Serum NGAL and copeptin levels as predictors of acute kidney injury in asphyxiated neonates

Background

Acute kidney injury (AKI) is the most common complication of perinatal asphyxia. Recent research indicates that serum neutrophil gelatinase-associated lipocalin (NGAL) is an early marker for AKI, but there are the lacks of data about its use in term neonates with perinatal asphyxia.

Methods

A prospective cohort study was conducted on 43 term neonates. Umbilical cord blood and 24 h after birth serum NGAL, copeptin, creatinine, and molality were measured in all asphyxiated and controls neonates.

Results

During the study period, 8 of asphyxiated nenates (18.6 %) suffered from AKI, while 35 newborns have no signs of AKI and 30 healthy infants. We did not observe any differences in creatinine and copeptin levels, as well as serum osmolality in all three investigated groups (AKI, no-AKI, and controls) in cord blood, and 24 h after birth. Serum NGAL levels in umbilical cord blood were significantly higher in the AKI group (174.3 ng/mL) compared with no-AKI (88.5 ng/mL, p = 0.01) and control groups (28.5 ng/mL, p < 0.001), and 24 h after birth (respectively, AKI 152.5 ng/mL vs no-AKI 74.9 ng/mL, p = 0.02 vs controls 39.1 ng/mL, p < 0.001). NGAL concentration showed a strong negative correlation to umbilical artery pH (Rho = ?0.42, p = 0.04), base excess (Rho = ?0.31, p = 0.03), and Apgar score in 1st min (Rho = ?0.41, p = 0.02) and 5th min of life (Rho = ?0.20, p = 0.001). ROC curve analysis demonstrated a good predictive value for NGAL levels (>140.7 ng/mL) which allows to diagnose AKI in asphyxiated patients with 88.9 % sensitivity (95 % CI 75–95 %) and 95.0 % specificity (95 % CI 76–99 %).

Conclusion

NGAL seems to be a promising marker, even in subclinical AKI in neonates, due to its high specificity, but copeptin did not meet expectations.

     

Longitudinal patterns of urine biomarkers in infants across gestational ages

Background

Urinary biomarkers may be indicators of acute kidney injury (AKI), although little is known of their developmental characteristics in healthy neonates across a full range of gestational age (GA). The purpose of this study was to examine patterns of urinary biomarkers across GA groups from birth to 3 months of age.

Methods

Fifty-two infants ranging from 24 to 41 weeks’ GA had urine assayed from birth through 3 months of age for 7 biomarkers including albumin (ALB), beta-2-microglobulin (B2M), cystatin-C (CysC), epidermal growth factor (EGF), neutrophil-gelatinase-associated lipocalin (NGAL), osteopontin (OPN), and uromodulin (UMOD).

Results

Of the seven urinary biomarkers, EGF and UMOD increased while others decreased with advancing GA. By 3 months of age, EGF and UMOD had increased in preterm infants to levels similar to those of term infants. UMOD/ml and EGF/ml appeared to be predominantly developmental biomarkers distinguishing estimated glomerular filtration rate (GFR) <30 ml/min/1.73 m² with receiver operator characteristic area under the curve (ROC-AUC) of 0.82; p?=?0.002. When factored by urine creatinine CysC/cr?+?ALB/cr were the most significant functional markers with AUC?=?0.79; p?=?0.004; sensitivity 96 %; specificity 58 %.

Conclusions

Among healthy neonates, urinary biomarkers vary with GA. These data support the use of urinary biomarkers in the assessment of normal kidney development in the absence of injury.

     

Serum cystatin C predicts acute kidney injury in preterm neonates with respiratory distress syndrome

Background

We aimed to compare serum cystatin C levels (sCysC) in preterm neonates with respiratory distress syndrome (RDS) with a control group and to investigate whether it could be used as a predictor for acute kidney injury (AKI).

