Reference values for serum creatinine in children younger than 1 year of age

When will the Glomerular Filtration Rate in Former Preterm Neonates Catch up with Their Term Peers?

AIMS

Whether and when glomerular filtration rate (GFR) in preterms catches up with term peers is unknown. This study aims to develop a GFR maturation model for (pre)term-born individuals from birth to 18 years of age. Secondarily, the function is applied to data of different renally excreted drugs.

METHODS

We combined published inulin clearance values and serum creatinine (Scr) concentrations in (pre)term born individuals throughout childhood. Inulin clearance was assumed to be equal to GFR, and Scr to reflect creatinine synthesis rate/GFR. We developed a GFR function consisting of GFRbirth (GFR at birth), and an Emax model dependent on PNA (with GFRmax, PNA50 (PNA at which half ofGFR max is reached) and Hill coefficient). The final GFR model was applied to predict gentamicin, tobramycin and vancomycin concentrations.

RESULT

In the GFR model, GFRbirth varied with birthweight linearly while in the PNA-based Emax equation, GA was the best covariate for PNA50, and current weight for GFRmax. The final model showed that for a child born at 26 weeks GA, absolute GFR is 18%, 63%, 80%, 92% and 96% of the GFR of a child born at 40 weeks GA at 1 month, 6 months, 1 year, 3 years and 12 years, respectively. PopPK models with the GFR maturation equations predicted concentrations of renally cleared antibiotics across (pre)term-born neonates until 18 years well.

CONCLUSIONS

GFR of preterm individuals catches up with term peers at around three years of age, implying reduced dosages of renally cleared drugs should be considered below this age.

Prolonged renal function impairment in infants born during the peri-viable period: A retrospective longitudinal cohort study

BACKGROUND

The number of infants born during the peri-viable period who survive has been increasing.

AIM

To clarify renal function in infants from the time of birth during the peri-viable period until their due date.

STUDY DESIGN

This retrospective cohort study was conducted at a single center.

SUBJECTS

We reviewed the data of infants born at ≤28 weeks of gestation between 2018 and 2022 at our hospital. The infants were divided into the following groups: born at 22-24 weeks vs. 25-28 weeks (appropriate-for-gestational age [AGA] infants), and AGA infants vs. small-for-gestational age (SGA) infants (born at 22-28 weeks).

OUTCOME MEASURES

We compared the perinatal data and renal function of the infants from birth until their due date.

RESULTS

Eighty-one infants were included. Their serum creatinine, fractional excretion of sodium, and urine glucose levels were high or positive soon after birth but gradually improved. The urine albumin level was significantly higher among AGA infants born at 22-24 weeks, even at term equivalent age, than among those born at 25-28 weeks.

CONCLUSIONS

Persistent renal insufficiency was observed even around the term equivalent age in peri-viable infants. Follow-up data collected after the neonatal period should be investigated in these infants.

Establishing age and gender-specific serum creatinine reference ranges for Thai pediatric population

Accurate assessment of kidney function in children requires age and gender-specific reference ranges for serum creatinine. Traditional reference values, often derived from adult populations and different ethnic backgrounds, may not be suitable for children. This study aims to establish specific reference ranges for serum creatinine in the Thai pediatric population, addressing the gap in localized and age-appropriate diagnostic criteria. This retrospective study analyzed serum creatinine levels from Thai children aged newborn to 18 years, collected from the Laboratory Information System of the Queen Sirikit National Institute of Child Health from January 2017 to December 2021. The Bhattacharya method was employed to establish reference ranges, considering different age groups and genders. The study compared these newly established reference values with international studies, including those of Schlebusch H., Pottel H., and Chuang GT., to validate their relevance and accuracy. A total of 27,642 data entries (15,396 males and 12,246 females) were analyzed. The study established distinct reference ranges for serum creatinine, which varied significantly across different age groups and between genders. These ranges were found to gradually increase with age from 2 months to 18 years. The study also highlighted notable differences in reference values when compared with other ethnic populations. The study successfully establishes tailored reference ranges for serum creatinine in Thai children, providing a valuable tool for more accurate diagnosis and monitoring of kidney health in this demographic. This initiative marks a significant advancement in pediatric nephrology in Thailand and suggests a need for continuous refinement of these ranges and further research in this area.

REstrictive versus StandarD FlUid Management in Mechanically Ventilated ChildrEn Admitted to PICU: study protocol for a pilot randomised controlled trial (REDUCE-1)

INTRODUCTION

Intravenous fluid therapy is the most common intervention in critically ill children. There is an increasing body of evidence questioning the safety of high-volume intravenous fluid administration in these patients. To date, the optimal fluid management strategy remains unclear. We aimed to test the feasibility of a pragmatic randomised controlled trial comparing a restrictive with a standard (liberal) fluid management strategy in critically ill children.

METHODS AND ANALYSIS

Multicentre, binational pilot, randomised, controlled, open-label, pragmatic trial. Patients <18 years admitted to paediatric intensive care unit and mechanically ventilated at the time of screening are eligible. Patients with tumour lysis syndrome, diabetic ketoacidosis or postorgan transplant are excluded.

INTERVENTIONS

1:1 random assignment of 154 individual patients into two groups-restrictive versus standard, liberal, fluid strategy-stratified by primary diagnosis (cardiac/non-cardiac). The intervention consists of a restrictive fluid bundle, including lower maintenance fluid allowance, limiting fluid boluses, reducing volumes of drug delivery and initiating diuretics or peritoneal dialysis earlier. The intervention is applied for 48 hours postrandomisation or until discharge (whichever is earlier).

ENDPOINTS

The number of patients recruited per month and proportion of recruited to eligible patients are feasibility endpoints. New-onset acute kidney injury and the incidence of clinically relevant central venous thrombosis are safety endpoints. Fluid balance at 48 hours after randomisation is the efficacy endpoint. Survival free of paediatric intensive care censored at 28 days is the clinical endpoint.

ETHICS AND DISSEMINATION

Ethics approval was gained from the Children's Health Queensland Human Research Ethics Committee (HREC/21/QCHQ/77514, date: 1 September 2021), and University of Zurich (2021-02447, date: 17 March 2023). The trial is registered with the Australia New Zealand Clinical Trials Registry (ACTRN12621001311842). Open-access publication in high impact peer-reviewed journals will be sought. Modern information dissemination strategies will also be used including social media to disseminate the outcomes of the study.

TRIAL REGISTRATION NUMBER

ACTRN12621001311842.

PROTOCOL VERSION/DATE

V5/23 May 2023.

Bone Disorders in Pediatric Chronic Kidney Disease: A Literature Review

Intense changes in mineral and bone metabolism are frequent in chronic kidney disease (CKD) and represent an important cause of morbidity and reduced quality of life. These disorders have conventionally been defined as renal osteodystrophy and classified based on bone biopsy, but due to a lack of bone biopsy data and validated radiological methods to evaluate bone morphology in children, it has been challenging to effectively assess renal osteodystrophy in pediatric CKD; the consequence has been the suboptimal management of bone disorders in children. CKD-mineral and bone disorder (CKD-MBD) is a new expression used to describe a systemic disorder of mineral and bone metabolism as a result of CKD. CKD-MBD is a triad of biochemical imbalances in calcium, phosphate, parathyroid hormone, and vitamin D; bone deformities and soft tissue calcification. This literature review aims to explore the pathogenesis, diagnostic approach, and treatment of CKD-MBD in children and the effects of renal osteodystrophy on growing skeleton, with a specific focus on the biological basis of this peculiar condition.

Diagnosis and management of mineral and bone disorders in infants with CKD: clinical practice points from the ESPN CKD-MBD and Dialysis working groups and the Pediatric Renal Nutrition Taskforce

BACKGROUND

Infants with chronic kidney disease (CKD) form a vulnerable population who are highly prone to mineral and bone disorders (MBD) including biochemical abnormalities, growth retardation, bone deformities, and fractures. We present a position paper on the diagnosis and management of CKD-MBD in infants based on available evidence and the opinion of experts from the European Society for Paediatric Nephrology (ESPN) CKD-MBD and Dialysis working groups and the Pediatric Renal Nutrition Taskforce.

METHODS

PICO (Patient, Intervention, Comparator, Outcomes) questions were generated, and relevant literature searches performed covering a population of infants below 2 years of age with CKD stages 2-5 or on dialysis. Clinical practice points (CPPs) were developed and leveled using the American Academy of Pediatrics grading matrix. A Delphi consensus approach was followed.

RESULTS

We present 34 CPPs for diagnosis and management of CKD-MBD in infants, including dietary control of calcium and phosphate, and medications to prevent and treat CKD-MBD (native and active vitamin D, calcium supplementation, phosphate binders).

CONCLUSION

As there are few high-quality studies in this field, the strength of most statements is weak to moderate, and may need to be adapted to individual patient needs by the treating physician. Research recommendations to study key outcome measures in this unique population are suggested. A higher resolution version of the Graphical abstract is available as Supplementary information.

Candida bloodstream infection among children hospitalised in three public-sector hospitals in the Metro West region of Cape Town, South Africa

BACKGROUND

Candida bloodstream infection (BSI) causes appreciable mortality in neonates and children. There are few studies describing the epidemiology of Candida BSI in children living in sub-Saharan Africa.

