Related Experiment Videos
Revisiting normal (51)Cr-ethylenediaminetetraacetic acid clearance values in children
1CHU St Pierre, Department of Radioisotopes, Brussels, Belgium. amypiepsz@yahoo.com
Summary
Previous estimates of normal pediatric renal (51)Cr-EDTA clearance may have overestimated values due to unrecognised hyperfiltration during infection. This study provides revised, likely more accurate, normal glomerular filtration rate (GFR) values for children.
Area of Science:
- Pediatric Nephrology
- Renal Physiology
- Diagnostic Imaging
Background:
- Previous normal (51)Cr-EDTA clearance values in children were established without accounting for hyperfiltration during acute renal infection.
- This oversight may have led to an overestimation of true normal glomerular filtration rate (GFR) in pediatric populations.
Purpose of the Study:
- To re-appraise and establish more accurate normal (51)Cr-EDTA clearance values in children.
- To address the potential overestimation of GFR in prior studies.
Main Methods:
- Two patient groups were studied using a single blood sample method for (51)Cr-EDTA clearance.
- Group 1: Patients with current/past UTI, normal DMSA scans, and normal left-to-right shunt ratio.
- Group 2: Patients with no recent UTI.
Main Results:
- Group 1 yielded results similar to previously published values.
- Group 2 showed significantly lower GFR values, with a mean of 104 ml/min/1.73 m(2) after age 2.
- This contrasts with the 117 ml/min/1.73 m(2) mean in Group 1.
Conclusions:
- The GFR values derived from Group 2 (no recent UTI) are likely more representative of true normal values.
- These revised values are applicable to the general pediatric population.
Related Concept Videos
01:25Drug Dosing in Renal Diseases: Measurement of Serum Creatinine Concentration and Clearance
In healthy individuals, serum creatinine levels remain stable due to a balance between its constant production—primarily from muscle metabolism—and renal excretion. Creatinine is freely filtered by the glomeruli, making it a valuable marker for estimating renal function. When the glomerular filtration rate (GFR) decreases, the kidneys can only eliminate less creatinine, causing serum levels to rise.Serum creatinine concentration is widely used to estimate creatinine clearance (Clcr), a...
01:26Pharmacokinetics in Pediatric Patients: Drug Excretion
In pediatric medicine, understanding the renal function and drug elimination nuances is crucial for administering safe and effective treatments. Newborns, in particular, display markedly slower renal functions than adults, profoundly affecting how drugs are cleared from their bodies. This slower drug clearance requires clinicians to extend the dosing intervals for many medications to prevent drug accumulation and toxicity while ensuring therapeutic efficacy.One key area where these adjustments...
01:24Pharmacokinetics in Pediatric Patients: Drug Metabolism
In pediatric care, understanding the nuances of hepatic drug metabolism is crucial, as it significantly differs from that of adults. This divergence is primarily due to the developmental stage of drug-metabolizing enzymes, which affects how medications are processed in the body. In neonates, for instance, the activity of Phase I enzymes—critical for the initial breakdown of drugs—is markedly reduced, functioning at just 20–40% of the levels seen in adults. This reduction poses a challenge in...
01:17Factors Affecting Renal Clearance: Renal Impairment
Renal dysfunction significantly impairs the renal clearance of drugs, leading to potential complications in drug therapy. Renal failure, which can be caused by various factors, poses a significant challenge in the elimination of drugs from the body.
One condition associated with renal failure is uremia. Uremia is characterized by impaired glomerular filtration and fluid accumulation in the body. This condition hinders the renal clearance of drugs, resulting in drug accumulation and potential...
One condition associated with renal failure is uremia. Uremia is characterized by impaired glomerular filtration and fluid accumulation in the body. This condition hinders the renal clearance of drugs, resulting in drug accumulation and potential...
01:23Renal Clearance
The glomerular filtration rate (GFR) is a critical marker of kidney function, reflecting the efficiency of filtration by the glomeruli. Renal clearance of specific substances, such as inulin or creatinine, is commonly used to measure GFR.
Renal clearance refers to the volume of plasma cleared of a specific substance, such as creatinine, per unit of time. To measure clearance, urine samples are collected over a 24-hour period during each bladder voiding, followed by a single blood sample at the...
Renal clearance refers to the volume of plasma cleared of a specific substance, such as creatinine, per unit of time. To measure clearance, urine samples are collected over a 24-hour period during each bladder voiding, followed by a single blood sample at the...
01:25Drug Dosing in Renal Diseases: Dose Adjustments Based on Drug Clearance and Elimination Rate Constant
In patients with renal disease, dosage adjustments are necessary to maintain therapeutic plasma drug concentrations and prevent toxicity or subtherapeutic exposure. Renal impairment alters drug pharmacokinetics, especially in conditions like uremia, where changes such as prolonged elimination half-life and altered apparent volume of distribution can significantly affect drug disposition. These changes require careful modification of the dosing regimen to achieve the desired clinical...