Acute kidney injury in children

DCoH: A novel biomarker for diagnosing acute kidney injury

Initial diagnosis of acute kidney injury (AKI) is usually based on measuring serum-creatinine and blood urea nitrogen levels; however such measurements are still poor in identifying renal injuries at initial stages. These standard matrices are not enough to monitor the outcome and progression of AKI. The prognosis prevents proper treatment and timely delay in providing putative therapeutic agents. The cost effective therapies to get delayed, patient health gets compromised and ultimately requires renal transplant due to end-stage renal disease, which is another major problematic factor due to shortage kidney donors. To establish effective therapies for AKI the need will be facilitated by developing and identifying reliable, sensitive biomarkers which can be detected early during all stages of AKI, even during preclinical and clinical studies. Although reaching to human clinical trials takes years of thorough evaluations, preliminary studies should be carried out effectively by: (a) Employing cell culture analysis, (b) use of AKI animal models, studying various gene regulated networks, and biomarkers, and (c) patient serum sampling and testing. As elevated phenylalanine are indicative of AKI onset within 4h, its levels is controlled, 4a-Hydroxy-tetrahydrobiopterin dehydratase/dimerization cofactor of HNF-1 (DCoH). There is a possibility of targeting DCoH to the current bedside list of biomarkers involved in AKI onset.

The multifaceted role of the renal microvasculature during acute kidney injury

Pediatric acute kidney injury (AKI) represents a complex disease process for clinicians as it is multifactorial in cause and only limited treatment or preventatives are available. The renal microvasculature has recently been implicated in AKI as a strong therapeutic candidate involved in both injury and recovery. Significant progress has been made in the ability to study the renal microvasculature following ischemic AKI and its role in repair. Advances have also been made in elucidating cell-cell interactions and the molecular mechanisms involved in these interactions. The ability of the kidney to repair post AKI is closely linked to alterations in hypoxia, and these studies are elucidated in this review. Injury to the microvasculature following AKI plays an integral role in mediating the inflammatory response, thereby complicating potential therapeutics. However, recent work with experimental animal models suggests that the endothelium and its cellular and molecular interactions are attractive targets to prevent injury or hasten repair following AKI. Here, we review the cellular and molecular mechanisms of the renal endothelium in AKI, as well as repair and recovery, and potential therapeutics to prevent or ameliorate injury and hasten repair.

Novel Use of an Ultrafiltration Device as an Alternative Method for Fluid Removal in Critically Ill Pediatric Patients with Cardiac Disease: A Case Series

Fluid overload (FO) is a common complication for pediatric patients in the intensive care unit. When conventional therapy fails, hemodialysis or peritoneal dialysis is classically used for fluid removal. Unfortunately, these therapies are often associated with cardiovascular or respiratory instability. Ultrafiltration, using devices such as the Aquadex™ system (Baxter Healthcare, Deerfield, IL, USA), is an effective tool for fluid removal in adult patients with congestive heart failure. As compared to hemodialysis, ultrafiltration can be performed using smaller catheters, and the extracorporeal volume and minimal blood flow rates are lower. In addition, there is no associated abdominal distension as is seen in peritoneal dialysis. Consequently, ultrafiltration may be better tolerated in critically ill pediatric patients. We present three cases of challenging pediatric patients with FO in the setting of congenital heart disease in whom ultrafiltration using the Aquadex™ system was successfully utilized for fluid removal while cardiorespiratory stability was maintained.

Health-related quality of life and mental health in parents of children with hemolytic uremic syndrome

BACKGROUND

Little is known about health-related quality of life (HRQoL) and mental health of parents having children with a history of hemolytic uremic syndrome (HUS).

METHODS

This study included 63 mothers and 58 fathers of a cohort of 63 HUS-affected children. At assessment, the mean time since a child experienced an acute episode of HUS was 6.4 years. Parental HRQoL, mental health and posttraumatic stress disorder (PTSD) were assessed with standardized self-report questionnaires. Medical data were extracted from patients' hospital records.

RESULTS

The HRQoL and mental health of both the mothers and fathers were not impaired compared to normative data. However, a shorter time since a child's acute HUS episode was a significant predictor of lower HRQoL among the mothers, while no such effect was found among the fathers. Two fathers (3%), but no mothers, met the criteria for a diagnosis of HUS-related full PTSD; one father (2%) and four mothers (6%) met the criteria for a diagnosis of HUS-related partial PTSD.

CONCLUSIONS

Our study shows that most parents of our study sample were doing well in terms of HRQoL and mental health, although a small number met the criteria for full or partial PTSD diagnosis due to their child's HUS. We therefore recommend that healthcare providers pay special attention to parents regarding PTSD symptoms during the clinical follow-up of a HUS-affected child since some parents may benefit from psychological support.

Severe acute kidney injury as presentation of Burkitt's lymphoma

We discuss a case of acute kidney injury (AKI) at a very young age caused by primary lymphomatous renal infiltration due to Burkitt's lymphoma and analyse the literature on this rare condition. At presentation, clinical examination showed impressive bilateral nephromegaly and hypertension. Blood analysis indicated severe AKI, mild anaemia and normal serum electrolytes. There were no signs of tumour lysis syndrome. Urine sediment was normal, with neither haematuria nor proteinuria. Abdominal ultrasound demonstrated bilateral renal enlargement (+12 SD), with increased corticomedullar differentiation. MRI demonstrated the presence of a homogenous renal enlargement with features of an infiltrative lesion. Ultimately, microscopic and immunohistochemical analysis of the renal biopsy confirmed the diagnosis of Burkitt's lymphoma. Early and aggressive therapy is the key to ensure a good outcome.

Reference intervals for renal injury biomarkers neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 in young infants

BACKGROUND

Reliable reference intervals for two novel urinary biomarkers of renal injury, neutrophil gelatinase-associated lipocalin (uNGAL) and kidney injury molecule-1 (uKIM-1) are lacking for infants. Therefore, the aim of our study was to establish reference intervals for urinary NGAL and KIM-1 absolute concentrations as well as normalized to urinary creatinine in young infants categorized in small age intervals.

METHODS

From June 2010 to March 2014, serum and urine samples of 106 basically healthy infants (born between 37 and 42 weeks of gestation) aged 1 day to 1 year were collected. Blood samples were assayed for serum creatinine levels to confirm a healthy renal status. Urine samples were assayed for creatinine, uNGAL (ng/mL) and uKIM-1 (ng/mL).

RESULTS

Two thirds of the study cohort were boys. uNGAL concentrations declined with increasing age (likelihood ratio test, p=0.001). Also, uNGAL concentrations were higher in girls (50th centile uNGAL was 27.1 ng/mL) than boys (50th centile uNGAL was 14.3 ng/mL) (two tailed Wald test, p<0.001) NGAL concentrations were not related to ethnicity. uKIM-1 concentrations were extremely low in almost all 106 subjects [median uKIM-1 was 0.08 (IQR 0.08-0.08) ng/mL] and not related with age, gender or ethnicity (all p>0.05).

CONCLUSIONS

Our data uniquely provide uNGAL and uKIM-1 reference intervals for the first year of life. Notably, only uNGAL levels decreased with increasing age and were higher in girls. These reference intervals enable future studies to evaluate the performance of both biomarkers in detecting early kidney tubular injury, particularly in the setting of critical care.

Drug-induced acute kidney injury in neonates

PURPOSE OF REVIEW

Acute kidney injury (AKI) is an independent risk factor for morbidity and mortality in critically ill neonates. Nephrotoxic medication exposure is common in neonates. Nephrotoxicity represents the most potentially avoidable cause of AKI in this population.

