Urine Neutrophil Gelatinase-Associated Lipocalin and Interleukin-18 Predict Acute Kidney Injury after Cardiac Surgery

Background. About 30–50% patients develop acute kidney injury (AKI) after cardiac surgery, which is still diagnosed by serum creatinine on clinic. However, the increase of serum creatinine is insensitive and delayed. The aim of this study is to test the hypothesis that neutrophil gelatinase-associated lipocalin (NGAL) and interleukin-18 (IL-18) are early biomarkers for AKI in patients after cardiac surgery. Methods. Thirty-three cases undergoing cardiac surgery were classified into an AKI group and non-AKI group, according to the AKI definition (> 26.5 μmol/L increase of serum creatinine, more than or equal to 50% increase of serum creatinine within 48 h, or a reduction in urine output < 0.5 mL/Kg per hour for more than six hours). The concentrations of serum NGAL, urine NGAL, and urine IL-18 at different time-points were measured. Results. Nine cases (27.27%) developed postoperative AKI, but diagnosis with serum creatinine was 12–48 h postoperation. The concentrations of serum NGAL were not significantly increased postoperation. The concentrations of urine NGAL and IL-18 were significantly increased in the AKI group, which reached the peak at 2–4 h postoperation, and a more significant difference could be seen after correction for urine creatinine. The concentrations of urine NGAL and IL-18 2 h postoperation, either corrected for urine creatinine or not, showed good sensitivity and specificity. Increased levels of urine NGAL and IL-18 2 h postoperation were significantly correlated with increased level of serum creatinine 12 h postoperation. Logistic regression analysis showed that urine NGAL corrected for urine creatinine 2 h postoperation and urine IL-18 2 h postoperation emerged as powerful independent predictors of AKI after cardiac surgery. Conclusions. The concentrations of urine NGAL and IL-18 could be useful biomarkers for AKI in patients after cardiac surgery, especially after correction for urine creatinine.     

心脏术后尿中性粒细胞明胶酶相关脂质运载蛋白和白细胞介素18与急性肾损伤的关系

目的 探讨接受体外循环心脏手术患者尿中性粒细胞明胶酶相关脂质运载蛋白（NGAL）和尿白细胞介素18（IL-18）与急性肾损伤（AKI）的关系。 方法 根据AKI的诊断标准，将33例体外循环心脏手术的患者分为AKI组及非AKI组，分别留取术前及术后不同时间点的血液和尿液标本，测定Scr、尿NGAL和IL-18水平。 结果 33例中有9例发生AKI，发生率为27.27%。AKI组Scr升高峰值出现在12～48 h内。与术前相比， AKI组术后2 h、4 h尿NGAL及IL-18水平升高，差异有统计学意义（P < 0.01）。与非AKI组比较，AKI组术后各时间点的尿NGAL水平、术后2 h及4 h的尿IL-18水平都较高，差异有统计学意义（P < 0.01）。经尿肌酐（Ucr）校正后，相应时间点的NGAL/Ucr和IL-18/Ucr差异仍有统计学意义（P < 0.01）。术后2 h尿NGAL和尿NGAL/Ucr的界定（cutoff） 值分别在250 µg/L和250 µg/mmol时；术后2 h尿IL-18和尿IL-18/Ucr的界定值分别在1800 ng/L和1800 ng/mmol时，体现出较好的敏感性和特异性。 AKI组术后12 h Scr水平与术后2 h尿NGAL水平呈正相关（r = 0.638，P < 0.05）。结论 体外循环下接受心脏手术的患者AKI发生率较高；术后2 h尿NGAL和NGAL/Ucr、术后2 h尿IL-18和尿IL-18/Ucr当达到一定界定值时，均可作为体外循环下心脏手术后AKI发生的早期诊断参考指标，其中术后2 h尿NGAL/Ucr为250 µg/mmol时更敏感。     

Neutrophil gelatinase associated lipocalin as an indicator of acute kidney injury and inflammation in burned children

Introduction

Neutrophil gelatinase associated lipocalin (NGAL) is a novel predictor of acute kidney injury (AKI), which increases with inflammation. We aimed to assess whether serum NGAL (SNGAL) and urine NGAL (UNGAL) can predict AKI in burned children.

