Mortality Risk Factors and Validation of Severity Scoring Systems in Critically Ill Patients with Acute Renal Failure

Figures & data

Table 1. Patients demographics

	All	Survivors	Nonsurvivors	P
N (%)	324	49 (15.1%)	275 (84.9%)
Age	60.1 ± 16.7	52.9 ± 17.6	61.4 ± 16.2	0.003
Sex
Male	213 (65.7%)	33 (65.3%)	180 (65.5%)	0.79
Female	111 (34.3%)	16 (32.7%)	95 (34.5%)
Type of ARF
Medical	221 (68.2%)	26 (53.1%)	195 (70.9%)	0.005
Surgical	102 (31.5%)	22 (44.9%)	80 (29.1%)
Obstetrical	1 (0.3%)	1 (2%)	0 (0%)
Etiology of ATN
Ischemia	276 (85.2%)	37 (75.5%)	239 (86.9%)	0.04
Nephrotoxins	48 (14.8%)	12 (24.5%)	36 (13.1%)

Table 2. Laboratory tests at referral to nephrologist and on the day of first dialysis

	All	Survivors	Nonsurvivors	P
BUN (mg/dL)
Referral	68.7 ± 29.4	57.5 ± 26.2	70.8 ± 29.4	0.002
Dialysis	88.8 ± 35.9	79.9 ± 35.5	90.2 ± 35.5	0.23
Creatinine (mg/dL)
Referral	3.8 ± 1.3	4.0 ± 1.4	3.7 ± 1.3	0.15
Dialysis	5.2 ± 2.8	5.9 ± 3.1	5.1 ± 2.8	0.26
Sodium (mEq/L)
Referral	139 ± 8	140 ± 8	139 ± 8	0.80
Dialysis	140 ± 8	140 ± 6	140 ± 8	0.85
Potassium (mEq/L)
Referral	4.8 ± 1.2	4.6 ± 1.2	4.8 ± 1.2	0.19
Dialysis	4.9 ± 1.2	4.9 ± 1.2	4.9 ± 1.2	0.68
pH
Referral	7.29 ± 0.11	7.35 ± 0.09	7.29 ± 0.11	0.001
Dialysis	7.27 ± 0.10	7.31 ± 0.09	7.27 ± 0.10	0.06
Bicarbonate (mEqL)
Referral	17.8 ± 5.8	19.6 ± 5.3	17.4 ± 5.8	0.017
Dialysis	17.5 ± 5.4	18.3 ± 3.3	17.4 ± 5.6	0.47
Albumin (g/L)
Referral	23.7 ± 6.7	25.8 ± 6.3	23.4 ± 6.8	0.026
Dialysis	24.1 ± 6.5	25.6 ± 6.9	23.9 ± 6.5	0.33
Protrombin time (%)
Referral	47.8 ± 22.2	51.3 ± 23.9	47.2 ± 21.9	0.27
Dialysis	46.6 ± 21.0	50.1 ± 24.0	46.2 ± 20.7	0.44
Hematocrit (%)
Referral	29.9 ± 5.7	29.2 ± 5.7	30.0 ± 5.7	0.22
Dialysis	29 ± 5	28 ± 4	29 ± 5	0.97
Leukocyte (mm^3)
Referral	12945 ± 7507	11683 ± 5316	13176 ± 7829	0.24
Dialysis	13927 ± 8073	13994 ± 7516	13920 ± 8147	0.93
Platelets (× 10^3/mm^3)
Referral	133 ± 105	148 ± 127	131 ± 100	0.41
Dialysis	134 ± 103	152 ± 141	132 ± 99	0.54

Table 3. Severity scores at referral to nephrologist and on the day of first dialysis

	All	Survivors	Nonsurvivors	P
APACHE II
Referral	31 ± 8.3	24 ± 8.7	32 ± 7.7	< 0.001
Dialysis	33 ± 7.4	26.9 ± 7.5	33.7 ± 7.1	< 0.001
SAPS II
Referral	49.4 ± 14.3	37.2 ± 13.3	51.5 ± 13.3	< 0.001
Dialysis	52.4 ± 13.4	44.4 ± 12.6	53.3 ± 13.2	0.002
ATN-ISI
Referral	0.57 ± 0.20	0.42 ± 0.21	0.59 ± 0.18	< 0.001
Dialysis	0.63 ± 0.18	0.52 ± 0.20	0.64 ± 0.17	0.004
LODS
Referral	7.5 ± 2.2	6.3 ± 1.9	7.6 ± 2.1	< 0.001
Dialysis	7.9 ± 2.2	7.3 ± 1.9	7.9 ± 2.2	0.25
SOFA
Referral	12.8 ± 4.3	10.5 ± 4.1	12.9 ± 4.2	< 0.001
Dialysis	13.9 ± 4.1	12.4 ± 4.5	14.2 ± 3.9	0.07
OSF
Referral	3.0 ± 0.9	2.7 ± 0.9	3.0 ± 0.9	0.06
Dialysis	3.0 ± 0.9	2.7 ± 0.9	3.0 ± 0.9	0.06

Table 4. Mortality risk factors for ARF in the ICU at referral to nephrologist

Risk factor	Odds ratio	95% CI	P
BUN ≥ 70 mg/dL	6.02	2.13–17.0	< 0.01
Sepsis ATN	3.09	1.27–7.51	< 0.05
Age ≥ 65 years	2.81	1.25–6.34	< 0.05
History of hypertension	2.53	1.08–5.95	< 0.05
Creatinine ≥ 3.5 mg/dL	0.42	0.19–0.94	< 0.05
Normal consciousness	0.27	0.13–0.57	< 0.001
SBP ≥ 100 mmHg	0.25	0.11–0.53	< 0.001

Figure 1 ROC curves (A) and Calibration analysis (B), constructed by plotting observed death rate (- -▪ - -) and predicted death rate (—•—) by APACHE II, SAPS II, LODS, and ATN-ISI stratified by deciles of risk at referral to nephrologist (^*Hosmer-Lemeshow chi-square test).

Figure 2 ROC curves (A) and Calibration analysis (B), constructed by plotting observed death rate (- -▪ - -) and predicted death rate (—•—) by APACHE II, SAPS II, LODS, and ATN-ISI stratified by deciles of risk on the day of first dialysis (^*Hosmer-Lemeshow chi-square test).