RECENT FINDINGS

Recent studies in critically ill children revealed the importance of recognizing AKI and potentially modifiable risk factors for the development of AKI such as nephrotoxic medication exposures. Data from critically ill children who have AKI suggest that survivors are at risk for the development of chronic kidney disease. Premature infants are born with incomplete nephrogenesis and are at risk for chronic kidney disease. The use of nephrotoxic medications in the neonatal intensive care unit is very common; yet the effects of medication nephrotoxicity on the short and long-term outcomes remains highly understudied.

SUMMARY

The neonatal kidney is predisposed to nephrotoxic AKI. Our ability to improve outcomes for this vulnerable group depends on a heightened awareness of this issue. It is important for clinicians to develop methods to minimize and prevent nephrotoxic AKI in neonates through a multidisciplinary approach aiming at earlier recognition and close monitoring of nephrotoxin-induced AKI.

Acute Kidney Injury and Fluid Overload in Neonates Following Surgery for Congenital Heart Disease

BACKGROUND

Acute kidney injury (AKI) and fluid overload have been shown to increase morbidity and mortality. The reported incidence of AKI in pediatric patients following surgery for congenital heart disease is between 15% and 59%. Limited data exist looking at risk factors and outcomes of AKI or fluid overload in neonates undergoing surgery for congenital heart disease.

METHODS

Neonates aged 6 to 29 days who underwent surgery for congenital heart disease and who were without preoperative kidney disease were included in the study. The AKI was determined utilizing the Acute Kidney Injury Network criteria.

RESULTS

Ninety-five neonates were included in the study. The incidence of neonatal AKI was 45% (n = 43), of which 86% had stage 1 AKI. Risk factors for AKI included cardiopulmonary bypass time, selective cerebral perfusion, preoperative aminoglycoside use, small kidneys by renal ultrasound, and risk adjustment for congenital heart surgery category. There were eight mortalities (five from stage 1 AKI group, three from stage 2, and zero from stage 3). Fluid overload and AKI both increased hospital length of stay and postoperative ventilator days.

CONCLUSION

To avoid increased risk of morbidity and possibly mortality, every attempt should be made to identify and intervene on those risk factors, which may be modifiable or identifiable preoperatively, such as small kidneys by renal ultrasound.

Clinical characteristics and mortality risk prediction in children with acute kidney injury

Background:

Acute kidney injury (AKI) is characterized by a reversible increase in the blood concentration of creatinine and nitrogenous waste products and by the inability of the kidney to regulate fluid and electrolyte homeostasis appropriately.

Objective:

AKI is a serious condition in critically ill patients. The aim of the study was to determine incidence rate, identify risk factors, and describe the clinical outcome of AKI in the Pediatric Intensive Care Unit (PICU).

Materials and Methods:

This prospective observational study was conducted in the PICU of a hospital in the South-east Area of Iran (Zahedan City), to study the clinico-etiological profile of AKI (defined according to the AKI network criteria). Over a period of 20 months from April 2012 to December 2014, 303 children were included in the study. Both the groups of patients, those who developed AKI and those who did not develop AKI, were then followed during the course of their hospital stay.

Results:

There were 303 cases included in the study, with the incidence rate of AKI of 14.9% in PICU. The most common PICU admission diagnoses in AKI were neurologic 85 (%28.05), followed by heart diseases 52 (17.18%) and 31 (10.23%) for respiratory diseases. AKI was 43.5 and 5.4 times more prevalent in renal and endocrine patients compared to those with heart disease respectively. The mortality rate was estimated to be higher in patients with AKI compared to their counterparts (40% vs. 17.8%). Chance of death increased in patients with AKI (odds ratio = 3.04).

Conclusion:

AKI is a serious problem, but its true incidence is unknown. Understanding the epidemiology of AKI by using of standard definition help us to find high-risk children that are the first step to improve outcomes. The future multiple-center study may benefit by better identifying risk factors and early detection of AKI by using biomarkers novel to prevent the developing of AKI.

Drugs as risk factors of acute kidney injury in critically ill children

BACKGROUND

Acute kidney injury (AKI) is a serious condition in critically ill children. Nephrotoxic medication exposure is a common contributing factor to AKI, but little literature is available in pediatrics. The aim of the present study was to assess potential associations between drugs and the risk of developing AKI.

METHODS

We performed a retrospective case-control study in a pediatric intensive care unit (PICU). Cases were patients who developed AKI during PICU stay. Patients without AKI served as controls and were matched to cases by age and gender in a one-to-one ratio.

RESULTS

One hundred case-control pairs were included. Cases were not statistically different from controls with regard to median weight and main diagnoses, but differed with regard to the need for mechanical ventilation, severity of illness, and median length of PICU stay. Multivariate models revealed a statistically significant higher risk of developing AKI for patients treated with metamizole, morphine, paracetamol, and tropisetron. A similar risk could be shown for medication groups, namely glucocorticoids, betalactam antibiotics, opioids, and non-steroidal anti-inflammatory drugs.

CONCLUSIONS

The results suggest that drugs are associated with acute renal dysfunction in critically ill children, but the multifactorial causes of AKI should be kept in mind.

Infectious Diseases and the Kidney in Children

The kidney is involved in a wide range of bacterial, viral, fungal, and parasitic diseases. In most systemic infections, renal involvement is a minor component of the illness, but in some, renal failure may be the presenting feature and the major problem in management. Although individual infectious processes may have a predilection to involve the renal vasculature, glomeruli, interstitium, or collecting systems, a purely anatomic approach to the classification of infectious diseases affecting the kidney is rarely helpful because most infections may involve several different aspects of renal function. In this chapter, a microbiological classification of the organisms affecting the kidney is adopted. Although they are important causes of renal dysfunction in infectious diseases, urinary tract infections and hemolytic uremic syndrome (HUS) are not discussed in detail because they are considered separately in chapters XX and XX, respectively.

Ibuprofen-associated acute kidney injury in dehydrated children with acute gastroenteritis

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) induce acute kidney injury (AKI) in volume-depleted patients; however the prevalence of this complication is likely underestimated. We assessed the impact of ibuprofen exposure on renal function among dehydrated children with acute gastroenteritis (AGE) to further characterize NSAID-associated AKI.

METHODS

Over a 1-year period dehydrated children with AGE (n = 105) were prospectively enrolled and grouped as cases, presenting with AKI (n = 46) or controls, not presenting with AKI (n = 59). AKI was defined by pediatric RIFLE (pRIFLE) criteria.

RESULTS

Among the children enrolled in the study, AKI prevalence was 44 %, and 34 (54 %) of the 63 patients who received ibuprofen developed renal impairment. Relative to the controls, children presenting with AKI were younger (median age 0.66 vs. 1.74 years; p < 0.001) and received ibuprofen more frequently (74 vs. 49 %, p = 0.01). After adjusting for the degree of dehydration, ibuprofen exposure remained an independent risk factor for AKI (p < 0.001, odds ratio 2.47, 95 % confidence interval 1.78-3.42). According to the pRIFLE criteria, 17 patients were at the 'risk' stage of AKI severity, 24 were at the 'injury' stage, and five were at the 'failure' stage; none required dialysis. Distribution of patients within categories was similar regardless of ibuprofen exposure. All cases fulled recovered from AKI.

CONCLUSIONS

Ibuprofen-associated AKI was 54 % in our cohort of dehydrated children with AGE. Drug exposure increased the risk for developing AKI by more than twofold, independent of the magnitude of the dehydration.