Methods

sCysC was measured in 62 neonates with RDS (n?=?28) and control neonates without RDS (n?=?34), whose gestational ages (GA) were between 27 and 29 weeks (subgroup 1) and 30–32 weeks (subgroup 2). AKI was defined as oliguria and/or increase of serum creatinine. Blood samples were obtained on postnatal days (PND) 3 and 30. sCysC levels were determined by particle-enhanced nephelometric immunoassay.

Results

There were six neonates with AKI (RDS-AKI subgroup) and 22 neonates without AKI (RDS-no AKI subgroup) during the first 7 days. Although sCysC levels were lower in neonates with RDS than controls on PND3 in both GA subgroups, the differences were not significant. However, in neonates with RDS and AKI, sCysC levels were significantly higher than neonates with RDS but no AKI and neonates in the control group on PND3. sCysC level was found to have a statistically significant association with AKI development in preterm neonates with RDS.

Conclusions

sCysC is an independent predictor of AKI in preterm neonates with RDS.     

Serum and urine acute kidney injury biomarkers in asphyxiated neonates

Background

We evaluated serum (s) cystatin C (CysC) and neutrophil gelatinase-associated lipocalin (NGAL) and urine (u) CysC, NGAL and kidney injury molecule-1 (KIM-1) as markers of acute kidney injury (AKI) in asphyxiated neonates.

Methods

AKI biomarkers were measured in 13 asphyxiated neonates born at ≥36?weeks gestational age (eight with AKI and five without AKI) and 22 controls. AKI was defined as serum creatinine ≥1.5?mg/dl for >24?h or rising values >0.3?mg/dl from day of life (DOL) 1. Biomarkers were measured on DOL 1, 3, and 10.

Results

Asphyxiated neonates had significantly higher sCysC on DOL 1 as well as sNGAL and uCysC and uNGAL (standardized to urine creatinine and absolute values) than controls at all time points. Compared to controls, significantly higher sNGAL, uCysC, and uNGAL values were observed in the asphyxia-AKI and asphyxia–no AKI subgroups. Regarding uKIM-1, only the absolute values were significantly higher in asphyxiated neonates (DOL 10). sNGAL, uCyst, and uNGAL had a significant diagnostic performance as predictors AKI on DOL 1.

Conclusions

sNGAL, uCysC, and uNGAL are sensitive, early AKI biomarkers, increasing significantly in asphyxiated neonates even in those not fulfilling AKI criteria. Their measurement on DOL 1 is predictive of post-asphyxia-AKI.     

Acute kidney injury in preterm infants admitted to a neonatal intensive care unit

Background

The factors that contribute to the development of acute kidney injury (AKI) and treatment outcome among prematurely born neonates are not clearly understood.

Methods

This retrospective study included 150 prematurely born neonates. AKI was defined as an increase of serum creatinine levels ≥0.3 mg/dl compared to basal values.

Results

The majority of neonates with AKI (94.8 %) had a body weight <1,500 g. Logistic regression analysis showed that the Apgar score in the 5th minute <5, serum lactate levels >5 on the first day of life, core body temperature <36?ºC on the first day of life, occurrence of sepsis, intracranial hemorrhage, necrotizing enterocolitis, patent ductus arteriosus, as well as a treatment with vancomycin or dopamine were independent risk factors for the development of AKI. After the groups of neonates with and without AKI were adjusted, the calculated risk ratio for a negative outcome of treatment (death) was 2.215 (CI 1.27–3.86) for neonates with AKI. Neonates with AKI had higher serum sodium levels in the third and fourth days of life.

Conclusions

AKI is associated with high mortality in preterm neonates. It is very important to identify, as quickly as possible, all infants who are at high risk of developing AKI.     

L-FABP can be an early marker of acute kidney injury in children

Background

Acute kidney injury (AKI) is a common postoperative complication following cardiopulmonary bypass (CPB) surgery. New biomarkers to identify patients with early AKI (before increases in serum creatinine) are needed to facilitate appropriate treatment. This study aimed to test the role of urinary liver fatty-acid-binding protein (L-FABP) as an early biomarker for AKI in children undergoing CPB surgery.

