Impaired cutaneous vasodilation and sweating in grafted skin during whole-body heating

The aim of this investigation was to identify the consequences of skin grafting on cutaneous vasodilation and sweating in split-thickness grafted skin during indirect whole-body heating 5 to 9 months after surgery. In addition, thermoregulatory function was examined at donor skin sites on a separate day. Skin blood flow and sweat rate (SR) were assessed from both grafted (n = 14) or donor skin (n = 11) and compared with the respective adjacent control skin during indirect whole-body heating. Cutaneous vascular conductance (CVC) was calculated from the ratio of skin blood flow (arbitrary units; au) to mean arterial pressure. Whole-body heating significantly increased internal temperature (37.0 ± 0.1°C to 37.8 ± 0.1°C; P < .05). Cutaneous vasodilation (ie, the increase in CVC from baseline, ΔCVC) during whole-body heating was significantly attenuated in grafted skin (ΔCVC = 0.14 ± 0.15 au/mm Hg) compared with adjacent control skin (ΔCVC = 0.84 ± 0.11 au/mm Hg; P < .05). Increases in sweat rate (ΔSR) were also significantly lower in grafted skin (ΔSR = 0.08 ± 0.08 mg/cm/min) compared with adjacent control skin (ΔSR = 1.16 ± 0.20 mg/cm/min; P < .05). Cutaneous vasodilation and sweating during heating were not significantly different between donor sites (ΔCVC = 0.71 ± 0.19 au/mm Hg; ΔSR = 1.04 ± 0.15 mg/cm/min) and adjacent control skin (ΔCVC = 0.50 ± 0.10 au/mm Hg; ΔSR = 0.83 ± 0.17 mg/cm/min). Greatly attenuated or absence of cutaneous vasodilation and sweating suggests impairment of thermoregulatory function in grafted skin, thereby, diminishing the contribution of this skin to overall temperature control during a heat stress.