Validation of Lung Ultrasound Score for Disease Severity and Outcomes in Pediatric Acute Respiratory Failure

OBJECTIVES: The objective of this study was to investigate the validity of global lung ultrasound (LUS) scores among critically ill children with different etiologies and severities of acute respiratory failure as well as associations with outcomes. DESIGN: Prospective, observational study. SETTING: PICUs at two large children's hospitals. PATIENTS: Children receiving noninvasive or invasive mechanical ventilation and met criteria for acute respiratory distress syndrome (ARDS), lower respiratory tract infection (LRTI), or control group (no lung disease). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: LUS was performed and LUS scores calculated at two time points: 1) within 24 hours of respiratory failure for all groups (time 1) and 2) at 24 hours of time 1 for patients with ARDS and LRTI (time 2). A total of 76 patients (25 ARDS, 26 LRTI, and 25 control) were included. There was a significant difference in median time 1 global LUS scores between groups (ARDS, 19; interquartile range [IQR], 12-24; LRTI, 8 [IQR, 2-11]; and control, 2 [IQR, 0-6]; p < 0.001). Global LUS scores remained similar from time 1 to time 2 in both ARDS (19 to 17) and LRTI (8 to 7) groups. There were moderate correlations between LUS scores and oxygen saturation index ( r = 0.67; p < 0.001), peripheral oxygen saturation/F io2 ratio ( r = -0.63; p < 0.001), mean airway pressure ( r = 0.63; p < 0.001), positive end-expiratory pressure ( r = 0.52; p < 0.001), and dynamic compliance ( r = -0.43; p = 0.001). Higher LUS scores were associated with fewer ventilator-free days at 28 days ( p < 0.001), fewer positive pressure ventilation-free days at 28 days ( p < 0.001), and fewer ICU-free days at 28 days ( p < 0.001). CONCLUSIONS: In critically ill children with acute respiratory failure, global LUS scores within 24 hours of admission differed by severity of parenchymal lung disease, correlated with oxygenation parameters, and were associated with patient-centered outcomes of duration of respiratory support and PICU length of stay.