[Application of three different methods for estimating of the plasma volume in children].

OBJECTIVE:To investigate the difference between three methods for estimating the plasma volume in children. METHODS:The blood volume of 57 children from 10 to 12 years old were estimated by weight, formula proposed by Woodhead, and by bioelectrical impedance analysis( BIA), the effect and consistency of three methods were also compared. RESULTS:There was no difference between three methods in blood volume estimating( P > 0. 05). According to the results of Passing & Bablok regression regression analysis, the residual standard deviation( RSD) was 85. 88, 122. 83 and 111. 24. The regression equation were: y_(Woodhead)= 577. 356224 + 0. 800525x_(BW); y_(BIA)=1091. 590338 + 0. 653032x( BW); y( BIA)= 560. 545257 + 0. 843899x_(Woodhead), and there was no obvious departure from the linear correlation( P > 0. 05). After regrouping by the percent body fat, there were differences between three methods in weight in overweight and obese children group( P < 0. 05), the blood volume estimated by weight was thehighest, and by the BIA was the lowest. While in normal group there was no difference between three groups(P<0. 05). CONCLUSION:Three methods in blood volume estimating has a good consistency, estimating by body weight and formula have the virtue of convenience. Method of BIA is extremely fit for application in children with higher body fat.