METHODS

A retrospective descriptive study was conducted at three public sector hospitals in Cape Town, South Africa. Demographic and clinical details, antifungal management and patient outcome data were obtained by medical record review. Candida species distribution and antifungal susceptibility testing results were obtained from the National Health Laboratory Service database.

RESULTS

Of the 97 Candida BSI episodes identified during a five-year period, 48/97 (49%) were Candida albicans (C. albicans), and 49/97 (51%) were non-C. albicans species. The overall incidence risk was 0.8 Candida BSI episodes per 1000 admissions at Red Cross War Memorial Children's Hospital. Of the 77/97 (79%) Candida BSI episodes with available clinical information, the median age (interquartile range) at the time of BSI was 7 (1-25) months, 36/77 (47%) were associated with moderate or severe underweight-for-age and vasopressor therapy was administered to 22/77 (29%) study participants. Most of the Candida BSI episodes were healthcare-associated infections, 63/77 (82%). Fluconazole resistance was documented among 17%, 0% and 0% of C. parapsilosis, C. tropicalis and C. albicans isolates, respectively. All Candida isolates tested were susceptible to amphotericin B and the echinocandins. The mortality rate within 30 days of Candida BSI diagnosis was 13/75 (17%). On multivariable analysis, factors associated with mortality within 30 days of Candida BSI diagnosis included vasopressor therapy requirement during Candida BSI, adjusted Odds ratio (aOR) 53 (95% confidence interval 2-1029); hepatic dysfunction, aOR 13 (95% CI 1-146); and concomitant bacterial BSI, aOR 10 (95% CI 2-60).

CONCLUSION

The study adds to the limited number of studies describing paediatric Candida BSI in sub-Saharan Africa. Non-C. Albicans BSI episodes occurred more frequently than C. albicans episodes, and vasopressor therapy requirement, hepatic dysfunction and concomitant bacterial BSI were associated with an increase in 30-day mortality.

Effect of Saline vs Gluconate/Acetate-Buffered Solution vs Lactate-Buffered Solution on Serum Chloride Among Children in the Pediatric Intensive Care Unit: The SPLYT-P Randomized Clinical Trial

Importance

Most children admitted to pediatric intensive care units (PICUs) receive intravenous fluids. A recent systematic review suggested mortality benefit in critically ill adults treated with balanced solutions compared with sodium chloride, 0.9% (saline). There is a lack of clinically directive data on optimal fluid choice in critically ill children.

Objective

To determine if balanced solutions decrease the rise of plasma chloride compared with saline, 0.9%, in critically ill children.

Design, Setting, and Participants

This single-center, 3-arm, open-label randomized clinical trial took place in a 36-bed PICU. Children younger than 16 years admitted to the PICU and considered to require intravenous fluid therapy by the treating clinician were eligible. Children were screened from November 2019 to April 2021.

Interventions

Enrolled children were 1:1:1 allocated to gluconate/acetate-buffered solution, lactate-buffered solution, or saline as intravenous fluids.

Main Outcomes and Measures

The primary outcome was an increase in serum chloride of 5 mEq/L or more within 48 hours from randomization. New-onset acute kidney injury, length of hospital and intensive care stay, and intensive care-free survival were secondary outcomes.

Results

A total of 516 patients with a median (IQR) age of 3.8 (1.0-10.4) years were randomized with 178, 171, and 167 allocated to gluconate/acetate-buffered solution, lactate-buffered solution, and saline, respectively. The serum chloride level increased 5 mEq/L or more in 37 patients (25.2%), 34 patients (23.9%), and 58 patients (40.0%) in the gluconate/acetate-buffered solution, lactate-buffered solution, and saline groups. The odds of a rise in plasma chloride 5 mEq/L or more was halved with the use of gluconate/acetate-buffered solution compared with saline (odds ratio, 0.50 [95% CI, 0.31-0.83]; P = .007) and with the use of lactate-buffered solution compared with saline (odds ratio, 0.47 [95% CI, 0.28-0.79]; P = .004). New-onset acute kidney injury was observed in 10 patients (6.1%), 6 patients (3.7%), and 5 patients (3.2%) in the gluconate/acetate-buffered solution, lactate-buffered solution, and saline groups, respectively.

Conclusions and Relevance

Balanced solutions (gluconate/acetate-buffered solution and lactate-buffered solution) administered as intravenous fluid therapy reduced the incidence of rise in plasma chloride compared with saline in children in PICU.

Trial Registration

anzctr.org.au Identifier: ACTRN12619001244190.

Proenkephalin A as a marker for glomerular filtration rate in critically ill children: validation against gold standard iohexol GFR measurements

OBJECTIVES

Accurate determination of glomerular filtration rate (GFR) is important. Several endogenous biomarkers exist for estimating GFR, yet, they have limited accuracy, especially in the paediatric population. Proenkephalin A 119-159 (PENK) is a novel and promising GFR marker, but its relation with age in children remains unknown. Also, the value of PENK has never been validated against measured GFR (mGFR) in children when compared to traditional GFR markers including serum creatinine (SCr), SCr-based estimated GFR (eGFR) and cystatin C (cysC).

METHODS

Critically ill children and term-born neonates were included in this single-centre, prospective study. Iohexol-based mGFR, SCr, and cysC were determined in each patient. eGFR was calculated using the bedside Schwartz equation, incorporating SCr and height. Spearman correlation coefficients were calculated to determine the correlation between mGFR and PENK, SCr, cysC and eGFR.

RESULTS

For 97 patients (56 children and 41 neonates), mGFR, SCr, cysC and PENK levels were available. PENK levels were higher in young children and decreased to adult PENK reference values around two years of age. PENK levels were highly correlated with mGFR (ρ=-0.88, p<0.001), and similar to mGFR-eGFR correlation (ρ=-0.87, p<0.001). For cysC and SCr the correlation with mGFR was lower (ρ=-0.77 and ρ=-0.46, respectively. Both p<0.001).

CONCLUSIONS

The correlation of PENK with mGFR was as good as SCr-based eGFR-mGFR correlation. To determine the added value of PENK in paediatric clinical care and prior to implementation, PENK reference values are needed and the development and validation of a paediatric PENK-based eGFR equation is necessary.

Glomerular filtration rate in critically ill neonates and children: creatinine-based estimations versus iohexol-based measurements

BACKGROUND

Acute kidney injury (AKI) and augmented renal clearance (ARC), both alterations of the glomerular filtration rate (GFR), are prevalent in critically ill children and neonates. AKI and ARC prevalence estimates are based on estimation of GFR (eGFR) using serum creatinine (SCr), which is known to be inaccurate. We aimed to test our hypothesis that AKI prevalence will be higher and ARC prevalence will be lower in critically ill children when using iohexol-based measured GFR (mGFR), rather than using eGFR. Additionally, we aimed to investigate the performance of different SCr-based eGFR methods.

METHODS

In this single-center prospective study, critically ill term-born neonates and children were included. mGFR was calculated using a plasma disappearance curve after parenteral administration of iohexol. AKI diagnosis was based on the KDIGO criteria, SCr-based eGFR, and creatinine clearance (CrCL). Differences between eGFR and mGFR were determined using Wilcoxon signed-rank tests and by calculating bias and accuracy (percentage of eGFR values within 30% of mGFR values).

RESULTS

One hundred five children, including 43 neonates, were included. AKI prevalence was higher based on mGFR (48%), than with KDIGO or eGFR (11-40%). ARC prevalence was lower with mGFR (24%) compared to eGFR (38-51%). eGFR equations significantly overestimated mGFR (60-71 versus 41 ml/min/1.73 m², p < 0.001-0.002). Accuracy was highest with eGFR equations based on age- and sex-dependent equations (up to 59%).

CONCLUSION

Iohexol-based AKI prevalence was higher and ARC prevalence lower compared to standard SCr-based eGFR methods. Age- and sex-dependent equations for eGFR (eGFR-Smeets for neonates and eGFR-Pierce for children) best approached measured GFR and should preferably be used to optimize diagnosis of AKI and ARC in this population. A higher resolution version of the Graphical abstract is available as Supplementary information.

Assessment of Kidney Function in Children

A good understanding of kidney function tests is essential for patient care. Urinalysis is the commonest used test for screening purposes in ambulatory settings. Glomerular function is assessed further by urine protein excretion and estimated glomerular filtration rate and tubular function by various tests such as urine anion gap and excretion of sodium, calcium, and phosphate. In addition, kidney biopsy and/or genetic analyses may be required to further characterize the underlying kidney disease. In this article, we discuss maturation and the assessment of kidney function in children.

Markers of Kidney Function in Early Childhood and Association With Maternal Comorbidity

IMPORTANCE

Kidney functional capacity is low at birth but doubles during the first 2 weeks of life and reaches near-adult levels at age 1 to 2 years. Existing reference intervals for markers of kidney function in newborns are mostly based on preterm newborns, newborns with illness, or small cohorts of term newborns, and the consequences of maternal comorbidities for newborn kidney function are sparsely described.

