Evaluation of Multi-Frequency Bio-Impedance Analysis for the Assessment of Extracellular and Total Body Water in Surgical Patients

Hannan, W. J.; Cowen, S. O.; Fearon, Kenneth C. H.; Plester, C.E.; Falconer, John; Richardson, Rosemary

doi:10.1042/cs0860479

Cited by 108 publications

(78 citation statements)

References 5 publications

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“…These equations had as dependent variables L 2 aR 50 with or without weight, gender and age. Multifrequency BIA generated new equations for ECW and TBW with regression equations based on L 2 aR x at ®xed frequencies (x), in which x was low (1 ± 5 kHz) for ECW 7,8,16 and high ( b 50 kHz) for TBW predictions, 7,8,16,17 or with the extrapolated resistance R ECW and R TBW . 12,13 The software of the Xitron 4000B model we used contains volume prediction equations-based emulsion sciences, a theory developed by Hanai.…”

Section: Volume Equationsmentioning

confidence: 99%

Validation of bio-impedance spectroscopy: Effects of degree of obesity and ways of calculating volumes from measured resistance values

Cox-Reijven¹,

Soeters

2000

Int J Obes

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BACKGROUND: Bioelectrical-impedance spectroscopy (BIS) is a very attractive method for body composition measurements in a clinical setting. However, validation studies often yield different results. This can partly be explained by the different approaches used to transform measured resistance values into body compartments. OBJECTIVE: The aim of this study was to compare the linear regression (LR) method with the Hanai Mixture theory (HM). Secondly, the effect of degree of overweight on the accuracy of BIS was analysed. DESIGN: In 90 people (10 M, 80 F; body mass index (BMI) 23 ± 62 kgam 2 ) total body water (TBW) and extracellular water (ECW) were measured by deuterium and NaBr dilution methods, respectively, and by BIS. Resistance values of ECW (R ECW ) and TBW (R TBW ) were used for volume calculations. Data of half the group were used for LR based on L 2 aR (L length, R resistance) to predict TBW and ECW and to calculate the constants used in the HM (k ECW ), k p ). Prediction equations and constants were cross-validated in Group 2. RESULTS: Bland and Altman analysis showed that the LR method underestimated TBW by 1.1 l (P`0.005) and ECW by 1.1 l (P`0.005). The HM approach underestimated ECW by 0.8 l (P`0.005). The correlations with the dilution methods and the SEEs for TBW and ECW were comparable for the two approaches. The prediction error of BIS for TBW and ECW correlated with BMI. The constant k ECW , and the speci®c resistivities of the ECW and intracellular water (ICW) p ECW and p ICW were also correlated with BMI. CONCLUSIONS: The mixture approach is slightly more accurate than linear regression, but not sensitive enough for clinical use. The constants used in the HM model are not constants in a population with a wide variation in degree of overweight. The physical causes of the correlation between BMI and constants used in the model should be studied further in order to optimize the mixture model.

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Section: Volume Equationsmentioning

confidence: 99%

Validation of bio-impedance spectroscopy: Effects of degree of obesity and ways of calculating volumes from measured resistance values

Cox-Reijven¹,

Soeters

2000

Int J Obes

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“…Baseline measurements of height, weight and total body water were undertaken. Total body water was measured using a Xitron 4000B bioimpedance spectrum analyser (Xitron Technologies, San Diego, CA, USA) as described previously (Hannan et al, 1994). Venous blood samples were taken for routine laboratory measurement of C-reactive protein, albumin, haemoglobin, total white blood cell count, differential white cell and platelet counts.…”

Section: Methodsmentioning

confidence: 99%

A pilot study of megestrol acetate and ibuprofen in the treatment of cachexia in gastrointestinal cancer patients

McMillan

O'Gorman²,

Fearon³

et al. 1997

Br J Cancer

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Summary Advanced gastrointestinal cancer patients with weight loss and an acute-phase response (n = 15) were given megestrol acetate (480 mg day-') and ibuprofen (1200 mg day-') for 6 weeks. Overall, there was an increase in body weight (P = 0.01) and a reduction in C-reactive protein concentrations (P = 0.02), with no change in total body water (P = 0.24) over this period. This regimen may be an effective non-toxic treatment for cancer cachexia and is worthy of further study.

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“…We used BIA on the standard 50 kHz frequency since measurements of R and Xc at multiple frequencies did not provide any clinically signi®cant improvement over measurements at only 50 kHz for the estimation of extracellular water and TBW. 22,23 First, we measured impedance vectors shorter than normal in about 50% of obese and 100% of edematous patients, which were well separable by a boundary line allowing 91% correct allocation, due to the difference in the phase angle of vectors (Figure 2). Therefore, in addition to con®rming the pattern of mean vectors from subject groups with fat or¯uid overload recognized in a previous pilot study, 8 we could mark a border on the lower pole of the genderspeci®c 75% tolerance ellipse discriminating between fat and¯uid overload in the individual subject.…”

Section: Discussionmentioning

confidence: 99%

Discriminating between body fat and fluid changes in the obese adult using bioimpedance vector analysis

et al. 1998

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OBJECTIVE: Conventional body composition methods may produce biased quanti®cation of fat and fat-free mass in obese subjects, due to possible violation of the assumption of constant (73%) tissue hydration. We used an assumption-free, graphical method for interpreting body weight variation in obesity using bioelectrical measurements. DESIGN: 540 obese subjects with body mass index (BMI) b 31 kgam 2 without apparent edema were compared to 726 healthy subjects with BMI`31 kgam 2 and to 50 renal patients with apparent edema. A subgroup of 48 obese subjects were evaluated again after weight loss (8.6 kg, 3 BMI units) following one-month energy restriction (5 MJad, 1200 kcalad). 32 obese uremic patients were evaluated before and after a dialysis session (3.2 kg¯uid removed). Direct measurements obtained from standard 50 kHz frequency bioelectrical impedance analyzer were used as impedance vectors in the Resistance-Reactance Graph. RESULTS: 1) Impedance vectors of obese subjects could be discriminated from those of edematous patients with 91% correct allocation; 2) A signi®cant lengthening of vectors was observed after¯uid loss of 3 kg in obese subjects; but 3) A body weight loss of about 9 kg after energy restriction was associated with no vector displacement. CONCLUSION: A different impedance vector pattern was associated with body weight loss in obesity due to¯uid removal (vector lengthening) versus an energy-restricted diet (no vector displacement).

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Evaluation of Multi-Frequency Bio-Impedance Analysis for the Assessment of Extracellular and Total Body Water in Surgical Patients

Cited by 108 publications

References 5 publications

Validation of bio-impedance spectroscopy: Effects of degree of obesity and ways of calculating volumes from measured resistance values

Validation of bio-impedance spectroscopy: Effects of degree of obesity and ways of calculating volumes from measured resistance values

A pilot study of megestrol acetate and ibuprofen in the treatment of cachexia in gastrointestinal cancer patients

Discriminating between body fat and fluid changes in the obese adult using bioimpedance vector analysis

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