Lung ultrasound aeration score in pediatric ARDS: associations with oxygenation impairment and RALE score

We evaluated associations of the lung ultrasound aeration score (LUS Aeration Score) and Radiographic Assessment of Lung Edema (RALE) score with oxygenation impairment in pediatric acute respiratory distress syndrome (PARDS) and explored whether either imaging score added incremental discrimination for ICU mortality. This single-center prospective observational study included 42 invasively ventilated children aged 2 months to 16 years with PARDS. LUS Aeration Score, RALE, and oxygenation index (OI) were assessed within 48 h of diagnosis (T1; n = 42) and 48 h later (T2; n = 35). Associations were assessed using Spearman correlation and T1 multivariable linear regression. PaO₂/FiO₂ was examined in sensitivity analyses, and mortality models used Firth penalized logistic regression. LUS Aeration Score correlated with OI at T1 (ρ = 0.65, 95% CI 0.44-0.80) and T2 (ρ = 0.74, 0.53-0.86); RALE also correlated with OI at T1 (ρ = 0.41, 0.12-0.63) and T2 (ρ = 0.65, 0.41-0.81). In the T1 multivariable model, LUS Aeration Score remained associated with ln(OI) (β = 0.0609, 95% CI 0.0290-0.0928; p < 0.001), whereas RALE did not (p = 0.591; R² = 0.417). Adding either imaging score to comorbidity and OI did not materially improve apparent discrimination (AUC 0.812 vs 0.817). Comorbidity remained associated with mortality (adjusted OR 10.09, 95% CI 2.02-99.21 in the LUS model; 11.84, 2.19-125.80 in the RALE model).

LUS Aeration Score was associated with oxygenation impairment and RALE. Lung ultrasound may provide a radiation-free supportive bedside imaging method for serial monitoring of lung injury; mortality analyses remain exploratory and hypothesis-generating.

• Quantitative lung ultrasound and RALE characterize loss of lung aeration and radiographic edema in acute respiratory failure. • Pediatric data directly comparing LUS Aeration Score, RALE, and OI remain limited.

• LUS Aeration Score was moderately to strongly associated with OI and was associated with RALE at two early time points. • PaO₂/FiO₂ analyses supported the oxygenation findings; neither imaging score materially improved mortality discrimination beyond comorbidity and OI.