Methods

Patients were referred within the 12 h of burn to our center. Serum samples for SNGAL, C-reactive protein (CRP), procalcitonin (PCT) and urine for UNGAL, microalbumine (Umalb), creatinine (Ucr) were obtained at both admission and the 5th day after burn. Blood urea nitrogen (BUN) and serum creatinine (Scr) were examined daily.

Results

Twenty-two subjects were enrolled and six (27.2%) of them developed AKI within the 48 h of injury. Burn size and abbreviated burn severity index (ABSI) were significantly increased in patients with AKI. CRP, PCT, SNGAL and UNGAL levels at admission and day 5 were significantly higher in patients with AKI than in those without AKI and controls. Scr was not significant between AKI and non-AKI groups at hospital days 1 and 5. A SNGAL level of 315 ng/ml and a UNGAL level of 100 ng/ml were determined as predictive cut-off values of AKI at admission (sensitivity and specificity: 71.4%, 83.3% and 93.3%, 93.7%, respectively). SNGAL and UNGAL were positively correlated with CRP, PCT, ABSI and Umalb/Ucr.

Conclusion

SNGAL and UNGAL are good early predictors of AKI in children with severe burn. NGAL might reflect the severity of burn insult and also could be used as an indicator of inflammation in burn children.     

尿NGAL、NAG及KIM-1联合检测在高龄老年急性肾损伤早期诊断中的价值

目的探讨尿中性粒细胞明胶酶相关脂质运载蛋白(uNGAL)、尿N-乙酰β-D氨基葡萄糖苷酶(uNAG)及尿肾损伤分子-1(uKIM-1)的联合检测老年急性肾损伤中的诊断价值。方法选择2016年6月至2018年6月在泰山疗养院住院的老年患者184例,根据急性肾损伤网络(AKIN)标准为诊断标准,诊断AKI组116例(1期55例、2期39例、3期24例),非AKI组68例,检测并比较各组尿NGAL、NAG、KIM-1水平,用受试者工作特征曲线(ROC)及曲线下面积(AUC)分析3项生物学标志物对AIK的诊断价值。结果①AKI组尿NGAL、NAG、KIM-1明显高于对照组(P<0.05),3期尿NGAL、NAG、KIM-1明显高于2期和1期,2期明显高于1期(P<0.05);②尿NGAL、NAG、KIM-1单独诊断AKI的AUC分别为0.734、0.804、0.705;③3项标志物联合诊断AKI的灵敏度、特异度分别为84.9%、90.7%,高于各单项诊断。结论尿NGAL、NAG、KIM-1是诊断AKI的较好指标,联合诊断对高龄老年急性肾损伤的早期诊断有着更重要的价值。     

The effect of dexmedetomidine on renal function in patients undergoing cardiac valve replacement under cardiopulmonary bypass: A double-blind randomized controlled trial

Study objectiveWe attempted to explore the effect of Dex on renal function in patients with cardiac valve replacement under cardiopulmonary bypass (CPB).DesignWe designed a prospective, randomized, placebo-controlled, single-center, parallel-arm double-blind trial.SettingOperating room.PatientsSeven-two eligible patients were randomly divided into Dex group and placebo group.InterventionsDexmedetomidine (Dex) (0.6 μg·kg^− 1) was administered in patients of Dex group at 15 min before anesthesia induction, followed by a treatment of 0.2 μg·kg^− 1·h^− 1 Dex until the end of operation. Patients in placebo group were treated with normal saline equally.MeasurementsThe levels of serum urea nitrogen (BUN), creatinine (Cr), neutrophil gelatinase-associated lipocalin (NGAL), urine interleukin-8 (IL-18) and superoxide dismutase (SOD) activity were tested before anesthesia induction (T1) and after operation at 0, 12 h, 24 h and 72 h (T2–5). The urine output during operation and the post-operative complication of acute kidney injury (AKI) were recorded.Main resultsThe levels of BUN and Cr were significantly increased at T5, and similar findings were found in the levels of NGAL and urine IL-18 at T3 and T4. The SOD activity was significantly declined at T2 and T3 in the two groups. The levels of BUN and Cr at T5 and the NGAL level at T3 and T4 were significantly lower in Dex group, comparable to placebo group. The intraoperative urine output was significantly increased and the postoperative incidence of AKI was significantly lower in Dex group.ConclusionsDex may attenuate the renal injury and decrease the incidence of AKI in patients undergoing cardiac valve replacement under CPB.     