OBJECTIVE

To establish robust reference intervals for creatinine and urea in healthy children in early childhood and to assess whether maternal comorbidity is associated with newborn creatinine and urea concentrations.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter, prospective, population-based cohort study assessed data and umbilical cord blood samples from participants in the Copenhagen Baby Heart Study (CBHS) who were born between April 1, 2016, and October 31, 2018, and venous blood samples from a subsample of CBHS participants who were enrolled in the COMPARE study between May 3, 2017, and November 4, 2018. Cord blood samples of 13 354 newborns from the CBHS and corresponding venous blood samples of 444 of those newborns from the COMPARE study were included. Blood samples were collected at birth, age 2 months, and age 14 to 16 months, with follow-up completed on February 12, 2020. Healthy nonadmitted term newborns from maternity wards at 3 hospitals in the Capital Region of Denmark were included.

EXPOSURES

Maternal comorbidity.

MAIN OUTCOMES AND MEASURES

Creatinine and urea concentrations.

RESULTS

Among 13 354 newborns in the CBHS cohort, characteristics of 12 938 children were stratified by sex and gestational age (GA). Of those, 6567 children (50.8%) were male; 5259 children (40.6%) were born at 37 to 39 weeks' GA, and 7679 children (59.4%) were born at 40 to 42 weeks' GA. Compared with children born at 40 to 42 weeks' GA, those born at 37 to 39 weeks' GA had lower birth weight, Apgar scores at 5 minutes, placental weight, and placental-fetal weight ratio. Children born at 37 to 39 weeks' GA vs those born at 40 to 42 weeks' GA were more frequently small for GA at birth and more likely to have placental insufficiency and exposure to maternal preeclampsia, maternal diabetes, maternal kidney disease, and maternal hypertension. Among children born at 37 to 39 weeks' GA, reference intervals were 0.54 to 1.08 mg/dL for creatinine and 5.32 to 14.67 mg/dL for urea; among children born at 40 to 42 weeks' GA, reference intervals were 0.57 to 1.19 mg/dL for creatinine and 5.60 to 14.85 mg/dL for urea. At birth, multifactorially adjusted odds ratios among children exposed to preeclampsia were 9.40 (95% CI, 1.68-52.54) for a venous creatinine concentration higher than the upper reference limit, 4.29 (95% CI, 1.32-13.93) for a venous creatinine concentration higher than the 90th percentile, and 3.10 (95% CI, 1.14-8.46) for a venous creatinine concentration higher than the 80th percentile.

CONCLUSIONS AND RELEVANCE

In this study, improved reference intervals for creatinine and urea concentrations were generated. Preeclampsia was associated with an increased risk of high newborn creatinine concentrations, suggesting that newborns of mothers with preeclampsia need closer observation of their kidney function.

Transdermal Measurement of Glomerular Filtration Rate in Mechanically Ventilated Piglets

Transdermal measurement of glomerular filtration rate (GFR) has been used to evaluate kidney function in conscious animals. This technique is well established in rodents to study acute kidney injury and chronic kidney disease. However, GFR measurement using the transdermal system has not been validated in pigs, a species with a similar renal system to humans. Hence, we investigated the effect of sepsis on transdermal GFR in anesthetized and mechanically ventilated neonatal pigs. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP). The transdermal GFR measurement system consisting of a miniaturized fluorescence sensor was attached to the pig's shaved skin to determine the clearance of fluorescein-isothiocyanate (FITC) conjugated sinistrin, an intravenously injected GFR tracer. Our results show that at 12 h post-CLP, serum creatinine increased with a decrease in GFR. This study demonstrates, for the first time, the utility of the transdermal GFR approach in determining renal function in mechanically ventilated, neonatal pigs.

Predicting factors of clinically significant urological anomalies after initial urinary tract infection among 2- to 24-month-old children

AIM

To find more effective criteria to identify clinically significant urological anomalies after initial urinary tract infection among children.

METHODS

Children aged 2-24 months with an initial urinary tract infection were consecutively recruited in a Japanese hospital from 2013 to 2019. Voiding cystourethrography, 99mTc dimercaptosuccinic acid scan and ultrasound were intended to perform for all cases. Clinically significant urological anomalies were defined as high-grade vesicoureteral reflux, obstructive and abnormal urinary tract lesions, need for surgical intervention, renal hypoplasia and scarring. Using classification and regression tree analysis, we sought the associated factors. We developed new criteria with these factors, retrospectively applied them to the original data, and calculated the sensitivity and specificity.

RESULTS

One hundred sixty-seven patients were eligible, and 39 had clinically significant urological anomalies. Classification and regression tree analysis showed that the associated factors were non-E. coli infections, serum creatinine levels and ultrasound abnormalities. When the gold standards were performed on children with non-E. coli infections or serum creatinine levels ≥0.21 mg/dl, sensitivity and specificity were 0.82 and 0.68, respectively.

CONCLUSION

The criteria including non-E. coli infections and high-normal or higher serum creatinine levels may efficiently predict clinically significant urological anomalies after initial urinary tract infections.

Neonatal hydrocolpos presenting as a rapidly progressive abdominal mass with inferior caval vein syndrome

A 7-week-old infant was presented at the emergency department with an abdominal mass, unilateral swelling of the groin and suspicion of an inferior caval vein syndrome with bluish discolouration and oedema of the lower extremities. Abdominal imaging showed two large cysts and profound bilateral hydronephrosis. Following laparotomy, an extreme hydrocolpos and an overdistended urinary bladder were found. These findings turned out to be secondary to a transverse vaginal septum. She was treated surgically and was hospitalised for 2 weeks. Long-term follow-up showed normalisation of previously present hypercalciuria and hydronephrosis.A hydro(metro)colpos should be considered in the differential diagnosis of a female infant presenting with an abdominal mass, to apply the appropriate investigations and therapy.

Maturation of Glomerular Filtration Rate in Term-Born Neonates: An Individual Participant Data Meta-Analysis

Background: The evidence from individual studies to support the maturational pattern of glomerular filtration rate (GFR) in healthy term-born neonates is inconclusive. We performed an individual participant data (IPD) meta-analysis of reported measured GFR (mGFR) data aimed to establish neonatal GFR reference values. Furthermore, we aimed to optimise neonatal creatinine-based GFR estimations Methods: We identified studies reporting mGFR measured by exogenous markers or creatinine clearance (CrCL) in healthy term-born neonates. The relationship between postnatal age and clearance was investigated using cubic splines with generalized additive linear mixed models. From our reference values, we estimated an updated coefficient for the Schwartz equation (eGFR(ml/min/1.73m²)=(k*height (cm))/serum creatinine(mg/dl)). Results: Forty-eight out of 1521 screened articles reported mGFR in healthy term-born neonates, and 978 mGFR values from 881 neonates were analysed. IPD were available for 367 neonates and the other 514 neonates were represented by 41 aggregated data points as means/medians per group. GFR doubled in the first five days after birth from 19.6 (95%CI 14.7;24.6) ml/min/1.73m² to 40.6 (95%CI 36.7;44.5) ml/min/1.73m², then more gradually increased to 59.4 (95%CI 45.9;72.9) ml/min/1.73m² by four weeks of age. A coefficient of 0.31 to estimate GFR best fitted the data. Conclusions: These reference values for healthy term-born neonates show a biphasic increase in GFR with the largest increase between days 1 and 5. Together with the re-examined Schwartz equation, this can help identify altered GFR in term-born neonates. To enable widespread implementation of our proposed eGFR equation, validation in a large cohort of neonates is required.

Long-term follow-up of patients after acute kidney injury in the neonatal period: abnormal ambulatory blood pressure findings

Background

Data on the long-term effects of neonatal acute kidney injury (AKI) are limited.

Methods

We invited 302 children who had neonatal AKI and survived to hospital discharge; out of 95 patients who agreed to participate in the study, 23 cases were excluded due to primary kidney, cardiac, or metabolic diseases. KDIGO definition was used to define AKI. When a newborn had no previous serum creatinine, AKI was defined as serum creatinine above the mean plus two standard deviations (SD) (or above 97.5^th percentile) according to gestational age, weight, and postnatal age. Clinical and laboratory features in the neonatal AKI period were recorded for 72 cases; at long-term evaluation (2–12 years), kidney function tests with glomerular filtration rate (eGFR) by the Schwartz formula, microalbuminuria, office and 24-h ambulatory blood pressure monitoring (ABPM), and kidney ultrasonography were performed.

Results

Forty-two patients (58%) had stage I AKI during the neonatal period. Mean age at long-term evaluation was 6.8 ± 2.9 years (range: 2.3–12.0); mean eGFR was 152.3 ± 26.5 ml/min/1.73 m². Office hypertension (systolic and/or diastolic BP ≥ 95^th percentile), microalbuminuria (> 30 mg/g creatinine), and hyperfiltration (> 187 ml/min/1.73 m²) were present in 13.0%, 12.7%, and 9.7% of patients, respectively. ABPM was performed on 27 patients, 18.5% had hypertension, and 40.7% were non-dippers; 48.1% had abnormal findings. Female sex was associated with microalbuminuria; low birth weight (< 1,500 g) and low gestational age (< 32 weeks) were associated with hypertension by ABPM. Twenty-three patients (33.8%) had at least one sign of microalbuminuria, office hypertension, or hyperfiltration. Among 27 patients who had ABPM, 16 (59.3%) had at least one sign of microalbuminuria, abnormal ABPM (hypertension and/or non-dipping), or hyperfiltration.

