scholarly journals The Effect of Blood Viscosity on Shear‐Induced Hemolysis using a Magnetically Levitated Shearing Device

2022 ◽  
Author(s):  
James A. Krisher ◽  
Richard A. Malinauskas ◽  
Steven W. Day
2021 ◽  
Author(s):  
James A Krisher ◽  
Richard A Malinauskas ◽  
Steven W Day

Introduction: Blood contacting medical devices, including rotary blood pumps, can cause shear-induced blood damage that may lead to adverse effects in patients. Due in part to an inadequate understanding of how cell-scale fluid mechanics impact red blood cell membrane deformation and damage, there is currently not a uniformly accepted engineering model for predicting blood damage caused by complex flow fields within ventricular assist devices (VADs). Methods: We empirically investigated hemolysis in an axial Couette flow device typical of a rotary VAD to expand our current understanding of shear-induced blood damage in two ways. First, we used a magnetically levitated device to accurately control the shear rate and exposure time experienced by blood and to minimize the effects of other uncharacterized stresses. Second, we explored the effects of both hematocrit and plasma viscosity on shear-induced hemolysis to characterize blood damage based on the viscosity-independent shear rate, rather than on shear stress. Results: Over a shear rate range of 20,000-80,000 1/s, the Index of Hemolysis was found to be largely independent of hematocrit, bulk viscosity, or the suspension media viscosity. Conclusion: It is recommended that future investigations of shear-induced blood damage report findings with respect to the viscosity-neutral term of shear rate, in addition to the bulk whole blood viscosity measured at an appropriate shear rate relevant to the flow conditions of the device.


2009 ◽  
Vol 56 (S 01) ◽  
Author(s):  
JFM Bechtel ◽  
EI Charitos ◽  
T Hanke ◽  
M Misfeld ◽  
C Schmidtke ◽  
...  

1995 ◽  
Vol 73 (01) ◽  
pp. 118-121 ◽  
Author(s):  
Noriko Yamamoto ◽  
Koichi Yokota ◽  
Akira Yamashita ◽  
Minoru Oda

SummaryUsing guinea pigs, a study was conducted on the effects of KBT-3022, a new anti-platelet agent, on hemorheological properties in various tests including blood filterability, blood viscosity, shear stress-induced red blood cell (RBC) deformability and contents of ATP and 2,3-diphosphoglycerate (2,3-DPG). Oral administration of KBT-3022 at 1 and 10 mg/kg significantly increased blood filterability, and significantly reduced blood viscosity at 10 mg/kg without changing the hematocrit, plasma fibrinogen concentration or plasma viscosity. KBT-3022 (10 mg/kg, p.o.) improved RBC deformability in response to shear stress, which was evoked by passing the blood through a thin tube. This dose of KBT-3022 also increased the contents of ATP and 2,3-DPG in RBC. These findings indicate that KBT-3022 may reduce blood viscosity as a sequel to improvement of RBC deformability through direct action on RBC. The increase in the intracellular levels of ATP and 2,3-DPG was considered to be involved in this improvement of hemorheological properties. These hemorheological effects of KBT-3022 appear to be promising for the treatment of patients with ischemic vascular disease.


1979 ◽  
Author(s):  
G. Palareti ◽  
M. Poggi ◽  
G. Fortunato ◽  
S. Coccheri

A series of 40 patients with TIA (25 males and 15 females) was thoroughly investigated by means of angiography and computerized tomography, and divided into a group (A) of 15 “sine materia”, and a group (B) of 25 with direct or indirect evidence of vascular occlusive or stenotic changes. Blood viscosity at 230 sec-1 37° was cp 4.2 ± 0.3 in the controls, cp 4.7 ± 0.7 in all patients (p < 0.05) cp 4.98 ± 0.7 in all male patients (p < 0.01 versus male controls), and cp 4.75 ± 0.8 in group B (p < 0.02). Haematocrit and Fibrinogen were also significantly increased in all male patients and in group B. Circulating platelet aggregates (CPA) were increased in 40% of the patients. Almost all patients with elevated CPA were males, with a slight prevalence in group B. Changes in blood viscosity parameters and in platelet aggregation in TIA patients were therefore related both to evidence of vascular lesions, and to sex, since they were found to prevail in male patients of both groups.


1979 ◽  
Author(s):  
G Cella ◽  
H de Haas ◽  
M Rampling ◽  
V Kakkar

Haemorrheological factors have been shown to be affected in many kings of vascular disease. The present study was undertaken to correlate these factors in normal subjects and patients suffering from peripheral arterial disease. Twenty-two patients were investigated; they had moderate or severe intermittent claudication, extent of disease being confirmed by aorto-arteriography and ankle-systolic pressure studies. Twenty-five controls with no symptoms or signs of arterial disease were selected with comparable age and sex distribution. Whole blood viscosity was measured at shear rates of 230 secs-1 and 23 secs-lat 37°c using a Wells Brookfield cone plate microvisco meter. Plasma viscosity was also measured in an identical manner. Erythrocyte flexibility was measured by centrifuge technique and fibrinogen concentration as well as haematocrit by standard techniques. The fibrinogen concentration appeared to be the only significant parameter; the mean concentration in patients with peripheral vascular disease of 463 ± 73mg/l00ml in the control group ( < 0.05). Although whole blood viscosity was high in patients, when corrected to a common haematocrit, there was no significant difference between patients and controls. The same megative correlation was found for plasma viscosity. The red cell flexibility was found to be increased in patients as compared to the control group, but this effect appeared to be simply proportional to the fibrinogen concentration.


1984 ◽  
Vol 52 (03) ◽  
pp. 253-255 ◽  
Author(s):  
C Isles ◽  
G D O Lowe ◽  
B M Rankin ◽  
C D Forbes ◽  
N Lucie ◽  
...  

SummaryWe have previously shown abnormalities of haemostasis suggestive of intravascular coagulation in patients with malignant hypertension, a condition associated with retinopathy and renal fibrin deposition. To determine whether such abnormalities are specific to malignant hypertension, we have measured several haemostatic and haemorheological variables in 18 patients with malignant hypertension (Group 1), 18 matched healthy controls (Group 2), and 18 patients with non-malignant hypertension (Group 3) matched for renal pathology, blood pressure and serum creatinine with Group 1. Both Groups 1 and 3 had increased mean levels of fibrinogen, factor VIIIc, beta-thrombo- globulin, plasma viscosity and blood viscosity (corrected for haematocrit); and decreased mean levels of haematocrit, antithrombin III and platelet count. Mean levels of fast antiplasmin and alpha2-macroglobulin were elevated in Group 1 but not in Group 3. We conclude that most blood abnormalities are not specific to malignant hypertension; are also present in patients with non-malignant hypertension who have similar levels of blood pressure and renal damage; and might result from renal damage as well as promoting further renal damage by enhancing fibrin deposition. However increased levels of fibrinolytic inhibitors in malignant hypertension merit further investigation in relation to removal of renal fibrin.


2006 ◽  
Vol 54 (S 1) ◽  
Author(s):  
A El-Banayosy ◽  
L Arusoglu ◽  
L Kizner ◽  
M Morshuis ◽  
P Sarnowski ◽  
...  

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