[Elevation of red cell distribution width during hospitalization predicts mortality in patients with sepsis]

To investigate the association of red cell distribution width (RDW) with prognosis in patients with sepsis.

Patients with sepsis admitted to intensive care unit (ICU) of the First Hospital of Soochow University from January 2011 to December 2016 were enrolled. All clinical data were collected for participants, which mainly included basic data, main underlying disease, site of infection, acute physiology and chronic health evaluation II(APACHE II) score, blood routine test, biochemical test, blood gas analysis, coagulation index, procalcitonin (PCT), hospitalization days, and 28-day and 90-day mortality. Patients were divided into two groups according to whether the RDW levels were higher than the time of admission or not. Kaplan-Meier survival curve was performed to analyze 28-day and 90-day cumulative survival rates in two groups. Multivariate Cox regression analysis was done to find the independent risk factors of death in patients with sepsis.

196 septic patients were eligible to participate into this study. 150 patients (53.57%) had higher RDW levels than those at the time of admission. Compared to negative or static change of RDW group, positive change of RDW group had higher APACHE II score (20.42±6.29 vs. 16.17±6.37), more percentage of chronic kidney insufficiency (35.24% vs. 19.78%), bloodstream infection (32.38% vs. 15.38%), continuous renal replacement therapy (CRRT: 32.38% vs. 16.48%), higher level of C-reactive protein [CRP (mg/L): 14.71±3.52 vs. 11.15±7.94], and higher serum creatinine [SCr (μmol/L): 128.0 (74.0, 263.5) vs. 90.0 (57.0, 145.5)], PCT [μg/L: 3.45 (2.39, 6.64) vs. 2.35 (0.56, 3.54)], and lactic acid [Lac (mmol/L): 3.40±1.72 vs. 2.70±1.61]; and had lower levels of hematocrit (Hct: 0.357±0.128 vs. 0.437±0.143), hemoglobin [Hb (g/L): 103.60±22.63 vs. 115.67±28.49], platelets [PLT (×10⁹/L): 133.37±87.29 vs. 191.43±87.65], albumin [Alb (g/L): 28.15±5.72 vs. 35.51±5.91], total cholesterol [TC (mmol/L): 2.43±1.12 vs. 3.05±1.55], estimated glomerular filtration rate [eGFR (mL×min^-1×1.73 m^-2): 82.02±63.90 vs. 125.46±83.47], and oxygenation index [PaO₂/FiO₂ (mmHg, 1 mmHg = 0.133 kPa): 229.69±60.61 vs. 264.21±74.78]; and longer time of hospitalization [days: 17.0 (12.0, 21.7) vs. 11.0 (7.0, 18.0)], higher 28-day and 90-day mortality (57.14% vs. 36.26%, 62.86% vs. 47.25%) with statistically significant differences (all P < 0.05). It was shown by Kaplan-Meier survival curve that the 28-day and 90-day cumulative survival rate in positive change of RDW group was significantly lower than that of negative or static change of RDW group (χ ₁² = 8.462, χ ₂² = 6.411, both P < 0.05). It was shown by multivariate Cox regression that high APACHE II score [odds ratio (OR) = 1.049, 95% confidence interval (95%CI) = 1.010-1.090, P = 0.013] and positive change of RDW (OR = 0.517, 95%CI = 0.280-0.953, P = 0.034) were the risk factors of death in patients with sepsis.

The change of RDW values during hospitalization was related to the poor outcomes in patients with sepsis. The increase of RDW predicts the progress of sepsis and bad prognosis. Serial surveillance of RDW values could provide useful information for long-term prognosis in sepsis.