Abstract
Frequent unloading is vital to avoid pressure ulcers of the seat area in patients with injuries to the spinal cord. The duration of unloading is probably as important as that of the sitting period in the prophylaxis of pressure ulcers. The aim of this study was to investigate the microcirculatory reactions after occlusion of the buttock skin after repeated ischaemic provocation. The perfusion of buttock skin was studied with a laser Doppler perfusion imager (LDPI) in healthy people after short and long periods of sitting (repeated four times). The perfusion increased significantly during the consecutive loadings compared with the first loading, and this effect was more profound after the long load. Repeated periods of ischaemia of the buttock skin without allowing the tissues to recover resulted in increasing reactive hyperaemia, and are therefore probably more damaging than single loadings. This is important when establishing clinical guidelines for the prophylaxis of pressure ulcers in patients with spinal cord injuries.