Urinary markers of acute kidney injury in newborns with perinatal asphyxia*

Background: Acute kidney injury (AKI) affects up to 60% of severely asphyxiated neonates. The diagnosis of AKI can be and is further challenged by a lack of good biomarkers. We studied the role of novel markers for AKI, neutrophil gelatinase-associated lipocalin (NGAL), interleukin-8 (IL-18), Netrin-1 (NTN-1), and sodium hydrogen exchanger isoform 3 (NHE3) on development and early diagnosis of AKI in newborns with perinatal asphyxia (PA). Methods: Forty-one newborns with a diagnosis of PA (15 with AKI and 26 without AKI) and 20 healthy matched controls were involved to the study. Urinary samples were obtained on postnatal days 1 and 4 for patients with PA and on postnatal day 1 for the control subjects. AKI was defined using a serum creatinine-based modification of the acute kidney injury network criteria. Results: The levels of NGAL, NTN-1, NHE3, and IL-18 on the first postnatal day urine samples were higher in patients compared to controls (p?<?0.001, p?<0.001, p <0.02, p <0.001, respectively). In patients with AKI, the levels of NGAL and IL-18 were higher when compared to patients without AKI (p?=?0.002, p <0.001, respectively). The levels of NTN-1 and NHE3 were similar in both groups. For the samples obtained on postnatal day 4, only NGAL levels were significantly higher in patients with AKI (p?=?0.004) compared to those without AKI. Conclusion: To our knowledge, this is the largest study, which evaluated the utility of urinary biomarkers in the diagnosis of AKI in newborns with PA. First day, urine NGAL and IL-18 levels have an important diagnostic power in such patients.     

尿热休克蛋白-70在体外循环术后急性肾损伤早期诊断中的价值

目的评估尿热休克蛋白(HSP)-70在心脏体外循环心肺转流术(CPB)后急性肾损伤(AKI)早期诊断中的价值。方法选取2018年5月至2018年7月在河南省人民医院接受CPB治疗的患者为研究对象。收集入选者术前及术后0、2、4、6、8、12、24、48 h尿液标本和临床资料。按照肾脏病改善全球预后组织(KDIGO)AKI诊断标准分为AKI组和非AKI组。酶联免疫吸附法测定尿HSP-70、金属蛋白酶组织抑制因子2(TIMP-2)和胰岛素样生长因子结合蛋白7(IGFBP7)水平;免疫比浊法测定尿中性粒细胞明胶酶相关脂质运载蛋白(NGAL)水平。绘制受试者工作特征曲线(ROC),计算尿HSP-70、[TIMP-2]×[IGFBP7]、NGAL诊断CPB术后发生AKI的临界值、敏感度及特异度。结果共纳入45例患者,其中AKI组24例,非AKI组21例。AKI组术后各时间点尿HSP-70、[TIMP-2]×[IGFBP7]和NGAL水平显著高于非AKI组,组间比较差异有统计学意义(均P<0.05)。AKI组尿HSP-70在CPB术后2 h达到峰值,明显早于尿[TIMP-2]×[IGFBP7]、尿NGAL达峰值时间(分别为术后12 h和术后4 h)。术后2 h尿HSP-70≥2.1μg/L预测CPB术后AKI的曲线下面积(AUC)=1.00,灵敏度为100.0%,特异度100.0%;术后12 h尿[TIMP-2]×[IGFBP7]>19.1μg2/L2预测CPB术后AKI的AUC=0.94,灵敏度87.5%,特异度100.0%;术后4 h尿NGAL>27.4μg/L预测CPB术后AKI的AUC=0.95,灵敏度95.8%,特异度85.7%。术后2 h尿HSP-70≥2.1μg/L预测CPB术后AKI的阳性预测值为100.0%,阴性预测值100.0%。结论CPB术后AKI患者尿HSP-70水平升高早于尿[TIMP-2]×[IGFBP7]、NGAL,尿HSP-70水平监测有助于AKI的早期发现。     

Urine NGAL and KIM-1 in children and adolescents with hyperuricemia

Background

The aim of this study was to test the hypothesis that urine levels of neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) are enhanced in pediatric patients with hyperuricemia.

