Abstract
BACKGROUND: Critically ill patients with acute respiratory distress syndrome (ARDS) are one of the leading causes of death worldwide. Although a number of relevant predictors of ARDS have been identified, the current predictors are not satisfactory. Recent studies have revealed the predictive value of red blood cell distribution width (RDW) for ARDS. Therefore, we conducted the first meta-analysis to explore the predictive value of RDW in critically ill patients with ARDS. METHODS: A literature search was conducted to identify relevant observational studies from January 1, 2000, to August 1, 2024. Eligible studies were screened and data were extracted. The standardized mean difference (SMD) with 95% confidence interval (CI) of the RDW levels for each study were combined under the random-effect model. RESULTS: Ten articles with a total of 2252 participants were included in the study. Elevated RDW levels on admission was significantly associated with significantly associated with an increased risk of ARDS morbidity (SMD = 1.09; 95% CI = 0.35-1.82; P = .004), and also significantly associated with an increased risk of ARDS mortality (SMD = 0.73; 95% CI = 0.53-0.93; P < .00001). Subgroup analysis further showed RDW ≥ 14.0 on admission could be regarded as a predictive morbidity factor for ARDS (SMD = 1.36; 95% CI = 0.66-2.07; P = .0002), and RDW ≥ 15.5 on admission could be also regarded as a predictive mortality factor for ARDS (SMD = 0.73; 95% CI = 0.49-0.97; P < .00001). CONCLUSION: RDW levels seems to be a useful tool for predicting the morbidity and mortality of critically ill patients with ARDS.