Conclusion

Even children who experienced stage 1 and 2 neonatal AKI are at risk for subclinical kidney dysfunction. Non-dipping is seen in four out of 10 children. Long-term follow-up of these patients is necessary.

Risk factors for acute kidney injury after pediatric cardiac surgery: a meta-analysis

BACKGROUND

Cardiac surgery-associated acute kidney injury (AKI) is associated with increased morbidity and mortality in both adults and children.

OBJECTIVES

This study aimed to identify clinical risk factors for AKI following cardiac surgery in the pediatric population.

DATA SOURCES

PubMed/MEDLINE, Embase, Scopus, and reference lists of relevant articles were searched for studies published by August 2020.

STUDY ELIGIBILITY CRITERIA

Studies were included if (1) the population consisted of pediatric patients (< 18 years old), (2) patients underwent cardiac surgery, (3) risk factors were compared between patients who developed AKI and those who did not, and (4) studies were prospective or retrospective observational studies or randomized controlled trials.

PARTICIPANTS AND INTERVENTIONS

Children undergoing pediatric cardiac surgery.

STUDY APPRAISAL AND SYNTHESIS METHODS

Random-effects meta-analysis was performed, comparing potential risk factors between pediatric patients who developed CS-AKI and those who did not.

RESULTS

Sixty-one publications including a total of 19,680 participants (AKI: 7257 participants; no AKI: 12,423 participants) were included from studies published between 2008 and 2020. The pooled estimated incidence of AKI was 34.3% (95% confidence interval 30.0-38.8%, I² = 96.8%). Binary risk factors that were significantly and consistently associated with AKI were the presence of pulmonary hypertension, cyanotic heart disease, univentricular heart, risk adjustment for congenital heart surgery 1 (RACHS-1) score ≥ 3, vasopressor use, cardiopulmonary bypass use, reoperation, and sepsis. Significant continuous risk factors included younger age, lower body weight, lower preoperative creatinine, higher preoperative estimated glomerular filtration rate (eGFR), higher RACHS-1 score, longer surgery time, longer cardiopulmonary bypass time, longer aortic cross-clamp time, and higher red blood cell transfusion volume.

LIMITATIONS

Results are limited by heterogeneity and potential residual confounding.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Our meta-analysis identified clinical risk factors that are associated with AKI in children undergoing cardiac surgery. This might help clinicians anticipate and manage more carefully this population and implement standardized preventive strategies.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42021262699. A higher resolution version of the Graphical abstract is available as Supplementary information.

Role of urinary NAG enzyme in early detection of renal impairment in cystic fibrosis patients

Background

Cystic fibrosis (CF) is the most common life-limiting autosomal recessive disease among people in the USA and Europe with increased prevalence in Egypt. Affected children are in danger of acute kidney injury and the development of chronic renal disease through exposure to multiple nephrotoxic agents. N-acetyl beta-D-glucosaminidase (NAG) is a lysosomal enzyme present in high concentrations in the proximal tubular cells, thus raising urinary NAG levels to reflect tubular dysfunction. The aim of our study is to detect the role of the urinary NAG enzyme in the early detection of renal impairment in CF patients. This cross-sectional study enrolled 40 CF patients diagnosed in the CF Clinic in Children’s Hospital of Cairo University. They were age- and sex-matched to 40 healthy controls. All patients had glomerular filtration rate (GFR), serum creatinine, blood urea nitrogen (BUN), albumin/creatinine (A/C) ratio measured, urine analysis, urinary NAG enzyme using enzyme-linked immunosorbent assay (ELISA), and renal ultrasound (U/S) were done.

Results

Our study showed high levels of urinary NAG in cases with a significant difference between cases and controls (P value < 0.001). There was a significant correlation between urinary NAG enzyme elevation and A/C ratio in urine, nephrotoxic drugs administration, and duration of disease (P value = 0.002, 0.005, 0.019), respectively.

Conclusion

Our study suggested that the NAG enzyme is a good early detector of renal impairment in CF patients before the conventional laboratory assays become deranged.

A Comparison of Mother’s Milk and the Neonatal Urine Metabolome: A Unique Fingerprinting for Different Nutritional Phenotypes

The ability of metabolomics to provide a snapshot of an individual’s metabolic state makes it a very useful technique in neonatology for investigating the complex relationship between nutrition and the state of health of the newborn. Through an ¹H-NMR metabolomics analysis, we aimed to investigate the metabolic profile of newborns by analyzing both urine and milk samples in relation to the birth weight of neonates classified as AGA (adequate for the gestational age, n = 51), IUGR (intrauterine growth restriction, n = 14), and LGA (large for gestational age, n = 15). Samples were collected at 7 ± 2 days after delivery. Of these infants, 42 were exclusively breastfed, while 38 received mixed feeding with a variable amount of commercial infant formula (less than 40%) in addition to breast milk. We observed a urinary spectral pattern for oligosaccharides very close to that of the corresponding mother’s milk in the case of exclusively breastfed infants, thus mirroring the maternal phenotype. The absence of this good match between the infant urine and human milk spectra in the case of mixed-fed infants could be reasonably ascribed to the use of a variable amount of commercial infant formulas (under 40%) added to breast milk. Furthermore, our findings did not evidence any significant differences in the spectral profiles in terms of the neonatal customize centile, i.e., AGA (adequate for gestational age), LGA (large for gestational age), or IGUR (intrauterine growth restriction). It is reasonable to assume that maternal human milk oligosaccharide (HMO) production is not or is only minimally influenced by the fetal growth conditions for unknown reasons. This hypothesis may be supported by our metabolomics-based results, confirming once again the importance of this approach in the neonatal field.

Ultrasound-Based Renal Parenchymal Area and Kidney Function Decline in Infants With Congenital Anomalies of the Kidney and Urinary Tract

Congenital anomalies of the kidney and urinary tract are the leading cause of chronic kidney disease in children. Noninvasive imaging biomarkers that predict chronic kidney disease progression in early infancy are needed. We performed a pilot study nested in the prospective Chronic Kidney Disease in Children cohort study to determine the association between renal parenchymal area (RPA) on first post-natal renal ultrasound and change in estimated glomerular filtration rate (eGFR) in children with congenital anomalies of the kidney and urinary tract. Among 14 participants, 78.6% were males, the median age at the time of the ultrasound was 3.4 months (interquartile range, 1.3-7.9 mo), and the median total RPA z-score at baseline was -1.01 (interquartile range, -2.39 to 0.52). After a median follow-up period of 7.4 years (interquartile range, 6.8-8.2 y), the eGFR decreased from a median of 49.4 mL/min per 1.73 m² at baseline to 29.4 mL/min per 1.73 m², an annual eGFR percentage decrease of -4.68%. Lower RPA z-scores were correlated weakly with a higher annual decrease in eGFR (Spearman correlation, 0.35; 95% confidence interval, -0.25 to 0.76). This pilot study shows the feasibility of obtaining RPA from a routine ultrasound and suggests that a lower baseline RPA may be associated with a greater decrease in eGFR over time. Further studies with larger patient cohorts are needed to confirm this association.

Proenkephalin as a new biomarker for pediatric acute kidney injury - reference values and performance in children under one year of age

Objectives Acute kidney injury (AKI) is common in critically ill children, but current biomarkers are suboptimal. Proenkephalin A 119-159 (PENK) is a promising new biomarker for AKI in adults, but pediatric data is lacking. We determined PENK reference intervals for healthy children, crucial for clinical implementation, and explored concentrations in critically ill infants aged under 1 year. Methods Observational cohort study in healthy infants and critically ill children aged 0-1 years. Reference values were determined using generalized additive models. Plasma PENK concentrations between healthy children and critically ill children with and without AKI, were compared using linear mixed modelling. The performance of PENK as AKI biomarker was compared to cystatin C (CysC) and β-trace protein (BTP) using receiver-operating-characteristic (ROC) analysis. Results PENK concentrations in 100 healthy infants were stable during the first year of life (median 517.3 pmol/L). Median PENK concentrations in 91 critically ill children, were significantly higher in those with AKI (n=40) (KDIGO Stage 1 507.9 pmol/L, Stage 2 704.0 pmol/L, Stage 3 930.5 pmol/L) than non-AKI patients (n=51, 432.2 pmol/L) (p < 0.001). PENK appeared to relate better to AKI diagnosis than CysC and BTP (AUROC PENK 0.858, CysC 0.770 and BTP 0.711) in the first 24 h after recruitment. Conclusions PENK reference values are much higher in young infants than adults, but clearly discriminate between children with and without AKI, with comparable or better performance than CysC and BTP. Our results illustrate the importance of establishing age-normalized reference values and indicate PENK as a promising pediatric AKI biomarker.

