Cherry Mammen

Long-term Risk of CKD in Children Surviving Episodes of Acute Kidney Injury in the Intensive Care Unit: A Prospective Cohort Study

BACKGROUND The development of standardized acute kidney injury (AKI) definitions has allowed for a better understanding of AKI epidemiology, but the long-term renal outcomes of AKI in the pediatric critical care setting have not been well established. This study was designed to: (1) determine the incidence of chronic kidney disease (CKD) in children 1-3 years after an episode of AKI at a tertiary-care pediatric intensive care unit (ICU), (2) identify the proportion of patients at risk of CKD, and (3) compare ICU admission characteristics in those with and without CKD. DESIGN Prospective cohort study. SETTING & PARTICIPANTS Patients admitted to the British Columbia Childrens Hospital pediatric ICU from 2006-2008 with AKI, as defined by AKI Network (AKIN) criteria. Surviving patients, most with short-term recovery from their AKI, were assessed at 1, 2, or 3 years after AKI. PREDICTORS Severity of AKI as defined by AKIN and several ICU admission characteristics, including demographics, diagnosis, severity of illness, and ventilation data. OUTCOMES & MEASUREMENTS CKD was defined as the presence of albuminuria and/or glomerular filtration rate (GFR) < 60 mL/min/1.73 m2. Being at risk of CKD was defined as having a mildly decreased GFR (60-90 mL/min/1.73 m2), hypertension, and/or hyperfiltration (GFR ≥ 150 mL/min/1.73 m2). RESULTS The proportion of patients with AKI stages 1, 2, and 3 were 44 of 126 (35%), 47 of 126 (37%), and 35 of 126 (28%), respectively. The number of patients with CKD 1-3 years after AKI was 13 of 126 (10.3% overall; 2 of 44 [4.5%] with stage 1, 5 of 47 [10.6%] with stage 2, and 6 of 35 [17.1%] with stage 3; P = 0.2). In addition, 59 of 126 (46.8%) patients were identified as being at risk of CKD. LIMITATIONS Several patients identified with AKI were lost to follow-up, with the potential of underestimating the incidence of CKD. CONCLUSIONS In tertiary-care pediatric ICU patients, ∼10% develop CKD 1-3 years after AKI. The burden of CKD in this population may be higher with further follow-up because several patients were identified as being at risk of CKD. Regardless of the severity of AKI, all pediatric ICU patients should be monitored regularly for long-term kidney damage.

Canadian Society of Nephrology Commentary on the 2012 KDIGO Clinical Practice Guideline for Glomerulonephritis: Management of Nephrotic Syndrome in Children

The KDIGO (Kidney Disease: Improving Global Outcomes) clinical practice guideline for management of glomerulonephritis was recently released. The Canadian Society of Nephrology convened a working group to review the recommendations and comment on their relevancy and applicability to the Canadian context. A subgroup of pediatric nephrologists reviewed the guideline statements for management of childhood nephrotic syndrome and agreed with most of the guideline statements developed by KDIGO. This commentary highlights areas in which there is lack of evidence and areas in need of translation of evidence into clinical practice. Areas of controversy or uncertainty, including the length of corticosteroid therapy for the initial presentation and relapses, definitions of steroid resistance, and choice of second-line agents, are discussed in more detail. Existing practice variation is also addressed.

Incidence and outcomes of neonatal acute kidney injury (AWAKEN): a multicentre, multinational, observational cohort study

