), however, its use is largely limited to research. Lung ultrasound (LUS) may play a role in monitoring lung aeration in preterm infants, however, whether it detects inhomogeneous lung aeration is unknown. Visual LUS scores and mean greyscale image analysis using computer assisted quantitative LUS (Q-LUSMGV) detects regional lung aeration differences when compared to EIT. This suggests LUS reliably detects aeration inhomogeneity warranting further investigation in human trials.

Role of Disease Progression Models in Drug Development

The use of Disease progression models (DPMs) in Drug Development has been widely adopted across therapeutic areas as a method for integrating previously obtained disease knowledge to elucidate the impact of novel therapeutics or vaccines on disease course, thus quantifying the potential clinical benefit at different stages of drug development programs. This paper provides a brief overview of DPMs and the evolution in data types, analytic methods, and applications that have occurred in their use by Quantitive Clinical Pharmacologists. It also provides examples of how these models have informed decisions and clinical trial design across several therapeutic areas and at various stages of development. It briefly describes potential new applications of DPMs utilizing emerging data sources, and utilizing new analytic techniques, and discuss new challenges faced such as requiring description of multiple endpoints, rapid model development, application of machine learning-based analytics, and use of high dimensional and real-world data. Considerations for the continued evolution future of DPMs to serve as community-maintained expert systems are also provided.

Lung ultrasound scores in neonatal clinical practice: A narrative review of the literature

Lung ultrasound (LU) has in recent years increasingly been used as a point-of-care method. Initially, LU was used as a so-called descriptive diagnostic method for neonatal respiratory diseases. Instead, this review article focuses on the use of LU as a "functional" tool using classification of findings in patterns or using semiquantitative scores. We review and describe the evidence that led to the implementation of LU in predicting the need for surfactant replacement therapy in preterm infants and in the identification of newborns at risk of developing bronchopulmonary dysplasia. LU appears to be a very promising method for the future of clinical management of newborns in both acute and chronic phases of pulmonary pathologies related to prematurity. However, further studies are needed to define its role before full implementation.