RESUMO
This study determined whether fingertip blood samples used to calculate percentage change in calculated plasma volume following exercise were in agreement with values obtained from venous blood samples. Twenty-five subjects engaged in two cycle ergometer exercises at 100 and 200 W, with percentage plasma volume shift (% PVS) determined after each from venous (VB) and fingertip (FT) blood. Values for % PVS were FT -6.25% compared with VB -8.04% (P less than 0.05), with the correlation between the two methods at r = 0.88. The following equation was established: corrected FT % PVS = (0.8662 * FT) - 2.625; SEE = 2.60%. In order to cross-validate this equation, fifteen additional subjects submitted to VB and FT. Corrected FT % PVS using the established equation resulted in a mean value of 9.53 compared with 10.53% for actual VB % PVS. Although these means were not significantly different, there was approximately a 25% chance that the corrected FT % PVS would be more than one standard error of estimate from the regression line. It was concluded that FT underestimates VB % PVS. However, when limited to group data, FT can be corrected to favorably represent VB % PVS following moderate to heavy cycle ergometer exercise.