High Performance Liquid Chromatography-Tandem Mass Spectrometry Method for Correlating the Metabolic Changes of Lactate, Pyruvate and L-Glutamine with Induced Tamoxifen Resistant MCF-7 Cell Line Potential Molecular Changes

Breast cancer is one of the most prevalent cancers worldwide usually treated with Tamoxifen. Tamoxifen resistance development is the most challenging issue in an initially responsive breast tumor, and mechanisms of resistance are still under investigation. The objective of this study is to develop and validate a selective, sensitive, and simultaneous high performance liquid chromatography–tandem mass spectrometry method to explore the changes in substrates and metabolites in supernatant media of developed Tamoxifen resistance MCF-7 cells. We focus on the determination of lactate, pyruvate, and L-glutamine which enables the tracking of changes in metabolic pathways as a result of the resistance process. Chromatographic separation was achieved within 3.5 min. using a HILIC column (4.6 × 100 mm, 3.5 µm particle size) and mobile phase of 0.05 M acetic acid–ammonium acetate buffer solution pH 3.0: Acetonitrile (40:60 v/v). The linear range was 0.11–2.25, 0.012–0.227, and 0.02–0.20 mM for lactate, pyruvate, and L-glutamine, respectively. Within- and between-run accuracy was in the range 98.94-105.50% with precision (CV, %) of ≤0.86%. The results revealed a significant increase in both lactate and pyruvate production after acquiring the resistant. An increase in L-glutamine levels was also observed and could be attributed to its over production or decline in its consumption. Therefore, further tracking of genes responsible of lactate, pyruvate, and glutamine metabolic pathways should be performed in parallel to provide in-depth explanation of resistance mechanism.

The use of urinary osmolality to evaluate postoperative renal function in children with ureteropelvic junction obstruction

INTRODUCTION

Split renal function measured in a diuretic renogram is the most popular tool in initial assessment and follow-up of patients with ureteropelvic junction obstruction (UPJO). This study aims to evaluate the use of maximum urinary osmolality after desmopressin administration (DDAVP) to detect renal dysfunction.

PATIENTS AND METHODS

56 children (33 males, 23 females) diagnosed with UPJO underwent quantification of the maximum urinary osmolality (UOsm) at diagnosis. 41 of these children (28 males, 13 females) underwent surgery for UPJO and quantification of the UOsm before and after the surgical intervention (six to 18 months postoperatively) and were included in this longitudinal study.

RESULTS AND DISCUSSION

At diagnosis, UOsm measured after desmopressin administration was abnormal in 64% of patients. After surgical intervention, this rate decreased to 53%. At initial assessment, high creatinine levels were found in 32% of infants younger than one year of age. Albumin/Cr and NAG/Cr ratios were elevated in 12% and 7% of cases, respectively. After surgical intervention, an improvement in the NAG/creatinine ratio and creatinine levels was observed. Preoperative split renal function of the affected kidney was less than 45% in 39% of cases, normal in 44%, and greater than 55% in 17%; in these three subgroups, no differences in renal function markers were found.

CONCLUSIONS

The most sensitive parameter to detect alterations in renal function in children with UPJO is the UOsm and, therefore, the most useful in the follow-up after surgery. No correlation was found between other functional and morphological parameters obtained on renal ultrasound and renogram.

0.9% Sodium chloride solution versus Plasma-Lyte 148 versus compound sodium lacTate solution in children admitted to PICU-a randomized controlled trial (SPLYT-P): study protocol for an intravenous fluid therapy trial

Background

Intravenous fluid therapy represents the most common intervention critically ill patients are exposed to. Hyperchloremia and metabolic acidosis associated with 0.9% sodium chloride have been observed to lead to worse outcomes, including mortality. Balanced solutions, such as Plasma-Lyte 148 and Compound Sodium Lactate, represent potential alternatives but the evidence on optimal fluid choices in critically ill children remains scarce. This study aims to demonstrate whether balanced solutions, when used as intravenous fluid therapy, are able to reduce the incidence of a rise in serum chloride level compared to 0.9% sodium chloride in critically ill children.

Methods

This is a single-centre, open-label randomized controlled trial with parallel 1:1:1 assignment into three groups: 0.9% sodium chloride, Plasma-Lyte 148, and Compound Sodium Lactate solutions for intravenous fluid therapy. The intervention includes both maintenance and bolus fluid therapy. Children aged < 16 years admitted to intensive care and receiving intravenous fluid therapy during the first 4 h of admission are eligible. The primary outcome measure is a ≥ 5mmol/L increase in serum chloride level within 48 h post-randomization. The enrolment target is 480 patients. The main analyses will be intention-to-treat.

Discussion

This study tests three types of intravenous fluid therapy in order to compare the risk of hyperchloremia associated with normal saline versus balanced solutions. This pragmatic study is thereby assessing the most common intervention in paediatric critical care.

This is a single-centre open-label study with no blinding at the level of delivery of the intervention. Certain paediatric intensive care unit (PICU) patient groups such as those admitted with a cardiac condition or following a traumatic brain injury are excluded from this study.

Trial registration

The study has received ethical approval (HREC/19/QCHQ/53177: 06/06/2019). It is registered in the Australian New Zealand Clinical Trials Registry (ACTRN12619001244190) from 9th September 2019. Recruitment commenced on 12th November 2019. The primary results manuscript will be published in a peer-reviewed journal.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05376-5.

Vancomycin-induced ototoxicity in very-low-birthweight infants

BACKGROUND

Vancomycin is an extensively used anti-infective drug in neonatal ICUs. However, exposure-toxicity relationships have not been clearly defined.

OBJECTIVES

To evaluate the risk profile for hearing deficits in vancomycin-exposed very-low-birthweight infants (VLBWI).

METHODS

In a large cohort study of the German Neonatal Network (GNN; n = 16 967 VLBWI) we assessed the association of vancomycin treatment and pathological hearing tests at discharge and at 5 year follow-up. We performed audits on vancomycin exposure, drug levels, dose adjustments and exposure to other ototoxic drugs in a subgroup of 1042 vancomycin-treated VLBWI.

RESULTS

In the GNN cohort, 28% (n = 4739) were exposed to IV vancomycin therapy. In multivariable logistic regression analysis, vancomycin exposure proved to be independently associated with pathological hearing test at discharge (OR 1.18, 95% CI 1.03-1.34, P = 0.016). Among vancomycin-treated infants, a cumulative vancomycin dose above the upper quartile (>314 mg/kg bodyweight) was associated with pathological hearing test at discharge (OR 2.1, 95% CI 1.21-3.64, P = 0.009), whereas a vancomycin cumulative dose below the upper quartile was associated with a reduced risk of pathological tone audiometry results at 5 years of age (OR 0.29, 95% CI 0.1-0.8, P = 0.02, n = 147).

CONCLUSIONS

Vancomycin exposure in VLBWI is associated with an increased, dose-dependent risk of pathological hearing test results at discharge and at 5 years of age. Prospective studies on long-term hearing impairment are needed.

Population Model of Serum Creatinine as Time-Dependent Covariate in Neonates

Serum creatinine (sCr) is a commonly measured biomarker to estimate glomerular filtration rate (GFR) and therefore widely used as a covariate in population pharmacokinetic models of renally excreted drugs. In neonates, sCr dynamically changes during the first few weeks after birth. Missing covariates are a common problem in pharmacokinetic modeling of neonates due to the limited availability of blood sampling in number and volume. The objective of this work is to develop a parsimonious population model describing time courses of sCr in neonates with the intent to be incorporated into pharmacokinetic models of various drugs where sCr values are sparse or missing. The data for model development consisted of sCr measurements in 1080 newborns with a gestational age of 24-42 weeks. The model is based on a pharmacokinetic model of sCr that involves GFR, backflow of creatinine from the renal tubules, and urinary flow. Gestational age is the only covariate explaining between-subject variability of sCr. The model adequately describes distinct features of the sCr time course such as a peak and decline to a plateau. For a neonate with a GA of 35 weeks, the typical value of sCr at birth was 0.584 mg/dL, the peak (0.794 mg/dL) occurred 2.3 days after birth, to reach a plateau of 0.255 mg/dL approximately after 24.7 days. Model simulations reveal that in neonates with a similar postnatal age, sCr decreases with increasing GA. In summary, our model is designed to be a part of full random effects pharmacokinetic models where sCr is a significant covariate.

Acute kidney injury: epidemiology and course in critically ill children

BACKGROUND

Acute kidney injury (AKI) is a major cause of morbidity and mortality in critically ill children. The aim of this paper was to describe the prevalence and course of AKI in critically ill children and to compare different AKI classification criteria.

METHODS

We conducted a retrospective observational study in our multi-disciplinary Pediatric Intensive Care Unit (ICU) from January 2015 to December 2018. All patients from birth to 16 years of age who were admitted to the pediatric ICU were included. The Kidney Disease Improving Global Outcomes (KDIGO) definition was considered as the reference standard. We compared the incidence data assessed by KDIGO, pediatric risk, injury, failure, loss of kidney function and end- stage renal disease (pRIFLE) and pediatric reference change value optimised for AKI (pROCK).

RESULTS

Out of 7505 patients, 9.2% developed AKI by KDIGO criteria. The majority (59.8%) presented with stage 1 AKI. Recovery from AKI was observed in 70.4% of patients within 7 days from diagnosis. Both pRIFLE and pROCK were less sensitive compared to KDIGO criteria for the classification of AKI. Patients who met all three-KDIGO, pRIFLE and pROCK criteria had a high mortality rate (35.0%).

CONCLUSION

Close to one in ten patients admitted to the pediatric ICU met AKI criteria according to KDIGO. In about 30% of patients, AKI persisted beyond 7 days. Follow-up of patients with persistent kidney function reduction at hospital discharge is needed to reveal the long-term morbidity due to AKI in the pediatric ICU.

