Impedance Analysis and Indicator Dilution (original) (raw)
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Journal of applied physiology (Bethesda, Md. : 1985), 2000
The purposes of this study were 1) to determine the compartmentation of body water in horses by using indicator dilution techniques and 2) to simultaneously measure bioelectrical impedance to current flow at impulse current frequencies of 5 and 200 kHz to formulate predictive equations that could be used to estimate total body water (TBW), extracellular fluid volume (ECFV), and intracellular fluid volume (ICFV). Eight horses and ponies weighing from 214 to 636 kg had catheters placed into the left and right jugular veins. Deuterium oxide, sodium thiocyanate, and Evans blue were infused for the measurement of TBW, ECFV, and plasma volume (PV), respectively. Bioelectrical impedance was measured by using a tetrapolar electrode configuration, with electrode pairs secured above the knee and hock. Measured TBW, ECFV, and PV were 0.677 +/- 0.022, 0.253 +/- 0.006, and 0.040 +/- 0.002 l/kg body mass, respectively. Strong linear correlations were determined among measured variables that allow...
BMC Research Notes, 2015
Background: Equations based on single-frequency bioelectrical impedance analysis at 50 kHz for determination of total body water content (TBW) have been previously validated in healthy non-sedated beagle dogs. We investigated whether these equations are predictive of TBW in various canine breeds by comparing the results of these equations with TBW values evaluated directly by deuterium oxide (D 2 O) dilution. Methods: Total body water content of 13 healthy adult pet dogs of various breeds was determined directly using D 2 O dilution and indirectly using previous equations based on values obtained with a portable bioelectric impedance device. Paired Student's t-tests were used to compare TBW obtained by single-frequency bioelectrical impedance analysis and D 2 O dilution. A p-value of <0.05 was considered statistically significant for all analyses. Results: Significant differences were observed between TBW determined by the reference method and the values obtained with both predictive equations. Conclusions: The proposed equations including single-frequency bioelectrical impedance analysis parameters validated at 50 kHz in healthy adult beagles need to be modified including morphological parameters such as body size and shape in a first approach. As in humans, morphological-specific equations have to be developed and validated.
The Journal of nutrition, 2002
KEY WORDS: • multifrequency bioelectrical impedance analysis • body composition • total body water • extracellular water • bioimpedance Multifrequency bioelectrical impedance analysis (MF-BIA 4 ) is a promising, noninvasive, rapid, safe, portable, reproducible, electrical method of assessing body composition that has the potential to quantify total body water (TBW), extracellular water (ECW) and intracellular water (ICW), and thereby enable prediction of the fat-free mass (FFM), fat mass (FM) and body cell mass (BCM) (1). To our knowledge, there have not been any reports evaluating the use of MF-BIA in cats. The purpose of this study was to develop the scaling constants and assess the effects of animal position, animal length measurement and electrode configuration on the volume prediction accuracy of the Hydra ECF/ICF Bioimpedance Analyzer (Model 4200; Xitron Technologies, San Diego, CA) compared to TBW estimated by deuterium water (D 2 O) space and ECW estimated by bromide (Br) space in healthy cats.
Equine and Comparative Exercise Physiology, 2004
The purpose of the present study was to determine the time course and magnitude of changes in extracellular and intracellular fluid volumes in relation to changes in total body water during prolonged submaximal exercise and recovery in horses. Seven horses were physically conditioned over a 2-month period and trained to trot on a treadmill. Total body water (TBW), extracellular fluid volume (ECFV) and plasma volume (PV) were measured at rest using indicator dilution techniques (D2O, thiocyanate and Evans Blue, respectively). Changes in TBW were assessed from measures of body mass, and changes in PV and ECFV were calculated from changes in plasma protein concentration. Horses exercised by trotting on a treadmill for 75–120 min incurred a 4.2% decrease in TBW. During exercise, the entire decrease in TBW (mean±standard error: 12.8±2.0 l at end of exercise) could be attributed to the decrease in ECFV (12.0±2.4 l at end of exercise), such that there was no change in intracellular fluid v...
PLOS ONE
Portable blood gas analyzers are used to facilitate diagnosis and treatment of disorders related to disturbances of acid-base and electrolyte balance in the ambulatory care of equine patients. The aim of this study was to determine whether 2 portable analyzers produce results in agreement with a stationary analyzer. Blood samples from 23 horses hospitalized for various medical reasons were included in this prospective study. Blood gas analysis and electrolyte concentrations measured by the portable analyzers VetStat and epoc were compared to those produced by the cobas b 123 analyzer via concordance analysis, Passing-Bablok regression and Bland-Altman analysis. Limits of agreement indicated relevant bias between the VetStat and cobas b 123 for partial pressure of oxygen (pO 2 ; 27.5-33.8 mmHg), sodium ([Na + ]; 4.3-21.6 mmol/L) and chloride concentration ([Cl-]; 0.3-7.9 mmol/L) and between the epoc and cobas b 123 for pH (0.070-0.022), partial pressure of carbon dioxide (pCO 2 ; 3.6-7.3 mmHg), pO 2 (36.2-32.7 mmHg) and [Na + ] (0.38.1 mmol/ L). The VetStat analyzer yielded results that were in agreement with the cobas b 123 analyzer for determination of pH, pCO 2 , bicarbonate ([HCO 3-]) and potassium concentration [K + ], while the epoc analyzer achieved acceptable agreement for [HCO 3-] and [K + ]. The Vet-Stat analyzer may be useful in performing blood gas analysis in equine samples but analysis of [Na + ], [Cl-] and pO 2 should be interpreted with caution. The epoc delivered reliable results for [HCO 3-] and [K + ], while results for pH, pCO2, pO2 and [Na + ] should be interpreted with caution.
