Mr Dale Edwick1,2,3, Mr Jeremy Rawlins2,5, Professor Fiona Wood1,3,4, A/Professor Dale Edgar1,2,3,4
1Fiona Wood Foundation, Murdoch, Australia, 2Burns Service Of Western Australia – Fiona Stanley Hospital, Murdoch, Australia, 3Burn Injury Research Node – The University of Notre Dame Australia, Fremantle, Australia, 4Burn Injury Research Unit – The University of Western Australia, Crawley, Australia, 5Department of Plastic and Maxillofacial Surgery – Royal Perth Hospital, Perth, Australia
Background: Bioimpedance spectroscopy (BIS) is a measure of body composition, which has been shown to detect non-clinical lymphedema, and has the sensitivity to measure the reduction in hand volume elicited by elevation for a period of three minutes. Alternate electrodes positions have been shown to be suitable for measuring fluid shifts using BIS in moderate to large burns, where wounds preclude standardized electrode placement.
Aim: The aim of this study was to determine if measurement of hand volume by BIS was comparable in four electrode configurations in non-injured subjects.
Methods: Electrode positions on the dorsum of the hand and forearm has previously been described for measuring hand volumes by BIS. Three alternate electrode configurations were assessed using a combination of volar and dorsal hand and forearm electrode placements. BIS measures were performed on 30 subjects (60 hands), and recorded in triplicate for each configuration.
Results: Hand volume impedance depended on the inter-electrode distance and electrode configurations. Compared to the standard configuration, as the inter-electrode distance increased from 5 to 9 cm, the volar/volar placement showed a percentage impedance difference decrease of 5.04 to -0.014% (4.88Ω to -0.02Ω). The dorsal hand/volar forearm configuration also showed a decrease in difference of 12.64 to -2.07% (12.23Ω to -2.52Ω) with increasing inter-electrode distance. The volar hand/dorsal forearm configuration demonstrated an increasing difference as distance increased (-2.23Ω to -13.14Ω).
Conclusion: Preliminary results indicate that alternate electrodes positions are comparable to the standard for hand volume measurement by BIS. Validation is required in a burns population.
Dale is a Senior Physiotherapist in the State Adult Burns Unit at Fiona Stanley Hospital in Western Australia. He is also a PhD candidate at The University of Notre Dame Australia, investigating proactive management of oedema following hand burn injury.