Renji acute kidney injury score is a useful tool to predict acute kidney injury after cardiac surgery / 中华肾脏病杂志

Objective To validate the effect of Renji acute kidney injury score (RAKIS) on predicting patients with acute kidney injury (AKI) after cardiac surgeries,and make comparison with Cleveland score,simplified renal index (SRI) and acute kidney injury following cardiac surgery (AKICS).Methods Patients undergoing open heart surgery from 2008/01/01 to 2010/10/31 in Renji hospital were enrolled,and their scores of those four scoring models were calculated.AKI patients were diagnosed by KDIGO,and those scores of AKI patients and non-AKI patients were compared.Receiver operating characteristic (ROC) curve and area under curve (AUC) were used to decide the predictive values of those models.Results A total of 1126 patients were chosen in this cohort,with the average age of (58.43±14.88) years (rang from 18 to 88).The male to female ratio was 1.47:1.And 355(31.5％) patients were developed AKI.AKI stage Ⅰ,Ⅱ and Ⅲ were 65.4％,23.7％ and 11.0％ respectively.RAKIS was significantly higher in AKI patients than in non-AKI patients (17.5 vs 9.0,P ＜ 0.001).The AUCs of RAKIS to predict AKI,AKI Ⅱ-Ⅲ stages,renal replacement therapy (RRT)and in-hospital death were 0.818,0.819,0.800 and 0.784 respectively.The AUCs of Cleveland score and SRI were 0.659 to 0.710,lower than those of RAKIS and AKICS.AKICS had lower value for predicting AKI and AKI Ⅱ-Ⅲ stages (AUC 0.766 and 0.793),but good value in predicting RRT and inhospital death after surgery (AUC 0.804 and 0.835) as compared with RAKIS.Conclusions RAKIS is valid and accurate in the discrimination of KDIGO defined AKI patients,while for predicting the composite end point,AKICS may be more useful.

Preoperative serum cystatin C combined with dipstick proteinuria predicts acute kidney injury after cardiac surgery / 中华胸心血管外科杂志

Objective To evaluate serum cystatin C combined with dipstick proteinuria as early markers to predict AKI available before surgery.Methods We prospectively followed 616 patients undergoing cardiac surgery.Univariate as well as multivariate regression was performed.Cystatin C combined with dipstick proteinuria before surgery was assessed for its' predictive value of AKI using receiver operator characteristic (ROC) curves.Results Patients in higher cystatin C quartiles were older(P ＜ 0.001),more often to have heavy proteinuria(P =0.021),hyperuricemia(P ＜ 0.001),heart failure(P ＜ 0.001)and recent MI (P =0.002).Those with heavy proteinuria were more often to have diabetes mellitus (DM) (P =0.010),hyperuricemia (P =0.043),worse cardiac function (P ＜ 0.001),higher creatinine levels (P ＜ 0.001) and lower eGFR levels (P ＜0.001).In a multiple logistic regression model,preoperative heavy proteinuria(OR =3.14) and preoperative cystatin C quartiles each associated with an increased odds of AKI,independent of advanced age (OR =1.04),hypertension (OR =1.88) and combined surgery(OR =3.47).The risk for adverse outcomes such as postoperative AKI,persistent AKI,severe AKI,dialysis and mortality were highest in patients with highest quartile of cystatin C(P ＜0.05,respectively) and heavy proteinuria (P ＜ 0.05,respectively).The area under the ROC curve(AUCs) for preoperative cystatin C combined with proteinuria to detect AKI,persistent AKI and severe AKI were 0.695,0.753 and 0.718,P ＜0.001 respectively.Conclusion These data suggest that preoperative serum cystatin C combined with dipstick proteinuria may improve prediction of AKI among patients undergoing cardiac surgery.

The level of the biomarkers at the time of nephrology consultation might predict the prognosis of acute kidney injury in hospitalized patients.