Influence of Acute Kidney Injury Defined by the Pediatric Risk, Injury, Failure, Loss, End-Stage Renal Disease Score on the Clinical Course of PICU Patients

OBJECTIVE

To evaluate the predictive value of the pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease criteria for disease course severity in patients with or without acute kidney injury admitted to a PICU.

DESIGN

Retrospective cohort study.

SETTING

A 12-bed PICU at a tertiary referral center in Southern Brazil.

PATIENTS

All patients admitted to the study unit over a 1-year period.

INTERVENTIONS

A database of all eligible patients was analyzed retrospectively.

MEASUREMENTS AND MAIN RESULTS

Patients were classified by pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease score at admission and worst pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease score during PICU hospitalization. The outcomes of interest were length of PICU stay, duration of mechanical ventilation, duration of vasoactive drug therapy, and mortality. The Pediatric Index of Mortality 2 was used to assess overall disease severity at the time of PICU admission. Of 375 patients, 169 (45%) presented acute kidney injury at the time of admission and 37 developed acute kidney injury during PICU stay, for a total of 206 of 375 patients (55%) diagnosed with acute kidney injury during the study period. The median Pediatric Index of Mortality 2 score predicted a mortality rate of 9% among non-acute kidney injury patients versus a mortality rate of 16% among acute kidney injury patients (p = 0.006). The mortality of patients classified as pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease F was double that predicted by Pediatric Index of Mortality 2 (7 vs 3.2). Patients classified as having severe acute kidney injury (pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease I + F) exhibited higher mortality (14.1%; p = 0.001) and prolonged PICU length of stay (median, 7 d; p = 0.001) when compared with other patients. Acute kidney injury is a very frequent occurrence among patients admitted to PICUs.

CONCLUSIONS

The degree of acute kidney injury severity, as assessed by the pediatric-modified Risk, Injury, Failure, Loss, End-stage renal disease criteria, is a good predictor of morbidity and mortality in this population. Pediatric Index of Mortality 2 tends to underestimate mortality in pediatric patients with severe acute kidney injury.

Acute Kidney Injury Recognition and Management: A Review of the Literature and Current Evidence

Acute renal failure is defined as a rapid decrease in the glomerular filtration rate, occurring over a period of hours to days and by the inability of the kidney to regulate fluid and electrolyte homeostasis appropriately. AKI is a catastrophic, life-threatening event in critically ill patients. AKI can be divided into pre-renal injury, intrinsic kidney disease (including vascular insults) and obstructive uropathies. The prognosis of AKI is highly dependent on the underlying cause of the injury. Children who have AKI as a component of multisystem failure have a much higher mortality rate than children with intrinsic renal disease. Treatment of AKI is subjected to risk stratification and ongoing damage control measures, such as patients with sepsis, exposure to nephrotoxic agents, ischemia, bloody diarrhea, or volume loss, could be helped by optimizing the fluid administrations, antibiotics possessing least nephrotoxic potential, blood transfusion where hemoglobin is dangerously low, limiting the use of nephrotoxic agents including radio contrast use, while maximize the nutrition. Acute kidney injury remains a complex disorder with an apparent differentiation in pathology between septic and nonseptic forms of the disease. Although more studies are still required, progress in this area has been steady over the last decade with purposeful international collaboration.

Urinary Neutrophil Gelatinase-Associated Lipocalin Predicts Renal Injury Following Extracorporeal Membrane Oxygenation

OBJECTIVE

To evaluate the course of urinary neutrophil gelatinase-associated lipocalin and urinary kidney injury molecule-1 levels in young children during extracorporeal membrane oxygenation and concomitant continuous hemofiltration. Furthermore, to evaluate whether these levels predict outcome.

DESIGN

Prospective observational cohort study from July 2010 to July 2013.

SETTING

ICU of a level III university children's hospital.

PATIENTS

Thirty-one extracorporeal membrane oxygenation-treated children up to 1 year were included.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were weaned from extracorporeal membrane oxygenation after a median of 162 hours (interquartile range, 83-304). Throughout the study, 58% of the patients met the criteria for acute kidney injury (i.e., Risk Injury Failure Loss End-Stage Renal Disease-Risk or higher defined as an increase in serum creatinine corresponding to ≥ 150% when compared with age-specific reference values). Levels of both biomarker patterns changed significantly throughout extracorporeal membrane oxygenation (urinary neutrophil gelatinase-associated lipocalin, p < 0.001 and urinary kidney injury molecule-1, p = 0.005, linear mixed model analyses). Urinary neutrophil gelatinase-associated lipocalin levels were already high before extracorporeal membrane oxygenation, whereas urinary kidney injury molecule-1 levels increased throughout the first extracorporeal membrane oxygenation day and peaked at 12-24 hours. Also, urinary neutrophil gelatinase-associated lipocalin levels at 12-24 hours of extracorporeal membrane oxygenation therapy were higher among patients with acute kidney injury post extracorporeal membrane oxygenation (p = 0.002, Mann-Whitney U test). Biomarker levels did not differ between survivors and nonsurvivors.

CONCLUSIONS

The increased urinary neutrophil gelatinase-associated lipocalin and urinary kidney injury molecule-1 levels confirm that renal tubular damage occurs in critically ill infants in need of extracorporeal membrane oxygenation. The fact that the maximal urinary neutrophil gelatinase-associated lipocalin levels were measured 24 hours earlier than urinary kidney injury molecule-1 supports the use of biomarker combinations rather than a single biomarker to identify patients at risk of acute kidney injury. Finally, since urinary neutrophil gelatinase-associated lipocalin levels at 12-24 hours of extracorporeal membrane oxygenation therapy were associated with acute kidney injury post extracorporeal membrane oxygenation, this marker may facilitate more timely adjustment of therapeutic interventions.

Detection of early renal injury in children with solid tumors undergoing chemotherapy by urinary neutrophil gelatinase-associated lipocalin

Acute kidney injury (AKI) is a complication in children with solid tumors undergoing chemotherapy, as it may prevent the use of therapy protocols and also hinder the supportive and diagnostic procedures. Thus, there is an urgent requirement for early predictive biomarkers of AKI. The most promising novel AKI biomarker is neutrophil gelatinase-associated lipocalin (NGAL). The aim of the present study was to compare the predictability of NGAL as a biomarker of AKI with creatinine as a traditional biomarker in children with solid tumors under chemotherapy. The study was performed on 30 patients with different types of solid tumors (reuroblastoma, Wilms tumor, medulloblastoma, rhabdomyosarcoma and Ewing sarcoma) and 20 control subjects. Urinary NGAL (uNGAL) and serum creatinine samples were taken three times: Baseline before the beginning of the treatment, one week after chemotherapy and at the end of the chemotherapy protocol. AKI is defined as a change in creatinine level by >50% of the baseline. The creatinine level only rises to this level in the third sample, while uNGAL increases significantly in the second and third samples with percentage of change 376.8 and 698.2%, respectively, which is highly significant (P<0.001). When comparing the predictive value of serum creatinine for AKI depending on the receiver operating characteristic curve with that of uNGAL, the area under the curve (AUC) for creatinine was 0.60 with a standard error (SE) of 0.086 and 95% confidence interval (CI) between 0.432 and 0.768, while that of uNGAL was highly predictive with an AUC of 0.847, SE 0.55 and 95% CI between 0.739 and 0.955. Depending only on the creatinine level for detecting the AKI will markedly delay the diagnosis; however, uNGAL is detected earlier, and is easier and more reliable as a marker for AKI in children with solid tumors undergoing chemotherapy.

