Extracellular Fluid Movement in Elevated Lymphoedematous and Healthy Elevated Limbs: A study using Bio-impedance Spectroscopy

Background: Elevation and use of compression garments are common methods for reducing extracellular fluid volume, however our understanding of resulting fluid movement is limited. Normal anatomical variation between right and left complicates the fluid movement picture. Differences in microvasculature, lymphatic distribution and muscle mass all appear to result in asymmetrical fluid flux. Furthermore, arm dominance alters the left/right fluid balance, resulting in an overall fluid movement picture that is difficult to interpret. We anticipate that enhancing understanding of fluid fluxes in healthy and lymphoedematous limbs will help guide management of lymphoedema.
Objectives: The present study aimed to establish the differences in extracellular fluid movement between left and right arms; between lymphoedematous and healthy arms, and between arms with a compression garment, versus those without.
Methods: Upper limb electrical resistance was measured via BioImpedance using an ImpediMed SFB7 machine. Three measurements were taken every minute during the initial rest phase, and every thirty seconds during the elevation and final rest phases. Alternate participants had compression garments fitted. Parameters such as handedness, surgical procedures, medical treatments, and other relevant medical conditions were recorded. Participants were grouped into ‘garments’ or ‘no garments’, lymphoedema ‘affected’ or ‘unaffected’ and ‘left’ or ‘right’.
Results: The present study showed that in phases of elevation and rest, right arm resistance increases more than left arm resistance, in all groups. ‘Garments’ increase resistance in the final rest phase more than ‘no garments’. There was no difference between ‘affected’ and ‘unaffected’ groups.
Conclusions: Fluid volume is inversely proportional to bioimpedance, so increases in resistance are attributed to fluid efflux from the limb, and vice versa. We observed that right limbs drain fluid more effectively than left, likely due to a combination of handedness and anatomical variation. Studies with more left-dominant subjects may clarify this. We also observed that compression garments increased fluid drainage in all limbs, supporting the therapeutic use of compression. Interestingly, we found no difference between affected and unaffected limbs, and suggest that segmental bioimpedance may better reflect fluid fluxes within more localised areas.