Assessment of cutaneous blood flow by using topographical perfusion mapping techniques

The ability of laser Doppler scanning to reproduce the spatial pattern of cutaneous vascular conductance (CVC) in a 6.25-cm2 area of skin was evaluated at supine rest (28 degrees C), during thermal stress (cold and heat), and during baroreceptor unloading with -40-mmHg lower body negative pressure (LBNP). The spatial pattern of resting CVC was similar on 3 different days, varying by 6 +/- 3%. During cold stress, 89 +/- 2% of the skin area showed a decrease in skin blood flow (37 +/- 2%), whereas heat stress increased CVC in 94 +/- 5% of the skin area. During LBNP, the pattern of CVC response was not uniform, and frequency analysis indicated that 47 +/- 5% of the pixels showed a reduction in CVC (>1 SE), 28 +/- 2% of the skin area were unaffected, and the remaining 26 +/- 5% of the pixels showed some increase in CVC. These data indicate the ability of topographical perfusion mapping to provide quantitative and reproducible information about the spatial distribution of CVC. In addition, the site-to-site variability in reflex control of skin blood flow during LBNP is intriguing and requires more rigorous evaluation.