Risk, Injury, Failure, Loss, And End-stage Criteria Research Articles

Sensitivity and Specificity of a Single Emergency Department Measurement of Urinary Neutrophil Gelatinase–Associated Lipocalin for Diagnosing Acute Kidney Injury

A single serum creatinine measurement cannot distinguish acute kidney injury from chronic kidney disease or prerenal azotemia. To test the sensitivity and specificity of a single measurement of urinary neutrophil gelatinase-associated lipocalin (NGAL) and other urinary proteins to detect acute kidney injury in a spectrum of patients. Prospective cohort study. Emergency department of Columbia University Medical Center, New York, New York. 635 patients admitted to the hospital with acute kidney injury, prerenal azotemia, chronic kidney disease, or normal kidney function. Diagnosis of acute kidney injury was based on the RIFLE (risk, injury, failure, loss, and end-stage) criteria and assigned by researchers who were blinded to experimental measurements. Urinary NGAL was measured by immunoblot, N-acetyl-beta-d-glucosaminidase (NAG) by enzyme measurement, alpha1-microglobulin and alpha(1)-acid glycoprotein by immunonephelometry, and serum creatinine by Jaffe kinetic reaction. Experimental measurements were not available to treating physicians. Patients with acute kidney injury had a significantly elevated mean urinary NGAL level compared with the other kidney function groups (416 microg/g creatinine [SD, 387]; P = 0.001). At a cutoff value of 130 microg/g creatinine, sensitivity and specificity of NGAL for detecting acute injury were 0.900 (95% CI, 0.73 to 0.98) and 0.995 (CI, 0.990 to 1.00), respectively, and positive and negative likelihood ratios were 181.5 (CI, 58.33 to 564.71) and 0.10 (CI, 0.03 to 0.29); these values were superior to those for NAG, alpha1-microglobulin, alpha1-acid glycoprotein, fractional excretion of sodium, and serum creatinine. In multiple logistic regression, urinary NGAL level was highly predictive of clinical outcomes, including nephrology consultation, dialysis, and admission to the intensive care unit (odds ratio, 24.71 [CI, 7.69 to 79.42]). All patients came from a single center. Few kidney biopsies were performed. A single measurement of urinary NGAL helps to distinguish acute injury from normal function, prerenal azotemia, and chronic kidney disease and predicts poor inpatient outcomes.

Karnofsky performance score in acute renal failure as a predictor of short‐term survival

Karnofsky Performance Scale Index (KPS) is a measure of functional status that allows patients to be classified according to their functional impairment. We aim to assess if the prior KPS may predict the risk of death among patients with acute renal failure (ARF). A cohort of 668 consecutive patients who had been admitted in an university-affiliated hospital between June 2000 and June 2006, and had been diagnosed with ARF, were studied. Three hundred and eighty-six patients with ARF who matched at least one of the RIFLE (Risk, Injury, Failure, Loss and End stage) criteria on increased serum creatinine were included for subsequent analysis. The group was divided into four categories, according to different Karnofsky scores measured by a nephrologist (>or=80, 70, 60 and <or=50). We used an adjusted logistic regression model to assess the relationship between the Karnofky score and mortality. A significant risk of in-hospital mortality within 90 days was observed when the other groups were compared with the >or=80 Karnofsky group. Adjusted odds ratios were 8.87 (95% confidence interval (CI) 3.03-25.99), 6.78 (95% CI 2.61-17.58) and 2.83 (95% CI 1.04-7.68), for Karnofsky groups of <or=50, 60 and 70, respectively. An adjusted odds ratio of 1.75 (95% CI 1.37-2.23) was observed for every 10 point decrease in KPS score. Functional status as indicated by the KPS is an independent predictor of death in this cohort of patients with ARF. Patients who presented lower scores had increased mortality rates.

Prognostic utility of RIFLE for acute renal failure in patients with sepsis

Acute renal failure (ARF) is common among patients with sepsis and increases mortality [1]. However, the prognostic utility of the newly released classification for ARF, entitled RIFLE (Risk, Injury, Failure, Loss, and End-stage kidney disease) [2], in predicting mortality in such patients has not yet been assessed. We sought to evaluate retrospectively the usefulness of RIFLE in predicting mortality in patients with sepsis admitted to the infectious disease intensive care unit (ICU) of our hospital between January 2005 and December 2006. Data were collected from the unit database. Sepsis was classified in accordance with American College of Chest Physicians and the Society of Critical Care Medicine consensus [3]. Patients with chronic kidney disease on dialysis were excluded from the analysis. The Simplified Acute Physiology Score (SAPS) version II was calculated based on the worst variables recorded during the first 24 hours of ICU admission. Mortality was assessed at day 60 [2]. Forward stepwise multivariate regression analysis was employed to evaluate independent predictors of mortality. The goodness-of-fit was tested by means of the Hosmer-Lemeshaw statistic. Area under the receiver operating characteristic curve (AUROC) was employed to evaluate the prognostic accuracy of RIFLE and SAPS II. A two-tailed P < 0.05 was considered statistically significant. One-hundred and eighty-two patients (mean age 56.2 ± 18.56 years; 120 male; 162 white) were analyzed. Fourteen patients had sepsis, 108 patients had severe sepsis and 60 patients had septic shock. Sixty-eight patients (37.4%) had ARF: 11 patients were in class 'risk' (in RIFLE), 21 patients were in class 'injury', and 36 patients were in class 'failure'. The mortality rate was 37.4%, and increased from classes 'normal' to 'failure' (normal, 9.6%; risk, 27.3%; injury, 28.6%; failure, 55%; P < 0.0001). Multivariate analysis including age above 60 years, sex, SAPS II above 50, comorbidity (namely cardiovascular disease), and RIFLE class revealed that SAPS II score above 50 (odds ratio 0.12, 95% confidence interval [CI] 0.04–0.29; P < 0.0001) and class 'failure' (odds ratio 3.59, 95% CI 1.44–8.94; P = 0.006) were independent predictors of mortality. Similarly, SAPS II score above 50 (AUROC 0.778, 95% CI 0.694–0.863; P < 0.0001) and ARF according to RIFLE (AUROC 0.725, 95% CI 0.63–0.81; P < 0.0001) had good prognostic accuracy. In summary, ARF, based on RIFLE criteria, is common in patients with sepsis, and is associated with increased mortality. RIFLE appears to be a useful prognostic tool in such patients.