Methods

This is a case–control study of children undergoing CPB. AKI was defined as 50 % increase in serum creatinine at 48 h after surgery. For each patient, five serum and urine samples were obtained corresponding to time 0 h (presurgery) and 2, 6, 24, and 48 h after surgery.

Results

Twenty-seven patients, median age 360 days, were enrolled. AKI developed in 11 patients (41 %); three needed renal replacement therapy (peritoneal dialysis); there were two deaths. There were significant differences between patients with and without AKI in L-FABP levels at 2, 6, and 48 h after surgery, length of hospital stay, and CPB time; there were no differences in gender, patient age, and body weight. L-FABP was normalized to urinary creatinine concentration at all time points, with area under the receiver operator curve (AUC ROC) 0.867 at 2 and 6 h postoperatively. Correlation coefficient between L-FABP and length of hospital stay after surgery was statistically significant (r?=?0.722, p value?=?0.000).

Conclusions

Our results suggest that urinary L-FABP can be used to diagnose AKI earlier than rise in serum creatinine in children undergoing CPB.     

A combination of SOFA score and biomarkers gives a better prediction of septic AKI and in-hospital mortality in critically ill surgical patients: a pilot study

Background

Sepsis is a syndrome characterized by a constellation of clinical manifestations and a significantly high mortality rate in the surgical intensive care unit (ICU). It is frequently complicated by acute kidney injury (AKI), which, in turn, increases the risk of mortality. Therefore, it is of paramount importance to identify those septic patients at risk for the development of AKI and mortality. The objective of this pilot study was to evaluate several different biomarkers, including NGAL, calprotectin, KIM-1, cystatin C, and GDF-15, along with SOFA scores, in predicting the development of septic AKI and associated in-hospital mortality in critically ill surgical patients.

Methods

Patients admitted to the surgical ICU were prospectively enrolled, having given signed informed consent. Their blood and urine samples were obtained and subjected to enzyme-linked immunosorbent assay (ELISA) to determine the levels of various novel biomarkers. The clinical data and survival outcome were recorded and analyzed.

Results

A total of 33 patients were enrolled in the study. Most patients received surgery prior to ICU admission, with abdominal surgery being the most common type of procedure (27 patients (81.8%)). In the study, 22 patients had a diagnosis of sepsis with varying degrees of AKI, while the remaining 11 were free of sepsis. Statistical analysis demonstrated that in patients with septic AKI versus those without, the following were significantly higher: serum NGAL (447.5?±?35.7 ng/mL vs. 256.5?±?31.8 ng/mL, P value 0.001), calprotectin (1030.3?±?298.6 pg/mL vs. 248.1?±?210.7 pg/mL, P value 0.049), urinary NGAL (434.2?±?31.5 ng/mL vs. 208.3?±?39.5 ng/mL, P value <?0.001), and SOFA score (11.5?±?1.2 vs. 4.4?±?0.5, P value <?0.001). On the other hand, serum NGAL (428.2?±?32.3 ng/mL vs. 300.4?±?44.3 ng/mL, P value 0.029) and urinary NGAL (422.3?±?33.7 ng/mL vs. 230.8?±?42.2 ng/mL, P value 0.001), together with SOFA scores (10.6?±?1.4 vs. 5.6?±?0.8, P value 0.003), were statistically higher in cases of in-hospital mortality. A combination of serum NGAL, urinary NGAL, and SOFA scores could predict in-hospital mortality with an AUROC of 0.911.

Conclusions

This pilot study demonstrated a promising panel that allows an early diagnosis, high sensitivity, and specificity and a prognostic value for septic AKI and in-hospital mortality in surgical ICU. Further study is warranted to validate our findings.

