Degree of Acute Kidney Injury before Dialysis Initiation and Hospital Mortality in Critically Ill Patients

Table 1

Baseline characteristics in AKI requiring dialysis patients by groups of severity of injury before dialysis initiation.

Risk factors in AKI requiring dialysis^¶	Group I	Group II	Group III	Group IV	P value
(N, 2,744)	N = 1,006%	N = 574%	N = 856%	N = 308%
Gender					0.010
Male (N, 2,694; 98.2%)	98.4	98.4	98.6	95.7
Female (N, 50; 1.8%)	1.6	1.6	1.4	4.3
Age					0.014
<39 years (N, 29; 1%)	0.9	0.9	1.0	1.9
40 to 59 years (N, 869; 31.7%)	32.8	28.9	29.2	39.9
60 to 79 years (N, 1,525; 55.6%)	55.1	56.6	58.5	47.1
>80 years (N, 321; 11.7%)	11.2	13.6	11.2	23.7
Race					<0.0001
White (N, 1,701; 61.2%)	56.6	59.2	65	64.9
Black (N, 627; 22.8%)	29.7	26.8	21.1	23.7
Other (N, 416; 15.2%)	13.7	13.9	13.9	11.4
Creatinine* (mg/dL); 2.3 (1.4–3.1)	3.0 (2.4–3.6)	2.2 (1.7–2.8)	1.3 (1.0–1.7)	3.0 (2.2–3.7)	<0.0001
BUN* (mg/dL); 34 (20–56)	47 (29–68)	38 (25–52)	21 (14–30)	52 (30–78)	<0.0001
CHF (N, 415; 15.1%)	19.3	13.1	11.7	15.3	<0.0001
Cardiac arrhythmias (N, 457; 16.6%)	15.5	18.3	16.7	17.2	0.545
Peripheral circulation disorders; (N, 203; 7.4%)	5.6	8.7	10.5	2.3	<0.0001
Hypertension (N, 284; 10.3%)	8.7	10.4	11.2	13	0.122
Chronic pulmonary disease; (N, 445; 16.22%)	17.6	15.8	14.8	16.2	0.446
Diabetes (uncomplicated); (N, 478; 17.4%)	19	19.3	13.3	20.1	0.0020
Diabetes (complicated); (N, 228; 8.3%)	11.4	8.5	4.1	9.4	<0.0001
Renal failure (N, 484; 17.6%)	22.3	20.9	11.3	13.4	<0.0001
Liver disease (N, 255; 9.3%)	11.5	7.7	7.4	10.4	0.0073
Solid tumors—no metastasis; (N, 207; 7.5%)	5.7	8.4	10	5.2	0.0013
Coagulopathy (N, 444; 16.2%)	15.7	16.5	16.9	14.9	0.815
Fluid and electrolyte disorders (N, 887; 32.3%)	31.3	30	28.7	50	<0.0001

Groups based on creatinine elevation before dialysis initiation: I: 0.3 mg/dL to <2 times increase in creatinine; II: 2 to <3 times increase; III: >3 times increase; IV: <0.3 mg/dL increase; *creatinine and blood urea nitrogen values: median and interquartile range; Chi-square tests and Kruskal-Wallis test.