Vascular and Extravascular Volumes of the Kidney of Man

Abstract

Indicator dilution techniques were used to determine the vascular and extravascular volumes of the normal human kidney. Renal volumes were corrected to 1.73 m 2 and refer to one kidney. The renal blood volume (V I0 ) averaged 34.8 ±3.1 ml; the water contained in the distribution volume of labeled inulin (Vi X ") averaged 48.8 ± 9.0 ml, and that of tritiated water ) were derived and averaged 27.4 ± 6.2 ml and 93.7 ± 14.3 ml, respectively.Correction for recirculation by exponential extrapolation was studied and appears satisfactory. Evidence is presented for the existence of significant fluctuations in renal blood flow during the indicator collection intervals, and it is suggested that renal volumes be based on flows determined from the recoveries of each indicator. ADDITIONAL KEY WORDSindicator dilution studies inulin renal extracellular volume renal blood volume creatinine renal water volume renal blood flow indocyanine green tritiated water• The in vivo measurement of the vascular and extravascular volumes of individual organs has been made possible in recent years by indicator dilution techniques. These measurements are based on the product of blood flows and mean transit times of indicators that gain access to one or more of the aqueous compartments of the organ. With this ap-

Renal Distribution Volumes of Indocyanine Green, [51Cr]EDTA, and 24Na in Man during Acute Renal Failure after Shock. IMPLICATIONS FOR THE PATHOGENESIS OF ANURIA

“…Despite the geometrical simplifications involved in this method it is probable that it yields a volume which closely approximates that of the kidney itself, the main renal vessels and the small amount of adjacent tissues supplied by the renal artery. This is supported by the results from the normal subjects in whom the mean was 215 ml, and thus only slightly above the value of 180 ml estimated as the in vivo volume of the human kidney by Effros, Lowenstein, Baldwin, and Chinard (25).…”

“…DIS CUSSION The reliability of the indicator-dilution technique for the measurements of total RBF and renal transit time "has been discussed in detail elsewhere (12,(23)(24)(25)29). In the present study, since relatively high RBF's were -found in some patients with acute anuria, it would seem relevant to consider whether this was the result of an overestimation due to errors of the dye-dilution method.…”

“…The reproducibility of the indicatordilution curves was satisfactory. Although the areas of consecutive curves from a patient varied somewhat, presumably reflecting rapid changes in renal circulation (25), when the means of the two sets of indocyanine green curves recorded in each patient were compared the coefficient of variation was low. In a series of 18 pairs of determinations of RBF (normal subj ects and patients with acute renal failure), the SE of the differences was 29.8 ml/min, the mean RBF was 428 ml/min, and the coefficient of variation was 7%o.…”

“…In previous studies we attempted to reduce the influence of the recirculating indicator on the surface calculation by drawing an oblique base line between the pre-and postinjection levels (6,12). Other investigators ignored the second wave and simply extrapolated the exponential downslope to 1% of the curve's peak height (23)(24)(25)(26). A better way is probably to subtract the recirculation wave recorded from the contralateral vein, which yields values that are between those from the two other methods.…”

The in vivo pH of the extravascular space of the lung

“…A volume of 0.9 ml absolute ethanol was added to 0.1 ml of blood, and the mixture in the tube was mixed and centrifuged. A volume of 0.2 ml of the alcohol supernatant was added to 10 ml of a dioxane scintillation mixture described earlier (24), and carbon-14 and tritium counts were obtained in a liquid scintillation spectrometer. Quinine determinations were made fluorometrically: A 0.5 ml volume of the alcohol supernatant was added to 5.0 ml of water and 0.5 ml of 1 N H2SO4.…”