A systematic review of acute kidney injury in pediatric allogeneic hematopoietic stem cell recipients

The process of allogeneic HSCT in children is associated with frequent AKI and mortality, but the epidemiology is not widely reported. The aim of this review was to summarize the available evidence on incidence, risk factors, timing, and prognosis of AKI in children following HSCT. We systematically reviewed all observational studies reporting incidence and outcomes of AKI in pediatric allogenic HSCT recipients. The minimum criteria for AKI were defined as an increase in sCr ≥ x1.5 or urine output ≤0.5 mL/kg/min over six h. Medline and Embase were searched until March 2014. From 993 electronic records, five were eligible for inclusion (n = 571 patients). The average incidence of AKI within the first 100 days following HSCT was 21.7% (range 11-42%), and the average time of onset was 4-6 wk post-transplant. Risk factors for AKI included cyclosporine toxicity, amphotericin B and foscarnet, SOS, and having a mismatched donor. There were conflicting reports on whether AKI was associated with the development of CKD. AKI is a common and potentially life-threatening complication following HSCT in children. Further quality observational studies are needed to accurately determine the epidemiology and prognosis of AKI in this population.

Association of definition of acute kidney injury by cystatin C rise with biomarkers and clinical outcomes in children undergoing cardiac surgery

IMPORTANCE

Research has identified improved biomarkers of acute kidney injury (AKI). Cystatin C (CysC) is a better glomerular filtration rate marker than serum creatinine (SCr) and may improve AKI definition.

OBJECTIVE

To determine if defining clinical AKI by increases in CysC vs SCr alters associations with biomarkers and clinical outcomes.

DESIGN, SETTING, AND PARTICIPANTS

Three-center prospective cohort study of intensive care units in New Haven, Connecticut, Cincinnati, Ohio, and Montreal, Quebec, Canada. Participants were 287 patients 18 years or younger without preoperative AKI or end-stage renal disease who were undergoing cardiac surgery. The study dates were July 1, 2007, through December 31, 2009.

EXPOSURES

For biomarker vs clinical AKI associations, the exposures were first postoperative (0-6 hours after surgery) urine interleukin 18, neutrophil gelatinase-associated lipocalin, kidney injury molecule 1, and liver fatty acid-binding protein. For clinical AKI outcome associations, the exposure was Kidney Disease: Improving Global Outcomes AKI definition (based on SCr or CysC).

MAIN OUTCOMES AND MEASURES

Clinical AKI, length of stay, and length of mechanical ventilation. We determined areas under the receiver operating characteristic curve and odds ratios for first postoperative biomarkers to predict AKI.

RESULTS

The SCr-defined vs CysC-defined AKI incidence differed substantially (43.6% vs 20.6%). Percentage agreement was 71% (κ = 0.38); stage 2 or worse AKI percentage agreement was 95%. Interleukin 18 and kidney injury molecule 1 discriminated for CysC-defined AKI better than for SCr-defined AKI. For interleukin 18 and kidney injury molecule 1, the areas under the receiver operating characteristic curve were 0.74 and 0.65, respectively, for CysC-defined AKI, and 0.66 and 0.58, respectively, for SCr-defined AKI. Fifth (vs first) quintile concentrations of both biomarkers were more strongly associated with CysC-defined AKI. For interleukin 18 and kidney injury molecule 1, the odds ratios were 16.19 (95% CI, 3.55-73.93) and 6.93 (95% CI, 1.88-25.59), respectively, for CysC-defined AKI vs 6.60 (95% CI, 2.76-15.76) and 2.04 (95% CI, 0.94-4.38), respectively, for SCr-defined AKI. Neutrophil gelatinase-associated lipocalin and liver fatty acid-binding protein associations with both definitions were similar. The CysC definitions and SCr definitions were similarly associated with clinical outcomes of resource use.

CONCLUSIONS AND RELEVANCE

Compared with the SCr-based definition, the CysC-based definition is more strongly associated with urine interleukin 18 and kidney injury molecule 1 in children undergoing cardiac surgery. Consideration should be made for defining AKI based on CysC in clinical care and future studies.

Histopathology of renal asphyxia in newborn piglets: Individual susceptibility to tubular changes

AIM: To analyze the effects on the kidney of hypoxia-reoxygenation in an experimental model of normocapnic asphyxia.

METHODS: To this end, 40 newborn Landrace/Large-White piglets aged 1-4 d were studied in this work. Hypoxia was induced by decreasing the inspired fiO2 to 0.06-0.08. Animals were resuscitated with different fiO₂ and subdivided into 4 groups: group 1, 2, 3 and 4 received 18%, 21%, 40% and 100% O₂ respectively. Macroscopic examination was carried out to evidence possible pathological features. Tissue sample were obtained from both kidneys. Four or five micron paraffin sections were stained with H-E and PAS stain and examined under an optical microscope.

RESULTS: Pathological changes, mainly affecting tubular cells, were observed in the vast majority of kidneys of asphyxiated piglets. The most frequent tubular changes were: tubular casts (95%), tubular dilatation (87.5%), tubular vacuolization (70%), tubular eosinophilia (52.5%), sloughing (50%), fragmentation of the brush border (50%), oedema (32.5%), apoptosis (15%) and glomerular changes (meningeal cell proliferation, capsular adhesion between the flocculus and Bowman’s capsule, glomerulosclerosis and fibrous or cellular crescents associated with collapse of the glomerular tuft). Statistical analysis was carried out on changes observed when the animals were allocated in the 4 groups (χ²-test 0.05). The statistical analysis showed no evidence of differences regarding kidney lesions among the animals groups.

CONCLUSION: Our data show that renal pathology in newborn piglets is characterized by interindividual variability to hypoxia and is not associated with oxygen concentration.

Urinary neutrophil gelatinase-associated lipocalin identifies critically ill young children with acute kidney injury following intensive care admission: a prospective cohort study

Introduction

Children admitted to a pediatric intensive care unit (ICU) are at high risk of developing acute kidney injury (AKI). Although serum creatinine (SCr) levels are used in clinical practice, they are insensitive for early diagnosis of AKI. Urinary neutrophil gelatinase-associated lipocalin (uNGAL) and kidney injury molecule-1 (KIM-1) are novel AKI biomarkers whose performance in pediatric ICU patients is largely unknown. In this study, we aimed to characterize uNGAL and KIM-1 patterns in children following ICU admission and to assess their properties in relation to identifying children at risk for AKI development.

Methods

From June 2010 until January 2014, we conducted a prospective observational cohort study of term-born children ages 1 day to 1 year on mechanical ventilation. Blood and urine samples were obtained every 6 to 12 hours up to 72 hours post-admission. Blood samples were assayed for SCr, and urine samples were assayed for uNGAL and KIM-1. The RIFLE (risk, injury, failure, loss, end-stage renal disease) classification as 150%, 200% or 300% of median SCr reference values was used to define AKI.

Results

A total of 100 children were included (80 survived). Their median age at admission was 27.7 days (interquartile range (IQR), 1.5 to 85.5). The median duration of mechanical ventilation was 5.8 days (IQR, 3.1 to 11.4). Thirty-five patients had evidence of AKI within the first 48 hours post-admission, of whom 24 (69%) already had AKI when they entered the ICU. uNGAL and KIM-1 concentrations in AKI peaked between 6 to 12 hours and between 12 to 24 hours post-admission, respectively. The maximal area under the receiver operating characteristic curve (AUC) for uNGAL was 0.815 (95% confidence interval (CI), 0.685 to 0.945, P <0.001) at 0 to 6 hours post-admission. The discriminative ability of KIM-1 was moderate, with a largest AUC of 0.737 (95% CI, 0.628 to 0.847; P <0.001) at 12 to 24 hours post-admission. At the optimal cutoff point (126 ng/ml), uNGAL concentration predicted AKI development correctly in 16 (84%) of 19 children, up to 24 hours before a rise in SCr became apparent.

