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Wu Y, Allegaert K, Flint RB, Goulooze SC, Välitalo PAJ, de Hoog M, Mulla H, Sherwin CMT, Simons SHP, Krekels EHJ, Knibbe CAJ, Völler S. When will the Glomerular Filtration Rate in Former Preterm Neonates Catch up with Their Term Peers? Pharm Res 2024; 41:637-649. [PMID: 38472610 PMCID: PMC11024008 DOI: 10.1007/s11095-024-03677-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 02/10/2024] [Indexed: 03/14/2024]
Abstract
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.
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Affiliation(s)
- Yunjiao Wu
- Division of Systems Pharmacology and Pharmacy, Leiden Academic Centre for Drug Research, Leiden University, 2333CC, Leiden, The Netherlands
| | - Karel Allegaert
- Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Development and Regeneration, and Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Robert B Flint
- Department of Hospital Pharmacy, Erasmus University Medical Center, Rotterdam, The Netherlands
- Department of Pediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Sebastiaan C Goulooze
- Leiden Experts On Advanced Pharmacokinetics and Pharmacodynamics (LAP&P), Leiden, The Netherlands
| | - Pyry A J Välitalo
- School of Pharmacy, University of Eastern Finland, Yliopistonranta 1 C, 70210, Kuopio, Finland
- Finnish Medicines Agency, Hallituskatu 12-14, 70100, Kuopio, Finland
| | - Matthijs de Hoog
- Department of Neonatal and Pediatric Intensive Care, Division of Pediatric Intensive Care, Erasmus MC Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Hussain Mulla
- Department of Pharmacy, University Hospitals of Leicester, Glenfield Hospital, Leicester, LE39QP, England
| | - Catherine M T Sherwin
- Department of Pediatrics, Wright State University Boonshoft School of Medicine/Dayton Children's Hospital, One Children's Plaza, Dayton, OH, USA
| | - Sinno H P Simons
- Department of Pediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, Rotterdam, The Netherlands
| | - Elke H J Krekels
- Division of Systems Pharmacology and Pharmacy, Leiden Academic Centre for Drug Research, Leiden University, 2333CC, Leiden, The Netherlands
- Certara Inc, Princeton, NJ, USA
| | - Catherijne A J Knibbe
- Division of Systems Pharmacology and Pharmacy, Leiden Academic Centre for Drug Research, Leiden University, 2333CC, Leiden, The Netherlands
- Department of Pediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, Rotterdam, The Netherlands
- Department of Clinical Pharmacy, St Antonius Hospital, Nieuwegein, The Netherlands
| | - Swantje Völler
- Division of Systems Pharmacology and Pharmacy, Leiden Academic Centre for Drug Research, Leiden University, 2333CC, Leiden, The Netherlands.
- Department of Pediatrics, Division of Neonatology, Erasmus MC Sophia Children's Hospital, Rotterdam, The Netherlands.
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2
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Yan R, Zhang C, Wang C, Sun Z, Peng X. Evaluation of glomerular filtration rate estimation equations based on serum creatinine in healthy Chinese children and adolescents: a nationwide cross-sectional study. BMJ Paediatr Open 2023; 7:e002132. [PMID: 37827805 PMCID: PMC10582894 DOI: 10.1136/bmjpo-2023-002132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 08/29/2023] [Indexed: 10/14/2023] Open
Abstract
BACKGROUND Several equations for glomerular filtration rate (GFR) estimation based on serum creatinine (SCr) have been proposed for children, but most were developed among patients with kidney disease. The association between SCr and GFR may be distorted by kidney dysfunction and thus not applicable to healthy children. This study aimed to evaluate the applicability of existing SCr-based GFR estimation equations in healthy Chinese children. METHODS GFR estimation equations that developed in healthy children were mainly analysed, including the Flanders Metadata (FM), simple height-independent (Simple), full age spectrum (FAS) and FAS-height equations. The FM equation assumed that GFR is proportional to the ratio of height to SCr. The Simple, FAS and FAS-height equations assumed that the ratio of GFR to population mean is equal to the reciprocal ratio of SCr to population mean (denoted by Q). Estimated GFR were calculated using data of SCr, age, sex and height collected from 12 208 healthy Chinese children aged 3 months to <20 years. The performance of GFR estimation equations was evaluated by the sex and age distribution of the estimated GFR and the deviation from the measured GFR reported by other literatures. RESULTS The FM and Simple equations performed well in their applicable age of 1 month to 14 years, but presented undesirable sex difference after adolescence. The FAS and FAS-height equations showed reasonable development trend of estimated GFR throughout childhood, and the FAS equation had higher consistency than the FAS-height equation compared with measured GFR in healthy children. The GFR estimated by the FAS equation increased with age before 2 years, and reached the adult level thereafter without important sex difference. CONCLUSIONS The FAS equation is applicable to healthy Chinese children.
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Affiliation(s)
- Ruohua Yan
- Center for Clinical Epidemiology and Evidence-based Medicine, Beijing Children's Hospital, Capital Medical University, National Center for Children Health, Beijing, China
| | - Chao Zhang
- Center for Clinical Epidemiology and Evidence-based Medicine, Beijing Children's Hospital, Capital Medical University, National Center for Children Health, Beijing, China
| | - Chen Wang
- Center for Clinical Epidemiology and Evidence-based Medicine, Beijing Children's Hospital, Capital Medical University, National Center for Children Health, Beijing, China
| | - Zimo Sun
- Center for Clinical Epidemiology and Evidence-based Medicine, Beijing Children's Hospital, Capital Medical University, National Center for Children Health, Beijing, China
| | - Xiaoxia Peng
- Center for Clinical Epidemiology and Evidence-based Medicine, Beijing Children's Hospital, Capital Medical University, National Center for Children Health, Beijing, China
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3
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Sun ZM, Zhou N, Peng XX, Wang H, Shen Y. Insufficient application of estimation equations of glomerular filtration rate: a survey of 1009 Chinese pediatricians. World J Pediatr 2022; 18:368-372. [PMID: 35267183 DOI: 10.1007/s12519-021-00509-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 12/22/2021] [Indexed: 11/28/2022]
Affiliation(s)
- Zi-Mo Sun
- Center for Clinical Epidemiology and Evidence-Based Medicine, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Nan Zhou
- Department of Nephrology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Xiao-Xia Peng
- Center for Clinical Epidemiology and Evidence-Based Medicine, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China.
| | - Hui Wang
- Department of Nephrology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
| | - Ying Shen
- Department of Nephrology, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing 100045, China
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4
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Holness JL, Brink A, Davids MR, Warwick JM. Estimated glomerular filtration rate in children: adapting existing equations for a specific population. Pediatr Nephrol 2021; 36:669-683. [PMID: 32995921 DOI: 10.1007/s00467-020-04770-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 07/17/2020] [Accepted: 09/09/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND Creatinine-based glomerular filtration rate (GFR)-estimating equations frequently do not perform well in populations that differ from the development populations in terms of mean GFR, age, pathology, ethnicity, and diet. After first evaluating the performance of existing equations, the aim of this study was to demonstrate the utility of an in-house modification of the equations to better fit a specific population. METHODS Estimated GFR using 8 creatinine-based equations was first compared to 2-sample 51Cr-ethylenediaminetetra-acetic acid plasma clearance in non-cancer and cancer groups independently. The groups were then divided into development and validation sets. Using the development set data, the Microsoft® Excel SOLVER add-in was used to modify the parameters of 7 equations to better fit the data. Using the validation set data, the performance of the original and modified equations was compared. RESULTS Two hundred fifty-six GFR measurements were performed in 160 children. GFR was overestimated in both groups (non-cancer 4.3-22.6 ml/min/1.73 m2, cancer 17.2-46.6 ml/min/1.73 m2). The root mean square error (RMSE) was 19.1-21.8 ml/min/1.73 m2 (non-cancer) and 18.6-20.8 ml/min/1.73 m2 (cancer). The P30 values were 49.1-73.0% (non-cancer) and 19.6-66.0% (cancer). Modifying the parameters of seven equations resulted in significant improvements in the P30 values in the non-cancer (65.0-85.0%) and cancer (79.6-87.8%) groups. CONCLUSIONS Modifying the parameters of pediatric GFR estimating-equations using a simple Excel-based tool significantly improved their accuracy in both non-cancer and cancer populations. Graphical abstract.
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Affiliation(s)
- Jennifer L Holness
- Nuclear Medicine Division, Department of Medical Imaging and Clinical Oncology, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa.
- Division of Nuclear Medicine, Department of Paediatrics and Child Health, University of Cape Town and Red Cross Children's Hospital, Cape Town, South Africa.
| | - Anita Brink
- Division of Nuclear Medicine, Department of Paediatrics and Child Health, University of Cape Town and Red Cross Children's Hospital, Cape Town, South Africa
| | - M Razeen Davids
- Division of Nephrology, Department of Medicine, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa
| | - James M Warwick
- Nuclear Medicine Division, Department of Medical Imaging and Clinical Oncology, Stellenbosch University and Tygerberg Hospital, Cape Town, South Africa
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5
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Characterizing dynamics of serum creatinine and creatinine clearance in extremely low birth weight neonates during the first 6 weeks of life. Pediatr Nephrol 2021; 36:649-659. [PMID: 32944826 PMCID: PMC7851041 DOI: 10.1007/s00467-020-04749-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 07/23/2020] [Accepted: 08/27/2020] [Indexed: 11/01/2022]
Abstract
BACKGROUND Characterizing the dynamics of serum creatinine concentrations (Scr) and associated creatinine clearance (CLcr) as a measure of kidney function in extremely low birth weight (≤ 1000 g; ELBW) neonates remains challenging. METHODS We performed a retrospective study that included longitudinal Scr (enzymatic assay) data from 148 ELBW neonates up to 6 weeks after birth. Change of Scr and inter-individual variability was characterized with nonlinear mixed-effect modeling. Key covariates such as gestational age (GA), mode of delivery (MOD), and treatment with ibuprofen or inotropic agents were investigated. RESULTS A total of 2814 Scr concentrations were analyzed. GA was associated with Scr at birth (higher with advancing GA), and GA and MOD showed an association with postnatal maturation of CLcr (faster clearance increase with advancing GA and after C-section). Small CLcr decrease (≤ 5%) was quantified during ibuprofen treatment. For a GA of 27 weeks, mean Scr (estimated CLcr) at birth was 0.61 mg/dl (0.23 ml/min), increasing to 0.87 mg/dl (0.27 ml/min) at day three, and decreasing to 0.36 mg/dl (0.67 ml/min) at day 42 after birth. CONCLUSIONS We report the first mathematical model able to characterize Scr and CLcr in ELBW neonates during the first 6 weeks of life in a quantitative manner as a function of GA, MOD, and ibuprofen treatment. This model allows the derivation of GA-adjusted reference ranges for ELBW neonates and provides a rationale for normative Scr concentrations, and as such will help clinicians to further optimize monitoring and treatment decisions in this vulnerable patient population.
