Red Cell Distribution Width as a Predictive Biomarker for Early Lung Injury in Pediatric Patients Following Cardiopulmonary Bypass

Abstract

Background: Red cell distribution width (RDW) has emerged as a prognostic biomarker in various clinical contexts. This retrospective study evaluated the predictive utility of RDW for cardiopulmonary bypass-associated acute lung injury (CPB-ALI) in pediatric patients undergoing cardiac surgery. Methods: A total of 166 children were enrolled and classified into CPB-ALI and non-ALI groups. Preoperative and postoperative RDW values were analyzed. Results: Postoperative RDW was significantly higher in the CPB-ALI group (15.40% vs. 13.78%, p < 0.001). Multivariate logistic regression identified postoperative RDW as an independent predictor of CPB-ALI (OR: 1.35, 95% CI: 1.10-1.64, p = 0.003). Receiver operating characteristic analyses yielded an AUC of 0.732, and restricted cubic spline analyses revealed a nonlinear association between RDW and CPB-ALI risks (p < 0.001). Higher postoperative RDW levels were positively correlated with prolonged mechanical ventilation duration, ICU stay, and total hospital stay (p < 0.001 for all). Conclusions: These findings suggest that postoperative RDW is a cost-effective and accessible biomarker for the early identification of CPB-ALI and may inform individualized perioperative management in pediatric cardiac surgery.

Keywords: acute lung injury (ALI); biomarker; cardiopulmonary bypass (CPB); pediatric cardiac surgery; red cell distribution width (RDW).

Figure 1

Flow chart of the study population. CPB-ALI, cardiopulmonary bypass–associated acute lung injury; CPB-NALI, no acute lung injury.

Figure 2

ROC curve and RCS analysis. (A) ROC curve analysis for postoperative RDW concentrations and the incidence of CPB-ALI in pediatric patients. solid blue line shows sensitivity versus 1 – specificity; dashed gray line is reference (AUC = 0.732); (B) RCS model showing the association between postoperative RDW concentrations and the incidence of CPB-ALI in pediatric patients. Solid red line shows odds ratio across RDW values; shaded area is 95% CI; vertical dashed line indicates cutoff (13.6%). AUC, Area under the curve; CI, confidence interval; RDW, red cell distribution width.

Figure 3

Scatter plots illustrating the association between postoperative RDW concentrations and clinical outcomes. (A) Mechanical ventilation (MV) duration, (B) intensive-care-unit (ICU) length of stay (LOS), and (C) total hospital LOS are presented. RDW, Red cell distribution width; ICU, intensive care unit; LOS, length of stay; MV, mechanical ventilation.