title: Hematocrit distribution and tissue oxygenation in large microcirculatory networks.
abstract: OBJECTIVE
  Oxygen tension in the brain is controlled by the microcirculatory supply of RBC, but the effect of non-Newtonian blood flow rheology on tissue oxygenation is not well characterized. This study assesses different biphasic blood flow models for predicting tissue oxygen tension as a function of microcirculatory hemodynamics.
  
  
  METHODS
  Two existing plasma-skimming laws are compared against measured RBC distributions in rat and hamster microcirculatory networks. A novel biphasic blood flow model is introduced. The computational models predict tissue oxygenation in the mesentery, cremaster muscle, and the human secondary cortex.
  
  
  RESULTS
  This investigation shows deficiencies in prior models, including inconsistent plasma-skimming trends and insufficient oxygen perfusion due to the high prevalence (33%) of RBC-free microvessels. Our novel method yields physiologically sound RBC distributions and tissue oxygen tensions within one standard deviation of experimental measurements.
  
  
  CONCLUSIONS
  A simple, novel biphasic blood flow model is introduced with equal or better predictive power when applied to historic raw data sets. It can overcome limitations of prior models pertaining to trifurcations, anastomoses, and loops. This new plasma-skimming law eases the computations of bulk blood flow and hematocrit fields in large microcirculatory networks and converges faster than prior procedures.
authors.affiliation: Department of Bioengineering, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Ian G
authors.initials: IG
authors.lastname: Gould
authors.forename: Andreas A
authors.initials: AA
authors.lastname: Linninger
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology; D006224:Cricetinae; D004912:Erythrocytes / Q000378:metabolism*; D006400:Hematocrit; D006801:Humans; D008833:Microcirculation / Q000502:physiology*; D008955:Models, Cardiovascular; D010100:Oxygen / Q000097:blood*; D051381:Rats
chemical_list: D010100:Oxygen
keywords: Fahraeus effect; plasma skimming; tissue oxygenation