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6
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Šebeková K, Gurecká R, Tóthová Ĺ, Podracká Ĺ. Creatinine-Based Formulae Poorly Match in the Classification of Hypofiltration or Hyperfiltration in a General Population of Adolescents: A Retrospective Analysis of a Cross-Sectional Study. Front Pediatr 2021; 9:719997. [PMID: 34778125 PMCID: PMC8581240 DOI: 10.3389/fped.2021.719997] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 09/24/2021] [Indexed: 11/17/2022] Open
Abstract
Pediatric formulae to estimate glomerular filtration rate (eGFR) give a broad range of values. Their consistency in assigning the subjects as hypofiltrating or hyperfiltrating is unknown. In 1993 apparently healthy adolescents (53.4% females) aged 14-17 years, we investigated the concordance of six creatinine-based formulae in the classification of the subjects into ≤ 5th or ≥95th percentile of eGFR, and the between-groups difference in the prevalence of cardiometabolic risk factors. Mean eGFR varied between 77 and 121 mL/min/1.73 m2. Arbitrary setting of hypofiltration or hyperfiltration to 5% returned 46 males and 53 females. At least one formula classified 89 males and 99 females as hypofiltrating and 105 males and 114 females as hyperfiltrating. All six formulae concordantly classified 15 males and 17 females as hypofiltrating and 9 and 14, respectively, as hyperfiltrating. Pairwise, formulae consistently classified hypofiltration in 42-87% of subjects with hyperfiltration in 28-94%. According to two out of the six formulae, hyperfiltration was associated with an increased prevalence of obesity and obesity-associated comorbidities. Hypofiltrating subjects did not manifest chronic kidney disease-associated comorbidities. Further studies in different populations of healthy adolescents are needed before it is possible to conclude which creatinine-based formula is appropriate for the classification of hypofiltration and hyperfiltration in nonclinical cohorts.
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Affiliation(s)
- Katarína Šebeková
- Faculty of Medicine, Institute of Molecular BioMedicine, Comenius University, Bratislava, Slovakia
| | - Radana Gurecká
- Faculty of Medicine, Institute of Molecular BioMedicine, Comenius University, Bratislava, Slovakia.,Faculty of Medicine, Institute of Medical Physics, Biophysics, Informatics and Telemedicine, Comenius University, Bratislava, Slovakia
| | - Ĺubomíra Tóthová
- Faculty of Medicine, Institute of Molecular BioMedicine, Comenius University, Bratislava, Slovakia
| | - Ĺudmila Podracká
- Department of Pediatrics, Faculty of Medicine, Comenius University, Bratislava, Slovakia.,Department of Pediatrics, The National Institute of Children's Health, Bratislava, Slovakia
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7
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Zhang Y, Mehta N, Muhari-Stark E, Burckart GJ, van den Anker J, Wang J. Pediatric Renal Ontogeny and Applications in Drug Development. J Clin Pharmacol 2020; 59 Suppl 1:S9-S20. [PMID: 31502684 DOI: 10.1002/jcph.1490] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 06/25/2019] [Indexed: 12/17/2022]
Abstract
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.
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Affiliation(s)
- Yifei Zhang
- Office of Drug Evaluation IV, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - Neha Mehta
- Office of Drug Evaluation IV, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | | | - Gilbert J Burckart
- Office of Clinical Pharmacology, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
| | - John van den Anker
- Division of Clinical Pharmacology, Children's National Health System, Washington, DC, USA.,Pediatric Pharmacology and Pharmacometrics Research Center, University of Basel Children's Hospital, Basel, Switzerland
| | - Jian Wang
- Office of Drug Evaluation IV, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, USA
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8
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Zhang Y, Sherwin CM, Gonzalez D, Zhang Q, Khurana M, Fisher J, Burckart GJ, Wang Y, Yao LP, Ganley CJ, Wang J. Creatinine-Based Renal Function Assessment in Pediatric Drug Development: An Analysis Using Clinical Data for Renally Eliminated Drugs. Clin Pharmacol Ther 2020; 109:263-269. [PMID: 32696977 DOI: 10.1002/cpt.1991] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/30/2020] [Indexed: 11/09/2022]
Abstract
The estimated glomerular filtration rate (eGFR) equations based on serum creatinine (SCR) have been used for pediatric dose adjustment in drug labeling. This study evaluated the performance of those equations in estimating individual clearance of drugs that are predominantly eliminated by glomerular filtration, using clinical data from the renally eliminated drugs gadobutrol, gadoterate, amikacin, and vancomycin. The eGFR was compared with the observed drug clearance (CL) in 352 pediatric patients from birth to 12 years of age. Multiple eGFR equations overestimated the drug CL on average, including the original and bedside Schwartz equations, which showed an average eGFR/CL ratio between 1 and 3. Further analysis with bedside Schwartz equation showed a higher eGFR/CL ratio in the subjects with a lower SCR or CL. Supraphysiological eGFR as high as 380 mL/min/1.73 m2 was obtained using the bedside Schwartz equation for some of the subjects, most of whom are children < 2 years of age with SCR < 0.2 mg/dL. Excluding the subjects with supraphysiological eGFR from the analysis did not change the overall trend of overestimation. In conclusion, Schwartz equations led to an overestimation of drug clearance for the drugs evaluated. When greater precision is required in predicting eGFR for pediatric patients, such as in drug dosing, revised k constants for the Schwartz equation or new methods of glomerular filtration rate estimation may be necessary.
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Affiliation(s)
- Yifei Zhang
- Office of Drug Evaluation IV, Office of New Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Catherine M Sherwin
- Department of Pediatrics, Wright State University School of Medicine, Dayton Children's Hospital, Dayton, Ohio, USA
| | - Daniel Gonzalez
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Qunshu Zhang
- Office of Drug Evaluation IV, Office of New Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Mona Khurana
- Division of Pediatric and Maternal Health, Office of Drug Evaluation IV, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Jeffrey Fisher
- Division of Biochemical Toxicology, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, Arkansas, USA
| | - Gilbert J Burckart
- Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Yaning Wang
- Office of Clinical Pharmacology, Office of Translational Sciences, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Lynne P Yao
- Division of Pediatric and Maternal Health, Office of Drug Evaluation IV, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Charles J Ganley
- Office of Drug Evaluation IV, Office of New Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Jian Wang
- Office of Drug Evaluation IV, Office of New Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
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Basalely A, Liu D, Kaskel FJ. Big equation for small kidneys: a newly proposed model to estimate neonatal GFR. Pediatr Nephrol 2020; 35:543-546. [PMID: 32006185 PMCID: PMC7117838 DOI: 10.1007/s00467-019-04465-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 12/13/2019] [Accepted: 12/18/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Abby Basalely
- Department of Pediatrics, Division of Pediatric Nephrology, The Children’s Hospital at Montefiore Bronx, NY
| | - Diane Liu
- Department of Pediatrics, Division of Pediatric Nephrology, The Children’s Hospital at Montefiore Bronx, NY
| | - Frederick J Kaskel
- Department of Pediatrics, Division of Pediatric Nephrology, The Children's Hospital at Montefiore Bronx, 3326 Bainbridge Avenue, Bronx, NY, 10467, USA.
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10
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Dart AB, McGavock J, Sharma A, Chateau D, Schwartz GJ, Blydt-Hansen T. Estimating glomerular filtration rate in youth with obesity and type 2 diabetes: the iCARE study equation. Pediatr Nephrol 2019; 34:1565-1574. [PMID: 31049718 DOI: 10.1007/s00467-019-04250-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 02/14/2019] [Accepted: 03/26/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND The validity of pediatric estimated glomerular filtration rate equations (eGFRs) in early stages of CKD including hyperfiltration is unknown. The purpose of this study was to develop an eGFR equation for adolescents with obesity and type 2 diabetes (T2D). METHODS eGFRs were developed from iohexol-derived GFRs (iGFRs) in 26 overweight/obese (BMI > 85th percentile) youth and 100 with T2D from the iCARE (Improving renal Complications in Adolescents with T2D through REsearch) cohort. Twenty percent of the cohort was withheld as a validation dataset. Linear regression analyses were used to develop the best formula based on body size, sex, creatinine, urea, ± cystatin C. Comparable validity of commonly used eGFR equations was assessed. RESULTS Mean age 15.4 + 2.4 years, BMI Z-score 2.5 + 1.2, 61% female, and mean iGFR 129.0 + 27.7 ml/min/ 1.73 m2. The best adjusted eGFR formula (ml/min/1.73 m2) was 50.7 × BSA0.816 × (height (cm)/creatinine)0.405 × 0.8994 if sex = female | 1 otherwise. It resulted in 53.8% of eGFRs within 10% of measured iGFR and 96.2% within 30%. Bland-Altman 95% limits of agreement in the external dataset were - 37.6 to 45.5 ml/min/1.73m2 (bias = 3.96), and the correlation was 0.62. This equation performed better than all previously published creatinine-based eGFRs. cystatin C did not significantly improve results; however, some other cystatin C formulas also performed well. CONCLUSIONS The iCARE equation provides a more accurate creatinine-based eGFR in obese youth with and without T2D. Further studies are warranted to evaluate within-subject variability and applicability to lower GFRs and other populations.
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Affiliation(s)
- A B Dart
- Department of Pediatrics and Child Health, Section of Nephrology, Children's Hospital Research Institute of Manitoba, Diabetes Research Envisioned and Accomplished in Manitoba Research Team, University of Manitoba, FE009 - 840 Sherbrook Street, Winnipeg, MB, R3A 1S1, Canada.
| | - J McGavock
- Department of Pediatrics and Child Health, University of Manitoba, FE009 - 840 Sherbrook Street, Winnipeg, MB, R3A 1S1, Canada
| | - A Sharma
- Department of Pediatrics and Child Health, University of Manitoba, FE009 - 840 Sherbrook Street, Winnipeg, MB, R3A 1S1, Canada
| | - D Chateau
- Department of Community Health Sciences, University of Manitoba, Winnipeg, Canada
| | - G J Schwartz
- University of Rochester Medical Center, Rochester, NY, USA
| | - T Blydt-Hansen
- Department of Pediatrics, University of British Columbia, Vancouver, Canada
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Wilson TG, d'Udekem Y, Winlaw DS, Cordina RL, Ayer J, Gentles TL, Weintraub RG, Grigg LE, Cheung M, Cain TM, Rao P, Verrall C, Plessis KD, Rice K, Iyengar AJ. Creatinine-based estimation of glomerular filtration rate in patients with a Fontan circulation. CONGENIT HEART DIS 2019; 14:454-463. [PMID: 30664330 DOI: 10.1111/chd.12746] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 11/17/2018] [Accepted: 01/03/2019] [Indexed: 11/30/2022]
Abstract
BACKGROUND Patients with a Fontan circulation are at risk of renal dysfunction. We analyzed cross-sectional data in pediatric and adult Fontan patients in order to assess the accuracy of commonly used serum creatinine-based methods in estimating glomerular filtration rate (GFR). METHODS A total of 124 Fontan patients (58 children, 66 adults) were enrolled across three study centers. Measurement of GFR (mGFR) using in vivo 99m Tc-DTPA clearance was performed. Various serum creatinine-based equations were used to calculate estimated GFR (eGFR). RESULTS Mean mGFR was 108 ± 28 mL/min/1.73 m2 in children and 92 ± 20 mL/min/1.73 m2 in adults. Fourteen children (25%) and 28 adults (45%) had an mGFR <90 mL/min/1.73 m2 . There was no significant correlation between mGFR and eGFR (Schwartz) in children (r = 0.22, P = .1), which substantially overestimated mGFR (bias 50.8, 95%CI: 41.1-60.5 mL/min/1.73 m2 , P < .0001). The Bedside Schwartz equation also performed poorly in the children (r = 0.08, P = .5; bias 5.9, 95%CI: -2.9-14.6 mL/min/1.73 m2 , P < .0001). There was a strong correlation between mGFR and both eGFR (CKD-EPI) and eGFR (MDRD) in adults (r = 0.67, P < .0001 in both cases), however, both methods overestimated mGFR (eGFR(CKD-EPI):bias 23.8, 95%CI: 20-27.6 mL/min/1.73 m2 , P < .0001; eGFR (MDRD):bias 16.1, 95%CI: 11.8-20.4 mL/min/1.73 m2 , P < .0001). None of the children with an mGFR <90 mL/min/1.73 m2 had an eGFR (Schwartz) <90 mL/min/1.73 m2 . Sensitivity and specificity of eGFR (CKD-EPI) and eGFR (MDRD) for mGFR <90 mL/min/1.73 m2 in adults were 25% and 92% and 39% and 100%, respectively. CONCLUSIONS This study identifies the unreliability of using creatinine-based equations to estimate GFR in children with a Fontan circulation. The accuracy of formulas incorporating cystatin C should be further investigated and may aid noninvasive surveillance of renal function in this population.