     

Epidemiology of cardiac surgery-associated acute kidney injury in neonates: a retrospective study

Background

Cardiac surgery is a known risk factor for acute kidney injury (AKI) in children. However, cardiac surgery-associated AKI (CS-AKI) in neonates has not been well studied. The objectives of this study were: (1) to describe the epidemiology of CS-AKI in neonates utilizing the Acute Kidney Injury Network (AKIN) definition, (2) to identify risk factors for neonatal CS-AKI, and (3) to determine if neonatal CS-AKI is associated with increased morbidity and mortality.

Methods

This was a retrospective study involving 122 neonates (≤28 days) undergoing cardiac surgery from 2006 to 2009. Neonates with and without AKI were identified using serum creatinine (SCr) and urine output (UO) data.

Results

Cardiac surgery-AKI occurred in 76 (62 %) neonates, of whom 22 (29 %) were AKIN stage 1, 19 (25 %) were stage 2, and 35 (46 %) were stage 3. AKI mostly occurred early as 75 % of patients achieved their maximal AKIN stage within the first 48 h post-operatively. In the multivariate analysis, cardiopulmonary bypass duration of ≥120 min was independently associated with AKI [odds ratio (OR) 2.53, 95 % confidence interval (CI) 1.03–6.30]. Severe AKI (AKIN stage 3) was independently associated with mortality (OR 6.70, 95 % CI 1.08–41.50) and a longer stay in the pediatric intensive care unit (hazard ratio 9.09, 95 % CI 1.35–60.95). The majority of severe AKI cases (65 %) were identified with AKIN UO criteria alone without significant rises in SCr.

Conclusions

Cardiac surgery-AKI is common in neonates when the AKIN definition is utilized and is associated with higher morbidity and mortality, especially in those with more severe AKI.     

Urine neutrophil gelatinase-associated lipocalin to predict acute kidney injury in preterm neonates. A pilot study

Background

The efficacy of urine neutrophil gelatinase-associated lipocalin (uNGAL) as an early acute kidney injury (AKI) biomarker in preterm neonates was evaluated.

Methods

Thirty-five preterm neonates were prospectively evaluated for serum creatinine (sCre)-documented AKI during the first 14 days of life. Urine samples were collected daily throughout the study period. Of the neonates evaluated, we analyzed 11 who developed AKI (cases) and an equal number of neonates without AKI (controls) matched for gestational and postnatal age (case–control study). uNGAL was measured on the day of AKI occurrence (day 0) and on the 2 days preceding the event (day ?1 and day ?2, respectively) using an enzyme-linked immunosorbent assay.

Results

Cases had significantly higher sCre levels than controls on day 0 (1.21?±?0.48 vs. 0.83?±?0.16 mg/dL, p?=?0.031) but not on days ?1 and ?2. Similarly, uNGAL levels (ng/mL) were significantly higher in cases than in controls only on day 0 (19.1?±?3.5 vs. 13.3?±?7.3, p?=?0.017) and not on days ?1 (18.8?±?3.4 vs. 16.3?±?5.9, p?=?0.118) and ?2 (19.3?±?1.8 vs. 19.4?±?0.8, p?=?0.979). The receiver operating characteristic curve analysis showed no significant ability of uNGAL to predict AKI on days ?2 and ?1.

Conclusions

In this pilot study in preterm neonates, although uNGAL detected sCre-based AKI upon its documentation, it failed to predict its development 1–2 days earlier.     

Acute kidney injury in scrub typhus

Background

We studied the urinary abnormalities and acute kidney injury (AKI) as per RIFLE criteria in scrub typhus.

Methods

A prospective case record-based study of scrub typhus was carried out from January 2009 to December 2010 in a tertiary hospital in South India. Patients were followed up until renal recovery or for at least 3 months after discharge. Univariate, chi-squared tests and multivariate logistic regression analyses were performed to identify the predictors of AKI.

