Published: June 30th, 2023
In this protocol, we explain how to obtain and interpret phase angle values and bioelectrical impedance vectorial analysis (BIVA) Z-score obtained by bioelectrical impedance in patients with acute heart failure admitted to the Emergency Department and their clinical applicability as a predictive marker for the prognosis of a 90-day event.
Acute heart failure is characterized by neurohormonal activation, which leads to sodium and water retention and causes alterations in body composition, such as increased body fluid congestion or systemic congestion. This condition is one of the most common reasons for hospital admission and has been associated with poor outcomes. The phase angle indirectly measures intracellular status, cellular integrity, vitality, and the distribution of spaces between intracellular and extracellular body water. This parameter has been found to be a predictor of health status and an indicator of survival and other clinical outcomes. In addition, phase angle values of <4.8° upon admission were associated with higher mortality in patients with acute heart failure. However, low phase angle values may be due to alterations-such as the shifting of fluids from an intracellular body water (ICW) compartment to an ECW (extracellular body water) compartment and a concurrent decrease in body-cell mass (which can reflect malnutrition)-that are present in heart failure. Thus, a low phase angle may be due to overhydration and/or malnutrition. BIVA provides additional information about the body-cell mass and congestion status with a graphical vector (R-Xc graph). In addition, a BIVA Z-score analysis (the number of standard deviations from the mean value of the reference group) that has the same pattern as that of the ellipses for the percentiles on the original R-Xc graph can be used to detect changes in soft-tissue mass or tissue hydration and can help researchers compare changes in different study populations. This protocol explains how to obtain and interpret phase angle values and BIVA Z-score analyses, their clinical applicability, and their usefulness as a predictive marker for the prognosis of a 90-day event in patients admitted to an emergency department with acute heart failure.
Acute heart failure (AHF) results from the rapid onset of signs, symptoms, and exacerbation of derivates of HF and a combination of clinical, hemodynamic, and neurohormonal abnormalities, including systemic inflammatory activation, which leads to sodium and water retention1. This long-term accumulation causes the interstitial glycosaminoglycan (GAG) networks to become dysfunctional, resulting in reduced buffering capacity and changing the form and function of the GAG networks1,2. This contributes to alterations in body composition due to the shifting of fluids from intracellular to....
The protocol was approved by the Research Ethics Committee of the National Institute of Medical Sciences and Nutrition Salvador Zubirán (REF. 3057). To conduct BIA measurements, tetrapolar multiple-frequency equipment was used (see Table of Materials). This equipment provided accurate raw values for the resistance (R), reactance (Xc), and phase angle (PhA) at a frequency of 50 kHz, which allowed the impedance to be measured with the best signal-to-noise ratio. The adhesive electrodes used needed to .......
According to the protocol described above, we present data from four AHF patients (two females and two males) who were admitted to an emergency department as an example of the clinical applicability of phase angle values and BIVA Z-score analysis. BIA measurements were performed using phase-sensitive multiple-frequency equipment within 24 h of admission.
To calculate the bivariate Z-score from the mean of the age group, the following formula was used: Z(R) = (R/H mean value of the age group - .......
This protocol describes the utility of using R-Xc Z-score analysis in clinical practice for patients admitted to an emergency department with AHF. Considering that in patients with AHF, the main reason for hospital admission is congestion, its quick and accurate detection, and evaluation are crucial for patients' outcomes6.
This article illustrates the variety of clinical manifestations of AHF and how BIVA Z-score analysis (congestion status and BCM) can be used to .......
The authors would like to thank Prof(s). Piccoli and Pastori of the Department of Medical and Surgical Sciences, University of Padova, Italy, for providing the BIVA software. This research did not receive any specific grant from funding, agencies in the public, commercial, or not-for-profit sectors. This protocol/research is part of the Ph.D. dissertation of María Fernanda Bernal-Ceballos supported by the National Council of Science and Technology (CONACYT) scholarship (CVU 856465).....
|Alcohol 70% swabs
|Any brand can be used
|BIVA software 2002
|Is a sofware created for academic use, can be download in http:// www.renalgate.it/formule_calcolatori/ bioimpedenza.htm in "LE FORMULE DEL Prof. Piccoli" section
|Any brand can be used
|Any brand can be used
|Leadwires square socket
|Long Bodystat 0525 electrodes
|Quadscan 4000 equipment
|Impedance measuring range:
20 - 1300 Ω ohms
Test Current: 620 μA
Frequency: 5, 50, 100, 200 kHz Accuracy: Impedance 5 kHz: +/- 2 Ω Impedance 50 kHz: +/- 2 Ω Impedance 100 kHz: +/- 3 Ω Impedance 200 kHz: +/- 3 Ω
Resistance 50 kHz: +/- 2 Ω
Reactance 50 kHz: +/- 1 Ω
Phase Angle 50 kHz: +/- 0.2° Calibration: A resistor is supplied for independent verification from time to time.
The impedance value should read between 496 and 503 Ω.
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