Errors of measurement for blood volume parameters: a meta-analysis

Christopher J. Gore, Will G. Hopkins, Caroline M. Burge
2005 Journal of applied physiology  
The volume of red blood cells (V RBC) is used routinely in the diagnostic workup of polycythemia, in assessing the efficacy of erythropoietin administration, and to study factors affecting oxygen transport. However, errors of various methods of measurement of V RBC and related parameters are not well characterized. We meta-analyzed 346 estimates of error of measurement of V RBC for techniques based on Evans blue (VRBC,Evans), 51 chromium-labeled red blood cells (VRBC,51Cr), and carbon monoxide
more » ... CO) rebreathing (V RBC,CO), as well as hemoglobin mass with the carbon-monoxide method (M Hb,CO), in athletes and active and inactive subjects undergoing various experimental and control treatments lasting minutes to months. Subject characteristics and experimental treatments had little effect on error of measurement, but measures with the smallest error showed some increase in error with increasing time between trials. Adjusted to 1 day between trials and expressed as coefficients of variation, mean errors for M Hb,CO (2.2%; 90% confidence interval 1.4 -3.5%) and V RBC,51Cr (2.8%; 2.4 -3.2%) were much less than those for V RBC,Evans (6.7%; 4.9 -9.4%) and VRBC,CO (6.7%; 3.4 -14%). Most of the error of VRBC,Evans was due to error in measurement of volume of plasma via Evans blue dye (6.0%; 4.5-7.8%), which is the basis of V RBC,Evans. Most of the error in VRBC,CO was due to estimates from laboratories with a relatively large error in M Hb,CO, the basis of VRBC,CO. VRBC,51Cr and MHb,CO are the best measures for research on blood-related changes in oxygen transport. With care, V RBC,Evans is suitable for clinical applications of bloodvolume measurement. reliability; hemoglobin mass; volume of red blood cells; Evans blue dye; carbon monoxide
doi:10.1152/japplphysiol.00505.2005 pmid:15976358 fatcat:vh5ktrxilzf3png2n4oagvsg2u