528 - Echocardiographic and Lung Ultrasound Changes in Preterm Infants Receiving Repeat-Dose Furosemide

Publication Number: 3509.528

Ianna Blanchard, University of Kentucky College of Medicine, Lexington, KY, United States; Mina Hanna, Kentucky Children's Hospital, Lexington, KY, United States; Rupin Kumar, University of Kentucky College of Medicine, Lexington, KY, United States; Prasad Bhandary, University of Kentucky, Lexington, KY, United States; Ravi Bhavsar, University of Kentucky College of Medicine, Lexington, KY, United States; Hemanthi Veligaram, University of Kentucky, Richmond, KY, United States; Preeti Ramachandran, Kentucky Childrens Hospital, Lexington, KY, United States

Background: Diuretics are often used in preterm infants with evolving bronchopulmonary dysplasia (BPD) to improve lung aeration, but clinical response is variable and assessed qualitatively. Furosemide can decrease preload and influence right ventricular function and ductal shunting, although hemodynamic impact remains unclear. We aimed to evaluate changes in predetermined echocardiographic (ECHO) parameters in preterm infants exposed to furosemide.

Objective: To assess changes in ECHO parameters and lung ultrasound scores (LUSc) following furosemide in preterm infants. To evaluate the relationship between changes in lung ultrasound scores (LUSc) and concurrent changes in ECHO parameters in preterm infants receiving furosemide.

Design/Methods: This is a secondary analysis of an observational study of infants born < 32 WGA with BW < 1.5kg requiring respiratory support who received a furosemide course for evolving BPD. LUSc were measured using a validated scoring tool. Informed consent was obtained. Infants with ECHO data within 7 days before and after furosemide initiation were included. ECHO parameters included patent ductus arteriosus (PDA) size, left atrium-to-aortic root (LA:Ao) ratio, E:A ratio, pulmonary artery acceleration time (PAAT), tricuspid annular plane systolic excursion (TAPSE), and LVEF. Results from both time points were compared. Statistical analysis utilized the Wilcoxon paired t-test and Spearman's rank-order correlation.

Results: Sixteen infants (52% of pilot cohort) underwent an ECHO prior to initiation and after a median of 8 days [IQR 5-9] of furosemide. Median GA was 26w4d and median BW was 780g; PMA at assessment was 29w4d. PDA was present in all 16 infants, with median diameter increasing from 2.0mm to 2.3mm following furosemide exposure (p < 0.05)(Table 1). TAPSE decreased from a median of 1.1cm (IQR 0.82-1.2) to 0.85cm (IQR 0.65-1.07)(p < 0.05)(Fig 1). No significant changes occurred in LVEF, E:A ratio, left ventricular end-diastolic dimension, or PAAT. LUSc improved from a median of 12 (IQR 12-13.75) to 10 (IQR 8-11)(p < 0.05). % reduction in LUSc correlated with % reduction in FiO₂(Spearman r=0.60, p< 0.005)(Fig 2). No significant correlation was observed between change in urine output and change in FiO2 or LUSc.

Conclusion(s): Furosemide was linked to a significant decrease in LUSc, which strongly correlated with reduced FiO2. In the subgroup with ECHOs, TAPSE decreased and PDA diameter increased, suggesting diuresis may reduce pulmonary edema but could impair right ventricular function and enlarge the PDA. Larger prospective studies are needed for validation and to inform safe diuretic use.

Table 1.
Comparison of Lung US scores and echocardiographic findings prior and post furosemide course
Comparison made using Wilcoxon matched-pairs signed rank test, with two tailed p values.

Figure 1.
Change in TAPSE from pre-furosemide to post-furosemide

Figure 2.
Correlation of % change in LUSc with % change in Fio2 from D0 to D3 on furosemide