Indexed glomerular filtration rate as a function of age and body size

2000 ◽  
Vol 98 (4) ◽  
pp. 439-444 ◽  
Author(s):  
A. M. PETERS ◽  
B. L. HENDERSON ◽  
D. LUI
Keyword(s):  
Body Weight ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Linear Function ◽  
Filtration Rate ◽  
Whole Body ◽  
Inverse Association ◽  
Single Compartment ◽  
Wide Range ◽  
51Cr Edta

The conventional way in which to scale or index a measurement of glomerular filtration rate (GFR) is to express it in relation to body surface area (BSA). However, BSA may not be appropriate for infants and children because, as individuals increase in size, their relative BSA decreases. Several other whole-body variables have been suggested as alternatives, including extracellular fluid volume (vECF). The purpose of the present study was to compare BSA and vECF as variables against which to index GFR, and in particular to look at this comparison in children versus adults. A total of 130 patients (age range 1–80 years; 40 patients < 12 years) undergoing clinically indicated routine measurement of GFR using the bolus-injection single-compartment technique were included in the study. GFR was measured as the plasma clearance of [51Cr]EDTA as assessed from three peripheral venous blood samples taken between 2 and 4 h after injection of [51Cr]EDTA. Volume of distribution (Vd) was obtained by extrapolation of the clearance curve to zero time. GFR was scaled to a BSA of 1.73 m2. GFR and GFR/1.73 m2 were corrected to account for the assumption of a single compartment. The rate constant of the exponential between 2 and 4 h was also corrected to give GFR/litre ECF. GFR and GFR/1.73 m2 were both divided by GFR/litre ECF, to give vECF and vECF/1.73 m2 respectively. Weight per unit BSA increases as a linear function of BSA. vECF is always less than Vd, on average by about 30%. vECF increased as an exponential function of BSA and as a linear function of body weight. vECF/70 kg body weight was higher in children (16.2±3 litres) than adults (13.4±2.3 litres), but vECF/1.73 m2 was lower in children (9.7±1.7 litres) compared with adults (12.4±2 litres). vECV/1.73 m2 increased as a function of both age and BSA, but vECF/kg decreased. GFR/12.5 litres vECF was higher than GFR/1.73 m2 in children, but these values were similar in adults, with the ratio of these two forms of indexed GFR falling significantly with both age and BSA. Although this was not a normal population, but one with a wide range of renal function, GFR/vECF showed a strong inverse association with age, whereas for GFR/BSA the association was weak. In conclusion, these data provide further evidence that vECF is more valid physiologically for indexing GFR than is BSA, especially in children. Nevertheless, a GFR measurement in a child should ideally be expressed as a percentage of normal for that child's age. However, such normal values are not yet available.

Hypertension and renal dysfunction in primary hyperparathyroidism: effect of parathyroidectomy

1989 ◽  
Vol 76 (3) ◽  
pp. 289-296 ◽  
Author(s):  
A. K. Salahudeen ◽  
T. H. Thomas ◽  
L. Sellars ◽  
S. Tapster ◽  
P. Keavey ◽  
...  
Keyword(s):  
Glomerular Filtration Rate ◽  
Essential Hypertension ◽  
Primary Hyperparathyroidism ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Plasma Renin ◽  
Whole Body ◽  
Before And After ◽  
51Cr Edta ◽  
Normotensive Control

1. Twenty-four patients with primary hyperparathyroidism were studied before and 18 restudied 6.5 months (mean) after parathyroidectomy, to investigate the pathogenesis of the hypertension which may accompany this condition. Comparison was made with age-matched patients with essential hypertension and with normotensive control subjects. 2. There was a significant inverse relationship between mean arterial pressure and 51Cr-labelled ethylenediaminetetra-acetate (51Cr-EDTA) clearance in patients with hyperparathyroidism both before and after parathyroidectomy, but not in patients with essential hypertension. 3. Creatinine clearance appeared to overestimate glomerular filtration rate in some patients with hyperparathyroidism, falling significantly after surgery while 51Cr-EDTA clearance was unchanged. This observation may explain the failure of some previous studies to relate hypertension to impairment of renal function. 4. Plasma renin activity, plasma aldosterone and whole-body exchangeable sodium did not differ between normotensive and hypertensive patients with primary hyperparathyroidism and were unchanged after surgery. 5. Parathyroidectomy did not result in any change in blood pressure or in glomerular filtration rate measured by 51Cr-EDTA clearance.

