A comparative study: Perfusion of the micro- and macrocirculation as a function of the hematocrit value

Driessen, G.; Scheidt, Holger A.; Inhoffen, Werner; Sobota, Anna; Malotta, H.; Schmid‐Schönbein, H.

doi:10.1016/0026-2862(88)90051-9

Cited by 6 publications

(5 citation statements)

References 7 publications

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“…1, post‐CEW‐exposure values of Hct were above 35%. At high Hcts, a large number of vessels in the microcirculation can become stagnant because of packed RBCs (46). Despite this, of the five groups in Fig.…”

Section: Specific Questions When Reviewing Resultsmentioning

confidence: 99%

Increased Hematocrit After Applications of Conducted Energy Weapons (Including TASER^® Devices) to *Sus scrofa**

Jauchem

2010

Journal of Forensic Sciences

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Conducted energy weapons (CEWs) are used by law enforcement personnel to incapacitate individuals quickly and effectively, without intending to cause lethality. CEWs have been deployed for relatively long or repeated exposures in some cases. In laboratory animal models, central venous hematocrit has increased significantly after CEW exposure. Even limited applications (e.g., three 5-sec applications) resulted in statistically significant increases in hematocrit. Preexposure hematocrit was significantly higher in nonsurvivors versus survivors after more extreme CEW applications. The purpose of this technical note is to address specific questions that may be generated when examining these results. Comparisons among results of CEW applications, other electrical muscle stimulation, and exercise/voluntary muscle contraction are included. The anesthetized swine appears to be an acceptable animal model for studying changes in hematocrit and associated red blood cell changes. Potential detrimental effects of increased hematocrit, and considerations during law enforcement use, are discussed.

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Section: Specific Questions When Reviewing Resultsmentioning

confidence: 99%

Increased Hematocrit After Applications of Conducted Energy Weapons (Including TASER^® Devices) to *Sus scrofa**

Jauchem

2010

Journal of Forensic Sciences

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“…The hematocrit reduction in narrow vessels explains why the total body hematocrit is 10% lower than the large vessel hematocrit (25). The viscosity reduction in narrow vessels explains why the viscosity measured in vivo is lower than that determined by means of a wide tube or rotational viscometer (27,28). In vivo studies of the Fahraeus and Fahraeus-Lindqvist effect do not appear to exist for neonates.…”

Section: Resultsmentioning

confidence: 99%

Blood Viscosity and Optimal Hematocrit in Preterm and Full-Term Neonates in 50– to 500–μm Tubes

1992

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“…To analyze the effects of the differing aggregation behavior on microcirculation in vivo, the microvascular bed of isolated rat mesentery (10) was perfused with moderately and strongly aggregating RBC solutions. The preparation of the rat mesentery has been described in detail elsewhere (11–17). The advantage of this technique is that the stretched rat mesentery almost always contains only a single microvessel per examined layer.…”

Section: Methodsmentioning

confidence: 99%

“…Friedman's hemodynamic model for AMD pathogenesis contributes to the hypothesis on the mechanism of action of rheopheresis for dry AMD (5,6). The decline of perfusion and microvessel function in the submacular choroidea, which is the supplying vascular bed of the macula region, is an important factor for the progressionof AMD (7–14). Additionally, impaired perfusion provokes pathological processes, such as local inflammation, immune reactions, and deposition of macromolecules in the retina, which cause further deterioration of perfusion (1,7).…”

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confidence: 99%

Effects of Fibrinogen and α₂‐Macroglobulin and Their Apheretic Elimination on General Blood Rheology and Rheological Characteristics of Red Blood Cell Aggregates

et al. 2008

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Methods of therapeutic apheresis, such as plasma exchange or rheopheresis eliminate moderately aggregating macromolecules like fibrinogen, as well as strongly aggregating substances like alpha2-macroglobulin from blood. In order to examine the specific effect of eliminating alpha2-macroglobulin as a highly aggregating macromolecule, this study aimed to analyze the different rheological properties of: (i) moderately aggregating red blood cells (RBCs; inducible by fibrinogen); and (ii) strongly aggregating RBCs (inducible by alpha2-macroglobulin). In vitro, RBC aggregate geometry was determined in the presence of strong and moderate aggregation inducing macromolecules. In vivo, flow behavior of RBC aggregates was analyzed by intravital microscopy. Using network scanning, the number of perfused and non-perfused microvessels was determined. In vitro, the higher adhesive forces of strongly aggregating RBCs led to both a higher packing density of single RBCs within aggregates, expressed as a significantly reduced thickness of individual RBCs, and greater deformation, expressed as a significantly diminished offset between RBCs and an increased curvature of RBCs at the ends of the aggregates. In vivo rheoscopy showed that only high aggregating RBCs persisted in the precapillary bed and led to the absence of RBCs in up to 40% of nutritive capillaries. These novel findings are of importance regarding recent developments in clinical hemorheology, specifically the clinical use of hemapheretic therapies for diseases in which impaired microcirculation plays a role in either their development or progression, such as age-related macular degeneration and complications of diabetes mellitus. Our data support that procedures reducing the concentration of alpha2-macroglobulin in blood by extracorporeal elimination might provide a more efficient improvement of overall blood fluidity in microcirculatory beds.

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A comparative study: Perfusion of the micro- and macrocirculation as a function of the hematocrit value

Cited by 6 publications

References 7 publications

Increased Hematocrit After Applications of Conducted Energy Weapons (Including TASER^® Devices) to *Sus scrofa**

Increased Hematocrit After Applications of Conducted Energy Weapons (Including TASER^® Devices) to *Sus scrofa**

Blood Viscosity and Optimal Hematocrit in Preterm and Full-Term Neonates in 50– to 500–μm Tubes

Effects of Fibrinogen and α₂‐Macroglobulin and Their Apheretic Elimination on General Blood Rheology and Rheological Characteristics of Red Blood Cell Aggregates

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A comparative study: Perfusion of the micro- and macrocirculation as a function of the hematocrit value

Cited by 6 publications

References 7 publications

Increased Hematocrit After Applications of Conducted Energy Weapons (Including TASER® Devices) to Sus scrofa*

Increased Hematocrit After Applications of Conducted Energy Weapons (Including TASER® Devices) to Sus scrofa*

Blood Viscosity and Optimal Hematocrit in Preterm and Full-Term Neonates in 50– to 500–μm Tubes

Effects of Fibrinogen and α2‐Macroglobulin and Their Apheretic Elimination on General Blood Rheology and Rheological Characteristics of Red Blood Cell Aggregates

Contact Info

Product

Resources

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Increased Hematocrit After Applications of Conducted Energy Weapons (Including TASER^® Devices) to *Sus scrofa**

Increased Hematocrit After Applications of Conducted Energy Weapons (Including TASER^® Devices) to *Sus scrofa**

Effects of Fibrinogen and α₂‐Macroglobulin and Their Apheretic Elimination on General Blood Rheology and Rheological Characteristics of Red Blood Cell Aggregates