Results

Scrub typhus was diagnosed in 259 patients. Urinary abnormalities were seen in 147 patients (56.7 %) with 60 patients (23.2 %) having AKI. All AKI patients had urinary abnormalities and 17 (28.3 %) were oliguric. Applying RIFLE (risk, injury, failure, loss, end-stage kidney disease) criteria, R, I, F were present in 23 (38.33 %), 13 (21.67 %), and 24 patients (40 %), respectively. Creatine phosphokinase (CPK) was raised in 33 patients (55 %) and hemodialysis was required in 6 patients (10 %). The case fatality rate in this study was 2 out of 259 (0.77 %), both having AKI and others recovering clinically. Significant predictors of AKI were tachycardia [odds ratio (OR) 2.28], breathlessness (OR 2.281), intensive care requirement (OR 2.43), mechanical ventilation (OR 3.33), thrombocytopenia (OR 2.90) and CPK >80 U/L (OR 1.76) by univariate analysis and intensive care requirement (adjusted OR 2.89) and thrombocytopenia (AOR 2.28) by multivariable logistic regression.

Conclusion

Scrub typhus should be part of the differential diagnosis of acute febrile illness with AKI. AKI in scrub typhus is usually mild, non-oliguric, and renal recovery occurs in most patients. Rhabdomyolysis may be contributory to AKI. Thrombocytopenia and intensive care requirement are significant predictors of AKI in scrub typhus.     

Acute kidney injury and its association with in-hospital mortality among children with acute infections

Background

We investigated prevalence of acute kidney injury (AKI) at hospitalization and its association with in-hospital mortality among Ugandan children hospitalized with common acute infections, and predictors of mortality among AKI children.

Methods

We enrolled 2,055 children hospitalized with primary diagnoses of acute gastroenteritis, malaria, or pneumonia. Serum creatinine, albumin, electrolytes, hemoglobin, and urine protein were obtained on admission. Participants were assessed for AKI based on serum creatinine levels. Demographic and clinical data were obtained using a primary care provider survey and medical chart review. Logistic regression was used to determine predictors of in-hospital mortality.

Results

A total of 278 (13.5 %) of children had AKI on admission; for 76.2 %, AKI was stage 2 (98/278) or stage 3 (114/278) defined as serum creatinine >2- or 3-fold above normal upper limit for age, respectively. AKI prevalence was particularly high in gastroenteritis (28.6 %) and underweight children (20.7 %). Twenty-five percent of children with AKI died during hospitalization, compared to 9.9 % with no AKI (adjusted odds ratio (aOR) 3.5 (95 % CI, 2.2–5.5)). In-hospital mortality risk did not differ by AKI stage. Predictors of in-hospital mortality among AKI children included primary diagnosis of pneumonia, aOR 4.5 (95 % CI, 1.8–11.2); proteinuria, aOR = 2.1 (95 % CI, 1.0–4.9) and positive human immunodeficiency virus (HIV) status, aOR 5.0 (95 % CI, 2.0–12.9).

Conclusions

Among children hospitalized with gastroenteritis, malaria, or pneumonia, AKI at admission was common and associated with high in-hospital mortality.     

Investigation of urinary neutrophil gelatinase associated lipocalin (NGAL) for early diagnosis of acute kidney injury after percutaneous nephrolithotomy

Introduction

Percutaneous nephrolithotomy (PCNL) could be mentioned as the most important treatment of choice for kidney staghorn stones. Previous publications reported that the novel biomarker urinary neutrophil gelatinase-associated lipocalin (NGAL) activity significantly increases in acute kidney injury (AKI) but there is not many published articles related to increase of NGAL after PCNL procedure.

Role of Urinary Neutrophil Gelatinase–Associated Lipocalin for Predicting the Severity of Renal Functions in Patients With Autosomal-Dominant Polycystic Kidney Disease

Background

Autosomal-dominant polycystic kidney disease (ADPKD) has a feature of disruption of tubular integrity with increased cellular proliferation and apoptosis. There are several known tubular membrane proteins in the pathogenesis of ADPKD, and one of these proteins is the neutrophil gelatinase-associated lipocalin (NGAL). NGAL is a protein expressed on renal tubular cells of which production is markedly increased in response to harmful stimuli such as ischemia or toxicity.

