Schwartz Formula: Is One k-Coefficient Adequate for All Children?

Souza, V. de; Rabilloud, Muriel; Cochat, Pierre; Selistre, Luciano; Hadj‐Aïssa, Aoumeur; Kassai, Behrouz; Ranchin, Bruno; Berg, Ulla; Herthelius, Maria; Dubourg, Laurence

doi:10.1371/journal.pone.0053439

Cited by 91 publications

(100 citation statements)

References 27 publications

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“…However, the study had a few limitations: (1) Very few patients (n=7) had CKD stage IV or V; (2) the performance of eGFR equations in patients with mGFR,30 ml/min per 1.73 m 2 could not be examined because of the small number of patients; (3) the influence of the immunosuppressive regimen could not be tested because this information was not regularly available for all patients (14); and (4) the study population included French patients and thus the results cannot be readily extrapolated to non-European pediatric populations.…”

Section: Discussionmentioning

confidence: 99%

“…These children belonged to the French cohort used for establishing the Schwartz-Lyon formula (14). They had been referred to the Unit "Exploration Fonctionnelle Rénale et Métabolique" for measurement of inulin clearance at Hôpital Edouard Herriot (Lyon, France) between July 2003 and July 2010.…”

Section: Patientsmentioning

confidence: 99%

“…The eGFR was obtained using six formulas: (1) two creatinine-based formulas (the bedside Schwartz [16] and Schwartz-Lyon [14] formulas); (2) two CysC-based formulas (the Hoek [13] and Filler [12] formulas); and (3) two combined formulas (the CKiD [18], which uses PCr, CystC, and urea, and the Zappitelli [15], which uses PCr and CystC). All the eGFRs were standardized for a body surface area of 1.73 m 2 and expressed in ml/min per 1.73 m 2 .…”

Section: Estimation Of Gfrmentioning

confidence: 99%

“…The reports about the value of CystC as a GFR marker, particularly in pediatric kidney transplantation, have been contradictory because of the influence of prednisone and calcineurin inhibitors on CystC concentration (10,11). Therefore, CystC-based or combined PCr-CystC GFR-predicting equations have been established in various populations, especially in pediatric patients (12)(13)(14)(15), but few equations have been specifically developed for transplant patients. Only the Zappitelli formula has a correction factor for pediatric kidney transplant patients (15).…”

Section: Introductionmentioning

confidence: 99%

“…Because of the growth retardation in the studied population, this formula has a single coefficient for all age groups but was validated in children with and without CKD (17). In 2012, De Souza et al described a locally adapted Schwartz formula (the Schwartz-Lyon formula, which has two coefficients for sex and age) and validated it in an external population (14). Finally, Schwartz et al established a new combined PCr-CystC equation, the CKD in Children (CKiD) formula (16), which was updated in 2012 using immunonephelemetric CystC determination (18).…”

Section: Introductionmentioning

confidence: 99%

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Accuracy of Different Equations in Estimating GFR in Pediatric Kidney Transplant Recipients

Souza¹,

Cochat²,

Rabilloud³

et al. 2015

Clinical Journal of the American Society of Nephrology

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Background and objective The knowledge of renal function is crucial for the management of pediatric kidney transplant recipients. In this population, the most commonly used plasma creatinine (PCr)-based or cystatin C (CystC)-based GFR-predicting formulas may underperform (e.g., corticosteroids and trimethoprim may affect PCr concentration, whereas prednisone and calcineurin inhibitors may affect CystC concentration). This study evaluated the performance of six formulas in pediatric kidney transplant recipients.Design, setting, participants, & measurements The study used PCr-based formulas (bedside Schwartz, SchwartzLyon), CystC-based formulas (Hoek, Filler), and combined PCr-CystC-based formulas (CKD in Children [CKiD] 2012 and Zappitelli). The performance of these formulas was compared using inulin clearance as reference and assessed according to CKD stages in a historical cohort that included 73 pediatric kidney transplant recipients (199 measurements). The ability of the formulas to identify GFRs,60, ,75, and ,90 ml/min per 1.73 m 2 was assessed.Results At measured GFR (mGFR) $90 ml/min per 1.73 m 2 (nine patients; 23 measurements), the Zappitelli formula had the highest 30% accuracy (P30) (95% [95% confidence interval (95% CI), 87% to 100%]) and the bedside Schwartz had the highest 10% accuracy (P10) (56% [95% CI, 32% to 72%]). At mGFR$60 and ,90 ml/min per 1.73 m 2 (22 patients; 91 measurements), all formulas had P30 values .80%. However, only the CKiD 2012 formula had a P10 value .50%. At mGFR,60 ml/min per 1.73 m 2 (42 patients; 85 measurements), the CKiD 2012 and Schwartz-Lyon formulas had the highest P10 (45% [95% CI, 34% to 55%] and 43% [95% CI, 33% to 54%]) and P30 (90% [95% CI, 84% to 97%] and 91% [95% CI, 86% to 98%]). All studied equations except Hoek and Filler had areas under the receiver-operating characteristic curves significantly .90% in discriminating patients with renal dysfunction at various CKD stages (GFR,60, ,75, and ,90 ml/min per 1.73 m 2 ).Conclusions In pediatric kidney transplant recipients, the CKiD 2012 formula had the best performance at mGFRs,90 ml/min per 1.73 m 2 . CystC-based formulas were not superior to PCr-based formulas.

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Section: Discussionmentioning

confidence: 99%

Section: Patientsmentioning

confidence: 99%

Section: Estimation Of Gfrmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Accuracy of Different Equations in Estimating GFR in Pediatric Kidney Transplant Recipients

Souza¹,

Cochat²,

Rabilloud³

et al. 2015

Clinical Journal of the American Society of Nephrology

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Creatinine‐Based Renal Function Assessment in Pediatric Drug Development: An Analysis Using Clinical Data for Renally Eliminated Drugs

Zhang

Sherwin

González

et al. 2020

Clin Pharma and Therapeutics

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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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Practical considerations to drug dosing in children with acute kidney injury

Assadi

Sharbaf

2016

The Journal of Clinical Pharma

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Medication dosing for children with acute kidney injury (AKI) needs to be individualized based on pharmacokinetic and pharmacodynamic principles of the prescribed drugswhenever possible to optimize therapeutic outcome and to minimize toxicity. The pediatric RIFLE criteria should be prospectively utilized to identify patients at highest risk of developing AKI. Serum creatinine and urine output along with volume status should be utilized to guide drug dosing when urinary biomarkers including kidney injury molecule 1, interleukin-18, or neutrophil gelatinase-associated lipocalin are not readily available. Because of the presence of a positive fluid balance in early stages of AKI, the dosing regimen for many drugs, especially antimicrobial agents, should be initiated at a larger loading dose based on the expected volume of distribution to achieve target serum concentrations.When possible, therapeutic drug monitoring should be utilized for those medications where serum drug concentrations can be obtained in a clinically relevant time frame. For these medications, close monitoring of serum drug concentrations is highly recommended. This review addresses drug-dosing strategies in pediatric patients with AKI including the roles of therapeutic drug monitoring and newer kidney injury biomarkers.

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Schwartz Formula: Is One k-Coefficient Adequate for All Children?

Cited by 91 publications

References 27 publications

Accuracy of Different Equations in Estimating GFR in Pediatric Kidney Transplant Recipients

Accuracy of Different Equations in Estimating GFR in Pediatric Kidney Transplant Recipients

Creatinine‐Based Renal Function Assessment in Pediatric Drug Development: An Analysis Using Clinical Data for Renally Eliminated Drugs

Practical considerations to drug dosing in children with acute kidney injury

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