Nomograms for the prediction of patient's plasma volume in plasma exchange therapy from height, weight, and hematocrit

Abstract

The knowledge of plasma volume (PV) is a basic requirement for the standardization of plasma exchange therapy. PV has to be determined by calculation, as the measurement of PV before every plasma exchange is too cost- and time consuming. A known correlation with measured values results from calculation of plasma volume by means of patient's height and weight. But the present equations are only reliable at normal hematocrit. For this reason we modified the Retzlaff-equations and compared the validity of plasma volume predictions, calculated by these and own equations, with plasma volume measured by the 51Cr-method in 59 patients with pathological hematocrit. The correlation coefficient was 0.82 for men and 0.81 for women (2 0.001) with the modified Retzlaff-equations. On the average the relative error was -1.5% for all and 2.8% for fat and thin men. No significant improvement of accuracy was achieved with other equations. Thus, plasma volume can accurately be calculated from height, weight, and hematocrit with our modified Retzlaff-equations in patients with pathological hematocrit, even if they are very fat or thin. Nomograms for men and women were constructed in order to facilitate the calculation.

Effects of protein A immunoadsorption in patients with advanced chronic dilated cardiomyopathy

“…The 2.5-fold plasma volume was treated every day. Patients' plasma volume was calculated as previously described [13]. Patients' body weight was measured daily before and after IA treatment and diuretics were administered if patient weight following the IA session had increased by more than 1 kg.…”

Estimating plasma volume in neonatal Holstein calves fed one or two feedings of a lacteal-based colostrum replacer using Evans blue dye and hematocrit values at various time points

“…Research in human physiology has indicated that PV can be estimated by using a patient's height, weight, and HCT; however, equations are only reliable at normal HCT. Sprenger et al (1987) were able to modify equations and allow for accurate calculation of PV even with the use of pathological HCT, but PV was measured using the 51CR-method and not EBD. Quigley et al (1998) reported that birth BW was the best predictor of PV, though the relationship was not linear; however, multiple regression analysis using HCT and BW yielded no correlation with PV.…”

Effects of protein A immunoadsorption in patients with chronic dilated cardiomyopathy

“…The 2.5-fold plasma volume was treated every day. Patients' plasma volume was calculated as previously described [8]. Patients' body weight was measured daily before and after IA treatment and diuretics were administered if patient weight following the IA session had increased by more than 1 kg (n 5 10, 19.6% of total).…”