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Affiliation(s)
- Thomas G Wilson
- Heart Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Department of Paediatrics, Faculty of Medicine, The University of Melbourne, Melbourne, Victoria, Australia
| | - Yves d'Udekem
- Heart Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Department of Paediatrics, Faculty of Medicine, The University of Melbourne, Melbourne, Victoria, Australia.,Department of Cardiac Surgery, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - David S Winlaw
- The Heart Centre for Children, The Children's Hospital at Westmead, Sydney, New South Wales, Australia.,Department of Paediatrics, University of Sydney, Sydney, New South Wales, Australia
| | - Rachael L Cordina
- Department of Paediatrics, University of Sydney, Sydney, New South Wales, Australia.,Department of Cardiology, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - Julian Ayer
- The Heart Centre for Children, The Children's Hospital at Westmead, Sydney, New South Wales, Australia.,Department of Paediatrics, University of Sydney, Sydney, New South Wales, Australia
| | - Thomas L Gentles
- Greenlane Paediatric and Congenital Cardiac Service, Starship Children's Hospital, Auckland, New Zealand
| | - Robert G Weintraub
- Heart Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Department of Paediatrics, Faculty of Medicine, The University of Melbourne, Melbourne, Victoria, Australia.,Department of Cardiology, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Leeanne E Grigg
- Department of Cardiology, The Royal Melbourne Hospital, Melbourne, Victoria, Australia
| | - Michael Cheung
- Heart Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Department of Cardiology, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Timothy M Cain
- Medical Imaging Department, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Padma Rao
- Medical Imaging Department, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Charlotte Verrall
- The Heart Centre for Children, The Children's Hospital at Westmead, Sydney, New South Wales, Australia
| | - Karin Du Plessis
- Heart Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - Kathryn Rice
- Greenlane Paediatric and Congenital Cardiac Service, Starship Children's Hospital, Auckland, New Zealand
| | - Ajay J Iyengar
- Heart Research Group, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.,Department of Cardiac Surgery, The Royal Children's Hospital, Melbourne, Victoria, Australia
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12
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Muhari-Stark E, Burckart GJ. Glomerular Filtration Rate Estimation Formulas for Pediatric and Neonatal Use. J Pediatr Pharmacol Ther 2018; 23:424-431. [PMID: 30697127 DOI: 10.5863/1551-6776-23.6.424] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Renal function assessment is of the utmost importance in predicting drug clearance and in ensuring safe and effective drug therapy in neonates. The challenges to making this prediction relate not only to the extreme vulnerability and rapid maturation of this pediatric subgroup but also to the choice of renal biomarker, covariates, and glomerular filtration rate (GFR) estimating formula. In order to avoid burdensome administration of exogenous markers and/or urine collection in vulnerable pediatric patients, estimation of GFR utilizing endogenous markers has become a useful tool in clinical practice. Several estimation methods have been developed over recent decades, exploiting various endogenous biomarkers (serum creatinine, cystatin C, blood urea nitrogen) and anthropometric measures (body length/height, weight, muscle mass). This article reviews pediatric GFR estimation methods with a focus on their suitability for use in the neonatal population.
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Llanos-Paez CC, Staatz C, Lawson R, Hennig S. Comparison of methods to estimate glomerular filtration rate in paediatric oncology patients. J Paediatr Child Health 2018; 54:141-147. [PMID: 29083076 DOI: 10.1111/jpc.13752] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 07/02/2017] [Accepted: 07/17/2017] [Indexed: 11/29/2022]
Abstract
AIMS Glomerular filtration rate (GFR) is estimated daily in paediatric oncology patients; however, few equations, particularly ones that do not include serum creatinine, have been evaluated in this population. We aimed to compare the predictive performance of different equations available to estimate GFR in paediatric oncology patients. METHODS GFR was measured (mGFR) in paediatric oncology patients based on a chromium 51-labeled ethylene diamine tetraacetic acid excretion test. GFR was estimated (eGFR) in these same patients using equations identified from the literature. mGFR and eGFR values were compared, and the predictive performance of various eGFR equations was assessed in terms of their bias, precision and accuracy. RESULTS In total, 124 mGFR values ranging from 7 to 146 mL/min were available for analysis from 73 children. Twenty-two equations were identified from the literature. The Flanders metadata equation displayed the lowest absolute bias (mean error of 0.9 mL/min) and the greatest precision (root mean square error of 13.1 mL/min). The univariate Schwartz equation predicted the highest percentage (81.5%) of eGFR values within 30% of mGFR values, and the Rhodin fat-free mass equation predicted the highest percentage (37.1%) of eGFR values within 10% of mGFR values. CONCLUSIONS A number of equations were identified that could be used to estimate renal function in paediatric oncology patients; however, none was found to be highly accurate. The Flanders metadata equation and univariate Schwartz performed the best in this study, and we would suggest that these two equations may be used cautiously in paediatric oncology patients for clinical decision making, understanding their limitations.
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Affiliation(s)
| | - Christine Staatz
- School of Pharmacy, University of Queensland, Brisbane, Queensland, Australia
| | - Rachael Lawson
- Pharmacy Department, Lady Cilento Children's Hospital, Brisbane, Queensland, Australia
| | - Stefanie Hennig
- School of Pharmacy, University of Queensland, Brisbane, Queensland, Australia
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14
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den Bakker E, Gemke RJBJ, Bökenkamp A. Endogenous markers for kidney function in children: a review. Crit Rev Clin Lab Sci 2018; 55:163-183. [DOI: 10.1080/10408363.2018.1427041] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Emil den Bakker
- Department of Pediatric Nephrology, VU Medical Centre, Amsterdam, The Netherlands
| | | | - Arend Bökenkamp
- Department of Pediatric Nephrology, VU Medical Centre, Amsterdam, The Netherlands
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15
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Hundeshagen G, Herndon DN, Capek KD, Branski LK, Voigt CD, Killion EA, Cambiaso-Daniel J, Sljivich M, De Crescenzo A, Mlcak RP, Kinsky MP, Finnerty CC, Norbury WB. Co-administration of vancomycin and piperacillin-tazobactam is associated with increased renal dysfunction in adult and pediatric burn patients. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2017; 21:318. [PMID: 29262848 PMCID: PMC5738705 DOI: 10.1186/s13054-017-1899-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 11/28/2017] [Indexed: 02/07/2023]
Abstract
Background Burn patients are prone to infections which often necessitate broad antibiotic coverage. Vancomycin is a common antibiotic after burn injury and is administered alone (V), or in combination with imipenem-cilastin (V/IC) or piperacillin-tazobactam (V/PT). Sparse reports indicate that the combination V/PT is associated with increased renal dysfunction. The purpose of this study was to evaluate the short-term impact of the three antibiotic administration types on renal dysfunction. Methods All pediatric and adult patients admitted to our centers between 2004 and 2016 with a burn injury were included in this retrospective review if they met the criteria of exposition to either V, V/IC, or V/PT for at least 48 h, had normal baseline creatinine, and no pre-existing renal dysfunction. Creatinine was monitored for 7 days after initial exposure; the absolute and relative increase was calculated, and patient renal outcomes were classified according to the Kidney Disease Improving Global Outcomes (KDIGO) criteria depending on creatinine increases and estimated creatinine clearance. Secondary endpoints (demographic and clinical data, incidences of septicemia, and renal replacement therapy) were analyzed. Antibiotic doses were modeled in logistic and linear multivariable regression models to predict categorical KDIGO events and relative creatinine increase. Results Out of 1449 patients who were screened, 718 met the inclusion criteria, 246 were adults, and 472 were children. Between the study cohorts V, V/IC, and V/PT, patient characteristics at admission were comparable. V/PT administration was associated with a statistically higher serum creatinine, and lower creatinine clearance compared to patients receiving V alone or V/IC in adults and children after burn injury. The incidence of KDIGO stages 1, 2, and 3 was higher after V/PT treatment. In children, the incidence of KDIGO stage 3 following administration of V/PT was greater than after V/IC. In adults, the incidence of renal replacement therapy was higher after V/PT compared with V or V/IC. Multivariate modeling demonstrated that V/PT is an independent predictor of renal dysfunction. Conclusion Co-administration of vancomycin and piperacillin-tazobactam is associated with increased renal dysfunction in pediatric and adult burn patients when compared to vancomycin alone or vancomycin plus imipenem-cilastin. The mechanism of this increased nephrotoxicity remains elusive and warrants further scientific evaluation. Electronic supplementary material The online version of this article (doi:10.1186/s13054-017-1899-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gabriel Hundeshagen
- Department of Surgery, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555, USA. .,Shriners Hospitals for Children, 815 Market St., Galveston, TX, 77550, USA. .,Department of Hand, Plastic and Reconstructive Surgery, Burn Trauma Center, BG Trauma Center Ludwigshafen, University of Heidelberg, Ludwig-Guttmann-Str. 13, 67071, Ludwigshafen, Germany.
