Lung ultrasound score assessing the pulmonary edema in pediatric acute respiratory distress syndrome received continuous hemofiltration therapy: a prospective observational study

BACKGROUND: Lung ultrasound score is a potential method for determining pulmonary edema in acute respiratory distress syndrome (ARDS). Continuous renal replacement therapy (CRRT) has become the preferred modality to manage fluid overload during ARDS. The aim of this study was to evaluate the value of lung ultrasound (LUS) score on assessing the effects of CRRT on pulmonary edema and pulmonary function in pediatric ARDS. METHODS: We conducted a prospective cohort study in 70 children with moderate to severe ARDS in a tertiary university pediatric intensive care unit from January 2016 to December 2019. 37 patients received CRRT (CRRT group) and 33 patients treated by conventional therapy (Non-CRRT group). LUS score was measured within 2 h identified ARDS as the value of 1st, and the following three days as the 2nd, 3rd, and 4th. We used Spearman correlation analysis to develop the relationship between LUS score and parameters related to respiratory dynamics, clinical outcomes as well as daily fluid balance during the first four days after ARDS diagnosed. RESULTS: The 1st LUS score in CRRT group were significantly higher than Non-CRRT group (P < 0.001), but the LUS score decreased gradually following CRRT (P < 0.001). LUS score was significantly correlated with Cdyn (dynamic lung compliance) (1st: r = − 0.757, 2nd: r = − 0.906, 3rd: r = − 0.885, 4th: r = − 0.834), OI (oxygenation index) (1st: r = 0.678, 2nd: r = 0.689, 3rd: r = 0.486, 4th: r = 0.324) based on 1st to 4th values (all P < 0.05). Only values of the 3rd and 4th LUS score after ARDS diagnosed were correlated with duration of mechanical ventilation [1st: r = 0.167, P = 0.325; 2nd: r = 0.299, P = 0.072; 3rd: r = 0.579, P < 0.001; 4th: r = 0.483, P = 0.002]. LUS score decreased from 22 (18–25) to 15 (13–18) and OI decreased from 15.92 (14.07–17.73) to 9.49 (8.70–10.58) after CRRT for four days (both P < 0.001). CONCLUSIONS: LUS score is significantly correlated with lung function parameters in pediatric ARDS. The improvement of pulmonary edema in patient with ARDS received CRRT can be assessed by the LUS score. Trial registration CCTR, ChiCTR-ONC-16009698. Registered 1 November 2016, prospectively registered, http://www.chictr.org.cn/edit.aspx?pid=16535&htm=4. This study adheres to CONSORT guidelines.