INTRODUCTION: The value of biomarkers at the time of nephrology consultation in predicting the prognosis of acute kidney injury (AKI) in hospitalized patients has not been well described. This study aimed to evaluate the possibility of biomarkers at the time of nephrology consultation in predicting the prognosis of AKI. METHODS: We prospectively enrolled 103 hospitalized patients who developed AKI. Urinary Neutrophil Gelatinase Associated Lipocalin (NGAL), IL-6, IL-18, N-Acetyl-ß-D-Glucosaminidase (NAG), and serum Cystatin C (CysC) were measured at the time of nephrology consultation. Baseline values of serum creatinine (bScr), serum creatinine on consultation (cScr) and the peak level of serum creatinine (pScr) were recorded. All the patients were followed-up till 28 days since consultation. Serum and urinary levels of the biomarkers were compared according to the patient or kidney prognosis. Each marker was assessed for its predictive value using receiver operator characteristic (ROC) curves to predict AKI prognosis. RESULTS: Patients were aged 54.28 ± 19.05. Male patients constituted 65% of the study group and baseline Scr was 93.54 ± 35.98 µmol/l. The mortality rate of the patients was 25.2% and kidney loss rate was 18.8% at 28 days after consultation. The level of urinary NGAL was significantly higher in death patients than that in survival patients [147.00 (31.59, 221.87) µg/ml vs. 22.43 (6.48, 89.77) µg/ml, p = 0.001], while the level of bScr, cScr, pScr, urinary IL-6 and NAG were similar in both these groups. The AUC of urinary NGAL for predicting patients' death was 0.723 (p = 0.001). Serum CysC and urinary IL-18 concentration was higher in the death patients with a marginal p value (p = 0.065 and 0.059 respectively). All the urinary markers, including NAG, NGAL, IL-6 and IL-18 were significantly higher in patients with kidney loss than in those with kidney survival, while no difference was found in Scr and serum CysC levels. The AUCs of these urinary biomarkers for predicting kidney survival were 0.663, 0.655, 0.705 and 0.663 respectively (p < 0.05). The concentrations of cScr, pScr, serum CysC, urinary IL-6 and NGAL were significantly higher in RRT patients (p < 0.05). The AUCs for predicting RRT were 0.628, 0.781, 0.768, 0.672 and 0.775 respectively. CONCLUSIONS: The level of biomarkers at the time of nephrology consultation might predict the prognosis of AKI in hospitalized patients. Further studies should be done to understand the role of the serum and urinary markers in the prognosis of AKI.

Analysis of the incidence and risk factors of acute kidney injury in respiratory failure patients / 中华肾脏病杂志

Objective To determine the incidence and risk factors of acute kidney injury (AKI) in respiratory failure patients.Method Clinical data of 235 patients diagnosed as respiratory failure admitted in respiratory division and internal medicine intensive care unit in Renji Hospital from January 2006 to December 2008 were analyzed retrospectively.Patients'demographics,clinical data and laboratory examinations before and after respiratory failure were collected.The incidence,clinical risk factors and hospital mortality of AKI in the respiratory failure patients were analyzed.Multivariate Logistic regression analysis was used to investigate the independent risk factors of AKI in these patients.Results Of the total 235 patients,the average age was (70.05±12.85) years old,the ratio of male to female was 1.90:1.Seventy-seven patients developed AKI and the incidence was 32.8％.The incidence of AKI in those with hypertension (44.4％ vs 26.6％,P＜0.01) or chronic kidney disease(66.7％ vs 31.3％,P＜0.01) was significantly higher.The incidence of AKI in patients with mechanical ventilation was much higher than those without mechanical ventilation(44.8％ vs 13.3％,P＜0.01).The incidence of multi-organ system failure (33.8％ vs 5.7％,P＜0.01),the failure of weaning from mechanical ventilation(69.2％vs 32.5％,P＜0.01) and the mortality (51.9％ vs 13.3％,P＜0.01) in AK1 patients were higher than those without AKI.Multivariate Logistic regression analysis showed that age (OR=1.668),anemia (OR=0.980),baseline serum creatinine (OR=1.071) and mechanical ventilation (OR=3.222) were independent risk factors of AKI.Conclusions Incidence and mortality of AKI are quite high in respiratory failure patients.Age,baseline serum creatinine,anemia and mechanical ventilation are independent risk factors of AKI.