Background Single-center studies suggest that neonatal acute kidney injury (AKI) is associated with poor outcomes. However, inferences regarding the association between AKI, mortality, and hospital length of stay are limited due to the small sample size of those studies. In order to determine whether neonatal AKI is independently associated with increased mortality and longer hospital stay, we analyzed the Assessment of Worldwide Acute Kidney Epidemiology in Neonates (AWAKEN) database. Methods All neonates admitted to 24 participating neonatal intensive care units from four countries (Australia, Canada, India, United States) between January 1 and March 31, 2014, were screened. Of 4273 neonates screened, 2022 (47·3%) met study criteria. Exclusion criteria included: no intravenous fluids ≥48 hours, admission ≥14 days of life, congenital heart disease requiring surgical repair at <7 days of life, lethal chromosomal anomaly, death within 48 hours, inability to determine AKI status or severe congenital kidney abnormalities. AKI was defined using a standardized definition —i.e., serum creatinine rise of ≥0.3 mg/dL (26.5 mcmol/L) or ≥50% from previous lowest value, and/or if urine output was <1 mL/kg/h on postnatal days 2 to 7. Findings Incidence of AKI was 605/2022 (29·9%). Rates varied by gestational age groups (i.e., ≥22 to <29 weeks =47·9%; ≥29 to <36 weeks =18·3%; and ≥36 weeks =36·7%). Even after adjusting for multiple potential confounding factors, infants with AKI had higher mortality compared to those without AKI [(59/605 (9·7%) vs. 20/1417 (1·4%); p< 0.001; adjusted OR=4·6 (95% CI=2·5–8·3); p=<0·0001], and longer hospital stay [adjusted parameter estimate 8·8 days (95% CI=6·1–11·5); p<0·0001]. Interpretation Neonatal AKI is a common and independent risk factor for mortality and longer hospital stay. These data suggest that neonates may be impacted by AKI in a manner similar to pediatric and adult patients. Funding US National Institutes of Health, University of Alabama at Birmingham, Cincinnati Children’s, University of New Mexico.

Assessment of Worldwide Acute Kidney Injury Epidemiology in Neonates: Design of a Retrospective Cohort Study

Introduction Acute kidney injury (AKI) affects ~30% of hospitalized neonates. Critical to advancing our understanding of neonatal AKI is collaborative research among neonatologists and nephrologists. The Neonatal Kidney Collaborative (NKC) is an international, multidisciplinary group dedicated to investigating neonatal AKI. The AWAKEN study (Assessment of Worldwide Acute Kidney injury Epidemiology in Neonates) was designed to describe the epidemiology of neonatal AKI, validate the definition of neonatal AKI, identify primary risk factors for neonatal AKI, and investigate the contribution of fluid management to AKI events and short-term outcomes. Methods and analysis The NKC was established with at least one pediatric nephrologist and neonatologist from 24 institutions in 4 countries (USA, Canada, Australia, and India). A Steering Committee and four subcommittees were created. The database subcommittee oversaw the development of the web-based database (MediData Rave™) that captured all NICU admissions from 1/1/14 to 3/31/14. Inclusion and exclusion criteria were applied to eliminate neonates with a low likelihood of AKI. Data collection included: (1) baseline demographic information; (2) daily physiologic parameters and care received during the first week of life; (3) weekly “snapshots”; (4) discharge information including growth parameters, final diagnoses, discharge medications, and need for renal replacement therapy; and (5) all serum creatinine values. Ethics and dissemination AWAKEN was proposed as human subjects research. The study design allowed for a waiver of informed consent/parental permission. NKC investigators will disseminate data through peer-reviewed publications and educational conferences. Discussion The purpose of this publication is to describe the formation of the NKC, the establishment of the AWAKEN cohort and database, future directions, and a few “lessons learned.” The AWAKEN database includes ~325 unique variables and >4 million discrete data points. AWAKEN will be the largest, most inclusive neonatal AKI study to date. In addition to validating the neonatal AKI definition and identifying risk factors for AKI, this study will uncover variations in practice patterns related to fluid provision, renal function monitoring, and involvement of pediatric nephrologists during hospitalization. The AWAKEN study will position the NKC to achieve the long-term goal of improving the lives, health, and well-being of newborns at risk for kidney disease.