Clinical usefulness of urinary liver-type fatty-acid-binding protein as a perioperative marker of acute kidney injury in patients undergoing endovascular or open-abdominal aortic aneurysm repair

Purpose

Acute kidney injury (AKI) is common after cardiovascular surgery and is usually diagnosed on the basis of the serum creatinine (SCr) level and urinary output. However, SCr is of low sensitivity in patients with poor renal function. Because urinary liver-type fatty-acid-binding protein (L-FABP) reflects renal tubular injury, we evaluated whether perioperative changes in urinary L-FABP predict AKI in the context of abdominal aortic repair.

Methods

Study participants were 95 patients who underwent endovascular abdominal aortic aneurysm repair (EVAR) and 42 who underwent open repair. We obtained urine samples before surgery, after anesthesia induction, upon stent placement, before aortic cross-clamping (AXC), 1 and 2 h after AXC, at the end of surgery, 4 h after surgery, and on postoperative days (PODs) 1, 2, and 3, for measurement of L-FABP. We obtained serum samples before surgery, immediately after surgery, and on PODs 1, 2, and 3, for measurement of SCr. We also plotted receiver-operating characteristic (ROC) curves to identify cutoff laboratory values for predicting the onset of AKI.

Results

With EVAR, urinary L-FABP was significantly increased 4 h after the procedure (P = 0.014). With open repair, urinary L-FABP increased significantly to its maximum by 2 h after AXC (P = 0.007). With AKI, SCr significantly increased (P < 0.001, P = 0.001) by POD 2. ROC analysis showed urinary L-FABP to be more sensitive than SCr for early detection of AKI.

Conclusion

Urinary L-FABP appears to be a sensitive biomarker of AKI in patients undergoing abdominal aortic repair.

     

Efficacy of urinary midkine as a biomarker in patients with acute kidney injury

Background

The mortality and morbidity associated with acute kidney injury (AKI) remains high, despite advances in interventions. A multifunctional heparin-binding growth factor, midkine (MK), is involved in the pathogenesis of ischemic kidney injury. However, the clinical relevance of MK has not yet been elucidated. The present study investigated whether urinary MK can serve as a novel biomarker of AKI.

Methods

We initially compared the predictive value of MK with other urinary biomarkers, including N-acetyl-β-d-glucosaminidase (NAG), interleukin (IL)-18, and neutrophil gelatinase-associated lipocalin (NGAL), for the detection and differential diagnosis of established AKI (549 patients). Subsequently, the reliability of MK for the early detection of AKI was prospectively evaluated in 40 patients undergoing elective abdominal aortic aneurysm surgery. Urine samples were obtained at baseline, the period of aortic cross-clamping and declamping, the end of the surgery, and on post-operative day 1.

Results

The areas under the receiver operating characteristic curves for the diagnosis of AKI in various kidney diseases were 0.88, 0.70, 0.72, and 0.84 for MK, NAG, IL-18, and NGAL, respectively. When the optimal cutoff value of urinary MK was set at 11.5 pg/mL, the sensitivity and specificity were 0.87 and 0.85, respectively. In the second study, urinary MK peaked at the period of aortic declamping, about 1 h after cross-clamping in patients with AKI. Interestingly, the rise of MK in AKI patients was very precipitous compared with other biomarker candidates.

Conclusion

Urinary MK was prominent in its ability to detect AKI and may allow the start of preemptive medication.

     

Short- and long-term outcomes after non-severe acute kidney injury

Background

Severe acute kidney injury (AKI) is associated with chronic kidney disease (CKD), cardiovascular events and increased mortality. However, little is known about the prognosis in hospitalized population suffering from non-severe AKI episodes. The aim of this study is to determine the impact of non-severe AKI episodes in cardiovascular events, mortality and CKD, on short and long term.