Methods

The study included 88 children and adolescents (60 males, 28 females) with a median age of 16 (range 11–18.5) years who had been referred to our department to rule out or confirm hypertension. The subjects were divided into two groups: the hyperuricemic (HU) group comprising 59 subjects with hyperuricemia (defined as serum uric acid?>4.8 and?>5.5 mg/dl in girls and boys, respectively) and the reference group comprising 29 patients with normouricemia. Urine NGAL and KIM-1 levels were evaluated using a commercially available kit.

Results

Concentrations of the examined biomarkers [urine NGAL, NGAL/creatinine (cr.) ratio, urine KIM-1, KIM-1/cr. ratio] were increased in the HU group compared with the reference group (p?<?0.01). There were positive correlations between the serum uric acid and urine NGAL/cr. ratio (R?=?0.67, p?<?0.001) and the urine KIM-1/cr. ratio (R?=?0.36, p?<?0.001). In the multiple regression models, serum uric acid, systolic blood pressure and cholesterol accounted for more than 49 % of the variation in the NGAL/cr. ratio (R?=?0.702, p?<?0.001). In the second model, serum uric acid, gender, age and systolic blood pressure accounted for more than 36 % of the variation in the KIM-1/cr. ratio (R?=?0.604, p?<?0.001).

Conclusion

We demonstrated that male, obese, hypertensive adolescents with hyperuricemia have higher urine NGAL and KIM-1 levels relative to a reference group with normouricemia.     

Improved performance of urinary biomarkers of acute kidney injury in the critically ill by stratification for injury duration and baseline renal function

To better understand the diagnostic and predictive performance of urinary biomarkers of kidney injury, we evaluated γ-glutamyltranspeptidase (GGT), alkaline phosphatase (AP), neutrophil-gelatinase-associated lipocalin (NGAL), cystatin C (CysC), kidney injury molecule-1 (KIM-1), and interleukin-18 (IL-18) in a prospective observational study of 529 patients in 2 general intensive care units (ICUs). Comparisons were made using the area under the receiver operator characteristic curve (AUC) for diagnosis or prediction of acute kidney injury (AKI), dialysis, or death, and reassessed after patient stratification by baseline renal function (estimated glomerular filtration rate, eGFR) and time after renal insult. On ICU entry, no biomarker had an AUC above 0.7 in the diagnosis or prediction of AKI. Several biomarkers (NGAL, CysC, and IL-18) predicted dialysis (AUC over 0.7), and all except KIM-1 predicted death at 7 days (AUC between 0.61 and 0.69). Performance was improved by stratification for eGFR or time or both. With eGFR <60?ml/min, CysC and KIM-1 had AUCs of 0.69 and 0.73, respectively, within 6?h of injury, and between 12 and 36?h, CysC (0.88), NGAL (0.85), and IL-18 (0.94) had utility. With eGFR >60?ml/min, GGT (0.73), CysC (0.68), and NGAL (0.68) had the highest AUCs within 6?h of injury, and between 6 and 12?h, all AUCs except AP were between 0.68 and 0.78. Beyond 12?h, NGAL (0.71) and KIM-1 (0.66) performed best. Thus, the duration of injury and baseline renal function should be considered in evaluating biomarker performance to diagnose AKI.     

Value of joint detection of multiple biomarkers on early diagnosis of acute kidney injury in critical patients

Objective To assess the value of joint detection of serum cysteine proteinase inhibitors C (sCys-C), urinary kidney injury molecule 1 (uKIM-1), urinary neutrophil gelatinase-associated lipocalin(uNGAL) and urinary interleukin 18 (uIL-18) for early diagnosis of acute kidney injury (AKI) in critically ill patients. Methods A total of 256 adult patients who stayed Intensive Care Unit for 24 hours in the Third People's Hospital of Liaocheng between Aug 2011 and Dec 2012 were enrolled. According to Kidney Injury Net(AKIN) work, the patients were divided into non-AKI group and AKI group (including state 1, 2 and 3). The concentrations of urine NGAL, KIM-1, IL-18 and serum sCys-C were measured. The diagnosis value of four biomarkers joint detection and single detection for AKI were analyzed with the receiver operating characteristic (ROC) curve and the area under curve (AUC). Results (1) The levels of uNGAL, uKIM-1, uIL-18 and sCys-C were higher in patients with AKI than the patients with no AKI (P﹤0.01). (2) The area under curves of uNGAL, uKIM-1, uIL-18, sCys-C and joint detection were 0.742, 0.871, 0.803, 0.703, 0.925 respectively. (3) The sensitivity and specificity of parallel tests and serial tests of four biomarkers were 97.9%, 62.8%, 64.3% and 96.2% respectively. There were significant differences of sensitivity or specificity between single test and joint tests. Conclusions The urine NGAL, KIM-1, IL-18 and serum Cys-C are sensitive indexes for the early diagnosis of acute kidney injury. Joint detection has high value for early diagnosis of AKI.     