The path to chronic kidney disease following acute kidney injury: a neonatal perspective

The risk of acute kidney injury (AKI) in hospitalized critically ill neonatal populations without primary renal disease continues to be high, in both term and premature infants. Observational studies have revealed high rates of chronic kidney disease (CKD) in survivors of neonatal AKI. Proposed mechanisms underlying the progression of CKD following AKI include nephron loss and hyperfiltration, vascular insufficiency and maladaptive repair mechanisms. Other factors, including prematurity and low birth weight, have an independent relationship with the development of CKD, but they may also be positive effect modifiers in the relationship of AKI and CKD. The large degree of heterogeneity in the literature on AKI in the neonatal population, including the use of various AKI definitions and CKD outcomes, has hampered the medical community’s ability to properly assess the relationship of AKI and CKD in this vulnerable population. Larger prospective cohort studies with control groups which utilize recently proposed neonatal AKI definitions and standardized CKD definitions are much needed to properly quantify the risk of CKD following an episode of AKI. Until there is further evidence to guide us, we recommend that all neonates with an identified episode of AKI should have an appropriate longitudinal follow-up in order to identify CKD at its earliest stages.

Canadian Society of Nephrology Commentary on the 2012 KDIGO Clinical Practice Guideline for Glomerulonephritis: Management of Glomerulonephritis in Adults

The KDIGO (Kidney Disease: Improving Global Outcomes) clinical practice guideline for management of glomerulonephritis was recently released. The Canadian Society of Nephrology convened a working group to review the recommendations and comment on their relevancy and applicability to the Canadian context. A subgroup of adult nephrologists reviewed the guideline statements for management of glomerular disease in adults and agreed with most of the guideline statements developed by KDIGO. This commentary highlights areas for which there is lack of evidence and areas in need of translation of evidence into clinical practice. Areas of controversy or uncertainty, including the choice of second-line agents, are discussed in more detail. Existing practice variation also is addressed. The relevance of treatment recommendations to the Canadian practitioner is discussed.

Standard Kt/V thresholds to accurately predict single-pool Kt/V targets for children receiving thrice-weekly maintenance haemodialysis

BACKGROUND Urea standard Kt/V (stdKt/V) provides a tool to normalize weekly small solute clearance for patients dialysed at various intervals, but it has not been studied in the paediatric haemodialysis (HD) population. METHODS Using retrospective monthly adequacy data from children with end-stage renal disease receiving chronic thrice-weekly haemodialysis (n = 30), single-pool (spKt/V), equilibrated (eKt/V) and standard Kt/V (stdKt/V) were calculated for each individual HD session. eKt/V was estimated using Goldsteins logarithmic extrapolation method. Standard Kt/V was calculated using Leypoldts formula based on eKt/V, duration and dialysis frequency. A spKt/V vs stdKt/V dose/frequency table was then derived from our thrice-weekly data. RESULTS Using spKt/V of >or=1.2 as the minimal acceptable HD dose, receiver operating characteristic curve analysis was used to determine the corresponding target stdKt/V across a number of potential cutoff values. Single-pool Kt/V >or=1.2 was delivered with near certainty [sensitivity: 93.5%, specificity: 96.7%, area under the curve (AUC): 0.98] when a stdKt/V >or=2.0 was targeted. For a spKt/V >or=1.4, a target of stdKt/V >or=2.2 provided sensitivity and specificity of 73.4 and 96.1%, respectively, with an AUC of 0.94. CONCLUSIONS Our data demonstrate that one should deliver a stdKt/V >or=2.0 for thrice-weekly paediatric HD in order to achieve a spKt/V >or=1.2; and if one wishes to ensure a spKt/V >or=1.4, then the stdKt/V must be >or=2.2. For children receiving a spKt/V >or=1.6 more than thrice weekly, the currently published adult dose/frequency table will overestimate the stdKt/V dose delivered and should be replaced by paediatric derived values.