| | - David N Herndon
- Department of Surgery, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555, USA.,Shriners Hospitals for Children, 815 Market St., Galveston, TX, 77550, USA
| | - Karel D Capek
- Department of Surgery, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555, USA.,Shriners Hospitals for Children, 815 Market St., Galveston, TX, 77550, USA
| | - Ludwik K Branski
- Department of Surgery, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555, USA.,Shriners Hospitals for Children, 815 Market St., Galveston, TX, 77550, USA.,Department of Plastic Surgery, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Charles D Voigt
- Department of Surgery, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555, USA.,Shriners Hospitals for Children, 815 Market St., Galveston, TX, 77550, USA
| | - Elizabeth A Killion
- Department of Plastic Surgery, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX, 77030, USA
| | - Janos Cambiaso-Daniel
- Division of Plastic, Aesthetic and Reconstructive Surgery, Department of Surgery, Medical University of Graz, Graz, Austria
| | - Michaela Sljivich
- Department of Surgery, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555, USA.,Shriners Hospitals for Children, 815 Market St., Galveston, TX, 77550, USA
| | - Andrew De Crescenzo
- Department of Surgery, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555, USA.,Shriners Hospitals for Children, 815 Market St., Galveston, TX, 77550, USA
| | - Ronald P Mlcak
- Department of Surgery, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555, USA.,Shriners Hospitals for Children, 815 Market St., Galveston, TX, 77550, USA
| | - Michael P Kinsky
- Department of Anesthesiology, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555, USA
| | - Celeste C Finnerty
- Department of Surgery, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555, USA.,Shriners Hospitals for Children, 815 Market St., Galveston, TX, 77550, USA
| | - William B Norbury
- Department of Surgery, University of Texas Medical Branch, 301 University Blvd., Galveston, TX, 77555, USA.,Shriners Hospitals for Children, 815 Market St., Galveston, TX, 77550, USA
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Consenso del Grupo Centroamericano y del Caribe para el Estudio y Tratamiento de la Enfermedad de Fabry. NEFROLOGÍA LATINOAMERICANA 2017. [DOI: 10.1016/j.nefrol.2016.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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17
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A Population Pharmacokinetic Model for 51Cr EDTA to Estimate Renal Function. Clin Pharmacokinet 2016; 56:671-678. [DOI: 10.1007/s40262-016-0489-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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18
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Evaluation of Vancomycin Use in Late-Onset Neonatal Sepsis Using the Area Under the Concentration-Time Curve to the Minimum Inhibitory Concentration ≥400 Target. Ther Drug Monit 2016; 37:756-65. [PMID: 26562817 DOI: 10.1097/ftd.0000000000000216] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
AIM To develop a vancomycin population pharmacokinetic model and assess the probability of attaining a pharmacodynamic target associated with clinical and microbiological success, a ratio of the 24-hour area under the concentration-time curve to the minimum inhibitory concentration (MIC) ≥ 400, in a 5-year clinical cohort of preterm and term neonatal patients with late-onset staphylococcal sepsis. METHODS Therapeutic drug monitoring data were obtained from septic neonates with ≥1 vancomycin concentration(s) from January 2006 to September 2011. Only neonates with a postnatal age of >72 hours and a positive microbiological culture were included. Population pharmacokinetic model was developed using nonlinear mixed effects modeling (NONMEM 7.2). Eleven demographic characteristics were evaluated as covariates. Probabilities of achieving the pharmacodynamic target were evaluated. RESULTS A 1-compartment model with first-order elimination was constructed from 528 vancomycin concentrations collected from 152 preterm and term neonates. Body weight, creatinine clearance (CL), and postmenstrual age were identified as significant covariates. Estimated vancomycin CL and volume of distribution for typical neonates were 0.068 ± 0.03 L·h·kg and 0.62 ± 0.13 L/kg, respectively. Coagulase-negative staphylococci (85.5%) and Staphylococcus aureus (14.5%) were the common pathogenic organisms. The distribution of vancomycin MIC breakpoints was composed of approximately 70% MIC breakpoint of ≤2 mcg/mL. Approximately 54% of neonates, with a median serum creatinine concentration of 0.44 mg/dL, achieved the target ratio of 24-hour area under the concentration-time curve to the MIC ≥ 400 with a median daily dose of 30 (interquartile range, 21-42) mg/kg. CONCLUSIONS Body weight, creatinine CL, and postmenstrual age significantly influenced vancomycin CL. The current vancomycin doses are acceptable at MICs ≤1 mcg/mL because they are likely to achieve the pharmacodynamic target in the majority of neonatal patients, although higher doses may be considered for more resistant staphylococcal infections.
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19
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Vroling AB, Dorresteijn EM, Cransberg K, de Rijke YB. The impact of estimated glomerular filtration rate equations on chronic kidney disease staging in pediatric renal or heart transplant recipients. Pediatr Nephrol 2016; 31:1145-55. [PMID: 26862053 PMCID: PMC4880629 DOI: 10.1007/s00467-016-3312-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 11/27/2015] [Accepted: 01/04/2016] [Indexed: 11/28/2022]
Abstract
BACKGROUND The aim of this study was to evaluate the performance of selected pediatric estimated glomerular filtration rate (eGFR) equations in relation to the clinical management of children after renal or heart transplantation or post-chemotherapy treatment. METHODS This study was a retrospective cross-sectional analysis of 61 children whose glomerular function (GFR) had been determined using a single-dose inulin clearance (iGFR) method. Eight equations for estimating the GFR were evaluated for bias, agreement, accuracy, and clinical stratification. RESULTS The outcome of all eight eGFR equations differed from the value determined using the iGFR method, with the mean bias ranging from -3.4 to 20.7 ml/min/1.73 m(2) and 90 % accuracy ranging from 16 to 26 %. All eGFR equations overestimated renal function in patients with decreased kidney function as determined by the iGFR method and underestimated renal function in patients with normal kidney function. Consequently, based on the eGFR values, patients with low GFR values according to the iGFR method were staged in a less severe chronic kidney disease (CKD) category, and patients with normal GFR values according to the iGFR method were staged in a more severe CKD category. The percentage of correctly classified patients ranged from 32.6 to 41.6 %. CONCLUSIONS In our cohort we found the CKiDIII equation to be the best alternative to calculating the GFR using the inulin clearance method, closely followed by the Hoste and the revised Grubb equations. The performances of all eight eGFR equations assessed were moderate at best and only slightly better than the easy-to-do bedside Schwartz equation.
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Affiliation(s)
- Aram Ben Vroling
- />Department of Clinical Chemistry, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Eiske Margaretha Dorresteijn
- Department of Pediatric Nephrology, Erasmus University Medical Center-Sophia Children's Hospital, Wytemaweg 80, 3015 CN, Rotterdam, The Netherlands.
| | - Karlien Cransberg
- />Department of Pediatric Nephrology, Erasmus University Medical Center–Sophia Children’s Hospital, Wytemaweg 80, 3015 CN Rotterdam, The Netherlands
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20
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Bhongsatiern J, Stockmann C, Yu T, Constance JE, Moorthy G, Spigarelli MG, Desai PB, Sherwin CMT. Renal Function Descriptors in Neonates: Which Creatinine-Based Formula Best Describes Vancomycin Clearance? J Clin Pharmacol 2015; 56:528-40. [PMID: 26412385 DOI: 10.1002/jcph.650] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 09/23/2015] [Indexed: 11/06/2022]
Abstract
Growth and maturational changes have been identified as significant covariates in describing variability in clearance of renally excreted drugs such as vancomycin. Because of immaturity of clearance mechanisms, quantification of renal function in neonates is of importance. Several serum creatinine (SCr)-based renal function descriptors have been developed in adults and children, but none are selectively derived for neonates. This review summarizes development of the neonatal kidney and discusses assessment of the renal function regarding estimation of glomerular filtration rate using renal function descriptors. Furthermore, identification of the renal function descriptors that best describe the variability of vancomycin clearance was performed in a sample study of a septic neonatal cohort. Population pharmacokinetic models were developed applying a combination of age-weight, renal function descriptors, or SCr alone. In addition to age and weight, SCr or renal function descriptors significantly reduced variability of vancomycin clearance. The population pharmacokinetic models with Léger and modified Schwartz formulas were selected as the optimal final models, although the other renal function descriptors and SCr provided reasonably good fit to the data, suggesting further evaluation of the final models using external data sets and cross validation. The present study supports incorporation of renal function descriptors in the estimation of vancomycin clearance in neonates.
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Affiliation(s)
- Jiraganya Bhongsatiern
- Department of Pharmaceutical Sciences, The James L. Winkle College of Pharmacy, University of Cincinnati, Cincinnati, OH, USA
| | - Chris Stockmann
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA.,Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT, USA
| | - Tian Yu
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Jonathan E Constance
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Ganesh Moorthy
- Department of Pharmaceutical Sciences, The James L. Winkle College of Pharmacy, University of Cincinnati, Cincinnati, OH, USA
| | - Michael G Spigarelli
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA.,Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT, USA
| | - Pankaj B Desai
- Department of Pharmaceutical Sciences, The James L. Winkle College of Pharmacy, University of Cincinnati, Cincinnati, OH, USA
| | - Catherine M T Sherwin
- Division of Clinical Pharmacology, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA.,Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, UT, USA.,Clinical Trials Office, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA
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21
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Rodieux F, Wilbaux M, van den Anker JN, Pfister M. Effect of Kidney Function on Drug Kinetics and Dosing in Neonates, Infants, and Children. Clin Pharmacokinet 2015; 54:1183-204. [PMID: 26138291 PMCID: PMC4661214 DOI: 10.1007/s40262-015-0298-7] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neonates, infants, and children differ from adults in many aspects, not just in age, weight, and body composition. Growth, maturation and environmental factors affect drug kinetics, response and dosing in pediatric patients. Almost 80% of drugs have not been studied in children, and dosing of these drugs is derived from adult doses by adjusting for body weight/size. As developmental and maturational changes are complex processes, such simplified methods may result in subtherapeutic effects or adverse events. Kidney function is impaired during the first 2 years of life as a result of normal growth and development. Reduced kidney function during childhood has an impact not only on renal clearance but also on absorption, distribution, metabolism and nonrenal clearance of drugs. 'Omics'-based technologies, such as proteomics and metabolomics, can be leveraged to uncover novel markers for kidney function during normal development, acute kidney injury, and chronic diseases. Pharmacometric modeling and simulation can be applied to simplify the design of pediatric investigations, characterize the effects of kidney function on drug exposure and response, and fine-tune dosing in pediatric patients, especially in those with impaired kidney function. One case study of amikacin dosing in neonates with reduced kidney function is presented. Collaborative efforts between clinicians and scientists in academia, industry, and regulatory agencies are required to evaluate new renal biomarkers, collect and share prospective pharmacokinetic, genetic and clinical data, build integrated pharmacometric models for key drugs, optimize and standardize dosing strategies, develop bedside decision tools, and enhance labels of drugs utilized in neonates, infants, and children.
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Affiliation(s)
- Frederique Rodieux
- Department of Pediatric Clinical Pharmacology, Pediatric Pharmacology and Pharmacometrics Research Center, University Children's Hospital (UKBB), University of Basel, Spitalstrasse 33, CH-4056, Basel, Switzerland.
| | - Melanie Wilbaux
- Department of Pediatric Clinical Pharmacology, Pediatric Pharmacology and Pharmacometrics Research Center, University Children's Hospital (UKBB), University of Basel, Spitalstrasse 33, CH-4056, Basel, Switzerland
| | - Johannes N van den Anker
- Department of Pediatric Clinical Pharmacology, Pediatric Pharmacology and Pharmacometrics Research Center, University Children's Hospital (UKBB), University of Basel, Spitalstrasse 33, CH-4056, Basel, Switzerland.
- Division of Pediatric Clinical Pharmacology, Children's National Health System, Washington, DC, USA.
- Intensive Care, Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, The Netherlands.
| | - Marc Pfister
- Department of Pediatric Clinical Pharmacology, Pediatric Pharmacology and Pharmacometrics Research Center, University Children's Hospital (UKBB), University of Basel, Spitalstrasse 33, CH-4056, Basel, Switzerland
- Quantitative Solutions LP, Menlo Park, CA, USA
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Montañés Bermúdez R, Gràcia Garcia S, Fraga Rodríguez G, Escribano Subias J, Diez de los Ríos Carrasco M, Alonso Melgar A, García Nieto V. Documento de consenso: recomendaciones sobre la utilización de ecuaciones para la estimación del filtrado glomerular en niños. An Pediatr (Barc) 2014; 80:326.e1-326.e13. [DOI: 10.1016/j.anpedi.2013.06.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 06/19/2013] [Indexed: 01/07/2023] Open
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23
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Green DM. Evaluation of renal function after successful treatment for unilateral, non-syndromic Wilms tumor. Pediatr Blood Cancer 2013; 60:1929-35. [PMID: 24039069 DOI: 10.1002/pbc.24738] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 07/25/2013] [Indexed: 01/26/2023]
Abstract
Impaired renal function may occur in experimental animals following surgical removal of most functioning renal tissue ("hyperfiltration injury"). Although end-stage renal disease is uncommon among long-term survivors of unilateral, non-syndromic Wilms tumor, concern has been expressed that there may be an increased risk of less serious, but progressive, renal function impairment among these individuals. The recent development of equations for estimating glomerular filtration rate (eGFR) has facilitated the study of renal function in Wilms tumor survivors. However, the estimating equations were developed to categorize individuals with chronic kidney disease and have significant limitations with regard to the accuracy of individual GFR estimates. These limitations must be considered when utilizing the estimating equations in cross-sectional or longitudinal evaluations of renal function in cohorts of patients who have been treated successfully for Wilms tumor or other childhood cancers.