Prediction of acute kidney injury complicated by sepsis with sTREM - 1 and NGAL as early marker

Objective To determine whether triggering receptor expressed on myeloid cells-1 (sTREM - 1) and urinary neutrophil gelatinase - associated lipocalin (NGAL) were early biomarkers of acute kidney injury (AKI) secondary to sepsis. Methods A total of 141 eligible patients were enrolled in this prospective study. Blood and urine samples were collected at different time points as soon as sepsis was diagnosed. The concentrations of serum creatinine (Scr), urine sTREM-1 and NGAL were measured. According to AKI criteria, patients were divided into the AKI group and non - AKI group. Dynamic changes of levels of Scr, urine sTREM-1 and NGAL were observed in two groups. The receiver operating characteristic curves were used to evaluate the early diagnostic value of urine sTREM-1 and NGAL. Results Among 141 septic patients, 44 (31.2%) cases had concomitant AKI. Twenty four hours after sepsis diagnosed, the level of Scr rose to 1.91 times of the baseline [(140.5±13.6) vs (82.6±15.3) μmol/L, P＜0.05], which met the diagnostic criteria of AKI. In the AKI group, urinary concentrations of sTREM-1 and NGAL at 8 h after the diagnosis of sepsis began to rise significantly from baseline [(100.5±17.4) vs (38.9±14.7) ng/L; (144.6±51.9) vs (56.2±43.8) μg/L, both P＜0.05].And at the following time points, urinary concentrations of sTREM - 1 and NGAL were significantly higher than the baseline levels and that of the non-AKI group (all P＜0.05). At 8 h time point, the area under the curve of urine sTREM-1 was 0.877 (95%CI 0.756-0.914), the sensitivity was 89.1% and specificity was 82.0% with a cutoff value of 70 ng/L. At 8 h time point, the area under the curve of urine NGAL was 0.862 (95% CI 0.703-0.958),the sensitivity was 87.4% and specificity was 85.5% with a cutoff value of 90 μg/L. Conclusions Urinary concentrations of sTREM-1 and NGAL at 8 h time point after the diagnosis of sepsis have predictive value for AKI and their diagnostic time is much earlier than that of Scr. Therefore, urinary sTREM-1 and NGAL can be used as early biomarkers of septic AKI.     

急性Stanford A型主动脉夹层术后急性肾损伤的肾叶间动脉血流动力学改变

目的探讨急性Stanford A型主动脉夹层术后急性肾损伤(AKI)的超声血流动力学指标改变情况。方法收集40例接受手术治疗的急性Stanford A型主动脉夹层患者,分别在手术前1天、术后即刻(进入重症监护室)、手术后6、24、48h测量双肾叶间动脉收缩期峰值流速(PSV)、舒张期最小流速(EDV)、搏动指数(PI)、阻力指数(RI),同时记录血肌酐(sCr)水平和尿量。以AKIN为标准将患者分为AKI组和无AKI组,比较两组间差异。结果 40例患者中,AKI组27例,无AKI组13例。无AKI组与AKI组患者术后6、24h肾叶间动脉EDV、PI、RI差异有统计学意义(P均0.05)。肾叶间动脉EDV与sCr呈负相关(r=-0.508,P=0.001),PI、RI与SCr呈正相关(r=0.411、0.443,P=0.009、0.005)。结论通过肾叶间动脉EDV、PI、RI可早期预测AKI发生,术后6、24h是超声测量肾叶间动脉血流动力学指标预测肾损伤的最佳时间。     