Risk factors for in-hospital mortality and acute kidney injury in neonatal-pediatric patients receiving extracorporeal membrane oxygenation

BACKGROUND

Acute kidney injury (AKI) is the most frequent complication in critically ill neonatal and pediatric patients receiving extracorporeal membrane oxygenation (ECMO) support. This study analyzed risk factors for in-hospital mortality and the incidence of AKI in neonatal and pediatric patients received ECMO support.

METHODS

We reviewed the medical records of 105 neonatal and 171 pediatric patients who received ECMO support at the intensive care unit (ICU) of a tertiary care university hospital between January 2008 and December 2015. Demographic, clinical, and laboratory data were retrospectively collected as survival and AKI predictors, utilizing the Kidney Disease Improving Global Outcome (KDIGO) consensus definition for AKI.

RESULTS

In the 105 neonatal and 171 pediatric patients, the overall in-hospital mortality rate were 58% and 55% respectively. The incidence of AKI at post-ECMO 24 h were 64.8% and 61.4%. A greater KDIGO_24-h severity was associated with a higher in-hospital mortality rate (chi-square test; p < 0.01) and decreased survival rate (log-rank tests, p < 0.01). In univariate logistic regression analysis of in-hospital mortality, the CVP level at post ECOMO 24-h increased odds ratio (OR) (OR = 1.27 [1.10-1.46], p = 0.001) of in-hospital mortality in neonatal group; as for pediatric group, elevated lactate (OR = 1.12 [1.03-1.20], p = 0.005) and PT (OR = 1.86 [1.17-2.96], p = 0.009) increased OR of in-hospital mortality. And the KDIGO_24h stage 3 had the strongest association with in-hospital mortality in both neonatal (p = 0.005) and pediatric (p = 0.001) groups. In multivariate OR of neonatal and pediatric groups were 4.38 [1.46-13.16] (p = 0.009) and 3.76 [1.70-8.33] (p = 0.001), respectively.

CONCLUSIONS

AKI was a significant risk factor for in-hospital mortality in the neonatal and pediatric patients who received ECMO support. A greater KDIGO24-h severity was associated with higher mortality rates and decreased survival rate in both neonatal and pediatric groups. Of note, KDIGO24h can be an easy and early tool for the prognosis of AKI in the neonatal and pediatric patients.

How should we assess renal function in neonates and infants?

AIM

Review of current knowledge on assessing renal function in term and preterm neonates.

METHODS

Literature review and analysis of own data.

RESULTS

Prematurity, genetic, environmental and maternal factors may alter peak nephron endowment and life-long renal function. Nephrogenesis continues until 34-36 weeks of gestation, but it is altered with premature delivery. Variability of nephron endowment has a substantial impact on the clearance of renally excreted drugs. Postnatally, glomerular function rate (GFR) increases daily, doubles by two weeks, and slowly reaches full maturity at 18 months of age. Ideally, renal function biomarkers should be expressed as age-independent z-scores, and evidence suggests indexing these values to post-conceptual age rather than chronological age. Newborn and maternal serum creatinine correlate tightly for more than 72 hours after delivery, rendering this biomarker unsuitable for the assessment of neonatal renal function. Cystatin C does not cross the placenta and may be the preferred biomarker in the neonate. Here, we provide preliminary data on the natural evolution of the cystatin C eGFR in infancy.

CONCLUSION

Cystatin C may be superior for GFR estimation in neonates, but the best approach to drug dosing of renally excreted drugs remains to be established.

Determination of vancomycin exposure target and individualised dosing recommendations for neonates: model-informed precision dosing

INTRODUCTION

Few studies incorporating population pharmacokinetic/pharmacodynamic (Pop-PK/PD) modelling have been conducted to quantify the exposure target of vancomycin in neonates. A retrospective observational cohort study was undertaken in neonates to determine this target and dosing recommendations (chictr.org.cn, ChiCTR1900027919).

METHODS

A Pop-PK model was developed to estimate PK parameters. Causalities between acute kidney injury (AKI) occurrence and vancomycin use were verified using Naranjo criteria. Thresholds of vancomycin exposure in predicting AKI or efficacy were identified via classification and regression tree analysis. Associations between exposure thresholds and clinical outcomes, including AKI and efficacy, were analysed by logistic regression. Dosing recommendations were designed using Monte Carlo simulations based on the optimised exposure target.

RESULTS

Pop-PK modelling included 182 neonates with 411 observations. On covariate analysis, neonatal physiological maturation, renal function and concomitant use of vasoactive agents (VAS) significantly affected vancomycin PK. Seven cases of vancomycin-induced AKI were detected. Area under the concentration-time curve from 0-24 hours (AUC_0-24) ≥ 485 mg•h/L was an independent risk factor for AKI after adjusting for VAS co-administration. The clinical efficacy of vancomycin was analysed in 42 patients with blood culture-proven staphylococcal sepsis. AUC_0-24 to minimum inhibitory concentration (AUC_0-24/MIC) ≥ 234 was the only significant predictor of clinical effectiveness. Monte Carlo simulations indicated that regimens in Neonatal Formulary 7 and Red Book (2018) were unsuitable for all neonates.

CONCLUSION

An AUC_0-24 of 240-480 (assuming MIC = 1 mg/L) is a recommended exposure target of vancomycin in neonates. Model-informed dosing regimens are valuable in clinical practice.

Short- and Long-term Outcomes of Kidney Transplants From Very Small (≤15 kg) Pediatric Donors With Acute Kidney Injury

BACKGROUND

Kidneys from small deceased pediatric donors with acute kidney injury (AKI) are commonly discarded owing to transplant centers' concerns regarding potentially inferior short- and long-term posttransplant outcomes.

METHODS

We retrospectively analyzed our center's en bloc kidney transplants performed from November 2007 to January 2015 from donors ≤15 kg into adult recipients (≥18 y). We pair-matched grafts from 27 consecutive donors with AKI versus 27 without AKI for donor weight, donation after circulatory death status, and preservation time.

RESULTS

For AKI versus non-AKI donors, median weight was 7.5 versus 7.1 kg; terminal creatinine was 1.7 (range, 1.1-3.3) versus 0.3 mg/dL (0.1-0.9). Early graft loss rate from thrombosis or primary nonfunction was 11% for both groups. Delayed graft function rate was higher for AKI (52%) versus non-AKI (15%) grafts (P = 0.004). Median estimated glomerular filtration rate was lower for AKI recipients only at 1 and 3 months (P < 0.03). Graft survival (death-censored) at 8 years was 78% for AKI versus 77% for non-AKI grafts. Late proteinuria rates for AKI versus non-AKI recipients with >4 years follow-up were not significantly different.

CONCLUSIONS

Small pediatric donor AKI impacted early posttransplant kidney graft function, but did not increase risk for early graft loss and decreased long-term function. The presently high nonutilization rates for en bloc kidney grafts from very small pediatric donors with AKI appear therefore unjustified. Based on the outcomes of the present study, we infer that the reluctance to transplant single kidneys from larger pediatric donors with AKI lacks a rational basis as well. Our findings warrant further prospective study and confirmation in larger study cohorts.

Early Acute Kidney Injury in Preterm and Term Neonates: Incidence, Outcome, and Associated Clinical Features

BACKGROUND

Critically ill neonates are at high risk of kidney injury, mainly in the first days of life. Acute kidney injury (AKI) may be underdiagnosed due to lack of a uniform definition. In addition, long-term renal follow-up is limited.

OBJECTIVE

To describe incidence, etiology, and outcome of neonates developing AKI within the first week after birth in a cohort of NICU-admitted neonates between 2008 and 2018. Renal function at discharge in infants with early AKI was assessed.

METHODS AND SUBJECTS

AKI was defined as an absolute serum Cr (sCr) value above 1.5 mg/dL (132 μmol/L) after the first 24 h or as stage 2-3 of the NIDDK neonatal definition. Clinical data and outcomes were collected from medical records and retrospectively analyzed.

RESULTS

From January 2008 to December 2018, a total of 9,376 infants were admitted to the NICU of Wilhelmina Children's Hospital/UMC Utrecht, of whom 139 were diagnosed with AKI during the first week after birth. In 72 term infants, the most common etiology was perinatal asphyxia (72.2%), followed by congenital kidney and urinary tract malformations (CAKUT) (8.3%), congenital heart disease (6.9%), and sepsis (2.8%). Associated conditions in 67 preterm infants were medical treatment of a hemodynamic significant PDA (27.2%), -CAKUT (21%), and birth asphyxia (19.4%). Among preterm neonates and neonates with perinatal asphyxia, AKI was mainly diagnosed by the sCr >1.5 mg/dL criterion. Renal function at discharge improved in 76 neonates with AKI associated with acquired conditions. Neonates with stage 3 AKI showed increased sCr values at discharge. Half of these were caused by congenital kidney malformations and evolved into chronic kidney disease (CKD) later in life. Neurodevelopmental outcome (NDO) at 2 years was favorable in 93% of surviving neonates with detailed follow-up.

CONCLUSION

During the first week after birth, AKI was seen in 1.5% of infants admitted to a level III NICU. Renal function at discharge had improved in most neonates with acquired AKI but not in infants diagnosed with stage 3 AKI. Long-term renal function needs further exploration, whereas NDO appears to be good.

