scholarly journals Citrate Anticoagulation for Extracorporeal Circuits: Effects on Whole Blood Coagulation Activation and Clot Formation

Nephron ◽  
2001 ◽  
Vol 89 (2) ◽  
pp. 233-236 ◽  
Author(s):  
A. Calatzis ◽  
M. Toepfer ◽  
W. Schramm ◽  
M. Spannagl ◽  
H. Schiffl
Keyword(s):  
Blood Coagulation ◽  
Whole Blood ◽  
Clot Formation ◽  
Coagulation Activation ◽  
Citrate Anticoagulation ◽  
Extracorporeal Circuits

Coagulation Differences Detectable in Deep and Lobar Primary Intracerebral Hemorrhage Using Thromboelastography

Neurosurgery ◽  
2020 ◽  
Vol 87 (5) ◽  
pp. 918-924
Author(s):  
David Roh ◽  
Glenda L Torres ◽  
Chunyan Cai ◽  
Christopher Zammit ◽  
Alexandra S Reynolds ◽  
...  
Keyword(s):  
Linear Regression ◽  
Intracerebral Hemorrhage ◽  
Blood Coagulation ◽  
Whole Blood ◽  
Medical Center ◽  
Linear Regression Analysis ◽  
Laboratory Data ◽  
Clot Formation ◽  
Stroke Severity ◽  
Coagulation Testing

Abstract BACKGROUND There are radiographic and clinical outcome differences between patients with deep and lobar intracerebral hemorrhage (ICH) locations. Pilot studies suggest that there may be functional coagulation differences between these locations detectable using whole blood coagulation testing. OBJECTIVE To confirm the presence of interlocation functional coagulation differences using a larger cohort of deep and lobar ICH patients receiving whole blood coagulation testing: thromboelastography (TEG; Haemonetics). METHODS Clinical and laboratory data were prospectively collected between 2009 and 2018 for primary ICH patients admitted to a tertiary referral medical center. Deep and lobar ICH patients receiving admission TEG were analyzed. Patients with preceding anticoagulant use and/or admission coagulopathy (using prothrombin time/partial thromboplastin time/platelet count) were excluded. Linear regression models assessed the association of ICH location (independent variable) with TEG and traditional plasma coagulation test results (dependent variable) after adjusting for baseline hematoma size, age, sex, and stroke severity. RESULTS We identified 154 deep and 53 lobar ICH patients who received TEG. Deep ICH patients were younger and had smaller admission hematoma volumes (median: 16 vs 29 mL). Adjusted multivariable linear regression analysis revealed longer TEG R times (0.57 min; 95% CI: 0.02-1.11; P = .04), indicating longer clot formation times, in deep compared to lobar ICH. No other TEG parameter or plasma-based coagulation differences were seen. CONCLUSION We identified longer clot formation times, suggesting relative coagulopathy in deep compared to lobar ICH confirming results from prior work. Further work is required to elucidate mechanisms for these differences and whether ICH location should be considered in future coagulopathy treatment paradigms for ICH.

scholarly journals Small-Volume Noncontact Assessment of Blood Coagulation Via Acoustic Tweezing Coagulometry

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3178-3178
Author(s):  
Nithya Kasireddy ◽  
Elizabeth M Cummins ◽  
Huy Q Pham ◽  
Amina Rafique ◽  
Damir B Khismatullin
Keyword(s):  
Blood Plasma ◽  
Blood Coagulation ◽  
Whole Blood ◽  
American Heart Association ◽  
American Heart ◽  
Formation Rate ◽  
Heart Association ◽  
Sample Volume ◽  
Clot Formation ◽  
Fviii Inhibitor