Influence of nifedipine on cyclosporin A nephrotoxicity after unilateral nephrectomy in the spontaneously hypertensive rat

1991 ◽  
Vol 81 (2) ◽  
pp. 271-279 ◽  
Author(s):  
P. G. McNally ◽  
F. Baker ◽  
N. Mistry ◽  
J. Walls ◽  
J. Feehally
Keyword(s):  
Body Weight ◽  
Glomerular Filtration Rate ◽  
Renal Impairment ◽  
Cyclosporin A ◽  
Glomerular Filtration ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Denervation ◽  
Renal Plasma Flow ◽  
Spontaneously Hypertensive

1. Nifedipine ameliorates cyclosporin A-induced renal impairment in surgically intact (two-kidney) rats. This study investigates the effect of nifedipine on cyclosporin A nephrotoxicity in spontaneously hypertensive rats after either uninephrectomy or uninephrectomy with contralateral renal denervation. 2. Fourteen days after uninephrectomy pair-fed rats were injected for 14 days with cyclosporin A (25 mg/kg body weight) via the subcutaneous route and with nifedipine (0.1 mg/kg body weight) via the intraperitoneal route. Renal and systemic haemodynamics were measured in conscious unrestrained rats. 3. Whole-blood levels of cyclosporin A did not differ between groups (overall 352 ± 22 ng/ml, means ± sem). After uninephrectomy, cyclosporin A decreased the glomerular filtration rate (olive oil versus cyclosporin A: 0.96 ± 0.04 versus 0.70 ± 0.06 ml min−1 100 g body weight, P < 0.02) and effective renal plasma flow (1.94 ± 0.10 versus 1.38 ± 0.13, P < 0.01), and increased renal vascular resistance {(20.2 ± 1.8) × 104 versus (31.6 ± 3.3) × 104 kPa l−1 s [(20.2 ± 1.8) × 103 versus (31.6 ± 3.3) × 103 dyn s cm−5], P < 0.02} and mean arterial pressure (146.7 ± 6.7 versus 167.3 ± 2.9 mmHg, P < 0.05). Neither renal denervation nor nifedipine prevented the reduction in glomerular filtration rate or effective renal plasma flow induced by cyclosporin A. 4. This study infers that the sympathetic nervous system does not play an active role in cyclosporin A nephrotoxicity and demonstrates that the concomitant administration of nifedipine to rats with reduced renal mass does not ameliorate cyclosporin A-induced renal impairment.

scholarly journals Influence of the background activity region selection on the measurement of glomerular filtration rate using the Gates method

2008 ◽  
Vol 65 (10) ◽  
pp. 729-732 ◽  
Author(s):  
Marija Dopudja ◽  
Boris Ajdinovic ◽  
Ljiljana Jaukovic ◽  
Marijana Petrovic ◽  
Zoran Jankovic
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Background Activity ◽  
Accurate Method ◽  
Lateral Side ◽  
Lower Pole ◽  
Region Selection ◽  
Significant Difference ◽  
51Cr Edta

Background/Aim. The most frequent method for the assessment of glomerular filtration rate GFR) in clinical practice is clearance of creatinine, clearance of chromium-51 radiolabelled ethylene diamine tetraacetic acid (51Cr-EDTA) and clearance of technetium-99m radiolabelled diethylene triamine pentaacetic acid (99mTc-DTPA). The Gates method for glomerular filtration rate assessment is based on distribution of 99mTc-DTPA in the kidney 2-3 minute after its applying. Calculation of GFR is corrected for the background and depth of the kidney and finally expressed as a percentage of the net injected counts. This value of GFR highly correlates with biexponential model as the most accurate method for the assessment of GFR. The aim of this study was to determine the influence of different background sites on GFR rate assessment using the Gates method. Methods. We analysed 50 patients who were divided into two groups: the group of healthy subjects (21 subjects, mean age 47.38 yrs) and the group of subjects with unilateral kidney damage (29 subjects, mean age 39.79 yrs). Three different background activity regions were chosen: a region drawn below the lower pole of each kidney, region drawn by the lateral side of each kidney and region drawn around the whole kidney. Results. Gromerular filtration rate calculated by the use of a region under the lower pole is statistically significantly higher than GFR calculated using a region by the lateral side and around the whole kidney (p < 0.0001). Glomerular filtration rate calculated using the region by the lateral side and region around the whole kidney did not show statistically significant difference (p > 0.05). Conclusion. The selection of background activity region has a significant influence on GFR rate measured by the Gates method. It is recommended to use only one method for choosing the region of background activity.

