Nomograms for the prediction of patient's plasma volume in plasma exchange therapy from height, weight, and hematocrit
✍ Scribed by Kuno B. G. Sprenger; Klaus Huber; Werner Kratz; Eberhard Henze
- Publisher
- John Wiley and Sons
- Year
- 1987
- Tongue
- English
- Weight
- 486 KB
- Volume
- 3
- Category
- Article
- ISSN
- 0733-2459
No coin nor oath required. For personal study only.
✦ Synopsis
Thc knowledge of plasma volume (PV) is a basic requirement for the standardization of plasma exchange therapy.
PV has to be detcrniined 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 o l 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 5'Cr-mcthod 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 Retzlaffcquations. On the avcrage 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, cven if they are very fat or thin.
Nomograms for men and women were constructed in order to facilitate the calculation.