Epidemiology of acute kidney injury in surgical intensive care at University Hospital in Egypt. A prospective observational study

IntroductionThe acute kidney injury (AKI) incidence in ICU patients varies widely from 3% to 30%, with mortality ranging from 36% to 90%, depending on the type of ICU, study population, the period during which the study is conducted, and the criteria used to define AKI.There have been many studies about the epidemiology and risk factors of AKI in critically ill patients in the different regions of the world. However, little data on the epidemiology of AKI in critically ill patients are available in Egypt.ObjectivesThe aim of this study was to assess the incidence of AKI among critical ill patients using RIFEL [risk (R), injury (I), failure (F), loss (L), and end-stage kidney disease (E)] classification and to determine the risk factors and outcome of patients who developed AKI in our surgical ICU.MethodsWe conducted a 6-month prospective observational study in the surgical ICU. Patients were classified daily using the RIFLE criteria. Patients were considered as having new AKI if they did not have AKI on ICU admission and subsequently reached at least class risk during their follow-up. Deterioration of AKI was diagnosed if the patient had increased in RIFLE class compared to the initial classification.ResultsOne hundred and twelve patients were studied. AKI occurred in 40 (35.7%) of patients. The most common risk factors for AKI are APACHE II score (acute physiology and chronic health evaluation score, version II.) and sepsis. APACHEII was lower in non-AKI group than AKI group (17.3 ± 7.5 versus 22.4 ± 7.4, p = 0.001), and sepsis was more common in AKI patients than non-AKI patients (77.5% versus 49% p = 0.004). Patients with AKI had a mortality rate of 67.5% which was more in patients with failure compared with risk patients. APACHEII, AKI, and needs for mechanical ventilation were independent risks for mortality.     

尿生物标志物在儿童急性肾损伤早期诊断中的作用研究

目的：评价尿NGAL,KIM-1和β2-MG在儿童不同基础疾病导致的AKI早期诊断中的价值。方法：我们做的是前瞻性临床研究,检测在我院儿科门急诊不同疾病患儿尿中性粒细胞明胶酶相关的脂质运载蛋白（NGAL）,肾脏损伤因子-1（KIM-1）和-β2微球蛋白（β2-MG）的水平,以AKIpRIFLE为分期标准将入选患儿分组,比较尿NGAL,KIM-1和β2-MG在儿童急性肾损伤诊断中的敏感性,特异性,阳性似然比,阴性似然比,分析比较这3个指标在急性肾损伤早期诊断中的作用。结果：入选262例患儿中,23例患儿可诊断为AKI,15例患儿为AKI-R期,8例患儿为AKI-I期,入选患儿中没有AKI-F期,23例患儿中只有5例临床有AKI的诊断。尿NGAL,KIM-1和β2-MG的水平在血肌酐没有明显升高之前已经升高,随着肾损伤的加重升高的更明显,不同组间差异有统计学意义。尿NGAL和β2-MG在预测儿童AKI的早期诊断方面好于尿KIM-1（AUC〉0.8）。结论：尿NGAL,KIM-1和β2-MG均可以在Scr没有升高之前预测儿童AKI的发生,是儿童AKI的早期生物标志物。尿NGAL在早期预测不同基础疾病可能发生AKI方面好于其他两项指标。     

Some biomarkers of acute kidney injury are increased in pre-renal acute injury

Pre-renal acute kidney injury (AKI) is assumed to represent a physiological response to underperfusion. Its diagnosis is retrospective after a transient rise in plasma creatinine, usually associated with evidence of altered tubular transport, particularly that of sodium. In order to test whether pre-renal AKI is reversible because injury is less severe than that of sustained AKI, we measured urinary biomarkers of injury (cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), γ-glutamyl transpeptidase, IL-18, and kidney injury molecule-1 (KIM-1)) at 0, 12, and 24?h following ICU admission. A total of 529 patients were stratified into groups having no AKI, AKI with recovery by 24?h, recovery by 48?h, or the composite of AKI greater than 48?h or dialysis. Pre-renal AKI was identified in 61 patients as acute injury with recovery within 48?h and a fractional sodium excretion <1%. Biomarker concentrations significantly and progressively increased with the duration of AKI. After restricting the AKI recovery within the 48?h cohort to pre-renal AKI, this increase remained significant. The median concentration of KIM-1, cystatin C, and IL-18 were significantly greater in pre-renal AKI compared with no-AKI, while NGAL and γ-glutamyl transpeptidase concentrations were not significant. The median concentration of at least one biomarker was increased in all but three patients with pre-renal AKI. Thus, the reason why some but not all biomarkers were increased requires further study. The results suggest that pre-renal AKI represents a milder form of injury.     