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Affiliation(s)
- Daniel M Green
- Department of Epidemiology and Cancer Control, St. Jude Children's Research Hospital, Memphis, Tennessee
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24
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Hoste L, Dubourg L, Selistre L, De Souza VC, Ranchin B, Hadj-Aïssa A, Cochat P, Martens F, Pottel H. A new equation to estimate the glomerular filtration rate in children, adolescents and young adults. Nephrol Dial Transplant 2013; 29:1082-91. [PMID: 24046193 DOI: 10.1093/ndt/gft277] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND A new estimated glomerular filtration rate (eGFR) equation, designed for isotope dilution mass spectrometry-standardized serum creatinine (Scr), is presented for use in children, adolescent boys and girls and young adults. METHODS The new equation, eGFR = 107.3/(Scr/Q), is based on the concept of normalized Scr: Q is the normalization value and is considered as the Scr concentration for the average healthy child, adolescent or young adult of a specific height (L) and is modeled as a height-dependent polynomial of the fourth degree. RESULTS The well-known Schwartz equation [eGFR = kL/Scr, k = 0.413 (Schwartz) or k = 0.373 (Schwartz-Lyon)] for children between 1 and 14 years can be seen as a special case of the new equation for which the Q-polynomial is simplified to a linear equation: Q = 0.0035 × L (cm). The new eGFR equation has been validated in a data set of n = 750 children, adolescents and young adults aged 10-25, against the true GFR (inulin method), and outperforms the selected (but most used) creatinine-based eGFR equations for children, mainly in the healthy GFR region. CONCLUSIONS The new Q(height)-eGFR equation serves as an excellent screening tool for kidney disease in 1-25-year-old children, adolescents and young adults.
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Affiliation(s)
- Liesbeth Hoste
- Interdisciplinary Research Facility Life Sciences, KU Leuven Kulak, Kortrijk, Belgium
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Robinson PD, Shroff RC, Spencer H. Renal complications following lung and heart-lung transplantation. Pediatr Nephrol 2013; 28:375-86. [PMID: 22733223 DOI: 10.1007/s00467-012-2200-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Revised: 03/20/2012] [Accepted: 03/26/2012] [Indexed: 11/30/2022]
Abstract
As survival improves after lung and heart-lung transplants, the long term detrimental impact of current management on renal function becomes more apparent as the number of non-renal solid organ transplant recipients on renal transplant waiting lists increases. Progressive chronic kidney disease (CKD) is a significant cause of morbidity and mortality in the transplant population. In this review we discuss the specific problems prior to lung or heart-lung transplant that predispose to CKD, as well as potential renal complications encountered during the peri- and post-transplant period. Significant acute and chronic nephrotoxicity is caused by calcineurin inhibitors (CNI). Mechanisms to decrease CNI exposure exist but have yet to be adopted in routine clinical care. Modifiable risk factors and the current screening and management approach taken at our institution are described. Pediatric nephrologists should be involved from an early stage. Future work will need to focus on identifying more accurate measures of renal function, given the limitations of current glomerular filtration rate estimation equations in a population where nutritional status may rapidly change post transplant. Multicentre studies of CNI minimisation strategies are required to guide future therapy that aims to minimise CKD development and progression in this vulnerable population.
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Affiliation(s)
- Paul D Robinson
- Department of Pediatric Heart and Lung Transplant, Great Ormond Street Hospital, London, England, UK.
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Comparison of the glomerular filtration rate in children by the new revised Schwartz formula and a new generalized formula. Kidney Int 2012; 83:524-30. [PMID: 23254901 DOI: 10.1038/ki.2012.388] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The most widely used formula for estimating glomerular filtration rate (eGFR) in children is the Schwartz formula. It was revised in 2009 using iohexol clearances with measured GFR (mGFR) ranging between 15 and 75 ml/min × 1.73 m(2). Here we assessed the accuracy of the Schwartz formula using the inulin clearance (iGFR) method to evaluate its accuracy for children with less renal impairment comparing 551 iGFRs of 392 children with their Schwartz eGFRs. Serum creatinine was measured using the compensated Jaffe method. In order to find the best relationship between iGFR and eGFR, a linear quadratic regression model was fitted and a more accurate formula was derived. This quadratic formula was: 0.68 × (Height (cm)/serum creatinine (mg/dl))-0.0008 × (height (cm)/serum creatinine (mg/dl))(2)+0.48 × age (years)-(21.53 in males or 25.68 in females). This formula was validated using a split-half cross-validation technique and also externally validated with a new cohort of 127 children. Results show that the Schwartz formula is accurate until a height (Ht)/serum creatinine value of 251, corresponding to an iGFR of 103 ml/min × 1.73 m(2), but significantly unreliable for higher values. For an accuracy of 20 percent, the quadratic formula was significantly better than the Schwartz formula for all patients and for patients with a Ht/serum creatinine of 251 or greater. Thus, the new quadratic formula could replace the revised Schwartz formula, which is accurate for children with moderate renal failure but not for those with less renal impairment or hyperfiltration.
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Nguyen C, Shapiro R. Renal failure and transplantation following nonrenal solid-organ transplantation. Curr Opin Organ Transplant 2012; 17:525-30. [DOI: 10.1097/mot.0b013e3283574388] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Lee CKK, Swinford RD, Cerda RD, Portman RJ, Hwang W, Furth SL. Evaluation of serum creatinine concentration-based glomerular filtration rate equations in pediatric patients with chronic kidney disease. Pharmacotherapy 2012; 32:642-8. [PMID: 22623290 DOI: 10.1002/j.1875-9114.2012.01095.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
STUDY OBJECTIVE To evaluate the accuracy of four equations based on serum creatinine concentration-the original Schwartz equation and the Leger, Bedside Chronic Kidney Disease in Children (CKiD), and Counahan-Barratt equations-for determining glomerular filtration rate (GFR) in pediatric patients with chronic kidney disease. DESIGN Retrospective, observational, cross-sectional study. SETTING Single-center, academic, outpatient pediatric nephrology clinic. PATIENTS Fifty-three pediatric patients with stages 2-5 chronic kidney disease who completed GFR assessment with (125) I-iothalamate between January 2002 and January 2005. MEASUREMENT AND MAIN RESULTS Data were collected from each patient's medical record. Glomerular filtration rate data were analyzed using 59 evaluations from the 53 pediatric patients. (125) I-iothalamate clearance was used as the index GFR. The Bedside CKiD and Counahan-Barratt equations outperformed the Schwartz and Leger equations when the index GFR was less than 60 ml/minute/1.73 m(2) ; the Schwartz and Counahan-Barratt equations performed best for index GFRs of 60 ml/minute/1.73 m(2) or greater. Overestimation was highest with the Schwartz and Leger equations (> 20% index GFR in 57.6% and 62.7% of patients, respectively). Underestimation was highest with the Bedside CKiD and Counahan-Barratt equations (> 20% index GFR in 30.5% and 28.8%, respectively). CONCLUSION The new Bedside CKiD equation performed well for pediatric patients with moderate-to-severe chronic kidney disease, but less well for pediatric patients with mild disease. Additional studies are needed to develop more precise GFR equations using serum creatinine concentration.
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Affiliation(s)
- Carlton K K Lee
- Department of Pediatrics, Johns Hopkins University, Baltimore, MD 21287-6180, USA.
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Hari P, Biswas B, Pandey R, Kalaivani M, Kumar R, Bagga A. Updated height- and creatinine-based equation and its validation for estimation of glomerular filtration rate in children from developing countries. Clin Exp Nephrol 2012; 16:697-705. [PMID: 22526484 DOI: 10.1007/s10157-012-0618-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 02/22/2012] [Indexed: 12/01/2022]
Abstract
BACKGROUND Since the original Schwartz formula overestimates glomerular filtration rate (GFR), it is proposed that the constant (k) that accounts for the method of creatinine estimation be derived locally. We derived a new k for height (cm)/serum creatinine (mg/dl) (ht/scr) equation by regression analysis. METHODS In a cross-sectional observational study, 197 children (2-18 years) with chronic kidney disease (CKD), who underwent reference GFR measurement by plasma clearance of diethylenetriamine pentaacetic acid (dGFR) at a tertiary care hospital, formed the index dataset for deriving the prediction equations for estimating GFR. Serum creatinine was estimated by the kinetic Jaffe method. The prediction equations were validated on a separate cohort of 225 children with CKD. RESULTS The median creatinine was 0.7 mg/dl and dGFR was 80.5 (interquartile range 18.1-137.5) ml/min/1.73 m(2). The new k (regression coefficient of height/creatinine) was 0.42 (R(2) = 0.61) and the updated equation was GFR = 0.42 × (ht/scr). Addition of age and mid-arm circumference (MAC) to this equation improved R (2) to 62.3%. Based on the above parameters, the new equation for estimating GFR was GFR (ml/min/1.73 m(2)) = 0.257 × [ht/scr](0.95) × [age (year)](-0.19) × [MAC (cm)](0.397). The two equations performed comparably, with a mean bias <2 ml/min/1.73 m(2). The updated ht/scr equation yielded 74% and 24% estimated GFR values that were within 30% and 10% of the measured dGFR, respectively. CONCLUSIONS The updated equation, with a k value of 0.42, provides a reasonably accurate bedside estimate of GFR in children in countries where creatinine is estimated by the kinetic Jaffe method.
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Affiliation(s)
- Pankaj Hari
- Department of Pediatrics, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India.
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Fadrowski JJ, Neu AM, Schwartz GJ, Furth SL. Pediatric GFR estimating equations applied to adolescents in the general population. Clin J Am Soc Nephrol 2011; 6:1427-35. [PMID: 21566103 DOI: 10.2215/cjn.06460710] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND AND OBJECTIVES We examined the distribution of estimated GFR (eGFR) in a healthy cohort of adolescents to inform clinical and research use. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Various creatinine-based (n = 3256) and/or cystatin C-based (n = 811) equations, including the recently developed complete and bedside equations from the Chronic Kidney Disease in Children (CKiD) study, were applied to U.S. adolescents 12 to 17 years of age participating in the 1999-2002 National Health and Nutrition Examination Survey (NHANES). RESULTS The median serum creatinine and cystatin C were 0.7 mg/dl and 0.83 mg/L, respectively. The distribution of eGFR varied widely, with the median GFR ranging from a low of 96.6 ml/min per 1.73 m(2) (CKiD) to a high of 140.0 ml/min per 1.73 m(2) (original Schwartz). The proportions of participants with eGFRs <75 ml/min per 1.73 m(2) are as follows: bedside CKiD 8.9%, Counahan 6.3%, Leger 0.4%, original Schwartz 0%, Filler 1.3%, Grubb 3.1%, Bouvet 2.5%, CKiD 1.8%, and Zappitelli 5.6%. By any equation examined, no group of participants with eGFR ≤10th percentile had an increased prevalence of comorbid conditions consistent with a low measured GFR. CONCLUSIONS Most pediatric-specific GFR estimating equations resulted in 25% to 50% of the participants having an eGFR <100 ml/min per 1.73 m(2). However, participants with eGFR in the lower ranges did not have an increased prevalence of morbidities associated with chronic kidney disease. Clinical validation of creatinine- or cystatin C-based estimated GFRs in healthy children is needed before it is possible to screen the general population for chronic kidney disease.
