Determination of the steady-state volume of distribution using arterial and venous plasma data from constant infusion studies with procainamide

1982 ◽  
Vol 34 (2) ◽  
pp. 132-134 ◽  
Author(s):  
Gilbert Lam ◽  
Win L. Chiou
Keyword(s):  
Steady State ◽  
Volume Of Distribution ◽  
Constant Infusion ◽  
Venous Plasma

Assessment of methods for improving tracer estimation of non-steady-state rate of appearance

1999 ◽  
Vol 87 (5) ◽  
pp. 1813-1822 ◽  
Author(s):  
A. Gastaldelli ◽  
A. R. Coggan ◽  
R. R. Wolfe
Keyword(s):  
Steady State ◽  
Infusion Rate ◽  
Traditional Approach ◽  
Volume Of Distribution ◽  
Constant Volume ◽  
Constant Infusion ◽  
Steady State Condition ◽  
Fixed Volume ◽  
The One ◽  
Infusion Technique

The most common approach for estimating substrate rate of appearance (Ra) is use of the single-pool model first proposed by R. W. Steele, J. S. Wall, R. C. DeBodo, and N. Altszuler. ( Am. J. Physiol. 187: 15–24, 1956). To overcome the model error during highly non-steady-state conditions due to the assumption of a constant volume of distribution (V), two strategies have been proposed: 1) use of a variable tracer infusion rate to minimize tracer-to-tracee ratio (TTR) variations (fixed-volume approach) or 2) use of two tracers of the same substrate with one infused at a constant rate and the other at a variable rate (variable-volume approach or approach of T. Issekutz, R. Issekutz, and D. Elahi. Can. J. Physiol. Pharmacol. 52: 215–224, 1974). The goal of this study was to compare the results of these two strategies for the analysis of the kinetics of glycerol and glucose under the non-steady-state condition created by a constant infusion of epinephrine (50 ng ⋅ kg−1 ⋅ min−1) with the traditional approach of Steele et al., which uses a constant infusion and fixed volume. The results showed that for glucose and glycerol the estimates of Raobtained with the constant and the variable tracer infusion rate and the equation of Steele et al. were comparable. The variable tracer infusion approach was less sensitive to the choice of V in estimating Ra for glycerol and glucose, although the advantage of changing the tracer infusion rate was greater for glucose than for glycerol. The model of Issekutz et al. showed instability when the ratio TTR1/TTR2approaches a constant value, and the model is more sensitive to measurement error than the constant-volume model for glucose and glycerol. We conclude that the one-tracer constant-infusion technique is sufficient in most cases for glycerol, whereas the one-tracer variable-infusion technique is preferable for glucose. Reasonable values for glucose Ra can be obtained with the constant-infusion technique if V = 145 ml/kg.

Noncompartmental Determination of the Steady‐State Volume of Distribution

1979 ◽  
Vol 68 (8) ◽  
pp. 1071-1074 ◽  
Author(s):  
Leslie Z. Benet ◽  
Renato L. Galeazzi
Keyword(s):  
Steady State ◽  
Volume Of Distribution

Method for the determination of the arteriovenous muscle protein balance during non-steady-state blood and muscle amino acid concentrations

2005 ◽  
Vol 289 (6) ◽  
pp. E1064-E1070 ◽  
Author(s):  
Christos S. Katsanos ◽  
David L. Chinkes ◽  
Melinda Sheffield-Moore ◽  
Asle Aarsland ◽  
Hisamine Kobayashi ◽  
...  
Keyword(s):  
Steady State ◽  
Amino Acid ◽  
Muscle Protein ◽  
Volume Of Distribution ◽  
Protein Balance ◽  
Nonsteady State ◽  
Balance Technique ◽  
Amino Acid Concentrations ◽  
Rate Of Accumulation

We describe a method based on the traditional arteriovenous balance technique in conjunction with muscle biopsies for the determination of leg muscle protein balance during the nonsteady state in blood amino acid concentrations. Six young, healthy individuals were studied in the postabsorptive state (pre-Phe) and after a bolus ingestion of ∼0.5 g phenylalanine (post-Phe). Post-Phe free phenylalanine concentrations in blood and muscle increased ( P < 0.05), but the respective concentrations of the amino acid threonine did not change. The average post-Phe leg net balance (NB) for threonine decreased from basal ( P < 0.05), but that for phenylalanine did not change. A volume of distribution for free phenylalanine in the leg was calculated based on the leg lean mass and the relative muscle water content and used to estimate the rate of accumulation of free phenylalanine in the leg. When the post-Phe NB for phenylalanine was corrected for the rate of accumulation of free phenylalanine in the leg, the post-Phe NB for phenylalanine decreased from basal ( P < 0.05). This corrected value was not different ( P > 0.05) from the value predicted for the phenylalanine NB based on the pre- and post-Phe NB responses for threonine. We conclude that the protein NB in non-steady-state blood phenylalanine concentrations can be determined from the arteriovenous phenylalanine NB by accounting for changes in free phenylalanine within its volume of distribution.

Changes in glycerol kinetics after E. coli endotoxin administration in dogs

1984 ◽  
Vol 246 (3) ◽  
pp. R325-R330
Author(s):  
O. P. McGuinness ◽  
J. J. Spitzer
Keyword(s):  
Steady State ◽  
Infusion Rate ◽  
Volume Of Distribution ◽  
Constant Infusion ◽  
Metabolic Clearance ◽  
Glycerol Concentration ◽  
Endotoxin Administration ◽  
E Coli ◽  
The Face ◽  
Anesthetized Dogs

The metabolic clearance rate (MCR) and maximal rate of glycerol removal (Rd max) were determined in anesthetized dogs at two time periods after the intravenous administration of either Escherichia coli endotoxin or saline. The nonisotopic method employed in these studies to determine the MCR of glycerol consisted of a constant infusion of glycerol at three different infusion rates. At each infusion rate a steady-state glycerol concentration was obtained. The reciprocal of the slope of the linear relationship between the glycerol infusion rate and the change in the steady-state arterial glycerol concentration was equal to the MCR of glycerol. Administration of endotoxin significantly decreased the MCR of glycerol, whereas the volume of distribution of glycerol was not altered significantly. The arterial glycerol turnover remained unaltered, whereas arterial glycerol concentration increased after endotoxin administration. The studies demonstrate that the elevated arterial glycerol concentration maintained the rate of glycerol turnover in the face of decreased efficiency of glycerol removal after endotoxin administration.

Sign in / Sign up

Export Citation Format

Share Document