Conclusions

Levels of uNGAL and KIM-1 increase in patients with AKI following ICU admission and peak at 6 to 12 hours and 12 to 24 hours post-admission, respectively. uNGAL seems to be a reliable marker for identifying children who will develop AKI 24 hours later.

Neurodevelopmental long-term outcome in children after hemolytic uremic syndrome

BACKGROUND

To investigate the long-term neurodevelopmental outcome in children after hemolytic uremic syndrome (HUS) and to compare outcome dependent on central nervous system (CNS) involvement during HUS.

METHODS

A single-center retrospective cohort of 47 children was examined at a median age of 10.6 (range 6-16.9) years and a median follow-up of 7.8 (range 0.4-15.3) years after having had HUS. Intellectual performance was assessed with the German version of the Wechsler Intelligence Scale 4th version and neuromotor performance with the Zurich Neuromotor Assessment (ZNA). The occurrence of neurological symptoms during the acute phase of HUS was evaluated retrospectively.

RESULTS

Mean IQ of the whole study population fell within the normal range (median full scale IQ 104, range 54-127). Neuromotor performance was significantly poorer in the domains "adaptive fine," "gross motor," "static balance" (all p < 0.05) and "associated movements" (p < 0.001); only the "pure motor" domain was within the normal reference range. Neurological findings occurred in 16/47 patients (34 %) during acute HUS. Neurodevelopmental outcome was not significantly different between children with or without CNS involvement.

CONCLUSIONS

Our follow-up of children after HUS showed a favorable cognitive outcome. However, neuromotor outcome was impaired in all study participants. Neurological impairment during acute HUS was not predictive of outcome.

The incidence and aetiology of acute kidney injury in children in Norway between 1999 and 2008

Aim

Primary acute kidney injury (AKI) is a direct cause of hospitalisation in children, but can also result from other conditions. There is limited information on the epidemiology of this condition. Our aim was to describe the national incidence rate and aetiology of acute kidney injury in children under the age of 16 in Norway from 1999 to 2008.

Methods

We carried out a retrospective study of medical records provided by all 18 of the paediatric hospital departments that specialise in treating paediatric patients with AKI.

Results

We identified 315 cases of AKI (53% male), with an estimated average annual incidence rate of 3.3 cases per 100 000 children and a median annual occurrence of 33 cases. Most cases (43%) were in children under five. We identified 53 aetiologies and classified these into 30 aetiological groups: 24% of the cases were prerenal (n = 75), 74% were intrinsic/renal (n = 234) and 2% were postrenal (n = 5). Nephritic syndromes was the major cause (44%) of AKI, followed by haemolytic-uraemic syndrome (HUS) (15%).

Conclusion

Nephritic syndromes and HUS are the most common aetiologies of AKI in Norway. Although our results could indicate a low incidence of paediatric AKI in Norway, the lack of other national studies makes comparisons difficult.

Thrombin-inhibiting nanoparticles rapidly constitute versatile and detectable anticlotting surfaces

Restoring an antithrombotic surface to suppress ongoing thrombosis is an appealing strategy for treatment of acute cardiovascular disorders such as erosion of atherosclerotic plaque. An antithrombotic surface would present an alternative to systemic anticoagulation with attendant risks of bleeding. We have designed thrombin-targeted nanoparticles (NPs) that bind to sites of active clotting to extinguish local thrombin activity and inhibit platelet deposition while exhibiting only transient systemic anticoagulant effects. Perfluorocarbon nanoparticles (PFC NP) were functionalized with thrombin inhibitors (either D-phenylalanyl-L-prolyl-L-arginyl-chloromethyl ketone or bivalirudin) by covalent attachment of more than 15 000 inhibitors to each PFC NP. Fibrinopeptide A (FPA) ELISA demonstrated that thrombin-inhibiting NPs prevented cleavage of fibrinogen by both free and clot-bound thrombin. Magnetic resonance imaging (MRI) confirmed that a layer of thrombin-inhibiting NPs prevented growth of clots in vitro. Thrombin-inhibiting NPs were administered in vivo to C57BL6 mice subjected to laser injury of the carotid artery. NPs significantly delayed thrombotic occlusion of the artery, whereas an equivalent bolus of free inhibitor was ineffective. For thrombin-inhibiting NPs, only a short-lived (∼10 min) systemic effect on bleeding time was observed, despite prolonged clot inhibition. Imaging and quantification of in vivo antithrombotic NP layers was demonstrated by MRI of the PFC NP. (19)F MRI confirmed colocalization of particles with arterial thrombi, and quantitative (19)F spectroscopy demonstrated specific binding and retention of thrombin-inhibiting NPs in injured arteries. The ability to rapidly form and image a new antithrombotic surface in acute vascular syndromes while minimizing risks of bleeding would permit a safer method of passivating active lesions than current systemic anticoagulant regimes.

Pediatric acute kidney injury: A syndrome under paradigm shift

The recent standardization and validation of definitions of pediatric acute kidney injury (pAKI) has ignited new dimensions of pAKI epidemiology and its risk factors. pAKI causes increased morbidity and mortality in critically ill-children. Among the hospitalized patients incidence of pAKI ranges from 1% to 31%, while mortality ranges from 28% to 82%, presenting a broad range due to lack of uniformly acceptable pAKI definition. In addition, cumulative data regarding the progression of pAKI to chronic kidney disease in children is rising. Despite these alarming figures, treatment modalities have failed to deliver significantly. In this review, we will summarize the latest developments of pAKI and highlight important aspects of pAKI management.

Management of hemolytic-uremic syndrome in children

Acute renal failure associated with a fulminant, life-threatening systemic disease is rare in previously healthy young children; however, when it occurs, the most common cause is hemolytic-uremic syndrome (HUS). In most cases (90%), this abrupt and devastating illness is a result of ingestion of food or drink contaminated with pathogens that produce very potent toxins. Currently, there are no proven treatment options that can directly inactivate the toxin or effectively interfere with the cascade of destructive events triggered by the toxin once it gains access to the bloodstream and binds its receptor. However, HUS is self-limited, and effective supportive management during the acute phase is proven to be a life saver for children affected by HUS. A minority of childhood HUS cases, approximately 5%, are caused by various genetic mutations causing uncontrolled activation of the complement system. These children, who used to have a poor prognosis leading to end-stage renal disease, now have access to exciting new treatment options that can preserve kidney function and avoid disease recurrences. This review provides a summary of the current knowledge on the epidemiology, pathophysiology, and clinical presentation of childhood HUS, focusing on a practical approach to best management measures.

Laboratory predictors of acute dialysis in hemolytic uremic syndrome

BACKGROUND

Strict guidelines on use of dialysis in children with post-diarrheal hemolytic uremic syndrome (D + HUS) are lacking. This study investigated laboratory predictors of acute dialysis because they are more objective than clinical features. Added to this, given that urine output is also an objective parameter, its ability to predict dialysis requirements was also investigated.

METHODS

Out of 153 D + HUS children reviewed, 88 received dialysis and 65 did not. Initial laboratory parameters and diuresis between both groups were analyzed.

