Limitations of Wright formula estimates of renal function.
Explore the source record for details and available documents.
Aged↗
Biomedical subjects
S G Poole
Publications and source records attributed to S G Poole.
Carboplatin dosing: gender bias and inaccurate estimates of glomerular filtration rate.
The aim was to compare doses of carboplatin calculated using the Calvert formula and Chatelut formula and also to compare doses calculated using Calvert formula, modified with non-isotopic estimation of GFR, using the Cockcroft and Gault formula or the Jelliffe formula. For formulae comparison, doses were calculated to target an AUC of 7 mg/ml x min. When compared with the dose derived from the Calvert formula, the doses calculated in 122 adult cancer patients using the Chatelut formula were significantly higher for males and significantly lower for females. There was a statistically significant difference between the dose per kg calculated for males and females (P<0.0001). The mean percentage difference in dose calculated with substituted measures of renal function with the Cockcroft and Gault formula and Jelliffe formula was -8% (standard deviation (S.D.) 17%) and -14% (S.D. 16%), respectively. Further prospective evaluation of the Chatelut formula is required before it can be recommended for routine clinical application.
Adult↗
A comparison of bedside renal function estimates and measured glomerular filtration rate (Tc99mDTPA clearance) in cancer patients.
BACKGROUND: The aim of this study was to compare measured glomerular filtration rate (GFR) with estimates of GFR derived from the population pharmacokinetic methods of Martin and Wright, and the creatinine clearance (CrCl) estimates of Cockcroft and Gault, and Jelliffe. PATIENTS AND METHODS: GFR was determined by technetium-99m diethyl triamine penta-acetic acid (Tc99DTPA) clearance in adult cancer patients. Height, actual body weight and serum creatinine were measured, and GFR and CrCl estimates calculated. RESULTS: One hundred and twenty-two patients were included. The mean measured GFR was 87 ml/min (range 30-174 ml/min). The mean bias (mean percentage error) was 2, 1, -10 and -17%, and the mean precision (mean absolute percentage error) was 18, 19, 21 and 23% for the Wright, Martin, Cockcroft and Gault, and Jelliffe formulas, respectively. The Martin formula significantly underestimates GFR for females (mean bias -10%) and overestimates GFR for males (mean bias 8%) (P <0.001 for bias of males versus females). The Wright and Martin formulas significantly overestimate GFR <50 ml/min (mean bias 39 and 30%; P = 0.03 and 0.05, respectively) and all formulas underestimate GFR >100 ml/min (mean bias -18, -16, -24 and -32% for Wright, Martin, Cockcroft and Gault, and Jelliffe formulas, respectively; P <0.001). CONCLUSIONS: All the assessed estimates for renal function were found to have significant limitations.
Adult↗
Poor correlation between body surface area and glomerular filtration rate.
PURPOSE: The aim of this study was to determine the correlation between body surface area (BSA) and glomerular filtration rate (GFR) measured by Tc-99m DTPA clearance in adult patients with cancer. METHODS: GFR was determined by Tc-99m DTPA clearance in adult patients with cancer. Height and actual body weight were measured. Ideal body weight was calculated. BSA was calculated using the Du Bois and Du Bois linear method using both actual and ideal body weight. RESULTS: Included in the study were 122 patients. The mean GFR measured by Tc-99m DTPA clearance was 87 ml/min (range 30-174 ml/min). The mean BSA (actual weight) was 1.76 m2 (median 1.73 m2, range 1.31-2.58 m2). The mean BSA (ideal body weight) was 1.63 m2 (median 1.63 m2, range 1.20-2.00 m2). The overall correlation between BSA (actual weight) and GFR in this adult population was r = 0.24, and the 95% confidence interval was 0.06-0.4. The correlation between BSA (ideal body weight) and GFR was r = 0.22. The correlation between BSA and GFR excluding patients with a BSA < 1.5 m2 or > 2.0 m2 was 0.12. When patients with GFR < 50 ml/min or > 100 ml/min were excluded, the correlation with BSA was 0.07. The correlations between GFR and height, actual weight and ideal weight were 0.22, 0.21 and 0.22, respectively. CONCLUSIONS: This study demonstrated a poor correlation between GFR determined by Tc-99m DTPA clearance and BSA calculated using the Du Bois and Du Bois linear method. The 95% confidence interval for the correlation between BSA and GFR was 0.06-0.4 indicating that a strong applicable clinical correlation is very unlikely.
Adult↗