Acute Kidney Injury in Children With Type 1 Diabetes Hospitalized for Diabetic Ketoacidosis

Importance Acute kidney injury (AKI) in children is associated with poor short-term and long-term health outcomes; however, the frequency of AKI in children hospitalized for diabetic ketoacidosis (DKA) has not been previously examined. Objectives To determine the proportion of children hospitalized for DKA who develop AKI and to identify the associated clinical and biochemical markers of AKI. Design, Setting, and Participants This medical record review of all DKA admissions from September 1, 2008, through December 31, 2013, was conducted at British Columbia Children’s Hospital, the tertiary pediatric hospital in British Columbia, Canada. Children aged 18 years or younger with type 1 diabetes and DKA and with complete medical records available for data analysis were included (n = 165). All data collection occurred between September 8, 2014, and June 26, 2015. Data analysis took place from August 25, 2015, to June 8, 2016. Main Outcomes and Measures Acute kidney injury was defined using Kidney Disease/Improving Global Outcomes serum creatinine criteria. Multinomial logistic regression was used to identify potential factors associated with AKI. Results Of the 165 children hospitalized for DKA, 106 (64.2%) developed AKI (AKI stage 1, 37 [34.9%]; AKI stage 2, 48 [45.3%]; and AKI stage 3, 21 [19.8%]). Two children required hemodialysis. In the adjusted multinomial logistic regression model, a serum bicarbonate level less than 10 mEq/L (compared with ≥10 mEq/L) was associated with a 5-fold increase in the odds of severe (stage 2 or 3) AKI (adjusted odds ratio [aOR], 5.22; 95% CI, 1.35-20.22). Each increase of 5 beats/min in initial heart rate was associated with a 22% increase in the odds of severe AKI (aOR, 1.22; 95% CI, 1.07-1.39). Initial corrected sodium level of 145 mEq/L or greater (compared with 135-144 mEq/L) was associated with a 3-fold increase in the odds of mild (stage 1) AKI (aOR, 3.29; 95% CI, 1.25-8.66). There were no cases of mortality in patients with or without AKI. Conclusions and Relevance This study is the first to date to document that a high proportion of children hospitalized for DKA develop AKI. Acute kidney injury was associated with markers of volume depletion and severe acidosis. Acute kidney injury is concerning because it is associated with increased morbidity and mortality as well as increased risk of chronic renal disease, a finding that is especially relevant among children who are already at risk for diabetic nephropathy. Strategies are needed to improve the diagnosis, management, and follow-up of AKI in children with type 1 diabetes.

A severe phenotype of Gitelman syndrome with increased prostaglandin excretion and favorable response to indomethacin

Our understanding of Gitelman syndrome (GS) and Bartter syndrome has continued to evolve with the use of genetic testing to more precisely define the tubular defects responsible. GS is caused by mutations in the SLC12A3 gene encoding the Na+–Cl− co-transporter of the distal convoluted tubule (NCCT) and tends to be associated with a milder salt-losing phenotype. We describe two female siblings presenting in infancy with a severe salt-losing tubulopathy and failure to thrive due to compound heterozygous mutations in the SLC12A3 gene encoding the NCCT. Both children were treated with indomethacin resulting in improved linear growth and polyuria. Some atypical biochemical findings in our cases are discussed including raised urinary prostaglandin (PGE2) excretion that normalized with intravenous fluid repletion.

Pediatric acute kidney injury and the subsequent risk for chronic kidney disease: is there cause for alarm?

Acute kidney injury (AKI) is characterized clinically as an abrupt decline in renal function marked by reduced excretion of waste products, disordered electrolytes, and disrupted fluid homeostasis. The recent development of a standardized AKI definition has transformed our understanding of AKI epidemiology and outcomes. We now know that in the short term, children with AKI experience greater morbidity and mortality; additionally, observational studies have established that chronic renal sequelae are far more common after AKI events than previously realized. Many of these studies suggest that patients who develop AKI are at greater risk for the subsequent development of chronic kidney disease (CKD). The goal of this review is to critically evaluate the data regarding the association between AKI and CKD in children. Additionally, we describe best practice approaches for future studies, including the use of consensus AKI criteria, the application of rigorous definitions for CKD and renal sequelae, and the inclusion of non-AKI comparator groups. Finally, based upon existing data, we suggest an archetypal approach to follow-up care for the AKI survivors who may be at greater CKD risk, including children with more severe AKI, those who endure repeated AKI episodes, patients who do not experience full recovery, and those with pre-existing CKD.