No abstract

With the use of information from a database of pediatric patients with concomitant nuclear GFR and serum creatinine (Cr), estimated GFR equations were derived on the basis of local laboratory methods and population. These formulas then were compared with those recommended by the National Kidney Foundation for estimating GFR in children. For this, their ability to estimate accurately an individual's true GFR and chronic kidney disease stage, identify patients whose true GFR was <60 ml/min per 1.73 m 2 , and to identify correctly deterioration in an individual's GFR over time was compared. Next, two methods to estimate GFR in children without the use of height or weight were developed. The first was a height-and weightindependent formula; the second was a novel approach using the Schwartz formula and calculating a Cr cutoff based on age-based estimates of height and GFR level of interest, i.e., <60 ml/min per 1.73 m 2 . Our results suggest that if local laboratory constants are derived and a height is known, then the Schwartz formula offers the most accuracy with least mathematical complexity to perform in the clinical setting. If height is not available but the local laboratory constants have been derived, then the British Columbia's Children's Hospital 2 formula is of value; however, in the setting of estimating pediatric renal function in the outpatient laboratory, where neither of these factors is commonly known, an approach whereby a Cr cutoff for a GFR of interest is developed is suggested. Provided are Cr levels that are based on a reference method of Cr measurement to facilitate this approach for the clinician. . The National Kidney Foundation (NKF) has recognized that to "further improve dialysis outcomes, it is necessary to improve the health status of those who reach ESRD . . . from earliest kidney damage through the various stages of progression to kidney failure" (3). As a first step toward achieving this goal, the NKF developed a chronic kidney disease (CKD) classification system, the NKF Disease Outcomes Quality Initiative (NKF-DOQI) classification, to "improve/standardize" care of the patient at all stages of CKD (3).In the adult nephrology literature, a move toward classification and management of CKD on the basis of GFR has led to the proposal for widespread implementation of equations to calculated estimated GFR (eGFR) (4). These equations are often derived from studies in patients with particular illnesses, e.g., cancer (5,6), renal dysfunction (7,8), and organ transplantation (9 -11). They use some combination of easily obtained demographics (e.g., height, weight, gender, race) and serum measurements (e.g., creatinine [Cr], urea, albumin) (12) to calculate the individual's GFR or Cr clearance.Similarly, the pediatric members of the NKF CKD working group clearly stated that "major emphasis is placed on the identification of children and adolescents with CKD by measuring the protein-to-Cr ratio in spot urine specimens and by estimating the GFR from serum Cr using prediction equations" (13).Recog...

No abstract

In this randomized double-blind crossover trial we compared the antiproteinuric effects of enalapril and losartan in six children with proteinuria and underlying renal injury. The primary endpoint was reduction in proteinuria during therapy. The study had two 8-week on-drug arms, with a 4-week washout period between. Baseline proteinuria was similar, enalapril 87 mg/m(2) per hour and losartan 77 mg/m(2) per hour. The mean reduction in proteinuria with enalapril was 48% (37%-57%) with a standard error of the mean of 3%; with losartan it was 31% (14%-52%) with a standard error of the mean of 7%. Although there was a significant reduction in proteinuria with the use of both drugs, the difference in reduction of proteinuria, 48% versus 31%, was not considered clinically significant. Potassium remained below 4.5 mmol/l in all patients. No patient's creatinine rose more than the standard deviation of our assay. Blood pressure (BP) control was acceptable in four of the six patients; two patients had persistently elevated or increased BP on each drug. Side effects were minimal; none requiring withdrawal, one requiring dose reduction. Studies have shown that angiotensin converting enzyme inhibitors can reduce proteinuria in children with renal disorders. No studies to date have examined the reduction of proteinuria achieved by angiotensin receptor blockers. Our study, although small, suggests that angiotensin receptor blockers may reduce proteinuria as effectively, and as safely, as angiotensin converting enzyme inhibitors.