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Affiliation(s)
- Jeffrey J Fadrowski
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
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Cystatin C, cardiometabolic risk, and body composition in severely obese children. Pediatr Nephrol 2011; 26:301-7. [PMID: 21088975 DOI: 10.1007/s00467-010-1679-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Revised: 09/17/2010] [Accepted: 09/23/2010] [Indexed: 10/18/2022]
Abstract
The aim of this study was to assess the relationship between cystatin C (CysC), cardiometabolic risk factors (CMRFs), and body composition in severely obese children. We evaluated 117 children aged 7-14 years old. Seventy-nine of these were severely obese (body mass index z-score ranging from 2.1 to 8.4), and 38 were children with normal nutrition state. CysC was determined by immunonephelometry. CMRFs (glucose, insulin, high-density lipoprotein cholesterol, triglycerides, homocysteine, uric acid, alanine aminotransferase, and high-sensitivity C-reactive protein) were measured by standard biochemical methods. Blood pressure was evaluated at the clinical examination. Renal function was estimated using the glomerular filtration rate (eGFR) based upon creatinine levels, and body weight (Léger formula). Body composition was assessed by segmental bioelectrical impedance. Obese children at the highest tertile of CysC values were characterized by their aggregation of CMRFs. CysC concentration was associated with insulin resistance, alanine aminotransferase, uric acid, and homocysteine after adjusting for age, gender, and eGFR. CysC values were also correlated with the fat-free mass and specifically with skeletal muscle mass. CysC levels were correlated with CMRFs factors independently of renal function, and affected by skeletal muscle mass in severely obese children, although they are less influenced by this than is creatinine.
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Pottel H, Mottaghy FM, Zaman Z, Martens F. On the relationship between glomerular filtration rate and serum creatinine in children. Pediatr Nephrol 2010; 25:927-34. [PMID: 20012996 DOI: 10.1007/s00467-009-1389-1] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 10/15/2009] [Accepted: 10/28/2009] [Indexed: 01/15/2023]
Abstract
The Schwartz formula (eGFR = kL/Scr, with k = 0.55) to determine the estimated glomerular filtration rate (eGFR) in children with chronic kidney disease (CKD), based on length (L) and serum creatinine (Scr) has recently been updated for enzymatic serum creatinine concentrations, resulting in k = 0.413. Based on a meta-analysis, we evaluated the validity of this updated equation and other published equations for healthy children. This is the first time that publicly available data for healthy children of uncorrected and body surface area (BSA)-corrected median GFR have been combined with median serum creatinine values and median lengths and weights from different sources in the literature to evaluate several statistical models to estimate GFR in children. For enzymatic serum creatinine, we show that the simple model for uncorrected GFR (uGFR = k'L(3)/Scr, with k' = 1.32 x 10(-5)) and the BSA-corrected GFR (cGFR = kL/Scr, analogous to the Schwartz formula), with an important age-dependent adaptation for k (k = 0.0414 x 1n (Age) + 0.3018), correlate extremely well with chromium-51-ethylenediamine tetra-acetic acid ((51)Cr-EDTA) data for children between 1 month and 14 years of age. With this age-dependent modification for k, presented here, the simple bedside calculation tool derived by Schwartz can be used for screening all children for CKD. When height information is not available, the Lund-Malmö equation is an excellent alternative.
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Affiliation(s)
- Hans Pottel
- Interdisciplinary Research Center, Catholic University of Leuven, Kortrijk Campus, Etienne Sabbelaan 53, Kortrijk, Belgium.
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van Stralen KJ, Tizard EJ, Jager KJ, Schaefer F, Vondrak K, Groothoff JW, Podracká L, Holmberg C, Jankauskiené A, Lewis MA, van Damme-Lombaerts R, Mota C, Niaudet P, Novljan G, Peco-Antic A, Sahpazova E, Toots U, Verrina E. Determinants of eGFR at start of renal replacement therapy in paediatric patients. Nephrol Dial Transplant 2010; 25:3325-32. [PMID: 20395256 DOI: 10.1093/ndt/gfq215] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Few studies have investigated the determinants of glomerular filtration rate (GFR) in paediatric patients starting on dialysis or with a transplant. METHODS Data were collected as part of the European Society of Paediatric Nephrology/European Renal Association-European Dialysis and Transplant Association registry from 14 European countries and referred to incident paediatric patients starting on renal replacement therapy (RRT) between 2002 and 2007 under the age of 18 years. Estimated glomerular filtration rate (eGFR) was calculated using the Schwartz formula. Data were adjusted for age, gender, treatment modality at start, primary cause of renal failure (PRD) and regions in Europe (eGFR(adj)). RESULTS Median eGFR in the 938 patients starting RRT was 10.4 mL/min/1.73 m(2) (5th and 95th percentile: 4.0-26.9). Twenty-six patients (2.8%), mainly infants with Finnish-type nephropathy, started with eGFR levels >50 mL/min/1.73 m(2). Younger age, female gender, starting on dialysis and having a short time between the first visit to a paediatric nephrologist (PN) and start of RRT were associated with lower eGFR at start of RRT. Gender differences were only present during adolescent age and disappeared when using the same K value for both genders. The various PRDs showed large differences in the rate of decline in eGFR between the first visit to a PN and start of RRT; however, this did not result in differences in eGFR(adj) at start of RRT. CONCLUSIONS The main determinants of eGFR at start of RRT were age, gender, treatment modality at start, and the time between the first visit to a PN and start of RRT. Research is needed to determine the consequences of these differences.
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Affiliation(s)
- Karlijn J van Stralen
- ESPN/ERA-EDTA Registry, Department of Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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Abstract
ABSTRACT
OBJECTIVES
To review pharmacokinetics in obese children and to provide medication dosing recommendations.
METHODS
EMBASE, MEDLINE, and International Pharmaceutical Abstracts databases were searched using the following terms: obesity, morbid obesity, overweight, pharmacokinetics, drug, dose, kidney function test, creatinine, pediatric, and child.
RESULTS
We identified 10 studies in which the authors examined drug dosing or pharmacokinetics for obese children. No information was found for drug absorption or metabolism. Obese children have a higher percent fat mass and a lower percent lean mass compared with normal-weight children. Therefore, in obese children, the volume of distribution of lipophilic drugs is most likely higher, and that of hydrophilic drugs is most likely lower, than in normal-weight children. Serum creatinine concentrations are higher in obese than normal-weight children. Total body weight is an appropriate size descriptor for calculating doses of antineoplastics, cefazolin, and succinylcholine in obese children. Initial tobramycin doses may be determined using an adjusted body weight, although using total body weight in the context of monitoring serum tobramycin concentrations would also be an appropriate strategy. We found no information for any of the opioids; antibiotics such as penicillins, carbapenems, vancomycin, and linezolid; antifungals; cardiac drugs such as digoxin and amiodarone; corticosteroids; benzodiazepines; and anticonvulsants. In particular, we found no information about medications that are widely distributed to adipose tissue or that can accumulate there.
CONCLUSIONS
The available data are limited because of the small numbers of participating children, study design, or both. The number and type of drugs that have been studied limit our understanding of the pharmacokinetics in obese children. In the absence of dosing information for obese children, it is important to consider the nature and severity of a child's illness, comorbidities, organ function, and side effects and physiochemical properties of the drug. Extrapolating from available adult data is possible, as long as practitioners consider the effects of growth and development on the pharmacokinetics relevant to the child's age.
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Affiliation(s)
| | - Roxane R. Carr
- Faculty of Pharmaceutical Sciences, The University of British Columbia
- Department of Pharmacy Department, Children's and Women's Health Centre of British Columbia, Vancouver, British Columbia
| | - Mary H. H. Ensom
- Faculty of Pharmaceutical Sciences, The University of British Columbia
- Department of Pharmacy Department, Children's and Women's Health Centre of British Columbia, Vancouver, British Columbia
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Fadrowski JJ, Navas-Acien A, Tellez-Plaza M, Guallar E, Weaver VM, Furth SL. Blood lead level and kidney function in US adolescents: The Third National Health and Nutrition Examination Survey. ACTA ACUST UNITED AC 2010; 170:75-82. [PMID: 20065202 DOI: 10.1001/archinternmed.2009.417] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
BACKGROUND Chronic, high-level lead exposure is a known risk factor for kidney disease. The effect of current low-level environmental lead exposure is less well known, particularly among children, a population generally free from kidney disease risk factors such as hypertension and diabetes mellitus. Therefore, in this study, we investigated the association between lead exposure and kidney function in a representative sample of US adolescents. METHODS Participants included 769 adolescents aged 12 to 20 years for whom whole blood lead and serum cystatin C were measured in the Third National Health and Nutrition Examination Survey, conducted from 1988-1994. The association between blood lead level and level of kidney function (glomerular filtration rate [GFR]), determined by cystatin C-based and creatinine-based estimating equations, was examined. RESULTS Median whole blood lead level was 1.5 microg/dL (to convert to micromoles per liter, multiply by 0.0483), and median cystatin C-estimated GFR was 112.9 mL/min/1.73 m(2). Participants with lead levels in the highest quartile (> or =3.0 microg/dL) had 6.6 mL/min/1.73 m(2)-lower estimated GFR (95% confidence interval, -0.7 to -12.6 mL/min/1.73 m(2)) compared with those in the first quartile (<1 microg/dL). A doubling of blood lead level was associated with a 2.9 mL/min/1.73 m(2)-lower estimated GFR (95% confidence interval, -0.7 to -5.0 mL/min/1.73 m(2)). Lead levels were also associated with lower creatinine-based estimated GFR levels, but the association was weaker than with cystatin C-based GFR and not statistically significant. CONCLUSIONS Higher blood lead levels in a range below the current Centers for Disease Control and Prevention-designated level of concern (10 microg/dL) were associated with lower estimated GFRs in a representative sample of US adolescents. This finding contributes to the increasing epidemiologic evidence indicating an adverse effect of low-level environmental lead exposure.
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Affiliation(s)
- Jeffrey J Fadrowski
- Welch Center for Prevention, Epidemiology and Clinical Research, Baltimore, MD, USA.
