Validation of the estimated glomerular filtration rate equation for Japanese children younger than 2 years

Background We have developed a simple and easy method of estimating the glomerular filtration rate (eGFR) of serum creatinine in Japanese children (eGFRUemura). The eGFR equation is for children aged 2–18 years. Therefore Uemura et al. developed an equation for children younger than 2 years (eGFRunder 2). The aim of the present study was to validate this new equation. Methods We collected the data of 13 patients from previous studies and compared the results of eGFRunder 2, eGFRUemura, and updated eGFR developed by Schwartz (eGFRSchwartz) with measured GFR using mean error (ME), root mean square error (RMSE), P30 and Bland–Altman analysis. Results The ME of eGFRunder 2, eGFRUemura and eGFRSchwartz were 2.3 ± 15.9, 7.7 ± 14.5, and 16.0 ± 18.2 ml/min/1.73m2, respectively. The RMSEs were 15.5, 15.9, and 49.6, respectively. The P30 values were 76.9%, 76.9%, and 53.8%, respectively. The graph of Bland–Altman bias analysis showed fan-shape. The eGFRunder 2 equation was the most accurate in the three equations. Conclusion The eGFRunder 2 equation was useful for Japanese children younger than 2 years.

Validity of Estimated Glomerular Filtration Rate Equation and Assessment of Bio-Impedance Analysis in Advanced Chronic Kidney Disease Patients

Introduction: This cross-sectional study was conducted to validate estimated glomerular filtration rate (eGFR) equation and assess body composition in chronic kidney disease (CKD) stage 5 non-dialysis (ND) participants.Methods: A total of 111 samples of Thai CKD stage 5 ND participants with eGFR below 15 mL/min/1.73 m2, calculated by using the CKD Epidemiology Collaboration (CKD-EPI) equation, were enrolled into the study. The 99mTc-DTPA plasma clearance was used as the reference GFR. Body composition analysis was measured by bio-impedance analysis (BIA) to assess volume as well as body composition.Results: The mean isotope for GFR was 17.39±6.83 mL/min/1.73m2. The mean bias values between isotope GFR and re-expressed MDRD equation, CKD-EPI equation, Thai equation, and cystatin C-based equation were 8.89±6.35, 9.47±6.13, 2.05±6.80, and 5.50±6.40 mL/min/1.73m2, respectively. The accuracy (root-mean-square error) values were 13.05, 13.68, 8.73, and 10.58 mL/min, respectively. Using BIA, the low muscle mass was 33.66%, excessive fat was 55.00 %, and the presence of edema was 48.5%. Participants with low muscle mass, excessive fat, and subclinical edema had higher bias of GFR measurement for all equations. The bias values for eGFR in participants with low muscle mass, excessive fat, and subclinical edema by re-expressed MDRD equation were 10.23, 9.61, 10.88 mL/min/1.73m2; by CKD-EPI equation: 8.49, 10.25, 11.63 mL/min/1.73m2; by the Thai eGFR equation: 3.16, 2.73, 4.77 mL/min/1.73m2; and by the cystatin C-based equation: 6.32, 6.6, 7.99 mL/min/1.73m2, respectively.Conclusions: The Thai equation was the most accurate and precise method to determine the renal function of Thai CKD stage 5 ND participants who had a high prevalence of low muscle mass, excessive fat, and subclinical edema. The result suggested that ethnic-specific eGFR equation should be recommended in advanced CKD patients. Alteration of the body composition in advanced CKD patients is of concern because it can affect the performance of all of the eGFR equations.

Glomerular filtration rate in children and young adults with haemato-oncological disease and infection is best described by three-compartmental iohexol model

Background. Children with cancer and infection may develop glomerular hyperfiltration (GH). With the aim to determine the prevalence of GH in children and young adults with haemato-oncological disease and infection we developed population pharmacokinetic model of iohexol. We further aimed to assess the accuracy of estimated glomerular filtration rate (eGFR) equations and single- or two-point measured GFR (mGFR) formulas compared with GFR based on iohexol clearance from our population pharmacokinetic model (iGFR). Procedure. Hospitalized patients (0.5-25 years) with haemato-oncological disease and infection were included if their eGFR was ≥80 mL/min/1.73 m2 at the screening visit. Iohexol plasma concentrations were described by population pharmacokinetic model. Bias, precision and accuracy of 23 eGFR equations and 18 mGFR formulas were calculated. Results. Total of 32 iohexol administrations was performed in 28 patients. Median (range) eGFR was 136 (74-234) mL/min/1.73 m2 and age 15.1 (0.8-26.0) years. Three-compartment model with allometric scaling of central, one peripheral compartment and clearance (with power 0.75) to weight fitted the best. Median (range) iGFR was 103 (68-140) mL/min/1.73 m2. All except one eGFR equation overestimated GFR. Lund-Malmö revised eGFR equation performed the best, followed by Gao equation. Of single- or two-point mGFR formulas 15 overestimated iGFR. Modified Jacobsson formula at 5.5 h performed the best, followed by Fleming formula at 3 h. Conclusions. In children and young adults with haemato-oncological disease and infection renal function is best described by iohexol clearance from three-compartmental pharmacokinetic model, while eGFR equations and single- and two-point mGFR formulas overestimate iGFR.

