Prognostic value of acute physiology and chronic health evaluation II and organ system failure in patients with acute renal failure requiring dialysis.
BACKGROUND
Despite advances in modern technology of dialysis, prognosis of patients with acute renal failure (ARF) remains poor. To give the clinicians the most useful information, a model that accurately predicts outcome early in the course of ARF is required. However, because ARF is a heterogeneous syndrome and occurs in patients with diverse etiologies and some coexisting diseases, predicting outcome early is hard. The aim of this study is to evaluate prospectively the Acute Physiology and Chronic Health Evaluation (APACHE II) and organ system failure (OSF) models, evaluated prior to dialysis, in predicting hospital mortality.


METHODS
From June 2002 to March 2004, ARF patients requiring dialysis at Chang Gung Memorial Hospital, Chiayi, were prospectively recruited for this study. The worst clinical and laboratory data in the 24 hours before initiation of dialysis were prospectively evaluated, and the patients' APACHE II score and OSF number were assessed.


RESULTS
A total of 61 patients (40 male and 21 female) were enrolled, of whom 38 (62.3%) died before discharge. By multivariate logistic regression, the APACHE II score (odds ratio 1.3 per increase in one score; P<0.001), or OSF number (odds ratio 1.9 per increase in one OSF; P<0.01) and oliguria (odds ratio 4.2; P=0.04), were found to be statistically significant prognostic factors for hospital mortality. Mortality increased progressively and significantly as OSF number (chi-square for trend; P=0.001) or the APACHE II score (chi-square for trend; P < 0.001) increased. By using Youden's index, the best cut-off value for APACHE II was 24, with 63% sensitivity and 96% specificity. The best cut-off value for OSF number was 2, with a sensitivity of 81.6% and a specificity of 60.9%. The areas under the receiver operating characteristic curves for APACHE II and OSF number were 0.847 (95% confidence interval (CI)=0.752-0.942; P<0.01) and 0.769 (95% CI=0.646-892; P<0.001), respectively, indicating good model discrimination.


CONCLUSIONS
This study concludes that APACHE II and OSF number measured prior to initiation of dialysis reliably predict outcomes of ARF patients requiring dialysis. The mortality rates increase as the APACHE II score or OSF number increases. For predicting mortality, the APACHE II score > or = 24 was found to have 63% sensitivity and 96% specificity, and OSF number> or = 2 had 81.6% sensitivity and 60.9% specificity.
Wang
I-Kuan
IK
Division of Nephrology, Chang Gung Memorial Hospital at Chiayi, Taiwan. ikwang@seed.net.tw
Wang
Shan-Tair
ST
Chang
Hung-Yu
HY
Lin
Chun-Liang
CL
Kuo
Huey-Liang
HL
Chen
Te-Chuan
TC
Lee
Chih-Hsiung
CH
Chuang
Feng-Rong
FR
D018806:APACHE; D058186:Acute Kidney Injury / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D015984:Causality; D002423:Cause of Death; D003422:Critical Care / Q000379:methods; D005260:Female; D017052:Hospital Mortality / Q000639:trends; D006801:Humans; D007362:Intensive Care Units; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy*; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D011446:Prospective Studies; D006435:Renal Dialysis / Q000009:adverse effects / Q000379:methods*; D018570:Risk Assessment; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D013624:Taiwan / Q000453:epidemiology; D016896:Treatment Outcome