BLOOD VISCOSITY, INTERNAL FLUIDITY OF THE RED CELL, DYNAMIC COAGULATION AND THE CRITICAL CAPILLARY RADIUS AS FACTORS IN THE PHYSIOLOGY AND PATHOLOGY OF CIRCULATION AND MICROCIRCULATION

1968 ◽  
Vol 1 (21) ◽  
pp. 920-920
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.


The Lancet ◽  
1977 ◽  
Vol 310 (8045) ◽  
pp. 943-945 ◽  
Author(s):  
A.N. Nicolaides ◽  
Tikva Horbourne ◽  
Rosemary Bowers ◽  
P.H. Kidner ◽  
E.M. Besterman

1983 ◽  
Vol 61 (10) ◽  
pp. 2344-2350 ◽  
Author(s):  
Mark S. Graham ◽  
Garth L. Fletcher

The effects of temperature, red cell concentration, and shear rate on the viscosity of blood from the winter flounder (Pseudopleuronectes americanus) were evaluated using a cone-plate viscometer. The viscosity of blood and plasma was shear rate dependent at all temperatures studied (−1 to 20 °C) with the highest values occurring at the lowest temperature and shear rate. At normal hematocrits (20%), plasma appeared to account for at least 50% of the total blood viscosity. The effects of hematocrit on viscosity were dependent on temperature. At higher temperatures (10–20 °C), increases in hematocrit resulted in a near-exponential increase in viscosity. At lower temperatures (5 °C) and shear rates (4.5 s−1) no significant increase in viscosity occurred between hematocrits of 11 and 43%. The influence of temperature and shear rate on blood viscosity suggest that winter flounder may have to contend with a fivefold increase in blood viscosity when acclimating from summer to winter water temperatures.


BMJ ◽  
1985 ◽  
Vol 290 (6461) ◽  
pp. 74-75 ◽  
Author(s):  
D P Mikhailidis ◽  
J Y Jeremy ◽  
M A Barradas ◽  
P Dandona ◽  
R A Hutton

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