Comparison of instruments for investigation of microcirculatory blood flow and red blood cell concentration

2009 ◽  
Vol 14 (3) ◽  
pp. 034025 ◽  
Author(s):  
Jim O’Doherty ◽  
Paul McNamara ◽  
Neil T. Clancy ◽  
Joey G. Enfield ◽  
Martin J. Leahy
Keyword(s):  
Blood Flow ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Cell Concentration ◽  
Microcirculatory Blood Flow

Trauma-hemorrhagic shock-induced red blood cell damage leads to decreased microcirculatory blood flow*

2009 ◽  
Vol 37 (3) ◽  
pp. 1000-1010 ◽  
Author(s):  
George W. Machiedo ◽  
Sergey B. Zaets ◽  
Tamara L. Berezina ◽  
Da-Zhong Xu ◽  
Eleonora Feketova ◽  
...  
Keyword(s):  
Blood Flow ◽  
Blood Cell ◽  
Hemorrhagic Shock ◽  
Red Blood Cell ◽  
Cell Damage ◽  
Microcirculatory Blood Flow

Effect of hematocrit on cerebral blood flow

1986 ◽  
Vol 251 (1) ◽  
pp. H63-H70 ◽  
Author(s):  
M. L. Hudak ◽  
R. C. Koehler ◽  
A. A. Rosenberg ◽  
R. J. Traystman ◽  
M. D. Jones
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Cell Concentration ◽  
Blood Gases ◽  
Red Cell ◽  
Sagittal Sinus ◽  
Arterial Blood ◽  
Independent Effects

Cerebral blood flow (CBF) falls as hematocrit (Hct) rises. Investigators have differed on the relative importance of the increases in arterial O2 content (CaO2) and red blood cell concentration in mediating the fall. Our experimental protocol attempted to determine the independent effects of these two variables. In 13 unanesthetized lambs (less than 7 days old) we measured arterial and sagittal sinus blood gases, and O2 contents, and CBF (microsphere technique) at oxyhemoglobin Hcts of approximately 20 and 40% and after an isovolemic exchange transfusion with a mixture of normal and pure methemoglobin (MHb) containing red cells. Following MHb exchange, Hct rose (19.7 +/- 0.3 vs. 38.2 +/- 0.4%, mean +/- SEM) with little change in CaO2 (9.3 +/- 0.2 vs. 10.0 +/- 0.3 vol%). Arterial PCO2, pH, mean arterial blood pressure, and cerebral O2 consumption (CMRO2) did not change. However, CBF fell (153 +/- 11 vs. 110 +/- 7 ml . 100 g-1 . min-1). CBF declined further when CaO2 rose (17.3 +/- 0.5 vol%) at the higher oxyhemoglobin Hct (36.9 +/- 0.8%). We calculated that the increase in red cell concentration accounted for 56% of the decrease in CBF that ordinarily occurs as Hct rises from 20 to 40%. The effect of red cell concentration on CBF varied among individual animals. It correlated closely (r = -0.77) with the initial cerebral fractional O2 extraction [E = CMRO2/(CBF X CaO2)]. Animals with the most luxuriant O2 supply (CBF X CaO2) relative to demand (CMRO2) had the greatest decrements in CBF as red blood cell concentration rose.

In vivo microvascular structural and functional consequences of muscle length changes

1997 ◽  
Vol 272 (5) ◽  
pp. H2107-H2114 ◽  
Author(s):  
D. C. Poole ◽  
T. I. Musch ◽  
C. A. Kindig
Keyword(s):  
Blood Flow ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Oxygen Delivery ◽  
Sarcomere Length ◽  
Flow Dynamics ◽  
Capillary Diameter ◽  
Luminal Diameter ◽  
Length Changes

As muscles are stretched, blood flow and oxygen delivery are compromised, and consequently muscle function is impaired. We tested the hypothesis that the structural microvascular sequellae associated with muscle extension in vivo would impair capillary red blood cell hemodynamics. We developed an intravital spinotrapezius preparation that facilitated direct on-line measurement and alteration of sarcomere length simultaneously with determination of capillary geometry and red blood cell flow dynamics. The range of spinotrapezius sarcomere lengths achievable in vivo was 2.17 +/- 0.05 to 3.13 +/- 0.11 microns. Capillary tortuosity decreased systematically with increases of sarcomere length up to 2.6 microns, at which point most capillaries appeared to be highly oriented along the fiber longitudinal axis. Further increases in sarcomere length above this value reduced mean capillary diameter from 5.61 +/- 0.03 microns at 2.4-2.6 microns sarcomere length to 4.12 +/- 0.05 microns at 3.2-3.4 microns sarcomere length. Over the range of physiological sarcomere lengths, bulk blood flow (radioactive microspheres) decreased approximately 40% from 24.3 +/- 7.5 to 14.5 +/- 4.6 ml.100 g-1.min-1. The proportion of continuously perfused capillaries, i.e., those with continuous flow throughout the 60-s observation period, decreased from 95.9 +/- 0.6% at the shortest sarcomere lengths to 56.5 +/- 0.7% at the longest sarcomere lengths and was correlated significantly with the reduced capillary diameter (r = 0.711, P < 0.01; n = 18). We conclude that alterations in capillary geometry and luminal diameter consequent to increased muscle sarcomere length are associated with a reduction in mean capillary red blood cell velocity and a greater proportion of capillaries in which red blood cell flow is stopped or intermittent. Thus not only does muscle stretching reduce bulk blood (and oxygen) delivery, it also alters capillary red blood cell flow dynamics, which may further impair blood-tissue oxygen exchange.

Influence of microflow on hepatic sinusoid blood flow and red blood cell deformation

2021 ◽  
Author(s):  
Tianhao Wang ◽  
Shouqin Lü ◽  
Yinjing Hao ◽  
Zinan Su ◽  
Mian Long ◽  
...  
Keyword(s):  
Blood Flow ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Cell Deformation ◽  
Hepatic Sinusoid

Slow Blood Flow Detection Based on Red Blood Cell Characteristic Volume Model Matching

2019 ◽  
Vol 39 (9) ◽  
pp. 0917002
Author(s):  
陈铭 Ming Chen ◽  
徐君宜 Junyi Xu ◽  
高志山 Zhishan Gao ◽  
朱丹 Dan Zhu ◽  
袁群 Qun Yuan
Keyword(s):  
Blood Flow ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Model Matching ◽  
Volume Model ◽  
Slow Blood Flow ◽  
Flow Detection ◽  
Characteristic Volume

Effect of red blood cell concentration on blood pH.

1969 ◽  
Vol 26 (4) ◽  
pp. 469-471 ◽  
Author(s):  
M De Raedt ◽  
N Portier ◽  
L Brasseur ◽  
K P Van de Woestijne
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Cell Concentration ◽  
Blood Ph
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