We had the pleasure of having Louise Koelmeyer (Lymphoedema Program Manager at Macquarie University) and Conrad Nguyen (Senior Director at Impedimed) over to the UK for the last 5 days.
During the week, we visited NHS and Private Breast Care and Lymphoedema services discussing the internationally recognised best practice of the early detection model of care for Lymphoedema. We met some incredible clinicians who are really passionate, patient-orientated people who welcomed the idea of early detection and really saw the value and benefits. The two workshops we ran in Taunton and Derby were well attended and we discussed the research and evidence behind the pathway of care and just how impactful it is. We even managed to fit in a quick selfie at Stonehenge and a typical English delicacy (fish and chips!).
What are we measuring?
When we are wanting to detect sub-clinical changes in patients at risk of developing Lymphoedema, we are just focusing on measuring extracellular fluid. Bioimpedance Spectroscopy (BIS) sends 256 frequencies through the body which is measuring all body composition;
- Total Body Water
- Extracellular Fluid
- Intracellular Fluid
- Fat Mass
- Fat-Free Mass
As Lymphoedema in early stage 0 and stage 1 is changes in extracellular fluid, the L-DEX was developed to just focus on this component. The device compares the BIS measurement of the affected arm/leg to the unaffected arm/leg as a control so we can track the changes over time.
“As a Lymphoedema Therapist I use the technology across all Lymphoedema” – Louise Koelmeyer.
Focussing on extracellular fluid changes allows us to be more objective and accurate. When comparing to tape measure and Perometry, it is important to remember what those methods are measuring. Within a circumferential volume measurement we measure everything;
- Connective Tissue
As we are measuring all these components, we cannot differentiate between these tissues so we are not truly being specific. As the SOZO device JUST measures extracellular fluid, we, the clinician, can be more specific, objective, and precise when monitoring for early changes. That is the key thing to remember, SOZO measures changes in fluid which are proven to be a more effective method for detecting early changes of Lymphoedema than volume measurements.
What do the readings mean?
“Stage 0 and stage 1 is where we see increases in extracellular fluid. If you go beyond stage 1, into stage 2 and 3 Lymphoedema we are seeing tissue changes, including the development of fibrotic tissue. If we used this technology across all Lymphoedema patients, then we have to understand what stage of Lymphoedema, the composition changes of the patient is and what’s going to happen with my Bioimpedance reading” – Louise Koelmeyer
“A pre-treatment measurement is recommended for monitoring each individual so you can get their baseline or ‘normal’ reading. For sub-clinical changes, we are now looking at a change of 6.5 L-DEX points instead of 10 from their baseline measurement. This is why it is so important to get the pre-treatment baseline test” – Louise Koelmeyer.
Bioimpedance spectroscopy (BIS) is the technology to measure early changes of Lymphoedema and the L-DEX score is the number that interprets the BIS data. There’s a normative range between –10 and +10 L-DEX points, which we would expect 99.7% of people without Lymphoedema to fit within that range.
Remember what the SOZO measures, Extracellular Fluid. The L-DEX score simply interprets the BIS raw data where it has compared the affected to the unaffected limb and is giving you a ratio between the two. We are looking for changes in that score from the patient’s pre-treatment baseline. For example, if a patients’ pre-treatment L-DEX is -5, during follow-ups, if their score moves to 1.5 points or higher this is where we would look to possibly intervene as this could signify subclinical changes.
Example of how to interpret the data
“I had a stage 2 patient with predominantly fibrotic tissue and the L-DEX score was ‘within range’ (+10 to -10), Why? They clearly have Lymphoedema but the L-DEX is coming up as normal?”
Remember the SOZO (L-DEX) is measuring for extracellular fluid, if you have a ‘normal’ L-DEX score, that must mean the fluid content is very small and the tissue is predominantly fibrotic changes so you are being presented with a Lymphoedema that is very fibrotic.
“We have found after a 4 week intensive course of treatment, the L-DEX reading was going up after we’ve done treatment, even though the volume measurements are going down – Why?”
We are changing simply changing the tissue content. If we are feeling the arm is much softer, it’s changing from fibrosis to fluid so as the fluid content goes up. It makes sense that the L-DEX is going up. And if we explain to the patients why there’s a high L-DEX which means the stage of Lymphoedema is reducing.
A huge thank you to Ali Batchelor in Taunton and Dr. Vaughan Keeley and Katie Riches of Derby for not only hosting the workshops but presenting as well, we really appreciate the support.