RESULTS

Dialyzed patients had higher creatinine, urea, alanine aminotransferase, hematocrit and leukocyte count; and lower sodium, bicarbonate, and pH compared to non-dialyzed ones. Serum creatinine was the only independent predictor (P = 0.003) of dialysis; therefore, its ability to predict dialysis was estimated on receiver operating characteristic (ROC) curve analysis and using the Acute Kidney Injury Network (AKIN) staging system. Area under the ROC curve was 0.92 (95% confidence interval [95%CI]: 0.83-1) with a creatinine cut-off of 1.25 mg/dL (sensitivity, 100%; specificity, 76.5%) for children <1 year, and 0.93 (95%CI: 0.88-0.98) with a threshold of 2 mg/dL (sensitivity, 91%; specificity, 87.5%) for older children. AKIN stage 3 at admission predicted dialysis with a sensitivity of 92% and specificity of 84.2%. Urine output had the highest accuracy for dialysis prediction (sensitivity, 100%; specificity, 95.3%).

CONCLUSIONS

Initial serum creatinine concentration was the best laboratory predictor of dialysis, but the first 24 h diuresis was even better for this purpose. But, given that serum creatinine is an immediate available parameter, the cut-offs identified may label D + HUS children who will probably need dialysis, prompting early referral to centers able to provide dialysis.

Motor and Behavioral Changes in Mice With Cisplatin-Induced Acute Renal Failure

We have previously shown that chronic renal failure in rats induces changes in motor activity and behavior. Similar work on the possible effects of acute renal failure (ARF) induced by cisplatin (CP) is lacking. This is the subject matter of the current work. CP was injected intraperitoneally (i.p.) at a single dose of 20 mg/kg to induce a state of ARF, and three days later, its effects on motor activity, thermal and chemical nociceptive tests, neuromuscular coordination, pentobarbitone-sleeping time, exploration activity and two depression models were investigated. The platinum concentration in the kidneys and brains of mice was also measured. The occurrence of CP-induced ARF was ascertained by standard physiological, biochemical and histo-pathological methods. CP induced all the classical biochemical, physiological and histopathological signs of ARF. The average renal platinum concentration of CP-treated mice was 5.16 ppm, but there was no measurable concentration of platinum in the whole brains. CP treatment significantly decreased motor and exploration activities, and increased immobility time in depression models, suggesting a possible depression-like state. There was also a significant decrease in neuromuscular coordination in CP-treated mice. CP, given at a nephrotoxic dose, induced several adverse motor and behavioral alterations in mice. Further behavioral tests and molecular and biochemical investigations in the brains of mice with CP-induced ARF are warranted.

Suspected piperacillin-tazobactam induced nephrotoxicity in the pediatric oncology population

Neutropenic fever is a common complication of myelosuppressive therapy in pediatric oncology patients. Piperacillin-tazobactam (PIP/TAZO) is a broad spectrum antibiotic used for empiric treatment of neutropenic fever. We describe four cases of suspected PIP/TAZO induced nephrotoxicity occurring in children with pediatric malignancies admitted to the hospital and treated for fever ± neutropenia. All patients exhibited acute renal injury shortly after PIP/TAZO administration with one of these cases having biopsy evidence of acute interstitial nephritis. These findings are suggestive of PIP/TAZO induced nephrotoxicity in pediatric oncology patients with fever ± neutropenia and that PIP/TAZO should be used judiciously in this population.

Etiology and outcomes of acute kidney injury in Chinese children: a prospective multicentre investigation

Background

The incidence of AKI appears to have increasing trend. Up to now, prospective, multi-center, large-sample epidemiological study done on pediatric AKI on aspects of epidemiological characteristics, causes and outcomes have not reported. It is necessary to develop prospective, multi-center, large-sample epidemiological study in our country on pediatric AKI. The aim of this study was to determine the clinical features, etiology, and outcomes of acute kidney injury (AKI) in Chinese children.

Method

Paediatric patients (≤18 years old) admitted to 27 hospitals (14 children’s hospitals and 13 general hospitals) affiliated with the Medical University were investigated. AKI was defined using the 2005 Acute Kidney Injury Network criteria.

Results

During the study period, 388,736 paediatric patients were admitted. From this total, AKI was diagnosed in 1,257 patients, 43 of whom died. The incidence and mortality of AKI was 0.32% and 3.4% respectively. The mean (± SD) age of patients was 48.4 ± 50.4 months. Among the 1,257 AKI paediatric patients, 632 were less than one year old. Among the AKI paediatric patients, 615 (48.9%) were in stage 1, 277 (22.0%) in stage 2, and 365 (29.0%) in stage 3. The most common causes of AKI were renal causes (57.52%), whereas postrenal (25.69%) and prerenal (14.96%) causes were the least common. The three most common causes of AKI according to individual etiological disease were urolithiasis (22.35%), of which exposure to melamine-contaminated milk accounted for the highest incidence (63.7%); acute glomerulonephritis (10.10%); and severe dehydration (7.48%). A total of 43 AKI patients (3.4%) died during their hospital stay; 15 (34.9%) of the 43 died as a result of sepsis.

Conclusion

Primary renal diseases are a major risk factor for paediatric AKI in China. In terms of specific etiological disease, urolithiasis (postrenal disease) was the leading cause of paediatric AKI in 2008, when the disease was linked to exposure to melamine-contaminated milk. Sepsis is the leading cause of death in Chinese paediatric AKI patients. Future studies should focus on effective ways of controlling renal disorders and sepsis to improve the clinical management of paediatric AKI in China.

Improvised peritoneal dialysis in an 18-month-old child with severe acute malnutrition (kwashiorkor) and acute kidney injury: a case report

Introduction

Severe acute malnutrition is common in developing countries. Children with severe acute malnutrition are prone to complications, including electrolyte imbalance and infections. Our patient was an 18-month-old boy who had severe acute malnutrition (kwashiorkor) and developed acute kidney injury, which was managed with peritoneal dialysis using improvised equipment. This case report illustrates the importance of improvisation in resource-limited settings in providing lifesaving treatment. To the best of our knowledge, this is the first case report on peritoneal dialysis in a child with severe acute malnutrition (kwashiorkor).

Case presentation

We report a case of an 18-month-old Bantu-African Tanzanian boy who had severe malnutrition and developed anuric acute kidney injury. He had severe renal dysfunction and was managed with peritoneal dialysis using an improvised catheter and bedside constituted fluids (from intravenous fluids) and was diuretic after 7 days of peritoneal dialysis, with complete recovery of renal functions after 2 weeks.

Conclusion

Children with severe acute malnutrition who develop acute kidney injury should be offered peritoneal dialysis, which may be provided using improvised equipment in resource-limited settings, as illustrated in this case report.

Preoperative plasma FGF23 levels predict acute kidney injury in children: results of a pilot study

BACKGROUND

Acute kidney injury (AKI) carries a large burden of morbidity and mortality. Early diagnosis may lead to better strategies of clinical care. Cardiac surgery involving cardiopulmonary bypass is associated with a significant incidence of AKI. The study objective was to determine whether or not preoperative fibroblast growth factor-23 (FGF23) levels differed among pediatric patients who did or did not develop AKI following cardiac surgery.

METHODS

A nested case-control study was performed. FGF23 levels were measured pre- and post-operatively in 19 children without chronic kidney disease (CKD) who underwent cardiopulmonary bypass. Five patients developed AKI and 14 patients served as controls.

RESULTS

FGF23 levels in patients who developed AKI following cardiac surgery were elevated above normal levels, both pre-operatively and post-operatively compared with those patients who did not develop AKI. Relative risk of developing AKI when the pre-operative FGF23 level was >86 RU/mL was 2.0 (p = 0.033). Preoperative FGF23 levels correlated with post-operative fluid gain (correlation coefficient 0.607, p = 0.0059).