Acute Kidney Injury After Pediatric Liver Transplantation

BackgroundThe aim of the present study is to assess acute kidney injury (AKI) incidence according to the pRIFLE and AKIN criteria and to evaluate the risk factors for early developing AKI in postoperative intensive care unit after pediatric liver transplantation (LT).MaterialsAfter exclusion of retransplantations, 7 cadaveric and 44 living donors, totaling 51 pediatric LT patients that were performed between 2005 and 2017, were reviewed retrospectively. AKI was defined according to both pediatric RIFLE (Risk for renal dysfunction, Injury to the kidney, Failure of kidney function, Loss of kidney function, and End-stage renal disease) and Acute Kidney Injury Network (AKIN) criteria. Documented data were compared between AKI and non-AKI patients.ResultsAKI incidences were 17.6% by AKIN and 37.8% by pRIFLE criteria. AKIN-defined AKI group had statistically lower serum albumin level, higher serum sodium level, higher furosemide dose, and higher rate of red blood cell (RBC) transfusion than the non-AKI group (P = .02, P = .02, P = .01 and P = .04, respectively). AKI patients had significantly prolonged mechanical ventilation (P = .01) and hospital LOS (P = .02). The pRIFLE-defined AKI group had significantly lower serum albumin level, higher blood urea nitrogen (BUN) level, and higher ascites drained and also showed higher requirement for RBC and 20% human albumin transfusions than the non-AKI group (P = .02, P = .04, P: =.007, P = .02 and P = .05, respectively).ConclusionWe evaluated that hypoalbuminemia, high requirement for RBC and 20% human albumin transfusions, high serum sodium, high furosemide use, and high flow of ascites are risk factors for AKI and high BUN levels can be predictive for AKI in pediatric LT patients. The effect of AKI on outcome variables were prolonged mechanical ventilation and hospital LOS.     

Assessment of fractional excretion of urea for early diagnosis of cardiac surgery associated acute kidney injury

Abstract

Background: Acute kidney injury (AKI) is a common complication after cardiac surgery (CS). Recently, neutrophil gelatinase-associated lipocalin (NGAL) was shown to predict AKI development earlier than serum creatinine, but it is not widely used in clinical practice. Fractional excretion of urea (FeU) has been referred to as a useful tool to discriminate between prerenal and established AKI. The aim of our study is to evaluate the sensitivity and specificity of FeU, in the early diagnosis of AKI in patients undergoing CS. Methods: We performed a prospective study on adults undergoing CS. AKI was defined by AKIN criteria. Individuals suffering from CKD, were excluded. Sensitivity and specificity of FeU, fractional excretion of sodium (FeNa) and urine NGAL, measured at 1, 6 and 24?h following CS, were assessed. Results: We included 66 patients (26% female) aging 68?±?11 years. AKI prevalence was 24% and mortality was 3.28%. Patients with AKI had a significantly lower FeU compared to those without AKI (23.89?±?0.67% vs. 34.22?±?0.58%; p?<?0.05) 6?h after CS, but not at the 1- and 24-h time points. NGAL was also statistically significant between both groups. FeU showed a 75% sensitivity and 79.5% specificity; the AUC was 0.786. ROC analysis of FeU and NGAL yielded similar values (p?=?NS). Conclusion: FeU is useful as an early biomarker to predict AKI after CS and it is comparable to the new biomarker NGAL.     

