Clinical Usefulness of Red Cell Distribution Width/Albumin Ratio to Discriminate 28-Day Mortality in Critically Ill Patients with Pneumonia Receiving Invasive Mechanical Ventilation, Compared with Lacate/Albumin Ratio: A Retrospective Cohort Study

Abstract

The value of the red cell distribution width (RDW) is associated with prognosis in critically ill patients. A simplex combined index—the RDW/albumin ratio—has been proposed for the prediction of mortality, as has the lactate/albumin ratio. The aim of this study was to evaluate the clinical utility of the RDW/albumin ratio regarding 28-day mortality in critically ill patients with pneumonia. Clinical data of critically ill patients with pneumonia who were hospitalized in the medical intensive care unit from May 2018 to December 2020, and received invasive mechanical ventilation (IMV), were reviewed retrospectively. The values of RDW, lactate, and albumin measured at the time of IMV, were used for the index calculations. Of the 234 patients, the median age was 76 years, and 74.2% were male. The 28-day mortality rate was 47.3%. The median RDW/albumin ratio was significantly higher in non-survivors than survivors at 28 days (5.8 vs. 4.9, p < 0.001). A higher RDW/albumin ratio was significantly associated with increased 28-day mortality (odds ratio [OR] 1.338, 95% confidence interval [CI] 1.094–1.637, p = 0.005). The area under the receiver operating curve (AUROC) was 0.694 (95% CI: 0.630–758, p < 0.005) to discern 28-day mortality without significant difference, compared with that of the lactate/albumin ratio. Our data suggest that high RDW/albumin ratio has a similar predictability to the lactate/albumin ratio in critically ill patients with pneumonia receiving IMV.

The Relationship Between Prognosis and Red Cell Distribution Width (RDW) and RDW-Albumin Ratio (RAR) in Patients with Severe COVID-19 Disease

“…In addition, the authors reported that the 28-day mortality rate was significantly higher in patients with a RAR cut-off value of >5.73 than in patients with a RAR cut-off value of <5.73 (52.3% sensitivity, 79.2% specificity, and AUC: 0.688). 4 In our study, the RAR levels were found to be higher in patients who died and in those who received MV and vasopressor support than in those who survived and did not receive support (for all p< 0.001). Furthermore, when the RAR cut-off value is >5.43, it seems to be as powerful a parameter as RDW in estimating mortality with 91.6% sensitivity, 93.7% specificity, 93.1% NPV and 0.965 AUC values.…”

“…Serum albumin is a laboratory marker that can be routinely measured in blood; it is an acute phase reactant, a protein that plays a role in the control of oncotic pressure and one that has antioxidant properties. 4 In addition, albumin has been shown to be an inflammation marker. 13 , 30 In the studies of Chen and Takegawa et al, the albumin levels were emphasized to be a prognostic factor in patients with pneumonia or sepsis.…”

“… 15 Two recent studies have indicated that the RAR is an independent marker for mortality in critically ill patients. 4 , 16 Yoo et al, associated RAR with mortality in patients with acute respiratory distress syndrome (ARDS). 17 Although RAR has been investigated in various inflammatory disorders, to the best of our knowledge, there are no studies available in the literature investigating the relationship between RAR and COVID-19.…”

Association Between Red Blood Cell Distribution Width–Albumin Ratio and Hospital Mortality in Chronic Obstructive Pulmonary Disease Patients Admitted to the Intensive Care Unit: A Retrospective Study

“…Recently, RAR has been gradually found to be associated with mortality from acute respiratory distress syndrome, 16 stroke, 13 severe pneumonia, 15 and heart failure. 33 However, few studies have shown that RAR is related to the mortality of COPD.…”

“…11,12 Given this, we conjecture that RAR is a negatively correlated indicator of COPD prognosis. Previous studies have also indicated that RAR is associated with mortality in patients with stroke, 13 diabetes, 14 severe pneumonia, 15 and acute respiratory distress syndrome. 16 However, there are few studies that explore the relationship between RAR and the prognosis of COPD patients.…”