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Tondel C, Ramaswami U, Aakre KM, Wijburg F, Bouwman M, Svarstad E. Monitoring renal function in children with Fabry disease: comparisons of measured and creatinine-based estimated glomerular filtration rate. Nephrol Dial Transplant 2009; 25:1507-13. [DOI: 10.1093/ndt/gfp658] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Schwartz GJ, Work DF. Measurement and estimation of GFR in children and adolescents. Clin J Am Soc Nephrol 2009; 4:1832-43. [PMID: 19820136 DOI: 10.2215/cjn.01640309] [Citation(s) in RCA: 658] [Impact Index Per Article: 43.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
GFR is the best indicator of renal function in children and adolescents and is critical for diagnosing acute and chronic kidney impairment, intervening early to prevent end-stage renal failure, prescribing nephrotoxic drugs and drugs cleared by a failing kidney, and monitoring for side effects of medications. Renal inulin clearance was the gold standard for GFR but is compromised by lack of availability, difficult assays, and problems of collecting timed urine samples, especially in children with vesicoureteral reflux or bladder dysfunction. Creatinine clearance-based estimates of GFR are often used in pediatrics. The addition of cimetidine to eliminate creatinine secretion permits accurate measurement of GFR in those who can completely empty their bladders to provide timed urine collections. Radioisotopes are used in plasma disappearance GFR determinations; however, these are not ideal for use in children, especially for repeated studies. The plasma disappearance of iohexol serves as a promising alternative GFR marker, because it is safe and not radioactive, easily measured, not metabolized or transported by the kidney, and excreted primarily by glomerular filtration. GFR estimating equations, based on serum concentrations of creatinine or cystatin C, are popular clinically and in research studies. Efforts are ongoing to improve these estimating equations for children and make the results readily available to clinicians obtaining standard chemistry profiles, as is being done for adults. However, at this time, there is no dependable substitute for an accurately determined GFR, and iohexol plasma disappearance offers the best combination of safety, accuracy, and reproducible precision.
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Affiliation(s)
- George J Schwartz
- Department of Pediatrics, Pediatric Nephrology, Box 777, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA.
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Estimation of renal function and its potential impact on carboplatin dosing in children with cancer. Br J Cancer 2009; 99:894-9. [PMID: 18781149 PMCID: PMC2538755 DOI: 10.1038/sj.bjc.6604612] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Renal function-based carboplatin dosing is used routinely in paediatric oncology clinical practice. It is important that accurate assessments of renal function are carried out consistently across clinical centres, a view supported by recently published British Nuclear Medicine Society (BNMS) guidelines for measuring glomerular filtration rate (GFR). These guidelines recommend the use of a radioisotope method for GFR determination, with between two and five blood samples taken starting 2 h after radioisotope injection and application of the Brochner-Mortensen (BM) correction factor. To study the likely impact of these guidelines, we have investigated current practices of measuring GFR in all 21 Children's Cancer and Leukaemia Group (CCLG) paediatric oncology centres in the United Kingdom. This information was used to evaluate the potential impact on renal function-based carboplatin dosing using raw 51Cr-EDTA clearance data from 337 GFR tests carried out in children with cancer. A questionnaire survey revealed that between two and four samples were taken after isotope administration, with BM and Chantler corrections used in 38% (8/21) and 28% (6/21) of centres, respectively. A change from Chantler to BM correction, based on the BNMS guidelines, would result in a > 10% decrease in carboplatin dose in at least 15% of patients and a > 25% decrease in 2% of patients. A greater proportion of patients would have an alteration in carboplatin dose when centres not using any correction factor implement the BM correction. The increase in estimated 51Cr-EDTA half-life observed by omitting the I h sample decreases carboplatin dose by > 10% in 23-52% of patients and by > 25% in 3% of patients. This study highlights current variations in renal function measurement between clinical centres and the potential impact on carboplatin dosing. A standard methodology for estimating GFR should be followed to achieve uniform dosing in children with cancer.
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Schwartz GJ, Muñoz A, Schneider MF, Mak RH, Kaskel F, Warady BA, Furth SL. New equations to estimate GFR in children with CKD. J Am Soc Nephrol 2009; 20:629-37. [PMID: 19158356 DOI: 10.1681/asn.2008030287] [Citation(s) in RCA: 2473] [Impact Index Per Article: 164.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The Schwartz formula was devised in the mid-1970s to estimate GFR in children. Recent data suggest that this formula currently overestimates GFR as measured by plasma disappearance of iohexol, likely a result of a change in methods used to measure creatinine. Here, we developed equations to estimate GFR using data from the baseline visits of 349 children (aged 1 to 16 yr) in the Chronic Kidney Disease in Children (CKiD) cohort. Median iohexol-GFR (iGFR) was 41.3 ml/min per 1.73 m(2) (interquartile range 32.0 to 51.7), and median serum creatinine was 1.3 mg/dl. We performed linear regression analyses assessing precision, goodness of fit, and accuracy to develop improvements in the GFR estimating formula, which was based on height, serum creatinine, cystatin C, blood urea nitrogen, and gender. The best equation was: GFR(ml/min per 1.73 m(2))=39.1[height (m)/Scr (mg/dl)](0.516) x [1.8/cystatin C (mg/L)](0.294)[30/BUN (mg/dl)](0.169)[1.099](male)[height (m)/1.4](0.188). This formula yielded 87.7% of estimated GFR within 30% of the iGFR, and 45.6% within 10%. In a test set of 168 CKiD patients at 1 yr of follow-up, this formula compared favorably with previously published estimating equations for children. Furthermore, with height measured in cm, a bedside calculation of 0.413*(height/serum creatinine), provides a good approximation to the estimated GFR formula. Additional studies of children with higher GFR are needed to validate these formulas for use in screening all children for CKD.
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Affiliation(s)
- George J Schwartz
- Department of Pediatrics, University of Rochester School of Medicine, Rochester, NY 14642, USA.
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40
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Human renal function maturation: a quantitative description using weight and postmenstrual age. Pediatr Nephrol 2009; 24:67-76. [PMID: 18846389 DOI: 10.1007/s00467-008-0997-5] [Citation(s) in RCA: 327] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Revised: 07/28/2008] [Accepted: 07/29/2008] [Indexed: 10/21/2022]
Abstract
This study pools published data to describe the increase in glomerular filtration rate (GFR) from very premature neonates to young adults. The data comprises measured GFR (using polyfructose, (51)Cr-EDTA, mannitol or iohexol) from eight studies (n = 923) and involved very premature neonates (22 weeks postmenstrual age) to adulthood (31 years). A nonlinear mixed effects approach (NONMEM) was used to examine the influences of size and maturation on renal function. Size was the primary covariate, and GFR was standardized for a body weight of 70 kg using an allometric power model. Postmenstrual age (PMA) was a better descriptor of maturational changes than postnatal age (PNA). A sigmoid hyperbolic model described the nonlinear relationship between GFR maturation and PMA. Assuming an allometric coefficient of 3/4, the fully mature (adult) GFR is predicted to be 121.2 mL/min per 70 kg [95% confidence interval (CI) 117-125]. Half of the adult value is reached at 47.7 post-menstrual weeks (95%CI 45.1-50.5), with a Hill coefficient of 3.40 (95%CI 3.03-3.80). At 1-year postnatal age, the GFR is predicted to be 90% of the adult GFR. Glomerular filtration rate can be predicted with a consistent relationship from early prematurity to adulthood. We propose that this offers a clinically useful definition of renal function in children and young adults that is independent of the predictable changes associated with age and size.
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Abstract
Chronic kidney disease (CKD) is a world-wide public health problem, with adverse outcomes of kidney failure, cardiovascular disease, and premature death. The National Kidney Foundation, through its Kidney Disease Quality Outcome Initiative (K/DOQI) and other National institutions, recommend glomerular filtration rate (GFR) estimates for the definition, classification, screening, and monitoring of CKD. Prediction equations based on serum creatinine values were chosen both for adults (Cockcroft-Gault [C-G] and Modification of Diet in Renal Disease [MDRD] study equations) and for children (Schwartz and Counahan-Barratt equations). This review aims to evaluate from recent literature the clinical efficiency and relevance of these equations in terms of bias, precision, and reproducibility in different specific indications (eg, screening CKD, assessment of disease progression, or therapy efficacy) in different populations. Because these prediction equations based on serum creatinine have limitations, especially in the normal or near-normal GFR range, kidney transplant recipients, and pediatric populations, other prediction equations based on serum cystatin C value were also considered as possibly more sensitive GFR surrogate markers. Recent guidelines state that the cystatin C-based prediction equation cannot be recommended for use in clinical practice. With prediction equations based on serum creatinine, the National Kidney Disease Education Program (NKDEP) recommendations are to report a numerical estimate in round numbers only for GFR values <60 mL/min per 1.73 m(2). The MDRD equation generally outperforms the C-G equation but may still have a high level of bias, depending on creatinine assay calibration, and low precision with, at best, approximately 80% of estimated GFR in the "accuracy range" of 70-130% of the measured GFR value, even in patients with known CKD. According to Kidney Disease Improving Global Outcomes (KDIGO) recommendations, many indications remain for GFR measurements using a clearance method. In that context, it should be recalled that radiolabeled-tracer plasma or urinary clearance methods, are safe, simple, accurate and reproducible.
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Affiliation(s)
- Alain Prigent
- Department of Biophysics, Nuclear Medicine and Clinical Neurophysiology, Bicêtre Hospital, Assistance Publique-Hôpitaux de Paris, University of Paris-Sud, Le Kremlin Bicêtre Cedex, France.
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Abstract
Growth and development can be investigated using readily observable demographic factors such as weight and age. Size is the primary covariate and can be referenced to a 70-kg person with allometry using a coefficient of 0.75 for clearance and 1 for volume. The use of these coefficients is supported by fractal geometric concepts and observations from diverse areas in biology. Fat free mass (FFM) might be expected to do better than total body weight when there are wide variations in fat affecting body composition. Clearance pathways develop in the fetus before birth. The use of postnatal age as a descriptor of maturation is unsatisfactory because birth may occur prematurely; therefore postmenstrual age is a superior predictor of elimination function. A sigmoid E(max) model (Hill equation) describes gradual maturation of clearance in early life leading to a mature adult clearance achieved at a later age.
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Affiliation(s)
- B J Anderson
- Department of Anaesthesiology, University of Auckland School of Medicine, Auckland, New Zealand.
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Gretz N, Schock D, Sadick M, Pill J. Bias and precision of estimated glomerular filtration rate in children. Pediatr Nephrol 2007; 22:167-9. [PMID: 17123113 DOI: 10.1007/s00467-006-0379-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2006] [Revised: 10/25/2006] [Accepted: 10/26/2006] [Indexed: 10/25/2022]
Abstract
Determining true glomerular filtration rate (GFR) using an exogenous marker is time-consuming and cumbersome. Therefore, creatinine-based estimates of GFR are used. Recent papers using new population-specific/local parameters in their prediction equations, standardizing creatinine determination or adding other endogenous surrogate markers of GFR, like cystatin C, could demonstrate an improvement of bias inherent in the results of the prediction equations. Precision, however, is still poor. Currently, we have to accept a precision (as defined in the so-called Bland-Altman plot) of +/-20% in adults and +/-30-40% in children. This problem of poor precision/uncertainty is especially bothering in the higher, near normal GFR range. Caution should be exercised when applying prediction equations in individuals in need of an accurate GFR determination. In that case, a real clearance procedure has to be performed. In the long run, the true clearance procedure should be simplified using new exogenous GFR markers and developing new devices, allowing GFR measurements to be performed, for example, transcutaneously. Such a procedure would be more acceptable for both patients and physicians.