Abstract Introduction: Blood coagulation analysis is routinely performed to assess bleeding and thrombotic risks in surgical and critical care patients as well as in patients with diseases that cause coagulation abnormalities (e.g., hemophilia, thrombophilia and sickle cell disease). Majority of coagulation assays are based on photo-optical measurement of coagulation onset in blood plasma such as prothrombin time (PT), international normalized ratio (INR), and activated partial thromboplastin time (aPTT) and viscoelastic measurement of coagulating whole blood, often referred to as "global coagulation analysis", mostly done by thromboelastography (TEG, ROTEM) but they require large sample volume (> 0.5ml) requiring venipuncture, have poor standardization, and are unreliable tools to predict bleeding/thrombotic risk. Acoustic tweezing coagulometry (ATC) is an innovative noncontact drop-of-blood coagulation analysis technique that can perform both photo-optical and viscoelastic coagulation analysis with a sample volume as low as 4 μl to provide a comprehensive set of clinically relevant coagulation parameters such as blood viscosity, elasticity, reaction time, clotting rate, maximum clot stiffness, fibrin formation rate and cross-linking kinetics helpful for diagnosis and prediction of bleeding and thrombotic risks. ATC is particularly valuable for the pediatric patients as it enables safe and reliable point of care coagulation assessment with minimal sample volume. Materials and Methods: In this project, we demonstrate the feasibility of ATC for coagulation analysis by validation and standardization of the technique using whole blood collected from healthy adult volunteers and commercially purchased blood plasma. Further, we present the ability of ATC to assess bleeding risk in commercial blood plasma with coagulation FVIII deficiency with and without inhibitors, as well as whole blood collected from pediatric Hemophilia A patients without inhibitors. The time dependent changes in elasticity (elastic tweezograph, Figure 1A) and viscosity (viscous tweezograph, Figure 1B) of coagulating blood plasma or whole blood sample are used to extract the following coagulation parameters: clot initiation time (CIT), clotting rate (CR), clotting time (CT), time to firm clot formation (TFCF), and maximum clot stiffness (MCS) from elastic tweezograph; reaction time (RT), fibrin formation rate (FFR), and maximum fibrin level (MFL) from viscous tweezograph. Results and Discussion: Figure 1C shows the elastic tweezograph and figure 1D shows the viscous tweezograph of the healthy plasma, plasma with coagulation FVIII deficieny and plasma with inhibitors for coagulation FVIII activated via the intrinsic pathway of coagulation. The tweezographs suggest that the clot initiation is faster in healthy plasma compared to the FVIII deficient plasma and FVIII inhibitor plasma. The clotting rate is highest for healthy plasma followed by the FVIII deficient plasma and is the lowest for the plasma with FVIII inhibitors suggesting a delayed clot formation in the deficient and inhibitor groups. They all reach a similar final clot stiffness, but the time to firm clot formation is least in healthy plasma as expected and increases in the FVIII deficient group and further increases in the FVIII inhibitor group. Conclusions: Acoustic tweezing coagulometry can successfully measure the viscosity, elasticity and coagulation of whole blood and blood plasma with only a drop of the sample. This technique can successfully assess the bleeding risks in pediatric and adult patients with Hemophilia. Acknowledgements: This study has been supported by American Heart Association pre doctoral fellowship 20PRE35210991, U.S. National Science Foundation grant 1438537, American Heart Association Grant-in-Aid 13GRNT17200013, and Tulane University intramural grants. The acoustic tweezing technology is protected by pending patents PCT/US14/55559, PCT/US2018/014879 and PCT/US21/15336. Figure 1 Figure 1. Disclosures Kasireddy: Levisonics Inc.: Current Employment. Rafique: Pfizer Inc.: Consultancy; CSL Behring: Consultancy; HEMA Biologics: Consultancy. Khismatullin: Levisonics Inc.: Current equity holder in publicly-traded company; Levisonics Inc.: Patents & Royalties: PCT/US14/55559 (pending); Levisonics Inc.: Patents & Royalties: PCT/US2018/014879 (issued) ; Levisonics Inc.: Patents & Royalties: PCT/US21/15336 (pending)..

THE EFFECT OF EARLY BLOOD TRANSFUSION ON THE OUTCOME OF GASTROINTESTINAL HAEMORRHAGE

1987 ◽  
Author(s):  
S D Blair ◽  
S B Javanvrin ◽  
C N McCollum ◽  
R M Greenhalgh
Keyword(s):  
Blood Transfusion ◽  
Blood Coagulation ◽  
Whole Blood ◽  
Randomised Trial ◽  
Gastrointestinal Haemorrhage ◽  
Clotting Time ◽  
Prospective Randomised Trial ◽  
Coagulation Tests ◽  
To Receive ◽  
Upper Gastrointestinal

It has been suggested that mortality due to upper gastrointestinal haemorrhage may be reduced by restricting blood transfusion [1], We have assessed whether this is due to an anticoagulant effect in a prospective randomised trial.One hundred patients with severe, acute gastrointestinal haemorrhage were randomised to receive either at least 2 units of blood during the first 24 hours of admission, or no blood unless their haemaglobin was lessthan 8g/dl or they were shocked. Minor bleeds and varices were excluded As hypercoagulation cannot be measured using conventional coagulation tests, fresh whole blood coagulation was measured by the Biobridge Impedance Clotting Time (ICT). Coagulation was assessed at 24 hour intervals and compared to age matched controls with the results expressed as mean ± sem.The ICT on admission for the transfusion group (n=50) was 3.2±0.2 mins compared to 10±0.2 mins in controls. This hyper-coagulable state was partially reversed to 6.4±0.3 mins at 24 hours (p<0.001). The 50 allocated to receive no blood had a similar ICT on admission of 4.4±0.4 mins but the hypercoagulable state was maintained with ICT at 24 hours of 4.320.4 mins. Only 2 patients not transfused rebled compared to 15 in the early transfusion group (p<0.001). Five patients died, and they were all in the early transfusion group.These findings show there is a hypercoagulable response to haemorrhage which is partially reversed by blood transfusion leading to rebleeding

The Haemocompatibility of Biomaterials In Vitro: Investigations on the Mechanism of the Whole-blood Clot Formation Test