CONCLUSIONS

FGF23 may serve as a pre-operative prognostic indicator of the development of AKI following cardiopulmonary bypass surgery in pediatric patients without CKD. Identifying patients more likely to have AKI following surgery provides a means of achieving closer clinical management of AKI and fluid balance.

Impact of platelet transfusions in children with post-diarrheal hemolytic uremic syndrome

BACKGROUND

Platelet transfusions should be avoided in children with post-diarrheal hemolytic uremic syndrome (D + HUS) because they might increase microthrombi formation, thereby aggravating the disease. As this possibility has not yet been explored, we investigated whether platelet transfusion in patients with D + HUS would lead to a worse disease course compared to that in patients who did not receive platelet transfusion.

METHODS

This was a case-control study in which data from D + HUS children who received platelet transfusions (cases, n  =  23) and those who did not (controls, n  =  54) were retrospectively reviewed and compared.

RESULTS

Both patient groups were similar in age (p = 0.3), gender (p  =  0.53), weight (p  =  0.86), height (p  =  0.45), prior use of non-steroidal anti-inflammatory drugs (p  =  0.59) or antibiotics (p  =  0.45) and presence of dehydration at admission (p  =  0.79). The two groups also did not differ in initial leukocyte count (p  =  0.98), hematocrit (p  =  0.44) and sodium (p  =  0.11) and alanine aminotransferase levels (p  =  0.11). During hospitalization, dialysis duration (p  =  0.08), number of erythrocyte transfusions (p  =  0.2), serum creatinine peak (p  =  0.22), presence of severe bowel (p  =  0.43) or neurologic (p  =  0.97) injury, arterial hypertension (p  =  0.71), need for intensive care (p  =  0.33) and death (p  =  1.00) were also comparable.

CONCLUSION

Our findings suggest that platelet transfusion does not aggravate the course of the disease. Conversely, no hemorrhagic complications were observed in the group of patients who did not receive a platelet transfusion. Until these observations are confirmed by further studies, the benefits and risk of platelet transfusion should be thoughtfully balanced on an individual case basis.

Urinary biomarkers and acute kidney injury in children: the long road to clinical application

Pediatric acute kidney injury is rising with the advances in technology available for children with chronic conditions or those who are critically ill. Serum creatinine and urine output, traditional markers of renal function, often allow only delayed and unreliable diagnosis of acute kidney injury. Biomarker development in pediatric patients with low disease prevalence is challenging (small cohorts, few analyzable events). In this issue of Pediatric Nephrology, Ivanisevic and colleagues report that urinary liver-type fatty-acid-binding protein (L-FABP) can be used for early identification of pediatric acute kidney injury in a small cohort undergoing cardiac surgery. Addition of the biomarker resulted in an improvement in early diagnosis compared with a clinical model (age, gender, body weight, cardiopulmonary bypass duration, and aortic clamp time). It is noteworthy that the preoperative clinical model performed excellently in predicting postsurgery pediatric acute kidney injury. Further work is needed before this or other novel biomarkers (alone or in combination) can be implemented in clinical practice. Large-scale observational studies are needed to test these biomarkers against hard clinical endpoints, independent of serial measurements of serum creatinine concentrations. Prospective randomized interventional trials using exclusively high biomarker levels to define acute kidney injury should demonstrate improved clinical outcomes.

Urine β 2-Microglobolin in the Patients with Congenital Heart Disease

BACKGROUND

This study aimed to evaluate the renal tubular function in the patients with congenital heart disease using β2-microglobulin.

METHODS

In this case-control study, based on oxymetry, the patients with congenital heart disease were divided into two groups of cyanotic (n=20) and acyanotic (n=20). Congenital heart disease was diagnosed by echocardiography. Healthy individuals within the same age and sex groups were used as controls. Na(+), β2-micro globulin, creatinine (Cr), and β2-microglobulin/Cr ratio were measured in random urine samples and the results were compared to the same parameters in the control group using Tukey, One-Way ANOVA, and X(2) tests.

RESULTS

Based on the study results, urine sodium in the patients with cyanotic heart disease was significantly different from that of the controls (P=0.023). The results also revealed a significant difference between the two groups with congenital heart disease regarding urine β2-microglobulin (P=0.045). In addition, the patients with cyanotic heart disease were significantly different from those with acyanotic heart disease and the controls regarding urine β2-micro globulin/Cr ratio (P=0.012 and P=0.026, respectively).

CONCLUSIONS

The results of this study demonstrated that renal tubular dysfunction began in the patients with congenital heart disease, especially in those with cyanotic congenital heart disease. Besides, early diagnosis before cardiac surgery leads to better control of renal tubular disease.

An uncommon cause of acute kidney injury in young children: cystinuria

Bilateral obstructive nephrolithiasis is a rare cause of acute kidney injury (AKI) in early childhood. As soon as the identification of AKI secondary to ureteral stone is made, it will necessitate an emergency treatment.

PATIENTS

We report three infants with AKI caused by bilateral obstructive ureteral cystine stones. They were diagnosed with acute post-renal injury due to obstructive bilateral ureteral stones based on ultrasound scan findings. Immediately, bilateral ureteral stents were inserted for urinary drainage. Once renal function recovered to normal, each patient underwent ureteroscopy and percutaneous nephrolithotomy at the same session. Cystinuria was diagnosed by stone analysis and increased urinary excretion of cystine. Patients were advised to maintain a high fluid intake and were treated with potassium citrate in addition to tiopronin.

CONCLUSIONS

With these three cases we would like to emphasize the importance of urolithiasis in the differential diagnosis of acute renal failure in young children, since urolithiasis may only cause nonspecific symptoms in this population. An early diagnosis with prompt treatment and a close follow-up are the key for achieving the best long-term outcome in cystinuria.

Paediatric acute kidney injury in a tertiary hospital in Nigeria: prevalence, causes and mortality rate

Background

The modest decline in child mortality in Africa raises the question whether the pattern of diseases associated with acute kidney injury (AKI) in children in Nigeria has changed.

Methods

A database of children, aged between one month and 16 years, with AKI (using modified pediatric RIFLE criteria) was reviewed. The cause of AKI was defined as the major underlying disease. The clinical and laboratory features of children with AKI who survived were compared to those who died.

Results

Of the 4 015 children admitted into Lagos University Teaching Hospital between July 2010 and July 2012, 70 episodes of AKI were recorded equalling 17.4 cases per 1000 children. The median age of the children with AKI was 4.8 (range 0.1–14.4) years and 68.6% were males. Acute kidney injury was present in 58 (82.9%) children at admission with 70% in ‘failure’ category. Primary kidney disease (38.6%), sepsis (25.7%) and malaria (11.4%) were the commonest causes. The primary kidney diseases were acute glomerulonephritis (11) and nephrotic syndrome (8). Nineteen (28.4%) children with AKI died. Need for dialysis [odds ratio: 10.04 (2.94–34.33)], white cell >15 000/mm³ [odds ratio: 5.72 (1.65–19.89)] and platelet <100 000/mm³ [odds ratio: 9.56 (2.63–34.77)] were associated with death.

Conclusion

Acute kidney injury is common in children admitted to hospitals. The common causes remain primary kidney diseases, sepsis and malaria but the contribution of sepsis is rising while malaria and gastroenteritis are declining. Acute kidney injury-related mortality remains high.

Biomarkers and clinical tools in critically ill children: are we heading toward tailored drug therapy?

