Lung Ultrasound Score, Severity of Acute Lung Disease, and Prolonged Mechanical Ventilation in Children

Rationale: Lung ultrasonography (US) may be useful for the prognostication of acute lung disease. Objectives: To assess whether the lung US score is associated with the severity of lung disease and may predict prolonged invasive mechanical ventilation (IMV) in critically ill children. Methods: Prospective observational multicenter study in children aged 1 month to 18 years who required respiratory support in the ICU. Children with chronic parenchymal lung disease were excluded. The lung US score was obtained at 12 hours and 48-72 hours after admission. Prolonged IMV was defined as at least 7 consecutive days. Correlation of the lung US score with oxygenation as well as its prognostic accuracy for prolonged IMV were investigated. Measurements and Main Results: A total of 538 children were included, and 62 (11.5%) required prolonged mechanical ventilation. In these subjects, the lung US score was higher at 12 (median, 24 [IQR, 19-26] vs. 8 [3-14]; P < 0.001) and 48-72 hours (16 [10.5-22.5] vs. 6 [3-11]; P < 0.001). At 12 hours, the lung US score correlated with oxygenation index (R² = 0.435 [95% CI, 0.293-0.566]; ρ coefficient, -0.705; P < 0.001) and oxygen saturation index (R² = 0.499 [95% CI, 0.370-0.613]; ρ coefficient, 0.651; P < 0.001). The lung US score at 12 hours had good accuracy in predicting prolonged IMV (area under the receiver operating characteristic curve [AUROC], 0.87; 95% CI, 0.81-0.93), and its use in a multivariable model had excellent accuracy in derivation (AUROC, 0.92; 95% CI, 0.89-0.95) and internal validation (AUROC, 0.91; 95% CI, 0.90-0.92). Conclusions: In critically ill children, the lung US score early after admission may predict prolonged IMV.