Lowering of the Neonatal Lung Ultrasonography Score after nCPAP Positioning in Neonates over 32 Weeks of Gestational Age with Neonatal Respiratory Distress

Abstract

Respiratory distress (RD) is one of the most common causes of admission to the neonatal intensive care unit. Correct diagnosis and timely intervention are crucial. Lung ultrasonography (LU) is a useful diagnostic tool for the neonatologist in the diagnosis of RD; the neonatal lung ultrasonography score (nLUS) can be used in the diagnostic process, but some authors hypothesise that it is also useful for the management of some neonatal RD. The aim of this study is to analyse the changes in nLUS score before (T0) and after (T1) the start of respiratory support with nasal CPAP in neonates over 32 weeks of age with RD. Thirty-three newborns were enrolled in this retrospective study. LU was performed before and after the start of CPAP. The median nLUS scores at T0 and T1 were 9 (IQR 7−12) and 7 (IQR 4−10), respectively, and showed a significant difference (p < 0.001). The magnitude of reduction in nLUS score, expressed as a percentage, was inversely related to the need for subsequent administration of exogenous surfactant. The study suggests the usefulness of the nLUS score in assessing the response to CPAP in neonates over 32 weeks gestational age.

Keywords: lung ultrasonography; preterm infants; respiratory distress syndrome.

Figure 1

Sonograms at T0 and at T1 of a patient diagnosed with RD. After the positioning of the nCPAP the nlus score has lowered accordingly with the reduction of the coalescent b lines areas. In the second sonogram, the appearance of A lines can easily be noticed.

Figure 2

The lung ultrasonography score (nLUS). Lungs are divided into three areas: upper anterior; lower anterior; lateral. Each area is scored. Score values are related to the patterns that are shown in the upper part of the figure. Scores is given as follows: 0, only A-lines; 1a,b, presence at least 3 B-lines or A-lines in the upper part of the lung, coalescent B-lines in the lower part of the lung; 2, coalescent B lines with or without consolidations limited to sub-pleural space; 3, extended consolidation.