1992 ◽  
Vol 20 (3) ◽  
pp. 390-395 ◽  
Author(s):  
Thomas Groth ◽  
Katrin Derdau ◽  
Frank Strietzel ◽  
Frank Foerster ◽  
Hartmut Wolf
Keyword(s):  
Whole Blood ◽  
Blood Clotting ◽  
Blood Clot ◽  
Formation Rate ◽  
Clot Formation ◽  
Coagulation Cascade ◽  
Contact Activation ◽  
Human Fibrinogen ◽  
Static Conditions

Twenty years ago Imai & Nose introduced a whole-blood clotting test for the estimation of haemocompatibility of biomaterials in vitro In our paper a modification of this assay is described and the mechanism of clot formation further elucidated. It was found that neither the inhibition of platelet function nor the removal of platelets from blood significantly changed the clot formation rate on glass and polyvinyl chloride in comparison to the rate tor whole blood. Scanning electron microscopy demonstrated that platelets were not involved in clot formation near the blood/biomaterial interface. Thus, it was concluded that the system of contact activation of the coagulation cascade dominates during clot formation under static conditions. The latter conclusion was supported by the fact that preadsorption of human serum albumin or human fibrinogen onto the glass plates used, decreased the clot formation rate in the same manner.

scholarly journals Numerical Simulation of the Coagulation Dynamics of Blood

2008 ◽  
Vol 9 (2) ◽  
pp. 83-104 ◽  
Author(s):  
T. Bodnár ◽  
A. Sequeira
Keyword(s):  
Blood Coagulation ◽  
Computational Study ◽  
Time Integration ◽  
Three Dimensional ◽  
Circular Cross Section ◽  
Clot Formation ◽  
Diffusion Reaction ◽  
Numerical Code ◽  
Injured Region ◽  
Reaction Equations

The process of platelet activation and blood coagulation is quite complex and not yet completely understood. Recently, a phenomenological meaningful model of blood coagulation and clot formation in flowing blood that extends existing models to integrate biochemical, physiological and rheological factors, has been developed. The aim of this paper is to present results from a computational study of a simplified version of this coupled fluid-biochemistry model. A generalized Newtonian model with shear-thinning viscosity has been adopted to describe the flow of blood. To simulate the biochemical changes and transport of various enzymes, proteins and platelets involved in the coagulation process, a set of coupled advection–diffusion–reaction equations is used. Three-dimensional numerical simulations are carried out for the whole model in a straight vessel with circular cross-section, using a finite volume semi-discretization in space, on structured grids, and a multistage scheme for time integration. Clot formation and growth are investigated in the vicinity of an injured region of the vessel wall. These are preliminary results aimed at showing the validation of the model and of the numerical code.

A Solid State Whole Blood Coagulation Time Device

1966 ◽  
Vol 46 (4) ◽  
pp. 463-471
Author(s):  
Joseph Beeman ◽  
Alma Miller ◽  
Sam CAmarena
Keyword(s):  
Solid State ◽  
Blood Coagulation ◽  
Whole Blood ◽  
Coagulation Time ◽  
Whole Blood Coagulation Time

Investigations of the Dose of Heparin and Whole Blood Coagulation Time during Endovascular Surgery

1997 ◽  
Vol 3 (2_suppl) ◽  
pp. 215-217 ◽  
Author(s):  
S. Nagai ◽  
A. Kurata ◽  
R. Tanaka ◽  
K. Irikura ◽  
Y. Miyasaka ◽  
...  
Keyword(s):  
Blood Coagulation ◽  
Whole Blood ◽  
Initial Level ◽  
Thrombus Formation ◽  
Constant Level ◽  
Bleeding Tendency ◽  
Coagulation Time ◽  
Continuous Administration ◽  
Heparin Administration ◽  
Whole Blood Coagulation Time

We chronologically determined whole blood coagulation time during continuous heparin administration, and investigated optimal doses of heparin in thirty-seven vascular surgery cases. ACT was determined with Hemochron 401. Heparin (2000 IU) was administered by bolus injection at the beginning of intravascular surgery, which was followed by continuous injection of 20 to 160 IU/kg/h. ACT determined before and 30 minutes after heparin administration were compared. There were no complications. ACT was maintained at a nearly constant level by continuous heparin administration. The dose of heparin required to maintain ACT at a level 1.5 to 2 times the initial level was 20 to 60 IU/kg/h. ACT was prolonged by more than three times in two of the ten subjects who were given heparin at a dose of 70 IU/kg/h or more. Continuous administration of heparin allowed maintenance of ACT at a nearly constant level during intravascular surgery. ACT was maintained within the range which is believed to be effective for prevention of thrombus formation (approximately 1.5 to 2.0 times larger than the initial level) by continuous administration of 20 to 60 IU/kg/h of heparin. ACT was, however, prolonged to more than three times the initial level in some subjects who were given 70 IU/kg/h or higher doses, suggesting the risk of a bleeding tendency. Accordingly, it is ideal to continue heparin administration at appropriate doses, while measuring ACT. The results of our study should serve as a useful standard for meeting this goal.

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