Effect of Urodilatin Infusion on Renal Haemodynamics, Tubular Function and Vasoactive Hormones

1997 ◽  
Vol 92 (4) ◽  
pp. 397-407 ◽  
Author(s):  
JAN Carstens ◽  
Kaare T. Jensen ◽  
Erling B. Pedersen
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Distal Part ◽  
Renal Haemodynamics ◽  
Sodium Reabsorption ◽  
Lithium Clearance ◽  
Short Term

1. The renal efficacy of urodilatin in humans has only been partly investigated. It is unknown whether intravenously infused urodilatin has an effect on sodium reabsorption in both the proximal and distal part of the nephron. 2. Twelve healthy subjects participated in this double-blind, placebo-controlled study in a crossover design. They received, in a randomized order, a short term (60 min) infusion of urodilatin in three different doses (10, 20 and 40 ng min−1 kg−1 of body weight) and placebo. Renal haemodynamics were estimated by clearance technique with radioactive tracers, and proximal tubular handling of sodium was evaluated by lithium clearance. 3. The 20 ng min−1 kg−1 dose increased the urinary sodium excretion and urinary flow rate compared with the effects of placebo. It increased the glomerular filtration rate and decreased the effective renal plasma flow. In addition, the dose increased the lithium clearance compared with placebo, but did not significantly change the fractional excretion of lithium. On the other hand, it markedly decreased the distal fractional reabsorption of sodium. It also had a suppressive effect on renin secretion. The systemic arterial blood pressure was unchanged, but the dose increased the pulse rate and the haematocrit. The highest dose (40 ng min−1 kg−1) induced a wide variation in the natriuretic and diuretic responses, probably due to a blood-pressure-lowering effect. 4. We conclude, that the urodilatin dose of 20 ng min−1 kg−1 of body weight was most efficacious in this short-term infusion study, and that it had potent natriuretic and diuretic qualities, probably due to stimulation of the glomerular filtration rate and inhibition of sodium reabsorption in the distal part of the nephron.

P1718COMPARISON OF MEASURED GLOMERULAR FILTRATION RATE USING 24-HOUR URINE CREATININE CLEARANCE WITH 51-CHROMIUM EDTA IN A MALAYSIAN COHORT OF LIVING KIDNEY DONOR CANDIDATES

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Chee Keong Thye ◽  
Yee Wan Lee ◽  
Maisarah Jalalonmuhali ◽  
Soo Kun Lim ◽  
Kok Peng Ng
Keyword(s):  
Glomerular Filtration Rate ◽  
Creatinine Clearance ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Urine Volume ◽  
Kidney Donor ◽  
Living Kidney Donor ◽  
Kidney Donors ◽  
Living Kidney Donors ◽  
51Cr Edta

Abstract Background and Aims All living kidney donors undergo assessment of renal function by evaluation of Glomerular Filtration Rate (GFR). 51Cr-EDTA is one of the most widely used marker for measuring GFR but it is hampered by cost and laboriousness as well as not being widely available in Malaysia. Measuring 24-hour urine for creatinine clearance (Ccr) is a common alternative when exogenous filtration markers are not available. Ccr suffers from over/underestimation of measured GFR (mGFR) due to errors in urine collection and tubular secretion of creatinine. This is a study to compare the correlation of Ccr against 51Cr-EDTA in measuring GFR among the living donors in Malaysian population. Method This is a cross-sectional, single-centre study of a cohort of living kidney donor candidates from January 2007 to March 2019. All candidates who had mGFR done with both 51Cr-EDTA and Ccr in University Malaya Medical Centre were enrolled. Special consideration was taken to account for adequate urine sampling for Ccr. Clinical data was analysed for correlation, bias, precision and accuracy between Ccr and 51Cr-EDTA. Results A total of 83 living kidney donors with a mean age of 45.60 ± 11.06 years and body mass index (BMI) of 24.36 ± 4.03 were enrolled. Female comprised 74.7% of the donors while Chinese, Malay and Indian accounted for 67.5%, 20.5% and 7.2% of the donors respectively. The study group had a mean serum creatinine of 63.37 ± 16.00 umol/L with a urine volume of 2.03 ± 0.81 L (range 0.70 – 3.82). mGFR from 51Cr-EDTA was 125.56 ± 27.64 ml/min/1.73m2 (range 77.0 – 194.3) whereas calculated Ccr was 136.05 ± 36.15 ml/min/1.73m2 (range 75.32 – 280.06). The correlation coefficient between Ccr and 51Cr-EDTA is moderate (r = 0.43) (p &lt; 0.01). Mean absolute bias between Ccr and 51Cr-EDTA was 10.59 ± 37.99 ml/min/1.73m2 (p &lt; 0.05). The accuracy of Ccr within 30% of 51Cr-EDTA was 77.11%. Conclusion Our study showed that Ccr significantly overestimates mGFR compared to 51Cr-EDTA. However, there is a significantly moderate positive correlation between Ccr and 51Cr-EDTA. Thus, in the absence of 51Cr-EDTA, Ccr is a clinically acceptable alternative if utilized with care and understanding its limitations.

Sign in / Sign up

Export Citation Format

Share Document