Intrarenal Blood Flow in Children with Normal Kidneys and Congenital Heart Disease: Changes Attributable to Angiography

Abstract

ExtractThirty 133Xe determinations of renal blood flow were made in 20 children ranging in age from l9f2 to I09i2 years. I n six normal kidneys average blood flows to the outer and inner cortex were 374 and 44 ml/min/100 g, respectively. Mean fractional flows to these areas were 84 and 15 ml/min/100 g, respectively. I n nine children with congenital heart disease (CHD) who were not in congestive heart failure and who were evaluated before angiography, a defect in outer cortical flow was demonstrated. Average blood flows to the outer and inner cortex were 250 ml/min/100 g ( P 0.0005) and 27 ml/min/100 g ( P 0.22). Mean fractional flows were 76y0 ( P 0.03) and 24% ( P 0.015), respectively.After cardiac angiography, a decrease in outer cor~ical flow occurred. The second flow study was performed 8-30 min after injection of contrast media (Hypaque-M, 75%) in amounts which ranged from 1.2 to 3.5 ml/kg body wt. After angiography, blood flows to the outer and inner cortex were 186 ml/min/100 g ( P 0.001) and 24.5 ml/min/100 g (P 0.68). Average fractional flow to the outer, 74y0 and inner: Z6Y0 cortex, did not change ( P 0.71). SpeculationKidneys of children with CHD have decreased outer cortical flow, which may result in increased renal renin production. Therefore, a child with CHD may suffer the long term consequences of hyperreninemia. Furthermore, the balance of any metabolic system whose metabolic pathways involve the outer cortex may be altered and hemodynamic response to stressful clinical situations may be greater in the kidneys of children. Zntroclz~ctioninjecting a bolus of into the renal artery and monitoring the rate of disappearance of the isotope by Although inforlnation of major importance relative to ol external counting devices over the renal blood flow (RBF) has been obtained using the kidney. Graphic analysis of the resultant data provides radionucleide 01 the inert gas, xenon (l3%e), in aniinformation relative to both the rate of nutrient flow rnals and in human adult subjects, this technique has and the fraction of total Aow which perfuses the outer not been used previously to invastigate problems speand inner cortical regions of the kidney. That the cifically related to pediatrics. The RBF is determined by 13"e technique provides useful hemodynamic data in

Renal blood flow in high and low positions of aortal catheter in rabbits

“…The measurement of RBF with an isotope technique is a reliable and accurate method if the isotope bolus is injected into the aorta [5]. This is also the most serious drawback of the method when considering human studies [10].…”

Neonatal and infant physiology—impact of cardiopulmonary bypass in the developing patient

“…123 Infants with cyanotic congenital heart disease appear to have similar patterns of distribution of flow of blood compared with normal term neonates. 124 The differences in renal function, blood flow, and perfusion seen in newborns and young children compared with those seen in older children and adults may well be attributable to changes in renal vascular resistance which are regulated by a variety of vasoactive agents: prostaglandins, bradykinins, angiotensin II, and catecholamines. The precise interaction between these vasoactive compounds is as yet undetermined.…”