(36) Correlation of Lung Field Ultrasound Scores and Sonographic Measurements of Diaphragmatic Excursion with Extubation Success in Intubated NICU Patients Receiving a Dexamethasone Taper

Background: Point-of-care ultrasound (POCUS) is an emerging tool in neonatology. Semiquantitative lung ultrasound scores (LUS), which use artifacts to grade lung aeration, can predict bronchopulmonary dysplasia (BPD) development. Similarly, diaphragmatic excursion (DE) measurements may predict extubation success in preterm neonates. While steroids may facilitate extubation from invasive mechanical ventilation (IMV), there is a lack of objective data on steroid response. We hypothesize that combined LUS and DE measurements can predict clinical response to dexamethasone in intubated preterm neonates.

Objectives: The goal of our study is to investigate whether LUS and DE measurements taken during a steroid course are correlated with a successful extubation or the need for long-term IMV via a tracheostomy.

Design/Methods: This prospective study includes infants with gestational age at birth < 29 weeks receiving IMV and receiving a dexamethasone taper per the DART protocol. Exclusion criteria include any chest, lung, or diaphragm malformations. Baseline LUS and DE scans are obtained within 24 hours of a steroid taper start, and post-extubation scans are obtained at least 48 hours after extubation attempt. A Respiratory Severity Score [RSS = MAP (mean airway pressure) x FiO2 (fraction of inspired oxygen)] is calculated on the same days that scans are done. Primary outcome is liberation from IMV at 72 hours after an extubation attempt. Secondary outcome is need for tracheostomy at NICU discharge. Results are reported using descriptive and nonparametric statistical methods.

Results: Data from 17 steroid courses have been analyzed. Twelve subjects were successfully extubated, and 5 were not. Clinical traits and baseline and post-extubation (post-E) LUS, DE, and RSS are summarized in Tables 1-2. Only the median post-E DE differed significantly from the successful extubation group (0.5 cm) to the unsuccessful extubation group (0.8 cm). There were no significant differences between the baseline and post-E LUS, DE, or RSS within either group. Between the 6 subjects who received a tracheostomy and the 8 who did not, there were no differences in LUS, DE, or RSS (Table 3).

Conclusions: Although our preliminary data suggest that comparing baseline and post-extubation LUS and DE values may not predict a preterm infant’s successful extubation during a steroid course, there may be utility in tracking DE on extubated preemies. Further enrollment is planned.