In-Hospital Outcomes of Acute Kidney Injury After Pediatric Cardiac Surgery: A Meta-Analysis

Background: Cardiac surgery-associated acute kidney injury (CS-AKI) is associated with increased morbidity and mortality in both adults and children. This study aimed to investigate the in-hospital outcomes of CS-AKI in the pediatric population. Methods: PubMed/MEDLINE, Embase, Scopus, and reference lists of relevant articles were searched for studies published by August 2020. Random-effects meta-analysis was performed, comparing in-hospital outcomes between patients who developed CS-AKI and those who did not. Results: Fifty-eight publications between 2008 and 2020 consisting of 18,334 participants (AKI: 5,780; no AKI: 12,554) were included. Higher rates of in-hospital mortality (odds ratio [OR] 7.22, 95% confidence interval [CI] 5.27-9.88), need for renal replacement therapy (RRT) (OR 18.8, 95% CI 11.7-30.5), and cardiac arrhythmias (OR 2.67, 95% 1.86-4.80) were observed in patients with CS-AKI. Furthermore, patients with AKI had longer ventilation times (mean difference [MD] 1.76 days, 95% CI 1.05-2.47), pediatric intensive care unit (PICU) length of stay (MD 3.31, 95% CI 2.52-4.10), and hospital length of stay (MD 5.00, 95% CI 3.34-6.67). Conclusions: CS-AKI in the pediatric population is associated with a higher risk of mortality, cardiac arrhythmias and need for RRT, as well as greater mechanical ventilation time, PICU and hospital length of stay. These results might help improve the clinical care protocols prior to cardiac surgery to minimize the disease burden of CS-AKI in children. Furthermore, etiology-specific approaches to AKI are warranted, as outcomes are likely impacted by the underlying cause.

Impact of haemolysis on vancomycin disposition in a full-term neonate treated with extracorporeal membrane oxygenation

INTRODUCTION

Extracorporeal membrane oxygenation (ECMO) is a lifesaving support technology for potentially reversible neonatal cardiac and/or respiratory failure. Pharmacological consequences of ECMO-induced haemolysis in neonates are not well understood.

CASE REPORT

We report a case report of a full-term neonate treated for congenital diaphragmatic hernia and sepsis with ECMO and with vancomycin. While the population elimination half-life of 7 h was estimated, fitting of the simulated population pharmacokinetic profile to truly observed drug concentration points resulted in the personalized value of 41 h.

DISCUSSION

The neonate developed ECMO-induced haemolysis with subsequent acute kidney injury resulting in prolonged drug elimination. Whole blood/serum ratio of 0.79 excluded possibility of direct increase of vancomycin serum concentration during haemolysis.

CONCLUSION

Vancomycin elimination may be severely prolonged due to ECMO-induced haemolysis and acute kidney injury, while hypothesis of direct increase of vancomycin levels by releasing the drug from blood cells during haemolysis has been disproved.

A New Approach to Recognize Neonatal Impaired Kidney Function

Introduction

Previous studies in term newborns with hypoxic ischemic encephalopathy showed that the rate of serum creatinine (SCr) decline during the first week of life could be used to identify newborns with impaired kidney function (IKF) who are missed by standard definitions of neonatal acute kidney injury (nAKI).

Methods

Retrospective review of the medical records of 329 critically ill newborns ≥27 weeks of gestational age (GA) admitted to a level 4 neonatal intensive care unit (NICU). We tested the hypothesis that the rate of SCr decline combined with SCr thresholds provides a sensitive approach to identify term and preterm newborns with IKF during the first week of life.

Results

Excluding neonates with nAKI, an SCr decline <31% by the seventh day of life, combined with an SCr threshold ≥0.7 mg/dl, recognized newborns of 40 to 31 weeks of GA with IKF. An SCr decline <21% combined with an SCr threshold ≥0.8 mg/dl identified newborns of 30 to 27 weeks of GA with IKF. Neonates with IKF (∼17%), like those with nAKI (7%), showed a more prolonged hospital stay and required more days of mechanical ventilation, vasoactive drugs, and diuretics, when compared with the controls. Changes in urine output did not distinguish newborns with IKF.

Conclusion

The rate of SCr decline combined with SCr thresholds identifies newborns with IKF during the first week of life. This distinctive group of newborns that is missed by standard definitions of nAKI, warrants close monitoring in the NICU to prevent further renal complications.

Pediatric Renal Ontogeny and Applications in Drug Development

The clinical applications of renal ontogeny mainly include renal function evaluation and optimal dosing of renally eliminated drugs in pediatric patients, which rely on pharmacometric models and/or bedside estimated glomerular filtration rate equations. However, these applications in drug development are based on an understanding of renal function development, especially when considering premature infants, and the renal biomarkers that can be used for renal function assessment. This review provides a general overview on (1) renal function development, (2) the biomarkers that are used to assess renal function, and (3) the practical application of this knowledge to drug dosing for renally eliminated drugs during pediatric development. While pharmacometric approaches for estimating renal function during development have improved considerably, the number of drug development programs that have studied premature infants is small and suggests that caution should be taken in estimating doses for renally eliminated drugs during periods of rapid change in renal function.

Prediction of Acute Kidney Injury on Admission to Pediatric Intensive Care

OBJECTIVES

Up to 37% of children admitted to the PICU develop acute kidney injury as defined by Kidney Disease: Improving Global Outcomes criteria. We describe the prevalence of acute kidney injury in a mixed pediatric intensive care cohort using this criteria. As tools to stratify patients at risk of acute kidney injury on PICU admission are lacking, we explored the variables at admission and day 1 that might predict the development of acute kidney injury.

DESIGN

Single-center retrospective observational study.

SETTING

Thirty-six-bed surgical/medical tertiary PICU.

PATIENTS

Children from birth to less than or equal to 16 years old admitted between 2015 and 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Clinical data were extracted from the PICU clinical information system. Patients with baseline creatinine at admission greater than 20 micromol/L above the calculated normal creatinine level were classified as "high risk of acute kidney injury." Models were created to predict acute kidney injury at admission and on day 1. Out of the 7,505 children admitted during the study period, 738 patients (9.8%) were classified as high risk of acute kidney injury at admission and 690 (9.2%) developed acute kidney injury during PICU admission. Compared to Kidney Disease: Improving Global Outcomes criteria as the reference standard, high risk of acute kidney injury had a lower sensitivity and higher specificity compared with renal angina index greater than or equal to 8 on day 1. For the admission model, the adjusted odds ratio of developing acute kidney injury for high risk of acute kidney injury was 4.2 (95% CI, 3.3-5.2). The adjusted odds ratio in the noncardiac cohort for high risk of acute kidney injury was 7.3 (95% CI, 5.5-9.7). For the day 1 model, odds ratios for high risk of acute kidney injury and renal angina index greater than or equal to 8 were 3.3 (95% CI, 2.6-4.2) and 3.1 (95% CI, 2.4-3.8), respectively.

CONCLUSIONS

The relationship between high risk of acute kidney injury and acute kidney injury needs further evaluation. High risk of acute kidney injury performed better in the noncardiac cohort.

Impact of transport on arrival status and outcomes in newborns with heart disease: a low-middle-income country perspective

OBJECTIVES

We sought to systematically study determinants of "clinical status at arrival after transport" of neonates with CHD and its impact on clinical outcomes in a low- and middle-income country environment.

METHODS AND RESULTS

Consecutive neonates with CHD (n = 138) transported (median distance 138 km; 5-425 km) to a paediatric cardiac programme in Southern India were studied prospectively. Among 138 neonatal transports, 134 were in ambulances. Four neonates were transported by family in private vehicles; 60% with duct-dependent circulation (n = 57) were transported without prostaglandin E1. Clinical status at arrival after transport was assessed using California modification of TRIPS Score (Ca-TRIPS), evidence of end-organ injury and metabolic insult.Upon arrival, 42% had end-organ injury, 24% had metabolic insult and 36% had Ca-TRIPS Score >25. Prior to surgery or catheter intervention, prolonged ICU stay (>48 hours), prolonged ventilation (>48 hours), blood stream sepsis, and death occurred in 48, 15, 19, and 3.6%, respectively. Ca-TRIPS Score >25 was significantly associated with mortality (p = 0.005), sepsis (p = 0.035), and prolonged ventilation (p < 0.001); end-organ injury with prolonged ICU stay (p = 0.031) and ventilation (p = 0.045); metabolic insult with mortality (p = 0.012) and sepsis (p = 0.015).Fifteen babies needed only medical management, 10 received comfort care (due to severe end-organ injury in 3), 107 underwent cardiac surgery (n = 83) or catheter intervention (n = 24), with a mortality of 6.5%. Clinical status at arrival after transport did not impact post-procedure outcomes.

CONCLUSION

Neonates with CHD often arrive in suboptimal status after transport in low- and middle-income countries resulting in adverse clinical outcomes. Robust transport systems need to be integrated in plans to develop newborn heart surgery in low- and middle-income countries.

Early prediction of pediatric acute kidney injury from the emergency department: A pilot study

BACKGROUND

Identifying acute kidney injury (AKI) early can inform medical decisions key to mitigation of injury. An AKI risk stratification tool, the renal angina index (RAI), has proven better than creatinine changes alone at predicting AKI in critically ill children.

