Characteristics of blood flow velocity in rat skin with alterations in core temperature as measured by laser doppler velocimetry

The skin's microcirculation plays an integral part in the regulation of body temperature in homeothermic organisms. Heat produce by the organism is transferred from the interior of the body to the skin's surface via the microcirculation. Although many medical and nursing therapies utilize heat and /or cold there is little research that explicates the effects of alterations in temperature and the resultant alterations in skin blood flow. The purpose of this study was to measure blood flow velocity utilizing the laser Doppler velocimeter (LDV) of abdominal skin in rats with and without a sandwich flap with alterations in core temperature. Blood flow measurements and skin temperature values were obtained from contralateral segments of abdominal skin in normal rats with every 1?C change in core temperature. In rats with a surgically constructed sandwich flap, blood flow velocity measurements and skin temperature values were obtained from the following skins: a) left abdominal skin, b) the host side of the sandwich flap, and c) the graft side of the sandwich flap at every 1?C change in core temperature. Each rat was cooled from 37?C to 25?C and when warmed up to 39?C. Blood flow velocity values varied from point to point between body sites of both rats with and without a sandwich flap. Additionally, as core temperature was decreased there was a resultant decrease in LDV and skin temperature values. As core temperature was increased, LDV and skin temperature values also increased. Both of these findings are consistent for rats with and without sandwich flaps. Linear regression demonstrated that for every 1?C change in core temperature there is also a 1?C change in skin temperature for rats with and without a sandwich flap. Lastly there appears to be approximately a 12.1 mv change in LDV values with every 1?C change in core temperature for normal rates. In contrast, there is approximately 11.4 mv change in LDV values for every 1?C change in core temperature in rats with a sandwich flap. The results of this study indicated a need for eliminating some of the large variability in the observed LDV values. Utilization of a computer for data acquisition could provide a higher sampling rate of LDV values and a more accurate mean blood flow velocity. In addition, a method to ensure that constant pressure is applied to the skin surface should also be investigated. In conjunct, repetition of this study utilizing a larger study population would allow more generalizability to the population at large.