Methods

Retrospective cohort study to 360 patients who met the criteria for diagnosis of AKI according ADQI guidelines with full recovery of renal function after the AKI episode, admitted between January 2000 and December 2010 in our hospital. Follow-up was 4 years after the diagnosis of AKI. Covariates included demographic variables, baseline creatinine and diagnosis of comorbidities.

Results

360 AKI survivor patients were included. Twenty five of them (6.7%) had developed CKD after 1-year follow-up. Hypertension (OR 1.62; 95% CI 1.2–2.6, p < 0.05) and serum creatinine >2.6 mg/dL in AKI (OR 1.7; 95% CI 1.2–3.7, p < 0.05) were independent risk factors. After 4-year follow-up, 40 patients (18.3%) had developed CKD; age >66 years was an independent risk factor (OR 1.03, 95% CI 1.03–1.06, p < 0.05). Mortality rate at 4 years was 25.3% and was significantly higher in CKD patients (OR 4.3, 95% CI 1.13–4.90, p < 0.05) and patients >66 years (OR 1.12, 95% CI 1.02–1.06, p < 0.05). The incidence of cardiovascular events also was higher in CKD patients than in non-CKD patients (62.7 vs. 21.7%, p < 0.05).

Conclusion

Even after fully recovered non-severe AKI episodes, some patients develop CKD and those have an increase in the incidence of cardiovascular events and long-term mortality.

     

Haematuria and acute kidney injury in elderly patients admitted to hospital with supratherapeutic warfarin anticoagulation

Background and objectives

Warfarin-related nephropathy is reported to occur with an INR >3.0 as a result of glomerular bleeding. There is a lack of prospective studies examining the effect of supratherapeutic warfarin anticoagulation on haematuria and acute kidney injury (AKI). Older patients may be susceptible due to greater warfarin use, prevalence of kidney disease and comorbidities. The objective of this study was to determine the incidence and nature of haematuria and AKI in older patients on warfarin and to determine any association with high INR levels.

Design, setting, participants and measurements

This was a prospective, observational study of 150 elderly patients receiving warfarin anticoagulation who were acutely hospitalised in a tertiary hospital. AKI was assessed using RIFLE criteria. Urinalysis was performed to quantify haematuria, characterise erythrocyte morphology and measure the albumin–creatinine ratio. Positive cases received follow-up at 4–6 weeks to determine resolution.

Results

An INR >3.0 was found in 54 % of patients. Pre-admission antibiotic use increased the risk of excessive anticoagulation. The incidence of isolated AKI, isolated haematuria and both was 18.7, 13.3 and 12 %, respectively. Factors associated with a higher risk of haematuria were an INR >4.0, non-urinary infection, catheterisation and albuminuria. Most cases of AKI were mild, and there was no demonstrable correlation between the admission INR and AKI. Admission with heart failure was significantly associated with an increased risk of persistent kidney impairment at follow-up.

Conclusions

Supratherapeutic warfarin anticoagulation was associated with an increased risk of haematuria, but not with AKI. The majority of cases of haematuria were transient.     

A pilot study of urinary fibroblast growth factor-2 and epithelial growth factor as potential biomarkers of acute kidney injury in critically ill children

Background

Acute kidney injury (AKI) increases the morbidity of critically ill children. Thus, it is necessary to identify better renal biomarkers to follow the outcome of these patients. This prospective case–control study explored the clinical value of a urinary biomarker profile comprised of neutrophil gelatinase lipocalin (uNGAL), fibroblast growth factor-2 (uFGF-2), and epidermal growth factor (uEGF) to follow these patients.

