The Importance of Bioimpedance
INTRODUCTION TO BIOIMPEDANCE
Measurements are one of the major challenges relating to the prevention, diagnosis, and treatment of lymphedema. New technology, through the use of bioimpedance, brings hope of having a simplified and practical technique for obtaining these essential measurements.
Bioimpedance (BIA) is a noninvasive method for estimating body composition based on the electrical conductive properties of various tissues.
Commonly known as BIA, it involves the use of low frequency electrical currents traveling through the extracellular fluid and tissues. Although the signals travel through the tissues, they do not penetrate the cell membranes.
Lymph, which is also known as extracellular fluid, is located between, but not within the cells of these tissues. As excess lymph accumulates within the tissues it cannot drain properly. This causes the condition known as lymphedema.
WHAT IS IMP® XCA
Lymphedema Progression as charted by BIA and photographs
(Courtesy of Impedimed)
The Imp™ XCA is the instrument shown above on the right. It is designed to assist in the clinical assessment of the developing, or presence of, unilateral secondary lymphedema of the arm related to the treatment of breast cancer.
The chart and photographs shown other ways of visualizing the differences.
The FDA has approved the ImpediMed XCA device, and the L-Dex system, for the clinical assessment of lymph only in the arms. More information on bioimpedance devices, and measurements associated with lymphedema, are available from the Impedimed website (www.Impedimed.com).
The device has the advantages of obtaining measurement that include:
Sufficient sensitivity to detect early, preclinical lymphedema, before the symptoms are noticeable.
The ability to monitor even the very smallest changes.
Accuracy in obtaining vital measurements plus the ability to repeat these accurate measurements.
Sufficient speed to have obtained measurements of both the right and left arms within five minutes.
The ability to detect lymphedema without having to rely on comparison with a limb that is not affected. This helps in cases of bilateral lymphedema affecting both limbs.
The ability to detect lymphedema in areas other than the limbs. The FDA is considering approval of these uses but has not yet given approval.
WHY ACCURATE MEASUREMENTS ARE SO IMPORTANT
Obtaining accurate measurements is one of the major challenges related to the diagnosis, treatment, and record keeping of lymphedema. These accurate measurements are important for these reasons:
Early detection, and prompt treatment, is essential. When a patient is at risk of developing secondary lymphedema, early detection and treatment increase the potential of controlling, and possibly even stopping the development of lymphedema.
Justifying continued treatment under certain reimbursement plans. Most healthcare plans require periodic measurements showing progress before ongoing treatment will be authorized.
During the maintenance phase of lymphedema treatment, accurate measurements are essential in evaluating the effectiveness of the treatment plan.
WHAT DOES ALL OF THIS MEAN?
Bioimpedance can detect developing lymphedema at Stage 0 which is even before any clinical signs are visible.
This reduces any the long term effects that are the result of delayed beginning of treatment until visible symptoms, such as swelling, are obvious.
With this simple test, breast cancer patients, and others who are at risk for developing lymphedema of the arms, can be monitored more closely and accurately.
This early detection, and the immediate beginning of treatment, can prevent problems including infection, fibrosis, and the accumulation of excess adipose (fat) tissue. In one study, bioimpedance predicted the onset of lymphedema up to 10 months before clinical diagnosis.
Lymphedema therapists can save time, and reduce frustration, by using bioimpedance instead of more tradition measurement methods. Reducing the time required for measurement frees up time that can be used for providing treatment procedures and for seeing additional patients.
Better data on the effectiveness of lymphedema treatment and self-care options ultimately leading to better care.
 “Early Diagnosis of Lymphedema Using Multiple Frequency Bioimpedance” by B. H. Cornish et. al. Lymphology, No 34, 2001.
 "Early Diagnosis of Lymphedema Using Multiple Frequency Bioimpedance" by B. H. Cornish et. al. Lymphology, No 34, 2001.
 "A New Technique for the Quantification of Peripheral Edema with Application in Both Unilateral and Bilateral Cases" by B. Cornish, PhD et. al. Angiology, Vol 53, No 1, 2002.
 "The Use of Bioimpedance Analysis to Evaluate Lymphedema" by A. Warren et. al. Annals of Plastic Surgery, Vol 58, No 5, May 2007.
 "Bioimpedance Analysis in the Assessment of Lymphoedema Diagnosis and Management" by S. Rockson, MD. Journal of Lymphoedema, 2007, Vol 2, No 1.
 "Understanding Lymphoedema in the New Millenium" by Professor N. Piller. Journal of Lymphoedema, 2006, Vol 6, No 1, pages 60-65.
 Position Statement of the NLN on The Diagnosis and Treatment of Lymphedema. Updated February 2011.
© LymphNotes.com 2011. This information does not replace the advice of a qualified health care professional.
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Category: Are You at Risk for Lymphedema? Updated: 2012-07-13