Evaluation of serum cysteine-rich protein 61 and cystatin C levels for assessment of acute kidney injury after cardiac surgery

Objective The occurrence of acute kidney injury (AKI) after cardiopulmonary bypass (CPB) can lead to morbidity and mortality. We hypothesized that cysteine-rich protein 61 (CYR61) and cystatin C (CysC) may be potential novel biomarkers of AKI after cardiopulmonary bypass. Methods Patients were classified into AKI and non-AKI group depending on serum creatinine. Levels of creatinine, CysC, and CYR61 were measured at five time-points before and within 48?h after the surgery. Results Fifty patients were included in the study. Serum creatinine pre-operative values were 74.0?±?43.3?μmol/L in AKI group vs. 64.8?±?17.9?μmol/L in non-AKI group. During 48?h, the values increased to 124.6?±?67.2?μmol/L in AKI group (p?<?0.001) but in non-AKI group they did not change significantly. Serum CysC values were significantly increased already 2?h after CBP in AKI group (949?±?557?μg/L, p?<?0.05) compared to non-AKI group (700?±?170?μg/L). Pre-operative serum CYR61 tended to be lower in AKI group (12.4?μg/L) than in non-AKI group (20.3?μg/L), but 24?h after the surgery, the levels in AKI group tended to be higher than non-AKI group. Conclusion Serum CYR61 does not seem to be an early predictor of AKI in patients after cardiac surgery with CPB, but it might possibly identify patients at risk of developing more severe kidney injury. Serum CysC could be a promising biomarker of AKI, differentiating patients at risk of developing AKI after cardiac surgery as early as 2?h after surgery.     

Urinary netrin-1 and KIM-1 as early biomarkers for septic acute kidney injury

Background: Acute kidney injury (AKI) during sepsis is associated with poor outcome. However, diagnosis of AKI with serum creatinine (SCr) level change is neither highly sensitive nor specific. Therefore, identification of novel biomarkers for early diagnosis of AKI is desirable. Aims: To evaluate the capacity of combining urinary netrin-1 and human kidney injury molecule type 1 (KIM-1) in the early diagnosis of septic AKI. Methods: We prospectively recruited 150 septic patients from Jun 2011 to Jun 2013 at Zhejiang Provincial People's Hospital, China. SCr, urinary netrin-1, and KIM-1 levels were recorded at 0, 1, 3, 6, 24, and 48?h of ICU admission and compared between AKI and non-AKI patients. In addition, we investigated the prognostic value of netrin-1 and KIM-1 between non-survivors and survivors in septic AKI patients. Results: SCr levels started to show elevation after 24?h of ICU admission. However, netrin-1 levels increased significantly as early as 1?h, peaked at 3–6?h and remained elevated up to 48?h of ICU admission in septic AKI patients. KIM-1 increased significantly by 6?h, peaked at 24?h and remained significantly elevated until 48?h of ICU admission. Furthermore, we observed significant higher urinary KIM-1 levels at 24?h and 48?h in non-survivors compared to survivors in AKI patients. Conclusions: Our results suggest that both netrin-1 and KIM-1 are clinically useful as early biomarkers in the diagnosis of septic AKI. In addition, persistent elevation of urinary KIM-1 level may be associated with poor prognosis.     

Artificial intelligence and machine learning for predicting acute kidney injury in severely burned patients: A proof of concept

BackgroundBurn critical care represents a high impact population that may benefit from artificial intelligence and machine learning (ML). Acute kidney injury (AKI) recognition in burn patients could be enhanced by ML. The goal of this study was to determine the theoretical performance of ML in augmenting AKI recognition.MethodsWe developed ML models using the k-nearest neighbor (k-NN) algorithm. The ML models were trained-tested with clinical laboratory data for 50 adult burn patients that had neutrophil gelatinase associated lipocalin (NGAL), urine output (UOP), creatinine, and N-terminal B-type natriuretic peptide (NT-proBNP) measured within the first 24 h of admission.ResultsHalf of patients (50%) in the dataset experienced AKI within the first week following admission. ML models containing NGAL, creatinine, UOP, and NT-proBNP achieved 90–100% accuracy for identifying AKI. ML models containing only NT-proBNP and creatinine achieved 80–90% accuracy. Mean time-to-AKI recognition using UOP and/or creatinine alone was achieved within 42.7 ± 23.2 h post-admission vs. within 18.8 ± 8.1 h via the ML-algorithm.ConclusionsThe performance of UOP and creatinine for predicting AKI could be enhanced by with a ML algorithm using a k-NN approach when NGAL is not available. Additional studies are needed to verify performance of ML for burn-related AKI.