Figure 40-6 Finger blood flow without (open squares) and with (filled circles) desflurane administration. Values were computed relative to the thresholds (finger flow = 1.0 mL/min) in each subject. Flows of exactly 1.0 mL/min are not shown because flows in each individual were averaged over 0.1°C or 0.05°C increments; each data point thus includes both higher and lower flows. The horizontal standard deviation bars indicate variability in the thresholds among the volunteers; although errors bars are shown only at a flow near 1.0 mL/min, the same temperature variability applies to each data point. The slopes of the flowversus-core temperature relationships (1.0 to approximately 0.15 mL/min) were determined by linear regression. These slopes defined the gain of vasoconstriction with and without desflurane anesthesia. Gain was reduced by a factor of 3, from 2.4 to 0.8 mL/min/°C (P < .01). (Redrawn from Kurz A, Xiong J, Sessler DI, et al: Desflurane reduces the gain of thermoregulatory arteriovenous shunt vasoconstriction in humans. Anesthesiology 83:1212–1219, 1995.)