Methods

Urine samples were collected from 21 healthy children, and 39 critically ill children (mean age 7.5 years?±?6.97 SD) admitted to a pediatric intensive care unit with sepsis or requiring extra corporeal membrane oxygenation (ECMO). uNGAL, uFGF-2, and uEGF levels were measured using ELISA kits during the first 24 h of admission to PICU, at peak of illness, and upon resolution of the critical illness.

Results

On admission, the uNGAL and uFGF-2 levels were increased, and the uEGF levels were decreased, in critically ill children with AKI (n?=?19) compared to those without AKI (n?=?20), and healthy controls. A biomarker score using the combined cut-off values of uNGAL, uFGF-2, and uEGF (AUC?=?0.90) showed the highest specificity to identify children with AKI, relative to each biomarker alone. uNGAL and uFGF-2 on admission showed high sensitivity and specificity to predict mortality (AUC?=?0.82).

Conclusions

The biomarker profile comprised of uNGAL, uFGF-2, and uEGF increased the specificity to detect AKI in critically ill children, when compared to each biomarker used alone. uNGAL and uFGF-2 may also predict the risk of death. Further validation of these findings in a large sample size is warranted.     

Usefulness of Stroke Volume Index Obtained with the FloTrac/Vigileo System for the Prediction of Acute Kidney Injury After Radical Esophagectomy

Purpose

To assess the impact of stroke volume index (SVI) at the end of esophagectomy upon postoperative renal function.

Methods

We reviewed medical records of 128 patients undergoing esophagectomy. Intraoperative hemodynamics were monitored with the FloTrac sensor/Vigileo monitor system in addition to standard monitors. Patients were divided into two groups according to SVI at the end of surgery: the normal SVI group (n = 76), with SVI ≥ 35 ml/m², and the low SVI group (n = 52), with SVI < 35 ml/m². We compared postoperative renal function, indicated by serum creatinine and estimated glomerular filtration rate, on postoperative days 0 through 3. We also compared numbers of patients who developed postoperative acute kidney injury (AKI).

Results

Although there were no intergroup differences in preoperative renal function or other intraoperative hemodynamic variables, including arterial pressure, central venous pressure, stroke volume variation, a volume of infusion, urine output, and the total intraoperative in–out balance, estimated glomerular filtration rate was significantly lower and serum creatinine was significantly higher in the low SVI group than in the normal SVI group on postoperative days 1 and 2 (P < 0.05). In addition, more patients developed postoperative AKI in the low SVI group than in the normal SVI group (12 of 52 vs. 5 of 76, P = 0.015).

Conclusions

Low SVI at the end of esophagectomy may represent a risk factor for AKI in the early postoperative period. Further studies are required to examine whether maintaining SVI above 35 ml/m² reduces the incidence of AKI after esophagectomy.     

Poor early graft function impairs long-term outcome in living donor kidney transplantation

Background

Poor early graft function (EGF) after living donor kidney transplantation (LDKT) has been found to decrease rejection-free graft survival rates. However, its influence on long-term graft survival remains inconclusive.

Methods

Data were collected on 472 adult LDKTs performed between July 1996 and February 2010. Poor EGF was defined as the occurrence of delayed or slow graft function. Slow function was defined as serum creatinine above 3.0 mg/dL at postoperative day 5 without dialysis.

Results

The incidence of slow and delayed graft function was 9.3 and 4.4%, respectively. Recipient overweight, pretransplant dialysis and warm ischemia were identified as risk factors for the occurrence of poor EGF. The rejection-free survival was worse for poor EGF as compared to immediate graft function with an adjusted hazard ratio (HR) of 6.189 (95% CI 4.075–9.399; p < 0.001). Long-term graft survival was impaired in the poor EGF group with an adjusted HR of 4.206 (95% CI 1.839–9.621; p = 0.001).

Conclusions

Poor EGF occurs in 13.7% of living donor kidney allograft recipients. Both, rejection-free and long-term graft survivals are significantly lower in patients with poor EGF as compared to patients with immediate graft function. These results underline the clinical relevance of poor EGF as phenomenon after LDKT.