British Journal of Nutrition, 2004
The present study was performed to determine how equilibrated fluctuations in hydration affected the validity of bioelectrical impedance analysis (BIA) for body composition assessment. Total body water (TBW) expansion was induced by a 4 d endurance trial and the subsequent water loss was obtained over the recovery period. Twelve healthy men exercised on a cycle and treadmill alternately for 5 h/d over 4 d at moderate intensity. TBW, fat mass (FM) and fat-free mass (FFM) were assessed 3 d before the trial (control), and on the first and eighth day of recovery (R1 and R8 respectively). TBW was evaluated by 2 H dilution (TBW 2H ) as a reference method and by BIA (TBW BIA ) at 100 kHz at the same time. TBW 2H increased significantly between the control day and R1 by 1·87 (SD 1·11) litres (P¼ 0·005) and TBW BIA by 1·38 (SD 1·56) litres (P¼0·009). Both values returned to the control level on R8. For each period, TBW 2H and TBW BIA did not differ significantly and were correlated (r 2 0·85, P¼0·0004 for the control day; r 2 0·63, P¼ 0·03 for R1; r 2 0·75, P¼0·02 for R8). Plasma Na concentration and osmolality did not differ between the control day, R1 and R8. FFM gain (1208 (SD 1983) g) and FM loss (21168 (SD 906) g) between the control day and R1 were followed by a FFM decrease (2624 (SD 1281) g) and a FM increase (860 (SD 1212) g) between R1 and R8. As expected, these FFM and FM changes were significantly correlated with TBW variations. The present results provide evidence that BIA may be a useful method for estimating TBW when fluid shifts are equilibrated and electrolyte concentrations are unchanged. However, it is not a valid technique for assessing FM and FFM under these conditions.
A physiological approach to fluid and electrolyte therapy in the horse
Equine Veterinary Journal, 1981
RésuméCet article discute d'une approche physiologique de la thérapie par les fluides commençant par l'examen de la distribution des fluides chez le cheval normal. Les fonctions des concentrations individuelles de plasmoélectrolytes sont abordées et les causes pratiques des déséquilibres aciees/base discutées. Lorsqu'une administration de fluide est nécessaire, la sélection du mode d'administration ainsi que du type de fluide sont des considérations importantes qui doivent être ajustées en fonction des besoins du cas individuel. Les solutions polyioniques équilibrées paraissent les mieux appropriées pour les applications générales, car les solutions salines normales peuvent entraîner une hypokaliémie et une acidose métabolique. L'emploi de bicarbonate est indiqué essentiellement lorsqu'il y a eu perte d'alcali (diarrhées par exemple) ou en cas d'acidose grave associée à une augmentation de la production de lactate. Les dilatateurs de volume plasmique ...
Medical & Biological Engineering & Computing, 2015
The objective of this study is to evaluate the accuracy of independent hydric data for the quantification of total body water (Vt), extracellular water (Ve) and intracellular water (Vi), obtained by a Z-Metrix multifrequency impedancemeter (ZM), in standing and lying position, with respect to the Xitron reference. In a second step, the aim is also to consider whether it is possible to quantify daily hydration. As part of the clinical study No. A01373-52-2008, 97 healthy subjects underwent ZM impedance with 29 of them also assessing Xitron. Note that the average repeatability error of the ZM impedancemeter is less than 0.5%. For total body water (Vt), we note a low R ² dispersion with an average of respectively 0.9 for men and 0.6 for women. The estimation of the total body water is more accurate for women with a maximum error of 1.8% in standing position against 3.9% for men in the same position. We note a low R ² dispersion respectively of 0.965 for men and of 0.84 for women. The estimation of extracellular water is equivalent with a maximum error of 3.1% in standing position for women against 2.97 % for men in the same position. The estimation of the total body water by direct measurement and by summing the volumes of extracellular and intracellular water obtained by the Z-Metrix ® shows very low dispersions with R ² equal to 0.89, and average error from 1.3 % for healthy women in lying position to 3.9% for healthy women in standing position. Finally, despite the impact of events on the daily impedance measurements, it is viable to track a subject's overall hydration.
American Journal of Veterinary Research, 2015
B ody composition analysis is essential for meaningful medical follow-up of individual patients, 1 but measurement of body weight alone is not a reliable method of evaluation. Therefore, simple and effective techniques for evaluation of body composition are highly desirable. Traditionally, the body is divided into 2 compartments (the water compartment and tissue compartment). The water compartment, or TBW, is divided into extracellular and intracellular compartments. The extracellular compartment consists of plasma and interstitial fluids in which cells are found. The tissue compartment consists of the FM and FFM. The FM is Indirect prediction of total body water content in healthy adult Beagles by single-frequency bioelectrical impedance analysis
Int J Environ Res Public Health, 2020
The aims of this study were to analyze the usefulness of raw bioelectrical impedance (BI) parameters in assessing water compartments and fluid distribution in athletes. A total of 202 men and 71 female athletes were analyzed. Total body water (TBW) and extracellular water (ECW) were determined by dilution techniques, while intracellular water (ICW) was calculated. Fluid distribution was calculated as the ECW/ICW ratio (E:I). Phase angle (PhA), resistance (R) and reactance (Xc) were obtained through BI spectroscopy using frequency 50kHz. Fat (FM) and fat-free mass (FFM) were assessed by dual-energy X-ray absorptiometry. After adjusting for height, FM, FFM, age and sports category we observed that: PhA predicted ICW (females: β = 1.62, p < 0.01; males: β = 2.70, p < 0.01) and E:I (males and females: β = -0.08; p < 0.01); R explained TBW (females: β = -0.03; p < 0.01; males: β = -0.06; p < 0.01) and ECW (females: β = -0.02, p < 0.01; males: β = -0.03, p < 0.01) and...