To determine the efficacy of elevation in the primary prevention and treatment of pressure ulcers by studying the blood flow in tissue at risk of ulceration.
A prospective study was used to compare different preventative devices with an elevating prosthesis.
Wollongong Hospital Wollongong, New South Wales, Australia.
Normal subjects and subjects with vasculopathy were tested with their heel resting on a hospital bed, medical-grade lamb's wool, or a viscoelastic gel overlay, with or without the test prosthesis. Skin perfusion was measured throughout using a laser Doppler monitor.
A device designed to elevate the heel off the bed and distribute the weight of the leg and foot on the calf.
MAIN OUTCOME MEASURE:
Heel capillary blood perfusion.
Perfusion in the heel was significantly greater when elevated than when using the other devices tested. The differences in mean red blood cell flux were significant, with P < .0001 for bed-normals, ie, subjects with no peripheral vascular disease on an α Xcell mattress overlay as the control with flux increasing from 7.6 to 163.1 arbitrary units (AU); P < .005 bed-vasculopathy, ie, subjects with peripheral vascular disease on an α Xcell mattress overlay as the control with flux increasing from 31.6 to 224.7 AU; P < .0001 viscoelastic overlay subjects where the viscoelastic overlay was the control with flux increasing from 26.6 to 291.4 AU; and P < .01 lamb's wool subjects where the lamb's wool was the control with flux increasing from 27.7 AU to 169.2 AU.
In this study, when the heels were elevated, tissue perfusion to that area was substantially increased. When the heel was transferred to the elevating splint, the heel capillary bed underwent reactive hyperemia, indicating the alleviation of tissue hypoxia. Elevation is therefore an important technique in pressure ulcer prevention and treatment and should be incorporated into health care practice.