Measurements In Normal Males and Response To Standing
This study included 58 subjects, age = 29 ± 9 years. Findings include:
The best method for normalizing pulse volume and flow measurements to account for the physical size of the subject (i.e. that method which produced the smallest standard deviation of the measurements) is to divide pulse volume by limb segment length, thus producing a measurement in microliters per cm (equal to the average change in the cross sectional area of the measured limb).
The 95% confidence limits of right calf pulse volume (two-tailed method) is 20-54 microliters/cm. Thus there is a "normal" range of pulse volume measurements with which new patients may be compared.
Standing produces venous pooling that decreases cardiac output. This, in turn, produces reflex vasoconstriction. These changes are similar to those seen in impending hypovolemic shock. Standing up caused a very consistent and large (33% ± 0.8%) decrease in calf pulse volume (p<0.0005).