402 - Baseline Lung Ultrasound Score Stratifies Short-Term Diuretic Response in Preterm Infants: A Pre–Post Observational Pilot Study

Publication Number: 1385.402

Zohaib Sayyed, Connecticut Children's Medical Center, Manchester, CT, United States; Jacob Kelner, Connecticut Children's Medical Center, Hartford, CT, United States; Naveed Hussain, Connecticut Children's Medical Center, Farmington, CT, United States

Background: Respiratory Severity Scores (RSS) and Lung Ultrasound Scores (LUS) are practical bedside measures in preterm infants with evolving chronic lung disease. Since LUS can provide a semi-quantitative method to measure pulmonary edema, it may help delineate which infants are likely to respond to diuretic therapy.

Objective: To (1) quantify short-term changes in RSS and LUS following a single clinically indicated dose of furosemide; (2) test whether the severity of lung disease (LUS ≥10 vs < 10) stratifies response; and (3) examine the association between ΔRSS and ΔLUS after furosemide administration.

Design/Methods: Prospective, single-center pre-post study in a Level IV NICU. Eligible assessments involved infants < 32 weeks' GA. LUS of the anterior, anterolateral, and posterolateral chest was performed ≤12 h pre-dose and 18-24 h post-dose. RSS (FiO₂ × mean airway pressure) was obtained from concurrent respiratory support settings. Repeat assessments were allowed if furosemide doses were ≥ 7 days apart.
Parametric and non-parametric testing were used to compare pre-post LUSs and RSSs for all infants and based on LUS severity (High-LUS ≥10, N=12; Low-LUS < 10, N=12). Linear regression analysis was used to assess the correlation between the change in LUS and the change in RSS.

Results: We analyzed 24 paired assessments from 17 infants. LUSs decreased from 9.8 (SD = 2.6) to 9.5 (SD = 3.0), but this was not statistically significant (p = 0.29). When stratified by baseline severity, infants with an initial High-LUS demonstrated a significant LUS reduction of 1.1 following furosemide (-1.1; p = 0.03), whereas Low-LUS infants showed an increase in LUS of 0.4 (p = 0.23). Change in RSS was correlated with the change in LUS (r = 0.45, p = 0.03). The average RSS across all infants decreased from 2.44 (SD = 1.45) to 2.28 (SD = 1.28), but did not reach statistical significance (p = 0.10). There was no difference in the change in RSS when grouped by High and Low LUSs.

Conclusion(s): Infants with higher LUSs showed a significant change in LUS after furosemide administration. No change was seen in infants with lower LUSs. Using lung ultrasound before furosemide administration may help predict which infants would benefit from diuretic therapy. However, since there was no significant change in RSS, the clinical benefit still requires further evaluation. Larger, more rigorous studies are warranted to test whether LUS-guided diuretic strategies improve clinically meaningful endpoints and reduce unnecessary exposure to diuretics.

Demographics, Respiratory Support, and Lung Ultrasound Scores
Table 1: Demographics, Respiratory Support, and Lung Ultrasound Scores

Change in LUS Vs change in RSS
Figure 1. Association between change in Lung Ultrasound Score and change in Respiratory Severity Score. Each point represents a paired observation (N = 24). Linear regression analysis showed a moderate positive correlation (r = 0.45, p = 0.027), suggesting that shifts in LUS track with concurrent changes in respiratory severity.

Change in Lung Ultrasound Score stratified by baseline LUS
Figure 2. Change in Lung Ultrasound Score stratified by baseline LUS. Box-and-whisker plots compare infants with high baseline LUS ≥10 (N=12) versus low baseline LUS <10 (N=12). The high-baseline group demonstrates a larger reduction in LUS (more negative ΔLUS; lower median and tighter IQR), indicating greater improvement from pre- to post-assessment.