Supplemental Table 1Clinical characteristics and outcomes of critically ill patients admitted in medical and surgical intensive care unit (ICU) during study period
Characteristics / Medical ICU(n=3722) / Surgical ICU
(n=3974)
Age, year, median (IQR) / 65 (53-77) / 66 (53-76)
Male sex, n (%) / 2050 (55) / 2434 (61)
White, n (%) / 3495 (94) / 3719 (94)
Body weight, kg, median (IQR) / 82 (68-98) / 84 (70-97)
Baseline creatinine, mg/dL, median (IQR) / 0.9 (0.7-1.2) / 0.9 (0.8-1.1)
Comorbidities, n (%)
-Diabetes mellitus
-Hypertension
-Coronary artery disease
-Congestive heart failure
-Chronic obstructive pulmonary disease
-Cirrhosis
-Chronic kidney disease* / 980 (26)
2133 (57)
967 (26)
517 (14)
261 (7)
261 (7)
1079 (29) / 836 (21)
2316 (58)
1092 (27)
365 (9)
490 (12)
86 (2)
971 (24)
Nephrotoxic medication, n (%)
-NSAIDs
-Gentamicin
-Amphotericin
-Calcineurin inhibitor / 216 (6)
27 (0.7)
36 (1)
78 (2) / 651 (16)
19 (0.5)
8 (0.2)
35 (1)
APACHE III score, median (IQR) / 44 (31-59) / 47 (35-60)
SOFA score, median (IQR) / 4 (2-6) / 5 (3-7)
Septic shock / 1021 (27) / 494 (12)
Fluid balance in ICU, liter, mean±SD / 1.8±6.1 / 2.8±4.4
ICU length of stay, day, median (IQR) / 1.4 (0.9-2.6) / 1.2 (0.9-2.4)
ICU mortality, n (%) / 160 (4) / 70 (2)
60-day mortality, n (%) / 544 (15) / 193 (5)
*Chronic kidney disease was defined by K/DOQI CKD stage III or worse (estimated glomerular filtration rate < 60 ml/min/1.73 m2 according to CKD-EPI formula)
Abbreviations: APACHE, Acute Physiology and Chronic Health Evaluation; SOFA, Sequential Organ Failure Assessment; IQR, interquartile range; ICU, intensive care unit
Supplemental Table 2.The effect of serum creatinine (SCr) adjustment for fluid balance on acute kidney injury (AKI)diagnosis and the risk for 60-day mortality in a) medical intensive care unit (ICU) and b) surgical intensive care unit (ICU)
a)Medical intensive care unit (ICU)(n=3722)
Fluid adjustment / No fluid adjustment / N / 60-daymortality rate / Adjusted OR (95% CI)*AKI / AKI / 1017 / 28.1% / 2.69 (2.19-3.30)
AKI / No AKI / 72 / 23.6% / 2.25 (1.21-3.99)
No AKI / AKI / 64 / 9.4% / 1.04 (0.39-2.32)
No AKI / No AKI / 2569 / 9.2% / Reference group
AKI; 29.0% before adjustment vs 29.3% after adjustment (P=.49)
* OR is adjusted for age, APACHE score, and fluid balance in ICU.
b) Surgical intensive care unit (ICU)(n=3974)
Fluid adjustment / No fluid adjustment / N / 60-daymortality rate / Adjusted OR (95% CI)*AKI / AKI / 756 / 15.0% / 5.73 (4.14-7.99)
AKI / No AKI / 102 / 10.8% / 3.13 (1.48-6.09)
No AKI / AKI / 23 / 4.4% / 2.08 (0.11-10.67)
No AKI / No AKI / 3093 / 2.2% / Reference group
AKI; 19.6% before adjustment vs 21.6% after adjustment (P<.001)
* OR is adjusted for age, APACHE score, and fluid balance in ICU
Abbreviations: AKI, acute kidney injury; APACHE, acute physiology and chronic health evaluation; CI, confidence interval; OR, odds ratio;
Supplemental Table 3. The effect of serum creatinine(SCr) adjustment for acute kidney injury (AKI) diagnosis in different tertiles of total fluid balance in intensive care unit (ICU)
a)Tertile 1: fluid balance (range -11.6 L to +0.5L)
AKI(no fluid adjustment) / AKI (fluid adjustment) / N (%)
Yes / No
Yes / 455 (17.7) / 86 (3.4) / 541(21.1)
No / 4 (0.2) / 2020 (78.8) / 2024 (78.9)
N (%) / 459 (17.9) / 2106 (82.1) / 2565
b)Tertile 2: fluid balance (range +0.5L to +2.9L)
AKI(no fluid adjustment) / AKI (fluid adjustment) / Total
N (5)
Yes / No
Yes / 468 (18.3) / 1 (0.04) / 469 (18.3)
No / 20 (0.8) / 2076 (80.9) / 2096 (81.7)
Total, N (%) / 488 (19.0) / 2077 (81.0) / 2565
c)Tertile 3: fluid balance (range +2.9 L to +36.6L)
AKI(no fluid adjustment) / AKI (fluid adjustment) / Total
N (5)
Yes / No
Yes / 850 (33.1) / 0 (0) / 850 (33.1)
No / 150 (5.9) / 1566 (61.0) / 1716 (66.9)
Total, N (%) / 1000 (39.0) / 1566 (61.0) / 2566
Abbreviations: AKI, acute kidney injury