SKIN MICROCIRCULATORY AND THERMAL-CHANGES IN ELDERLY SUBJECTS WITH EARLY-STAGE OF PRESSURE SORES

Elderly subjects are prone to develop pressure sores over the sacrum a rea mainly due to external pressure and shear effects which negatively affect the skin microcirculation. The aim of the study described here was to measure skin microcirculatory and thermal changes in twelve el derly patients with an early stage of pressure sore and in ten elderly subjects without pressure sore. The total skin microcirculation at a damaged risk area, the sacrum, and a reference area of undamaged skin over the gluteal region, was evaluated using the laser Doppler fluxmet ry. The nutritive transport of small solutes, characterized by the tra nscapillary exchange of sodium fluorescein, was evaluated using the fl uorescein flowmetry technique. The skin temperature was measured with a thermoelement. The skin microcirculation at the area with an early s tage of pressure sore was significantly higher than at undamaged skin as measured by both techniques. The total microcirculatory blood flow increased >16 times (P<0.001) and the nutritive transport approximate to 5 times (P<0.01) compared to the reference value, and the calculate d blood flow of subpapillary tissue layers increased 17-19 times (P<0. 001). However, the skin temperatures in damaged and undamaged skin did not differ significantly. These results show an increased skin microc irculation in the early stage of pressure sores but no increase in ski n temperature. The more strongly increased skin blood flow in subpapil lary tissue layers effectively conducts away the heat caused by the da mage and the increased metabolic activity.