Effect of plasma expander viscosity on the cell free layer.

The effect of low and high viscosity hemodilution with plasma expanders on the extent of the cell free layer (CFL) width was analyzed in the microcirculation of the exteriorized cremaster muscle preparation of Sprague-Dawley male rats. Anesthetized animals were subjected to 40% hemodilution by blood volume, using 5% human serum albumin (HSA) or 6% Hetastarch (hydroxyethyl starch 670 kDa). Arterioles (n=5 for each treatment) were investigated. Mean arterial pressure, heart rate, vessel flow velocity and CFL width were measured at baseline and 5, 20 and 40 min post-exchange transfusion. Blood and plasma viscosity was determined from terminal blood collections. CFL width and pseudoshear rate, diameter and flow, normalized to baseline, were significantly elevated at all post-exchange assessments. Peripheral vascular resistance decreased. The increase of the CFL width was greater with HSA by comparison with Hetastarch hemodilution (p<0.05). Hetastarch blood and plasma viscosities increased significantly compared to those of HSA (p<0.05). This study shows that CFL widths are influenced by plasma expander viscosity, a phenomenon proportional to the increase in molecular weight of the colloids in solution.

[1]  H. Landgraf,et al.  Influence of Intravenous Infusions of Hydroxyethylstarch (HES) (MW 40,000 and 450,000) on the Blood Flow Properties of Healthy Volunteers , 1985, Angiology.

[2]  D. Buerk,et al.  Elevated plasma viscosity in extreme hemodilution increases perivascular nitric oxide concentration and microvascular perfusion. , 2005, American journal of physiology. Heart and circulatory physiology.

[3]  R. Bagnold.  Experiments on a gravity-free dispersion of large solid spheres in a Newtonian fluid under shear , 1954, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[4]  S Chien,et al.  In vivo measurements of "apparent viscosity" and microvessel hematocrit in the mesentery of the cat. , 1980, Microvascular research.

[5]  A. Popel,et al.  Model of nitric oxide diffusion in an arteriole: impact of hemoglobin-based blood substitutes. , 2002, American journal of physiology. Heart and circulatory physiology.

[6]  Michael M. Dupin,et al.  Blood Cell Interactions and Segregation in Flow , 2008, Annals of Biomedical Engineering.

[7]  M. Intaglietta,et al.  Microcirculatory effects of intravenous fluids in critical illness: plasma expansion beyond crystalloids and colloids , 2009, Current opinion in anaesthesiology.

[8]  M. Baker,et al.  On-line volume flow rate and velocity profile measurement for blood in microvessels. , 1974, Microvascular research.

[9]  N Tateishi,et al.  Flow dynamics of erythrocytes in microvessels of isolated rabbit mesentery: cell-free layer and flow resistance. , 1994, Journal of biomechanics.

[10]  M Intaglietta,et al.  Rheological effects of red blood cell aggregation in the venous network: a review of recent studies. , 2001, Biorheology.

[11]  Prosenjit Bagchi,et al.  Mesoscale simulation of blood flow in small vessels. , 2007, Biophysical journal.

[12]  S. G. Mason,et al.  The flow of suspensions through tubes. I. Single spheres, rods, and discs , 1962 .

[13]  P. Cabrales,et al.  Plasma viscosity regulates systemic and microvascular perfusion during acute extreme anemic conditions. , 2006, American journal of physiology. Heart and circulatory physiology.

[14]  J. Liao,et al.  Effective diffusion distance of nitric oxide in the microcirculation. , 1998, The American journal of physiology.

[15]  J. Liao,et al.  Intravascular flow decreases erythrocyte consumption of nitric oxide. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[16]  Hiromi Sakai,et al.  Plasma viscosity regulates capillary perfusion during extreme hemodilution in hamster skinfold model. , 1998, American journal of physiology. Heart and circulatory physiology.

[17]  P. Cabrales,et al.  HYPEROSMOTIC-HYPERONCOTIC VERSUS HYPEROSMOTIC-HYPERVISCOUS: SMALL VOLUME RESUSCITATION IN HEMORRHAGIC SHOCK , 2004, Shock.

[18]  P. Cabrales,et al.  The variability of blood pressure due to small changes of hematocrit. , 2010, American journal of physiology. Heart and circulatory physiology.

[19]  P. Cabrales,et al.  Increased plasma viscosity prolongs microhemodynamic conditions during small volume resuscitation from hemorrhagic shock. , 2008, Resuscitation.

[20]  S. Baez,et al.  An open cremaster muscle preparation for the study of blood vessels by in vivo microscopy. , 1973, Microvascular research.

[21]  Daniel M Tartakovsky,et al.  The effect of small changes in hematocrit on nitric oxide transport in arterioles. , 2011, Antioxidants & redox signaling.

[22]  Paul C. Johnson,et al.  The cell-free layer in microvascular blood flow. , 2009, Biorheology.

[23]  Aleksander S Popel,et al.  Temporal and spatial variations of cell-free layer width in arterioles. , 2007, American journal of physiology. Heart and circulatory physiology.

[24]  Dov Jaron,et al.  The influence of radial RBC distribution, blood velocity profiles, and glycocalyx on coupled NO/O2 transport. , 2006, Journal of applied physiology.

[25]  Dov Jaron,et al.  Impact of the Fåhraeus Effect on NO and O2 Biotransport: A Computer Model , 2004, Microcirculation.

[26]  P. Cabrales,et al.  Alginate plasma expander maintains perfusion and plasma viscosity during extreme hemodilution. , 2005, American journal of physiology. Heart and circulatory physiology.

[27]  S. G. Mason,et al.  Axial Migration of Particles in Poiseuille Flow , 1961, Nature.

[28]  N. Otsu.  A threshold selection method from gray level histograms , 1979 .

[29]  A. Pries,et al.  A model for red blood cell motion in glycocalyx-lined capillaries. , 1998, The American journal of physiology.

[30]  I. Megson,et al.  Diffusion of nitric oxide and scavenging by blood in the vasculature. , 1998, Biochimica et biophysica acta.

[31]  R. G. Owens,et al.  Mathematical modelling of the cell-depleted peripheral layer in the steady flow of blood in a tube. , 2010, Biorheology.

[32]  W. Reinhart,et al.  Albumin affects erythrocyte aggregation and sedimentation , 1995, European journal of clinical investigation.

[33]  M. Soutani,et al.  Quantitative evaluation of flow dynamics of erythrocytes in microvessels: influence of erythrocyte aggregation. , 1995, The American journal of physiology.

[34]  A. Popel,et al.  Effects of erythrocyte aggregation and venous network geometry on red blood cell axial migration. , 2001, American journal of physiology. Heart and circulatory physiology.

[35]  P. Johnson,et al.  Cardiovascular benefits in moderate increases of blood and plasma viscosity surpass those associated with lowering viscosity: Experimental and clinical evidence. , 2010, Clinical hemorheology and microcirculation.

[36]  S. G. Mason,et al.  The flow of suspensions through tubes 1VIII. Radial Migration of Particles in Pulsatile Flow , 1968 .

[37]  Aleksander S Popel,et al.  A Computer‐Based Method for Determination of the Cell‐Free Layer Width in Microcirculation , 2006, Microcirculation.