Hematocrit, Volume Expander, Temperature, and Shear Rate Effects on Blood Viscosity

Eckmann, David M.; Bowers, Shelly; Stecker, Mark M.; Cheung, Albert T.

doi:10.1213/00000539-200009000-00007

Cited by 138 publications

(57 citation statements)

References 22 publications

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“…Among these factors, the concentration of blood cells contributes the most to determining blood viscosity. [3][4][5] A strong correlation has been demonstrated between blood viscosity and the concentration of blood cells. 5 Shear rate is an important factor regulating blood viscosity with non-Newtonian characteristics in the circulatory system.…”

Section: Introductionmentioning

confidence: 99%

Increased Blood Viscosity in Ischemic Stroke Patients with Small Artery Occlusion Measured by an Electromagnetic Spinning Sphere Viscometer

Furukawa

Abumiya

Sakai

et al. 2016

Journal of Stroke and Cerebrovascular Diseases

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Section: Introductionmentioning

confidence: 99%

Increased Blood Viscosity in Ischemic Stroke Patients with Small Artery Occlusion Measured by an Electromagnetic Spinning Sphere Viscometer

Furukawa

Abumiya

Sakai

et al. 2016

Journal of Stroke and Cerebrovascular Diseases

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“…The apparent viscosity of whole blood, as measured using devices based on force or torque balance, may be altered by a variety of factors [19][20][21]. The most fundamental contributing factors are plasma viscosity [22], hematocrit, cell deformability [23][24][25], and aggregability [23].…”

Section: Factors That Contribute To the Viscosity Of Bloodmentioning

confidence: 99%

“…Plasma viscosity is primarily affected by temperature [26] and the concentration of large molecules such as proteins, lipids, and polysaccharides [22,27]. Hematocrit can be altered by the hydration status of the individual [28], changes in the plasma osmotic pressure which affects the size of the red blood cells (RBCs) [29,30], the use of volume expanders [20], diseases like polycythemia [21] or anemias, and other conditions. The deformability of RBCs depends on their size and shape, membrane composition, cytoskeletal structure, temperature [19,26] (i.e., in the case of hypothermia), intracellular hemoglobin viscosity [31], rate of erythropoiesis, and cell age [32].…”

Section: Factors That Contribute To the Viscosity Of Bloodmentioning

confidence: 99%

A Quasi-Mechanistic Mathematical Representation for Blood Viscosity

Hund

Kameneva

Antaki

2017

Fluids

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Blood viscosity is a crucial element for any computation of flow fields in the vasculature or blood-wetted devices. Although blood is comprised of multiple elements, and its viscosity can vary widely depending on several factors, in practical applications, it is commonly assumed to be a homogeneous, Newtonian fluid with a nominal viscosity typically of 3.5 cP. Two quasi-mechanistic models for viscosity are presented here, built on the foundation of the Krieger model of suspensions, in which dependencies on shear rate, hematocrit, and plasma protein concentrations are explicitly represented. A 3-parameter Asymptotic Krieger model (AKM) exhibited excellent agreement with published Couette experiments over four decades of shear rate (0-1000 s −1 , root mean square (RMS) error = 0.21 cP). A 5-parameter Modified Krieger Model (MKM5) also demonstrated a very good fit to the data (RMS error = 1.74 cP). These models avoid discontinuities exhibited by previous models with respect to hematocrit and shear rate. In summary, the quasi-mechanistic, Modified-Krieger Model presented here offers a reasonable compromise in complexity to provide flexibility to account for several factors that affect viscosity in practical applications, while assuring accuracy and stability.

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“…Given a constant circulatory volume, the higher cardiac preload indices indicated that a fraction of the 'unstressed' blood volume reserve was recruited and mobilised into the haemodynamically active circulatory compartment [21]. Since relative fluid viscosity varies inversely with shear rate, increasing blood fluidity produces larger changes in the venous 'slow flow' (low shear rate) compartment than in the arterial 'fast flow' (high shear rate) side [22]. Accordingly, lowering the blood viscosity with ANH led to an accelerated venous return, resulting in higher cardiac filling pressure with increased LV enddiastolic size, and in turn increased SV according to the Franck-Starling relationship.…”

Section: ó 2004 Blackwell Publishing Ltdmentioning

confidence: 99%

Cardiovascular response to acute normovolaemic haemodilution in patients with severe aortic stenosis: assessment with transoesophageal echocardiography

Licker¹,

Ellenberger²,

Murith³

et al. 2004

Anaesthesia

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SummaryUsing multiplane transoesophageal echocardiography (TOE), we investigated the haemodynamic response to acute normovolaemic haemodilution (ANH) in anaesthetised patients with critical aortic stenosis. Twenty-eight patients were randomly assigned to ANH or control groups. In the control group, haemodynamic data remained unchanged over a 20-min period. In the ANH group, haemoglobin levels decreased from a mean (SD) of 134 (7) to 91 (9) g.l )1 (p < 0.001) whereas stroke volume, central venous pressure and left ventricular (LV) end-diastolic area all increased significantly (mean (SD) +15 (6) ml; +2.0 (1.1) mmHg; +2.1 (0.8) cm 2 , respectively). During ANH, the accelerated blood flow through the stenotic valve caused an increased loss (SD) in LV stroke work: from 24 (8)% to 30 (10)%), (p < 0.01). Hence, lowering viscosity with ANH resulted in improved venous return, higher cardiac preload and increased stroke volume. However, this adaptive haemodynamic response was limited by less efficient LV stroke work due to dissipation of fluid kinetic energy.

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Hematocrit, Volume Expander, Temperature, and Shear Rate Effects on Blood Viscosity

Cited by 138 publications

References 22 publications

Increased Blood Viscosity in Ischemic Stroke Patients with Small Artery Occlusion Measured by an Electromagnetic Spinning Sphere Viscometer

Increased Blood Viscosity in Ischemic Stroke Patients with Small Artery Occlusion Measured by an Electromagnetic Spinning Sphere Viscometer

A Quasi-Mechanistic Mathematical Representation for Blood Viscosity

Cardiovascular response to acute normovolaemic haemodilution in patients with severe aortic stenosis: assessment with transoesophageal echocardiography

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