Value of urine L-FABP and its combination with urine NGAL in early diagnosis of acute kidney injury after cardiac surgery in adults / 中华肾脏病杂志

Objective To investigate the value of urinary liver-type fatty acid-binding protein (L-FABP),neutrophil gelatinase-associated lipocalin (NGAL) and their combination in predicting the development and the severity of acute kidney injury (AKI) following cardiac surgery in adults. Methods Scr,urinary L-FABP and NGAL corrected by urine creatinine at preoperation,0 h and 2 h postoperative time points were examined.The differences of above indexes between AKI and non-AKI groups were compared.Receiver operating characteristic (ROC)curves and area under curves (AUC) were used to evaluate the diagnostic value of urinary L-FABP,NGAL and their combination for AKI. Results The cohort consisted of 109 patients,26(23.9％) developed AKI,and AKIN stage Ⅰ, Ⅱ and Ⅲ was 46.2％,34.6％ and 19.2％ respectively.Levels of urinary L-FABP and NGAL were significantly higher in AKI patients at 0 h and 2 h postoperatively.AUC to predict AKI or AKI stage Ⅱ-Ⅲ was 0.81 to 0.87 using either of the biomarkers.The performance of combining two biomarkers was better with AUC of 0.911 to 0.927. Conclusions Urinary L-FABP and NGAL increase at the early stage after cardiac surgery.Combination of these two biomarkers enhances the accuracy of the early diagnosis of postoperative AKI after cardiac surgery before a rise of Scr.

Combined detection of markers in the early diagnosis of acute kidney injury following cardiac surgery / 中华肾脏病杂志

Objective To investigate the markers in early diagnosis of acute kidney injury (AKI) in patients undergoing heart surgery.Methods Markers included serum cystatin C (CyC),and urinary neutrophil gelatinase-associated lipocalin(NGAL),interleukin 18(IL-18),retinol binding protein(RBP)and N-acetyl-β-D-glucosaminidase(NAG).Twenty-nine cardiac surgical patients hospitalized were enrolled in the study.Serial blood and urine samples were collected immediately before incision and at various time intervals after surgery.The primary outcome measure was AKI.defined as a 50%increase in Scr from baseline. Results The cohort consisted of 29 patients aged(62.9±13.7)years,and baseline Scr was(73.2±11.9)μmol/L.There were no significant differences in demographics between cases and controls,while the aortic clamp time was predictably longer in AKI cases as compared to controls[(60.63±13.92)vs(43.00±9.20)rain,P<0.05].Each biomarker difiered significantly between cases and controls at least one timepoint.Optimal AUCs were for CyC at 10 houm with sensitivity (ST)0.71,specificity(SP)0.92,AUC=0.83(0.67-1.00),cut-off(CO)1.31 mg/L;NGAL at 0 hour with ST 0.84,SP 0.80,Auc=0.85(0.70-1.00),CO 49.15 μg/g Ucr;IL-18 at 2 hours with ST 0.85,SP 0.73,AUC=0.81(0.64-0.97),CO 285.65 ng/g Ucr;RBP at 0 hour with ST 0.75,SP 0.67,AUC=0.77(0.60-0.95),CO 2934.65μg/g Ucr and NAG at 4 hours with ST 0.86,SP 0.67,AUC=0.72(0.53-O.92),CO 37.05 U/mg Ucr.Using a combination of all the 5 biomarkers analyzed at the optimal time-point as above,an AUC of 0.98(0.93-1.02)(P<0.01)in this limited sample was able to obtain. Conclusions Application of serum and urinary biomarkers for the prediction of AKI in patients undergoing cardiac surgery is highly dependent on the sampling time.Of the evaluated markers,uNGAL has the best predictive profile.uRBP also shows similar predictive power.Combining all the five above biomarkers is able to predict significantly more cases,suggesting that the use of more than one marker may be beneficial clinically.

Acute kidney injury is a risk factor for the long-term prognosis of cardiac surgery / 中华肾脏病杂志

Objective To investigate the long-term prognosis and possible risk factors of acute kidney injury(AKI)following cardiac surgeries. Methods Clinical data of 941 patients undergoing open heart surgery from January 2004 to June 2007 were retrospectively analyzed.Survival and renal function of above patients were informed through telephone or clinic follow-up till February 2010.Long-term survival was analyzed using risk-adjusted Cox proportional hazards regression model. Results Of the 941 patients after cardiac surgery,275(29.2%)developed AKI and 666(70.8%)did not.Survival was worse in patients with AKI(67.8%vs 85.6%,P<0.01)and was proportional to its severity (AKIN 1,2 and 3 stages:70.7%,62.3%and 58.6%,P<0.01).Although 90.5% of patients had complete renal recovery after AKI at discharge of hospital,they still had an increased risk for death during follow-up compared with patients without AKI (69.6% vs 85.6%,P<0.01).In the Cox proportional hazards regression model,age(HR=2.238),anemia (HR=1.625),prolonged operation time (HR=1.153),AKI severity (HR=1.473)were independent risk factors for long-term prognosis after cardiac surgery.At the end of the follow-up,patients with AKI had statistically higher Scr than non-AKI patients(107.6 μmol/L vs 83.0 μmol/L,P=0.014),and among those AKI patients,34.0%progressed into CKD 3-5 stages,34.8%developed double serum creatinine. Conclusions AKI is a risk factor for the long-term prognosis of cardiac surgery.Patients with complete renal recovery after AKI still has an increased risk for death and poor renal function compared with patients without AKI.

