Vol 7, No 1 (2004)
Research paper
Published online: 2004-01-22
Clinical significance of optimal red cell mass and plasma volume estimation methods
Nucl. Med. Rev 2004;7(1):31-38.
Abstract
BACKGROUND: The aim of this study was to present and compare the results
of proposed methods for optimal red cell mass and plasma volume (RCM&PV) estimation,
and their influence on the interpretation of obtained results.
MATERIAL AND METHODS: In 120/280 patients with polycythaemia rubra vera, subjected to RCM&PV determination with autologous erythrocytes in vitro labelled with 51Cr-sodium chromate, optimal volumes were determined using:
1. traditional ml/kg of:
- the real body weight method (ml/kg RBW);
- the optimal body weight method (ml/kg OBW).
2. the body weight, height, and sex based method (Retzlaff's tables),
3. the method recommended by the International Council for Standardization in Haematology (ICSH), based on body surface area.
RESULTS: Different interpretation of the same results of 120 RCM&PV measurements was registered in 48/120 patients (40%). The greatest disagreement existed between ml/kg RBW and ml/kg OBW methods (in 39/120 subjects, 32.5%). In underweight patients the ml/kg RBW method, and in overweight patients the ml/kg OBW method, offered better agreement with ICSH&Retzlaff's methods. The ml/kg RBW method disagreed with ICSH&Retzlaff's methods and ml/kg OBW in 25% and 19.2% of patients respectively. ICSH and Retzlaff's methods disagreed in 10/120 patients (8.3%). The ICSH method yielded significantly lower optimal volumes than Retzlaff's.
CONCLUSION: Three methods for optimal RCM&PV estimation lead to different interpretations of the same results of RCM&PV measurements with 51Cr-erythrocytes in 40% of patients. Two ml/kg body weight methods show greater disagreement in comparison with ICSH and Retzlaff's methods, which differ significantly. The ICSH method yields lower optimal values compared to Retzlaff's.
MATERIAL AND METHODS: In 120/280 patients with polycythaemia rubra vera, subjected to RCM&PV determination with autologous erythrocytes in vitro labelled with 51Cr-sodium chromate, optimal volumes were determined using:
1. traditional ml/kg of:
- the real body weight method (ml/kg RBW);
- the optimal body weight method (ml/kg OBW).
2. the body weight, height, and sex based method (Retzlaff's tables),
3. the method recommended by the International Council for Standardization in Haematology (ICSH), based on body surface area.
RESULTS: Different interpretation of the same results of 120 RCM&PV measurements was registered in 48/120 patients (40%). The greatest disagreement existed between ml/kg RBW and ml/kg OBW methods (in 39/120 subjects, 32.5%). In underweight patients the ml/kg RBW method, and in overweight patients the ml/kg OBW method, offered better agreement with ICSH&Retzlaff's methods. The ml/kg RBW method disagreed with ICSH&Retzlaff's methods and ml/kg OBW in 25% and 19.2% of patients respectively. ICSH and Retzlaff's methods disagreed in 10/120 patients (8.3%). The ICSH method yielded significantly lower optimal volumes than Retzlaff's.
CONCLUSION: Three methods for optimal RCM&PV estimation lead to different interpretations of the same results of RCM&PV measurements with 51Cr-erythrocytes in 40% of patients. Two ml/kg body weight methods show greater disagreement in comparison with ICSH and Retzlaff's methods, which differ significantly. The ICSH method yields lower optimal values compared to Retzlaff's.
Keywords: labelled red blood cellslabelled erythrocytesblood volume51Cr-sodium chromateoptimal plasma volumeoptimal red blood cells massoptimal erythrocytes volume
