ABSTRACT
BACKGROUND: Red blood cell distribution width (RDW) value is gaining popularity as a prognostic factor in critically ill patients. However, its role in transfused patients is unclear. The aim of this study was to evaluate the predictive value of Red blood cell distribution width (RDW) on Intensive Care Unit (ICU) admission for 90-day mortality among either transfused or non-transfused critically ill patients. METHODS: This observational cohort study includes 286 patients with at least 48 hours of ICU length of stay. Patients were analyzed separately in two groups, depending on whether or not they were transfused in the last 72 hours before ICU admission. RESULTS: One hundred seventeen (117) patients (41%) were transfused. Patients with high RDW on admission (N.=181, 63%) had higher 90-day mortality both in non-transfused (26/87, 30% vs. 12/82, 14% P=0.03) or transfused (39/94, 41% vs. 2/23, 8% P=0.003) patients. The area under the curve of admission RDW values to predict 90-day mortality was 0.660 and 0.610 for non-transfused and transfused patients, respectively. The Youden Index analysis showed that an RDW value of 14.3% was the best cut-off to predict mortality in the non-transfused group, while 15.3% was the best cut-off in the transfused group. CONCLUSIONS: High RDW values on ICU admission are independently associated with 90-day mortality in critically ill patients regardless of previous red blood cells transfusion. However, we identified two different cut-offs of "high RDW" to be used in ICU in transfused and non-transfused patients.
Subject(s)
Critical Illness/therapy , Erythrocyte Indices , Erythrocyte Transfusion , Adult , Aged , Aged, 80 and over , Area Under Curve , Biomarkers , Cohort Studies , Critical Illness/mortality , Erythrocyte Transfusion/mortality , Female , Humans , Intensive Care Units , Length of Stay , Male , Middle Aged , Predictive Value of Tests , Prognosis , Prospective StudiesABSTRACT
BACKGROUND: Red blood cell distribution width (RDW) is a measure of anisocytosis, generally used in the differential diagnosis of anemia. Recently, RDW was associated with increased mortality in critically ill patients. Red blood cell (RBC) transfusions are potential confounders on RDW values interpretation. The aim of this study was to analyze the changes in RDW after RBC transfusion in intensive care unit (ICU) patients. STUDY DESIGN AND METHODS: This was a prospective, observational study including patients admitted to ICU requiring 1 RBC unit. We analyzed RDW values of the patients at four study points: before RBC transfusion (T1), immediately after transfusion (T2), 24 hours after transfusion (T3), and 48 hours after transfusion (T4). We also collected laboratory data from donors and RBC units. Changes of RDW (ΔRDW) were computed as the difference between baseline RDW value and RDW at each time point after transfusion. RESULTS: We enrolled 36 patients. RDW values increased after transfusion (p < 0.001 at all points vs. baseline), with the highest level at T3. At T3, 34 of 36 patients (94%) had an abnormal RDW value (vs. 26/36, 72%) at baseline (p = 0.023). The maximum ΔRDW for each patient was moderately correlated with the difference between mean corpuscular volume (MCV)donors and MCVpatient (r = 0.478, p = 0.005). Subgroups analysis showed that the maximum ΔRDW was greater in patients with baseline MCV lower than 80 fL or higher than 100 fL (n = 7) or baseline RDW of more than 14.5% (n = 19). CONCLUSION: RBC transfusion significantly increased RDW values. This intervention should be accurately reported in the studies evaluating the prognostic role of RDW.
