Research Article

Red Cell Distribution Width to Platelet Ratio Is Associated with Increasing In-Hospital Mortality in Critically Ill Patients with Acute Kidney Injury

Table 1

Characteristics of the included patients.

VariablesAll patients ()RPR value
<0.093 ()≥0.093 ()

Demographic features
 Age (years)68 (56-78)67 (55-77)68 (57-78)<0.001
 Male, (%)13897 (57.5)8745 (56.4)5152 (59.5)<0.001
 Caucasian ethnicity, (%)17338 (71.7)11163 (72.0)6175 (71.3)0.283
Comorbidities
 Congestive heart failure, (%)7823 (32.4)4956 (32.0)2867 (33.1)0.064
 Chronic pulmonary, (%)5759 (23.8)3819 (24.6)1940 (22.4)<0.001
 Diabetes, (%)7587 (31.4)5012 (32.3)2575 (29.7)<0.001
 Obesity, (%)1776 (7.3)1303 (8.4)473 (5.5)<0.001
Laboratory parameters
 Bicarbonate (mmol/L)23.5 (21-26)24 (21.5-26.5)23.5 (20-25.5)0.061
 Bilirubin (mg/dL)0.6 (0.4-1.15)0.55 (0.4-0.9)0.9 (0.5-2.0)<0.001
 Chloride (mmol/L)105 (101.5-108)105 (101.5-108)106.5 (101.5-109)<0.001
 Glucose (mg/dL)136.5 (116-165.5)137.5 (117.5-167)134.5 (114-163)<0.001
 Hematocrit (%)32 (28.6-36)33 (29.5-36.9)30.4 (27.5-34)<0.001
 Hemoglobin (g/dL)10.7 (9.55-12.1)11.05 (9.8-12.5)10.2 (9.2-11.4)<0.001
 Lactate (mmol/L)1.85 (1.35-2.65)1.8 (1.3-2.5)2.0 (1.4-3.0)<0.001
 Potassium (mmol/L)4.2 (3.85-4.65)4.2 (3.85-4.6)4.2 (3.9-4.7)0.128
 Sodium (mmol/L)138.5 (136-140.5)138.5 (136-140.5)138 (136-140.5)0.294
 WBC (109/L)11.2 (8.35-14.9)11.75 (9.1-15.5)10 (7.1-13.9)<0.001
 Lymphocyte (%)11.5 (6.9-18.4)11.7 (7-18.5)11.2 (6.3-18.4)<0.001
 Neutrophile (%)80 (71.1-86.9)80.5 (71.9-87)79.3 (70-86.6)<0.001
 APTT (seconds)32.2 (27.3-42)30.6 (26.4-39)35.5 (29.5-46.5)<0.001
 INR (seconds)1.3 (1.15-1.6)1.25 (1.1-1.45)1.4 (1.2-1.75)<0.001
 RDW (%)14.8 (13.8-16.4)14.4 (13.5-15.7)15.7 (14.4-17.5)<0.001
 Platelet (109/L)200 (146-267.5)234.5 (195-288)129 (100-153.5)<0.001
 NLR7.5 (4.2-12.5)6.2 (3.0-10.8)10.2 (5.8-15.5)<0.001
 PLR159 (39.5-211)132.4 (24.5-182)191 (43.7-255)<0.001
Scoring systems
 SOFA4 (2-7)4 (2-5)6 (4-8)<0.001
 SAPS II36 (24-46)34 (27-44)40 (32-50)<0.001
Therapies
 Renal replacement therapy, (%)1310 (5.4)637 (4.1)673 (7.8)<0.001
 Mechanical ventilation, (%)13457 (55.7)8339 (53.8)5118 (59.1)<0.001
 Vasopressor use, (%)10532 (55.7)6186 (39.9)4346 (50.2)<0.001
Vital signs
 SBP (mmHg)115 (106-128)116 (107-129)113 (105-125)<0.001
 DBP (mmHg)59 (53-66)59 (53-66)58 (52-64)<0.001
 Temperature (°C)36.8 (36.4-37.2)36.8 (36.5-37.2)36.8 (36.4-37.2)0.521
 Respiratory rate (beats/min)18 (16-21)18 (16-21)18 (16-21)0.779
 Heart rate (beats/min)85 (75-96)85 (75-95)85 (75-96)0.505
 SpO2 (%)97.6 (96.2-98.7)97.5 (96.1-98.7)97.6 (96.2-98.8)0.071
Renal function
 Creatinine (mg/dL)1.05 (0.8-1.6)1.0 (0.75-1.45)1.15 (0.8-1.95)<0.001
 BUN (mg/dL)20.5 (14.5-33.5)19 (13.5-30)23.5 (16-39.5)<0.001
AKI stage, (%)<0.001
 Stage 17010 (29.0)4664 (30.1)2346 (27.1)
 Stage 212015 (49.7)8065 (52.0)3950 (45.6)
 Stage 35141 (21.3)2780 (17.9)2361 (27.3)

APTT: activated partial thromboplastin time; AKI: acute kidney injury; BUN: blood urea nitrogen; DBP: diastolic blood pressure; INR: international normalized ratio; NLR: neutrophil to lymphocyte ratio; PLR: platelet to lymphocyte ratio; RDW: red cell distribution width; RPR: red cell distribution width to platelet ratio; SAPS II: simplified acute physiology score II; SBP: systolic blood pressure; SOFA: sequential organ failure assessment; SpO2: oxygen saturation; WBC: white blood cell.