In pediatric critical care, validated biomarkers are essential for guiding drug therapy. The aim of this article is to present examples of current biomarker developments in its full breadth, including biochemical substances, physiological measurements and clinical scoring tools, with a focus on the field of circulatory, renal and neurophysiologic failure. Within each field we consecutively discuss the rationale for the selected biomarkers, studies in critically ill children, biomarker validation stage and biomarker use or potential use in drug studies and clinical drug dosing. This article demonstrates that there is paucity of properly validated biomarkers. Nevertheless, recent developments in, for instance, the field of sepsis, point us toward a future wherein, for critically ill children, drug therapy may be personalized using proteomic profiling instead of a small number of biomarkers, in order to establish a personal and dynamic disease profile.

Acute kidney injury after surgery for congenital heart disease

BACKGROUND

The RIFLE criteria (risk, injury, failure, loss, and end-stage kidney disease) have been used to assess acute kidney injury (AKI) in various populations of critically ill children. There are limited reports of AKI using RIFLE criteria in large pediatric populations undergoing congenital heart disease surgery.

METHODS

Records of patients 18 years and younger who underwent surgery for congenital heart disease between January 2006 and November 2009 were reviewed. The RIFLE score was determined for each patient postoperatively. Multivariate logistic regression analyses were performed to determine risk factors for AKI and the association with clinical outcomes, with subanalyses of patients 1 month of age or younger.

RESULTS

Data for 458 patients (median age, 7.6 months) were collected and analyzed. Evidence of AKI was demonstrated in 234 patients (51%), the vast majority of whom recovered within 48 hours. Younger age, higher RACHS-1 (risk-adjusted classification for congenital heart surgery) category, and longer cardiopulmonary bypass time were associated with development of AKI. Acute kidney injury was associated with longer duration of ventilation and lengths of intensive care unit and hospital stay. Incidence of AKI in patients 1 month of age or younger was 60.9%, of which more than half required greater than 72 hours to recover. In patients 1 month of age or younger, use of cardiopulmonary bypass, lower preoperative serum creatinine, and higher preoperative blood urea nitrogen were associated with AKI, and AKI was the only factor associated with longer intensive care unit and hospital lengths of stay.

CONCLUSIONS

Incidence of AKI based on RIFLE criteria in patients undergoing congenital heart disease surgery is higher than previously reported. Risk factors include age 1 month or younger and use of cardiopulmonary bypass. Acute kidney injury is associated with longer lengths of stay.

Dehydration at admission increased the need for dialysis in hemolytic uremic syndrome children

BACKGROUND

Oligoanuric forms of postdiarrheal hemolytic uremic syndrome (D+ HUS) usually have more severe acute stage and higher risk of chronic sequelae than nonoligoanuric forms. During the diarrheal phase, gastrointestinal losses could lead to dehydration with pre-renal injury enhancing the risk of oligoanuric D+ HUS. Furthermore, it had been shown that intravenous volume expansion during the prodromal phase could decrease the frequency of oligoanuric renal failure. Thus, we performed this retrospective study to determine whether dehydration on admission is associated with increased need for dialysis in D+ HUS patients.

CASE-DIAGNOSIS/TREATMENT

Data from 137 children was reviewed, which were divided into two groups according to their hydration status at admission: normohydrated (n = 86) and dehydrated (n = 51). Laboratory parameters of the dehydrated patients reflected expected deteriorations (higher urea, higher hematocrit and lower sodium, bicarbonate, and pH) than normohydrated ones. Likewise, the dehydrated group had a higher rate of vomiting and need for dialysis (70.6 versus 40.7 %, p = 0.0007).

CONCLUSIONS

Our data suggests that dehydration at hospital admission might represent a concomitant factor aggravating the intrinsic renal disease in D+ HUS patients increasing the need for dialysis. Therefore, the early recognition of patients at risk of D+ HUS is encouraged to guarantee a well-hydrated status.

Acute kidney injury: A pediatric experience over 10 years at a tertiary care center

BACKGROUND

The etiology of acute kidney injury (AKI) varies in different countries. In addition, the etiology of AKI in hospitalized children is multifactorial. The importance of diagnosing AKI is not only because of short-term high morbidity and mortality rate, but also for its effect on developing chronic kidney disease.

OBJECTIVES

we studied retrospectively AKIs of children who were hospitalized over 10 years in a University hospital.

MATERIALS AND METHODS

A retrospective analysis of the medical recorded data of 180 children less than 18 years treated for AKI in Alzahra Hospital, Isfahan, Iran, were performed during the period of March 2001 to February 2011. For each patient, demographic and anthropometric data, laboratory data, electrocardiographic findings, ultrasound results, etiology of AKI and short-term outcomes were recorded.

RESULTS

The male to female ratio was 1.57 to 1. Mean age was 5.28 ± 6.3 (SD) years and the median was 1.8 years. The more frequent age group was children less than 2 years. The mortality rate was 22.2% (40 patients). The mortality was not correlated with age (p= 0.74). Renal replacement therapy was recommended for 62 patients (34.4%). Mean of the first and last glomerular filtration rate (GFR) were 18.33± 1.12 ml/min/1.73 m² and 52.53 ± 2.98 ml/min/1.73 m², respectively. The most common urinary sediment finding in approximately 70% of the patients was either renal epithelial cell or renal cell cast. Increased kidney echogenicity was the most common ultrasound finding (48%). Using ANOVA regression analysis, the etiology of disease was the only predictor of mortality (p=0.0001).

CONCLUSIONS

We concluded that the mortality is still high in AKI. Furthermore, the poor outcome (defined as low GFR) are higher among patients with low levels of first GFR and higher RIFLE score.

Protective and therapeutic effects of licorice in rats with acute tubular necrosis

OBJECTIVES

Various protective and therapeutic effects such as antioxidant, anti-inflammatory, anticancer, antihistaminic, and antibacterial effects have been depicted for licorice. However, its biological effects in the kidney are still not clear. Therefore, we aimed to investigate the efficiency of licorice in rats with gentamicin (GM)-induced acute tubular necrosis.

DESIGN AND METHODS

Rats were randomized into the control group (only saline for 12 days), licorice group (licorice for 12 days), GM group (GM for 12 days), GM + licorice group, and licorice-treated GM group (licorice for 12 days after taking GM for 12 days). Blood urea, creatinine, and uric acid levels were measured and histopathological analyses of the kidneys were performed. The oxidative side of oxidant-antioxidant balance was evaluated by detecting lipid peroxidation (LPO) and total peroxide levels, and antioxidative side was determined by measuring total antioxidant capacity (TAC) and reduced glutathione (GSH) levels in plasma and kidney tissues.

RESULTS

The oxidant-antioxidant balance seemed to be shifted to the oxidative side in the GM group when compared with the control and GM + licorice groups. In GM group, biochemical profiles showed a remarkable increase in blood uric acid, urea, and creatinine levels, and depletion of renal tissue and plasma TAC and GSH levels. In addition, histopathologic studies revealed severe acute tubular necrosis, congestion, and hyaline casts, verifying GM-induced nephrotoxicity. Licorice was effective in reduction of blood urea, creatinine, and uric acid levels, and also effective in decreasing the tubular necrosis score. Licorice treatment also significantly reduced LPO and total peroxide levels, and increased TAC and GSH levels in both renal tissue and blood. Moreover, these changes in rats subjected to the combined therapy (GM + licorice) were significantly less than those of GM group.

CONCLUSIONS

Licorice ameliorates GM-induced nephrotoxicity and oxidative damage by scavenging oxygen free radicals, decreasing LPO, and improving antioxidant defense.