Table 3.

Characteristics of the study population by presence or absence of early Cr elevation

VariableNo Early Cr ElevationWith Early Cr ElevationP Value
N292214
Age (yr)61 (47–74)69 (59–78)<0.001
Men163 (55.8)138 (64.5)0.05
BMI (kg/m2)21.2 (19.1–23.6)21.2 (19.4–24.4)0.23
SAPS II41 (33–50)46 (39–55)<0.001
SOFA4 (2–6)7 (4–9)<0.001
APACHE II16 (12–20)20 (15–25)<0.001
Serum creatinine, admission (mg/dl)0.8 (0.6–1.0)1.2 (0.8–1.5)<0.001
Serum urea, admission (mg/dl)34 (23–48)54 (33–80)<0.001
Urine output, ICU day 1 (ml/kg per hour)1.2 (0.8–1.9)1.2 (0.7–1.9)0.22
Bilirubin, admission (mg/dl)0.7 (0.5–1.0)0.7 (0.5–1.1)0.22
Number of risk factors for AKI
 Number of chronic major risk factors1 (0–2)1 (0–2)<0.001
 Number of chronic major risk factors≥279 (27.1)91 (42.5)<0.001
 Number of chronic minor risk factors1 (0–2)1 (1–2)0.12
 Number of chronic minor risk factors≥290 (30.8)77 (36)0.25
 Number of acute risk factors1 (0–1)2 (1–2)<0.001
 Number of acute risk factors≥268 (23.3)115 (53.7)<0.001
Hazard tier
 Very high risk10 (3.4)94 (43.9)<0.001
 High risk129 (44.2)77 (36.0)<0.001
 Moderate risk109 (37.3)43 (20.1)<0.001
Chronic major risk factors
 Age>70 yr111 (38)104 (48.6)0.01
 Diabetes48 (16.4)44 (20.6)0.24
 Cardiovascular disease97 (33.2)110 (51.4)<0.001
 CKD4 (1.4)27 (12.6)<0.001
Chronic minor risk factors
 Hypertension121 (41.4)107 (50)0.06
 BMI>30 kg/m221 (7.2)13 (6.1)0.72
 Bilirubin>2 mg/dl17 (5.8)24 (11.2)0.03
 Cerebrovascular accident124 (42.5)92 (43)0.93
 AIDS1 (0.3)2 (0.9)0.58
 Cancer31 (10.6)21 (9.8)0.88
Acute risk factors
 Hypotension48 (16.4)114 (53.3)<0.001
 Vasoactive therapy14 (4.8)98 (45.8)<0.001
 Sepsis55 (18.8)74 (34.6)<0.001
 Mechanical ventilation206 (70.5)174 (81.3)0.01
 High-risk surgery95 (32.5)76 (35.5)0.51
 Nephrotoxin exposure66 (22.6)68 (31.8)0.02
ICU outcomes
 Severe AKI6 (2.1)53 (24.8)<0.001
 RRT5 (1.7)31 (14.5)<0.001
 Mortality29 (9.9)76 (35.5)<0.001
 Severe AKI or death31 (10.6)98 (45.8)<0.001
 Length of ICU stay (d)4 (2–11)8 (4–16)<0.001
  • Categorical variables are expressed as n (%). Continuous variables are expressed as median (interquartile range). BMI, body mass index.