Creatinine-Based Renal Function Estimates and Dosage of Postoperative Pain Management for Elderly Acute Hip Fracture Patients

Many analgesics and their metabolites are renally excreted. The widely used Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)-estimated glomerular filtration rate (eGFR) equations are not developed for use in the elderly, while the recent Berlin Initiative Study (BIS), Full Age Spectrum (FAS), and Lund-Malmö revised (LMR) equations are. This observational study investigated differences between creatinine-based eGFR equations and how the choice of equation influences dosage of analgesics in elderly (≥70 years) patients admitted with acute hip fracture. eGFR was calculated by the CKD-EPI, BIS, Cockcroft-Gault (CG), FAS, LMR, and Modification of Diet in Renal Disease (MDRD) equations. Standard daily dose for postoperative pain medications ibuprofen, morphine and gabapentin was simulated for each equation according to dosage recommendations in Renbase®. For 118 patients, mean eGFR from the CKD-EPI, BIS, CG, FAS, LMR, and MDRD equations was 67.3 mL/min/1.73 m2, 59.1 mL/min/1.73 m2, 56.9 mL/min/1.73 m2, 60.3 mL/min/1.73 m2, 58.9 mL/min/1.73 m2, and 79.1 mL/min/1.73 m2, respectively (p < 0.0001). Mean difference to CKD-EPI was −10.4 mL/min/1.73 m2 to 11.8 mL/min/1.73 m2. Choice of eGFR equation significantly influenced the recommended dose (p < 0.0001). Shifting to BIS, FAS, or LMR equations led to a lower recommended dose in 20% to 31% of patients. Choice of eGFR equation significantly influenced dosing of ibuprofen, morphine, and gabapentin.

Renal Function and Death in Older Women: Which eGFR Formula Should We Use?

Background. The Berlin Initiative Study (BIS) eGFR equations were developed specifically for aged populations, but their predictive validity compared to standard formulae is unknown in older women.Methods. In a prospective study of 1289 community-dwelling older women (mean age 79.5 years), we compared the performance of the BIS1 SCr-based equation to the CKD-EPIcrand the BIS2 SCr- and Scysc-based equation to the CKD-EPIcr,cyscto predict cardiovascular and all-cause mortality.Results. Prevalence of specific eGFR category (i.e., ≥75, 60–74, 45–59, and <45) according to eGFR equation was 12.3%, 38.4%, 37.3%, and 12.0% for BIS1; 48.3%, 27.8%, 16.2%, and 7.8% for CKD-EPIcr; 14.1%, 38.6%, 37.6%, and 9.6% for BIS2; and 33.5%, 33.4%, 22.0%, and 11.1% for CKD-EPIcr,cysc, respectively. Over9±4years, 667 (51.8%) women died. For each equation, women with eGFR <45 were at increased risk of mortality compared to eGFR ≥75 [adjusted HR (95% CI): BIS1, 1.5 (1.1–2.0); CKD-EPIcr, 1.7 (1.3–2.2); BIS2, 2.0 (1.4–2.8); CKD-EPIcr,cysc, 1.8 (1.4–2.3);p-trend <0.01]. Net reclassification analyses found no material difference in discriminant ability between the BIS and CKD-EPI equations. Results were similar for cardiovascular death.Conclusions. Compared to CKD-EPI, BIS equations identified a greater proportion of older women as having CKD but performed similarly to predict mortality risk. Thus, the BIS equations should not replace CKD-EPI equations to predict risk of death in older women.

Efficient reporting of the estimated glomerular filtration rate without height in pediatric patients with cancer

Background:The updated bedside Schwartz equation requires constant, serum creatinine concentration and height measurements to calculate the estimated glomerular filtration rate (eGFR) in pediatric patients. Unlike the serum creatinine levels, obtaining height information from the laboratory information system (LIS) is not always possible in a clinical laboratory. Recently, the height-independent eGFR equation, the full age spectrum (FAS) equation, has been introduced. We evaluated the performance of height-independent eGFR equation in Korean children with cancer.Methods:A total of 250 children who underwent chromium-51-ethylenediamine tetra acetic-acid (Results:The FAS equation showed significantly lower bias (mL/min/1.73 mConclusions:The height-independent eGFR-FAS equation was less biased and as accurate as the updated Schwartz equation in Korean children. The use of the height-independent eGFR equation will allow for efficient reporting of eGFR through the LIS in clinical laboratories.