Value of urine NGAL and L-FABP in early diagnosis of acute kidney injury after liver transplantation / 中华肾脏病杂志

Objective To investigate the value of urinary neutrophil gelatinase-associated lipocalin (NGAL) and liver-type fatty acid-binding proteins (L-FABP) in early diagnosis of acute kidney injury (AKI) after liver transplantation. Methods During 2007-2008, 25 liver transplant recipients were recruited. Blood and urinary samples were collected before operation and at 2, 4, 6,12, 24, 48, 72, 120 h after portal vein opening, and used to determine serum creatinine (Scr), as well as urinary NGAL and L-FABP, which were normalized to urinary creatinine. According to the Acute Kidney Injury Network (AKIN) criteria of AKI, all the patients were divided into AKI and non-AKI groups. Standard statistics were used along with ROC analysis to evaluate the diagnose value of selected markers. Results There were no significant differences in clinical parameters between non-AKI (n=14) and AKI (n=11) groups. Both groups had a transient rise in Scr 2-12 hours after surgery, but the rise lasted longer in AKI patients (2-24 hours). While urinary L-FABP rose transiently in both groups 2-120 hours following surgery, urinary NGAL was only slightly elevated at 2 h in the non-AKI group, but rose and stayed high from 2 to 6 h in the AKI group.ROC analysis revealed that NGAL (cut-off 43.02, 26.97 and 17.19 ng/mgCr, AUC 0.766, 0.773 and 0.773 at 2, 4 and 6 h, respectively) was better than L-FABP (cut-off 3451.75 ng/mgCr, AUC 0.760 at 4 h). Conclusion Urinary NGAL appears to be a sensitive and specific marker of AKI in liver transplant recipients, but these data need to be validated in larger prospective studies.

Comparison of RIFLE and AKIN diagnosis criteria for acute kidney injury in patients undergoing cardiac surgery / 上海交通大学学报（医学版）

Objective To compare the RIFLE and AKIN diagnosis criteria for acute kidney injury ( AKI) in patients undergoing cardiac surgery. Methods Patients undergoing cardiac surgery from January 2004 to June 2007 were retrospectively evaluated. RIFLE and AKIN criteria were employed for the diagnosis and staging of AKI which occurred 7 d after cardiac surgery. The diagnosis sensitivity and precision for prediction of hospital mortality were compared between these two criteria. Results One thousand and fifty-six patients were included in this study. There was no significant difference between the prevalence of AKI after cardiac surgery diagnosed by RIFLE criteria and that diagnosed by AKIN criteria (29.55% vs 31.06%, P>0.05). There was no significant difference between the total hospital mortality and the hospital mortality of each stage of AKI diagnosed by RIFLE criteria and those diagnosed by AKIN criteria ( P > 0. 05). Logistic regression analysis suggested that the relative risk of hospital mortality for AKI was similar between patients diagnosed by AKIN criteria and those diagnosed by RIFLE criteria. The area under the ROC curve for hospital mortality was 0. 856 for RIFLE and 0.865 for AKIN in all patients (P<0.001). Conclusion Compared to RIFLE criteria, AKIN criteria do not improve the sensitivity of diagnosis and predictive ability of hospital mortality of AKI after cardiac surgery.

Incidence of acute kidney injury and its association with prognosis after liver transplantation / 中华肾脏病杂志