OBJECTIVE

To derive and test performance of an "acute" RAI (aRAI) in the Emergency Department (ED) for prediction of inpatient AKI and to evaluate the added yield of urinary AKI biomarkers.

METHODS

Study of pediatric ED patients with sepsis admitted and followed for 72 h. The primary outcome was inpatient AKI defined by a creatinine >1.5× baseline, 24-72 h after admission. Patients were denoted renal angina positive (RA+) for an aRAI score above a population derived cut-off. Test characteristics evaluated predictive performance of the aRAI compared to changes in creatinine and incorporation of 4 urinary biomarkers in the context of renal angina were assessed.

RESULTS

118 eligible subjects were enrolled. Mean age was 7.8 ± 6.4 years, 16% required intensive care admission. In the ED, 27% had a +RAI (22% had a >50% creatinine increase). The aRAI had an AUC of 0.92 (0.86-0.98) for prediction of inpatient AKI. For AKI prediction, RA+ demonstrated a sensitivity of 94% (69-99) and a negative predictive value of 99% (92-100) (versus sensitivity 59% (33-82) and NPV 93% (89-96) for creatinine ≥2× baseline). Biomarker analysis revealed a higher AUC for aRAI alone than any individual biomarker.

CONCLUSIONS

This pilot study finds the aRAI to be a sensitive ED-based tool for ruling out the development of in-hospital AKI.

Kidney Disease: Improving Global Outcomes in neonates with acute kidney injury after cardiac surgery

BACKGROUND

Acute kidney injury (AKI) after cardiac surgery (CS-AKI) in children with congenital heart disease is a serious complication closely associated with high morbidity and mortality. Kidney Disease: Improving Global Outcomes (KDIGO) AKI staging demonstrates high sensitivity for detecting AKI and predicting associated in-hospital mortality. However, neonatal-modified KDIGO criteria (n-KDIGO), recently introduced as a standard diagnostic tool, for CS-AKI have not been fully validated. Here, we evaluated the incidence of risk factors and postoperative outcomes of neonatal CS-AKI.

METHODS

We retrospectively studied 114 consecutive neonates who underwent cardiac surgery at the Kagoshima University Hospital. CS-AKI was classified using the n-KDIGO criteria. Risk adjustment in congenital heart surgery (RACHS-1) score was used to predict the complexity-adjusted mortality and % fluid overload (%FO) was used to monitor fluid balance in pediatric cardiac surgery.

RESULTS

Among 81 patients, neonatal CS-AKI occurred in 57 (70.4%) patients according to n-KDIGO criteria. Of these, 28 (34.6%) patients reached n-KDIGO 1, 17 (21.0%) reached n-KDIGO 2, and 12 (14.8%) reached n-KDIGO 3. Patients with CS-AKI had significantly higher vasoactive-inotropic score levels, longer operative times, and higher %FO than patients without CS-AKI. Notably, increased duration of cardiopulmonary bypass times and %FO were risk factors for the development of neonatal CS-AKI. The n-KDIGO-based severe AKI grade had higher risk of in-hospital mortality; however, the n-KDIGO-based mild AKI grade was not associated with any postoperative outcomes.

CONCLUSIONS

CS-AKI based on n-KDIGO criteria is common in neonates and is closely associated with higher mortality, especially in patients with severe CS-AKI.

Severe Hyperkalemia Immediately After Birth

BACKGROUND Hyperkalemia is an important cause of arrhythmias and a medical emergency that requires urgent treatment. The etiology is usually multifactorial. It is most frequently caused by impaired potassium secretion, followed by transcellular potassium shifts and an increased potassium load. CASE REPORT A male newborn developed monomorphic ventricular tachycardia 2 hours after birth. He was born in the 35th week of gestation by urgent C-section following placental abruption. Laboratory results showed hemolytic anemia (Hb 99 g/L, Hct 0.31) with increased bilirubin levels and reticulocytosis, thrombocytopenia (39×10⁹/L), hypoglycemia (0.8 mmol/L), and severe hyperkalemia (9.8 mmol/L). Umbilical artery blood gas analysis showed hypoxemia with acidosis (pO₂ 3.8 kPa, pH 7.21, pCO₂ 7.84 kPa, HCO₃ 23.3 mmol/L, BE -5 mmol/L). Creatinine (102 µmol/L) and urea (9.8 mmol/L) were mildly elevated. Inflammatory markers were also increased (CRP 26 mg/L, blood leukocyte count 24×10⁹/L). Early-onset sepsis, caused by Candida albicans, was confirmed approximately 24 hours after birth. Non-invasive ventilation with 35-40% O₂ was necessary due to transient tachypnea. The neonate received a transfusion of packed red blood cells, a 10% glucose infusion, and empirical antibiotic therapy. Hyperkalemia accompanied by arrhythmias was treated with calcium gluconate, insulin, Sorbisterit enema, and, finally, by exchange transfusion. CONCLUSIONS We report a case of severe hyperkalemia in a newborn immediately after birth. Making a decision as early as possible regarding exchange transfusion is essential in patients with hyperkalemia with electrocardiogram changes and hemodynamic instability.

Early Diagnosis and Prognostic Value of Acute Kidney Injury in Critically Ill Patients

Background and objectives: In hospitalized children, acute kidney injury (AKI) remains to be a frequent and serious condition, associated with increased patient mortality and morbidity. Identifying early biomarkers of AKI and patient groups at the risk of developing AKI is of crucial importance in current clinical practice. Specific human protein urinary neutrophil gelatinase-associated lipocalin (uNGAL) and interleukin 18 (uIL-18) levels have been reported to peak specifically at the early stages of AKI before a rise in serum creatinine (sCr). Therefore, the aim of our study was to determine changes in uNGAL and uIL-18 levels among critically ill children and to identify the patient groups at the highest risk of developing AKI. Materials and methods: This single-center prospective observational study included 107 critically ill children aged from 1 month to 18 years, who were treated in the Pediatric Intensive Care Unit (PICU) of Lithuanian University of Health Sciences Hospital Kauno Klinikos from 1 December 2013, to 30 November 2016. The patients were divided into two groups: those who did not develop AKI (Group 1) and those who developed AKI (Group 2). Results: A total of 68 (63.6%) boys and 39 (36.4%) girls were enrolled in the study. The mean age of the patients was 101.30 ± 75.90 months. The mean length of stay in PICU and hospital was 7.91 ± 11.07 and 31.29 ± 39.09 days, respectively. A total of 32 (29.9%) children developed AKI. Of them, 29 (90.6%) cases of AKI were documented within the first three days from admission to hospital. In all cases, AKI was caused by diseases of non-renal origin. There was a significant association between the uNGAL level and AKI between Groups 1 and 2 both on day 1 (p = 0.04) and day 3 (p = 0.018). Differences in uNGAL normalized to creatinine in the urine (uCr) (uNGAL/uCr) between the groups on days 1 and 3 were also statistically significant (p = 0.007 and p = 0.015, respectively). uNGAL was found to be a good prognostic marker. No significant associations between uIL-18 or Uil-18/uCr and development of AKI were found. However, the uIL-18 level of >69.24 pg/mL during the first 24 h was associated with an eightfold greater risk of AKI progression (OR = 8.33, 95% CI = 1.39–49.87, p = 0.023). The AUC for uIL-18 was 73.4% with a sensitivity of 62.59% and a specificity of 83.3%. Age of <20 months, Pediatric Index of Mortality 2 (PIM2) score of >2.5% on admission to the PICU, multiple organ dysfunction syndrome with dysfunction of three and more organ systems, PICU length of stay more than three days, and length of mechanical ventilation of >five days were associated with a greater risk of developing AKI. Conclusions: Significant risk factors for AKI were age of <20 months, PIM2 score of >2.5% on admission to the PICU, multiple organ dysfunction syndrome with dysfunction of 3 and more organ systems, PICU length of stay of more than three days, and length of mechanical ventilation of > five days. uNGAL was identified as a good prognostic marker of AKI. On admission to PICU, uNGAL should be measured within the first three days in patients at the risk of developing AKI. The uIL-18 level on the first day was found to be as a biomarker predicting the progression of AKI.

Investigating the presence of human anti-mouse antibodies (HAMA) in the blood of laboratory animal care workers

Background

In the present study, the researchers evaluated the presence of human anti-mouse antibodies (HAMA) in a normal population and laboratory animal care providers for the first time in the world. Also, the cause of HAMA incidence in the human body through a close contact with mice was identified.

Methods

The study population consisted of 40 laboratory animal care providers aged between 24 and 57 years with a close contact with mice (e.g. taking care of mice, feeding mice, etc.) and 40 individuals of the same age as the above group with no contact with mice. HAMA was measured in both the case and control groups using sandwich enzyme-linked immunosorbent assay (ELISA) method. Data were analyzed using SPSS 18. Univariate and multivariate linear regression and independent t-test were used. The significance of results was measured based on p < 0.05.

Results

The present study revealed that the animal care providers had (p = 000) a higher titer of HAMA (4.95 ng/mL) in their blood than the control group (1.67 ng/mL). Also, the individuals in the case group (exposed to mice) were more allergic (43.6%) than those in the control group (15%) (p = 0.003).

Conclusions

The results of this study revealed that exposure to mice in laboratory care centers can cause production of HAMA in the human body but its titer is possibly lower in Iranian working staff than those in the other parts of the world.