Single frequency versus bioimpedance spectroscopy for the assessment of lymphedema

Background The aims were to determine (i) whether single frequency bioimpedance analysis (SFBIA) is as accurate as bioimpedance spectroscopy (BIS) in measurement of extracellular fluid and (ii) whether change in extracellular fluid was specific to only the limb directly affected by surgery. Methods Arms of the control (n = 28) and arm lymphedema group (n = 28) and legs of the leg lymphedema group (n = 16) were assessed with SFBIA. All four limbs in all participants were assessed with BIS. All measurements occurred in a single session. Results BIS-measured ratios were highly concordant with those obtained with SFBIA (r (c) = 0.99, P < 0.001). Repeated measures ANOVA revealed that the ratio involving the lymphedema limb was different to the ratio of the non-oedematous limbs which was not significantly different to the arm or leg ratios of the control group. Conclusions SFBIA is a simple accurate alternative to BIS for the clinical assessment of unilateral lymphedema. BIS discriminates those with clinical diagnosis of unilateral lymhoedema from those without the diagnosis.