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Zappitelli M, Joseph L, Gupta IR, Bell L, Paradis G. Validation of child serum creatinine-based prediction equations for glomerular filtration rate. Pediatr Nephrol 2007; 22:272-81. [PMID: 17120061 DOI: 10.1007/s00467-006-0322-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2006] [Revised: 08/14/2006] [Accepted: 08/17/2006] [Indexed: 12/01/2022]
Abstract
Equations for estimating glomerular filtration rate (GFR) are vital in caring for patients with renal disease and the current standard, the Schwartz formula, lacks precision. We evaluated several child serum creatinine-based GFR prediction equations. Subjects aged 2-21 years who underwent iothalamate GFR (IoGFR) testing between 1999 and 2004 were studied retrospectively. GFR was estimated using: (1) Schwartz formula (SchwartzGFR), using a local k value; (2) Schwartz model (SchwartzMod) using regression-derived coefficients; (3) Leger GFR (LegerGFR) using original coefficients; and (4) Leger model (LegerMod) using regression-derived coefficients. Bias, precision, and diagnostic characteristics were evaluated. There were 195 subjects [61% male; mean (SD) age 12.4 (4.5) years; mean (SD) IoGFR 78.9 (33.4) ml/min per 1.73 m(2)]. Only the LegerGFR overestimated IoGFR (5.5 ml/min per 1.73 m(2)). Precision for all formulae was poor (95% limits of agreement approximately -40 to 40 ml/min per 1.73 m(2)), but >or=72% of estimates were within 30% of IoGFR. Sensitivities for detecting IoGFR <30 and 90 ml/min per 1.73 m(2) were highest using the SchwartzGFR (80%) and SchwartzMod (90%), respectively. The LegerGFR was most specific. Using local coefficients, the Schwartz and Leger models were imprecise estimates of GFR, but the Schwartz model was most unbiased and sensitive. Future research should derive more precise equations for GFR in children.
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Affiliation(s)
- Michael Zappitelli
- Baylor College of Medicine, Texas Children's Hospital, Houston, TX, USA.
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Bartelink IH, Rademaker CMA, Schobben AFAM, van den Anker JN. Guidelines on paediatric dosing on the basis of developmental physiology and pharmacokinetic considerations. Clin Pharmacokinet 2007; 45:1077-97. [PMID: 17048973 DOI: 10.2165/00003088-200645110-00003] [Citation(s) in RCA: 249] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The approach to paediatric drug dosing needs to be based on the physiological characteristics of the child and the pharmacokinetic parameters of the drug. This review summarises the current knowledge on developmental changes in absorption, distribution, metabolism and excretion and combines this knowledge with in vivo and in vitro pharmacokinetic data that are currently available. In addition, dosage adjustments based on practical problems, such as child-friendly formulations and feeding regimens, disease state, genetic make-up and environmental influences are presented. Modification of a dosage based on absorption, depends on the route of absorption, the physico chemical properties of the drug and the age of the child. For oral drug absorption, a distinction should be made between the very young and children over a few weeks old. In the latter case, it is likely that practical considerations, like appropriate formulations, have much greater relevance to oral drug absorption. The volume of distribution (V(d)) may be altered in children. Hydrophilic drugs with a high V(d) in adults should be normalised to bodyweight in young children (age <2 years), whereas hydrophilic drugs with a low V(d) in adults should be normalised to body surface area (BSA) in these children. For drugs that are metabolised by the liver, the effect of the V(d) becomes apparent in children <2 months of age. In general, only the first dose should be based on the V(d); subsequent doses should be determined by the clearance. Pharmacokinetic studies on renal and liver function clarify that a distinction should be made between maturation and growth of the organs. After the maturation process has finished, the main influences on the clearance of drugs are growth and changes in blood flow of the liver and kidney. Drugs that are primarily metabolised by the liver should be administered with extreme care until the age of 2 months. Modification of dosing should be based on response and on therapeutic drug monitoring. At the age of 2-6 months, a general guideline based on bodyweight may be used. After 6 months of age, BSA is a good marker as a basis for drug dosing. However, even at this age, drugs that are primarily metabolised by cytochrome P450 2D6 and uridine diphosphate glucuronosyltransferase should be normalised to bodyweight. In the first 2 years of life, the renal excretion rate should be determined by markers of renal function, such as serum creatinine and p-aminohippuric acid clearance. A dosage guideline for drugs that are significantly excreted by the kidney should be based on the determination of renal function in first 2 years of life. After maturation, the dose should be normalised to BSA. These guidelines are intended to be used in clinical practice and to form a basis for more research. The integration of these guidelines, and combining them with pharmacodynamic effects, should be considered and could form a basis for further study.
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Affiliation(s)
- Imke H Bartelink
- Department of Pharmacy, University Medical Center, Utrecht, The Netherlands.
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van der Vorst MMJ, Kist JE, van der Heijden AJ, Burggraaf J. Diuretics in pediatrics : current knowledge and future prospects. Paediatr Drugs 2006; 8:245-64. [PMID: 16898855 DOI: 10.2165/00148581-200608040-00004] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
This review summarizes current knowledge on the pharmacology, pharmacokinetics, pharmacodynamics, and clinical application of the most commonly used diuretics in children. Diuretics are frequently prescribed drugs in children. Their main indication is to reduce fluid overload in acute and chronic disease states such as congestive heart failure and renal failure. As with most drugs used in children, optimal dosing schedules are largely unknown and empirical. This is undesirable as it can potentially result in either under- or over-treatment with the possibility of unwanted effects. The pharmacokinetics of diuretics vary in the different pediatric age groups as well as in different disease states. To exert their action, all diuretics, except spironolactone, have to reach the tubular lumen by glomerular filtration and/or proximal tubular secretion. Therefore, renal maturation and function influence drug delivery and consequently pharmacodynamics. Currently advised doses for diuretics are largely based on adult pharmacokinetic and pharmacodynamic studies. Therefore, additional pharmacokinetic and pharmacodynamic studies for the different pediatric age groups are necessary to develop dosing regimens based on pharmacokinetic and pharmacodynamic models for all routes of administration.
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Anderson BJ, Allegaert K, Holford NHG. Population clinical pharmacology of children: modelling covariate effects. Eur J Pediatr 2006; 165:819-29. [PMID: 16807729 DOI: 10.1007/s00431-006-0189-x] [Citation(s) in RCA: 135] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2006] [Accepted: 05/11/2006] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Population modelling using mixed effects models provides a means to study variability in paediatric drug responses among individuals representative of those in whom the drug will be used clinically. DISCUSSIONS Explanatory covariates explain the predictable part of the between-individual variability. Growth and development are two major aspects of children not seen in adults. These aspects can be investigated by using size and age as covariates. Problems attributable to co-linearity can be approached by using size as the first covariate. Size standardisation is achieved using allometric scaling, a mechanistic approach that has a strong theoretical and empirical basis. Age is used to describe the maturation of clearance. The quantitative models (linear, exponential, first-order, variable slope sigmoidal) used to describe this maturation process vary depending on the span of the ages under investigation. Measures of response are not always straightforward and can be more difficult to quantify in children. CONCLUSION Covariate investigation in children is improving the understanding of developmental aspects of drug disposition and effects in the paediatric population, ultimately leading to more effective use of medications.
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Affiliation(s)
- Brian J Anderson
- Department of Anaesthesiology, University of Auckland, Auckland, New Zealand.
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Bouvet Y, Bouissou F, Coulais Y, Séronie-Vivien S, Tafani M, Decramer S, Chatelut E. GFR is better estimated by considering both serum cystatin C and creatinine levels. Pediatr Nephrol 2006; 21:1299-306. [PMID: 16794818 DOI: 10.1007/s00467-006-0145-z] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2006] [Revised: 03/06/2006] [Accepted: 03/06/2006] [Indexed: 10/24/2022]
Abstract
Serum cystatin C (cysC) is a potential marker of the glomerular filtration rate (GFR) that has generated conflicting reports in children. A prospective study was conducted to assess the benefit of considering cysC together with serum creatinine (SCr) and demographic and morphologic characteristics to better estimate the 51Cr-ethylenediaminetetraacetate (EDTA) clearance (CL), i.e., the GFR. Plasma 51Cr-EDTA data from 100 children or young adults (range: 1.4-22.8 years old) were analyzed according to the population pharmacokinetic approach by using the nonlinear mixed effects model (NONMEM) program. The actual CL was compared to the CL predicted according to different covariate equations. The best covariate equation (+/-95% confidence interval) was: GFR (ml/min)=63.2(+/-3.4) . [(SCr (microM)/96)(-0.35 (+/-0.20))] . [(cysC (mg/l)/1.2)(-0.56 (+/-0.19))] . [(body weight (kg)/45)(0.30 (+/-0.17))] . [age (years)/14)(0.40 (+/-0.16))]. This equation was associated with a less biased and more precise estimation than the Schwartz equation. CysC improves the estimation of the GFR in children if considered with other covariates within the mathematical formula.
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Affiliation(s)
- Yann Bouvet
- Department of Clinical Biology and EA3035, Institut Claudius-Regaud, Toulouse, France
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Chen N, Aleksa K, Woodland C, Rieder M, Koren G. Ontogeny of drug elimination by the human kidney. Pediatr Nephrol 2006; 21:160-8. [PMID: 16331517 DOI: 10.1007/s00467-005-2105-4] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2005] [Revised: 08/15/2005] [Accepted: 08/18/2005] [Indexed: 01/20/2023]
Abstract
Renal clearance is an important route of drug elimination. While during the neonatal period there is minimal glomerular filtration and active tubular secretion of drugs, there is a well-described rapid development in these processes in the post-neonatal period. A less appreciated fact is that during toddlerhood, there is an "overshoot" of the glomerular filtration rate (GFR) well above the levels encountered in older children and adults, and there is an early achievement of adult levels in active drug secretion, which stays at a plateau throughout childhood and adulthood with an "overshoot" in toddlers due to specific transport mechanisms. This phenomenon leads to dose requirements for renally excreted drugs in this age group being, on a per-kilogram basis, much larger than in adults. This review discusses the mechanisms related to renal ontogeny in drug handling.
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Affiliation(s)
- Nancy Chen
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
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Mattman A, Eintracht S, Mock T, Schick G, Seccombe DW, Hurley RM, White CT. Estimating pediatric glomerular filtration rates in the era of chronic kidney disease staging. J Am Soc Nephrol 2005; 17:487-96. [PMID: 16371435 DOI: 10.1681/asn.2005010034] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
With the use of information from a database of pediatric patients with concomitant nuclear GFR and serum creatinine (Cr), estimated GFR equations were derived on the basis of local laboratory methods and population. These formulas then were compared with those recommended by the National Kidney Foundation for estimating GFR in children. For this, their ability to estimate accurately an individual's true GFR and chronic kidney disease stage, identify patients whose true GFR was <60 ml/min per 1.73 m(2), and to identify correctly deterioration in an individual's GFR over time was compared. Next, two methods to estimate GFR in children without the use of height or weight were developed. The first was a height- and weight-independent formula; the second was a novel approach using the Schwartz formula and calculating a Cr cutoff based on age-based estimates of height and GFR level of interest, i.e., <60 ml/min per 1.73 m(2). Our results suggest that if local laboratory constants are derived and a height is known, then the Schwartz formula offers the most accuracy with least mathematical complexity to perform in the clinical setting. If height is not available but the local laboratory constants have been derived, then the British Columbia's Children's Hospital 2 formula is of value; however, in the setting of estimating pediatric renal function in the outpatient laboratory, where neither of these factors is commonly known, an approach whereby a Cr cutoff for a GFR of interest is developed is suggested. Provided are Cr levels that are based on a reference method of Cr measurement to facilitate this approach for the clinician.
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Affiliation(s)
- Andre Mattman
- Laboratory Medicine, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada
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