Objective To investigate the incidence of acute kidney injury (AKI) post-orthotopic liver transplant (OLT) and its association with prognosis. Methods Data of 28 patients received single OLT in our hospital from 2004 to 2006 were retrospectively analyzed. The incidence of AKI was investigated by new acute kidney injury network (AKIN) criteria. The follow-up was over one year. The prognosis of AKI patients at day 28 and 1 year was evaluated by Kaplan-Meier survival analysis. The association between AKI and prognosis was examined. Results A total of 193 patients were enrolled. The average age was (48.07±10.02) years old. The ratio of male to female was 4:1. One hundred and sixteen (60.1%) patients of post-OLT AKI were found, whose AKI stage 1, 2 and 3 were 50.0%, 21.6% and 28.4% respectively. Ten (8.6%) patients required renal replacement therapy (RRT) after OLT. In AKI post-OLT patients, day 28 and 1 year mortality were significantly higher than those in non-AKI patients (15.5% vs 0, 25.9% vs 3.9%, respectively, both P<0.05). Kaplan-Meier survival analysis showed the 1-year survival rates of AKI stage 1, 2, 3 post-OLT and non-AKl were 84.0%, 81.0%, 42.4% and 90.9%, respectively. The 1-year survival rate of non-AKI was significantly higher than that of AKI stage 1, 2, 3. The 1-year survival rate of AKI stage 3 was significantly lower than that of stage 1 and 2. There was no significant difference between AKI stage 1 and 2. Sct at 1 year post-OLT was significantly higher than that of baseline [(88.35±37.15) vs (73.70±33.88) μmol/L, P<0.05). The change of Scr value at 1 year compared to baseline in AKI patients was similar to non-AKI patients. However such change in AKI stage 2 and 3 was higher than that in stage 1. Conclusions The incidence of AKI post-OLT is quite high and associated to the poor prognosis in short and long periods. Renal function may decrease gradually which is associated to the AKI stage pest-OLTI.

Incidence of acute kidney injury according to AKI Network after cardiac surgery and analysis of risk factors and outcome / 中华肾脏病杂志

Objective To investigate the incidence, risk factors and outcome of acute kidney injury (AKI) following cardiac surgeries. Methods Clinical data of 1056 patients undergoing open heart surgery in Renji Hospital from January 2004 to June 2007 were retrospectively analyzed. Univariate and multivariate analyses were used to evaluate possible pre-,intra-, and post-operative parameters associated with AKI according to AKI Network (AKIN). Results Of the 1056 patients, 328 (31.06%) developed AKI. In-hospital mortality was 4.07% in all discharges while 11.59% in AKI patients (P<0.01). Multivariate logistic regression analysis revealed that increased age (OR=1.40), pre-operative hyperurieemia (OR=1.97), pre-operative left ventricular insufficiency (OR=2.53), combined surgery (OR=2.79), prolonged operation time (OR=1.43), post-operative circulation volume insufficiency (OR=11.08) were risk factors of AKI. Conclusions AKI is a common complication and associated with increased mortality following cardiac surgery. Increased age, pre-operative hyperuricemia, pre-operative left ventricular insufficiency, combined surgery, prolonged operation time, post-operative circulation volume insufficiency are useful in stratifying risk factors for the development of AKI.

Value of urinary neutrophil gelatinase-associated lipocalin in early diagnosis of acute kidney injury after adult cardiac surgery / 中华肾脏病杂志

Objective To prospectively investigate the value of urinary neutrophil gelatinase-associated lipocalin (NGAL) in the diagnosis of acute kidney injury (AKI) following adult cardiac surgery. Methods Twenty-nine hospitalization patients undergone cardiac surgery were enrolled in the study. Serial blood and urinary samples were collected immediately before incision and at various time intervals after surgery. The primary outcome measure was acute kidney injury, defined as a 50% increase in the level of serum creatinine (Scr) from baseline. Results Fourteen of 29 developed acute kidney injury. The diagnosis time point with Ser was at 24 (10, 48) h after cardiac surgery. By contrast, the concentration of urinary NGAL rose from a median of 3.42(1.60, 9.92) μg/L at baseline to 20.51(13.42, 50.02) μg/L at admission to ICU (P=0.006),and the median concentration of urinary NGAL in patients who developed AKI was significantly higher at admission to ICU compared with patients who did not develop AKI [20.51 (13.42, 50.02) μg/L vs 2.91 (0.72,8.61) μg/L, P=0.002]. As to urinary NGAL at admission to ICU, the area under the receiver-operating characteristic (ROC) curve was 0.824, the sensitivity was 85.7% and the specificity was 80.0% with a cutoff value of 10.95 μg/L. Significant correlation was found between urinary NGAL at admission and the levd of Scr at 24 h in ICU (r=0.545, P=0.002), as well as estimated GFR (r=-0.546,P=0.002). Conclusion Urinary NGAL concentration is significantly higher in patients developing postoperative AKI at the early time of admission to ICU, which may be a useful early biomarker of AKI after adult cardiac surgery.