Anticoagulation techniques

Extracorporeal medical machines (e.g., artificial kidney, pump-oxygenator) perfused with blood have been an effective part of the therapeutic armamentarium for many years. These devices all rely on systemic heparinization to provide blood compatibility. Despite continuous efforts to improve anticoagulation techniques, many patients still develop coagulation abnormalities with the use of these devices (1-3). Even longer perfusion times may occur with machines such as the membrane oxygenator. In such cases, the drawbacks of systemic heparinization are multiplied (4). A number of ap-... 

The hemorrhagic diathesis in patients with coagulation disorders is because of either an abnormaUty of one or more plasma proteins and/or platelets necessary for normal blood coagulation or the spontaneous presence of a circulating anticoagulant. Specific laboratory techniques are required for the precise identification of these disorders. 

Fergusson, D. (1994). The effects of 4-hydroxycoumarin Anticoagulant Rodenticides on Birds and the Development of Techniques for Non-destructively Monitoring Their Ecological Effects, Ph.D. Thesis, University of Reading, UK. 

The blood is collected using an aseptic technique into sterile containers. It can then be allowed to clot with subsequent recovery of the antibody-containing antisera by centrifugation. Alternatively, the blood may be collected in the presence of heparin, or another suitable anticoagulant, with subsequent removal of the suspended cellular elements, again by centrifugation. In this case, the resultant antibody-containing solution is termed plasma . 

ESI-MS/MS analysis. Also Becker et al. employed a combination of NMR with chemical analysis and additional biophysical techniques to deduce the structure of 2-sulfated, 3-linked ot-L-galactan and a-L-fucans.46 It was indicated that the extremely different conformations of the two polysaccharides could help to explain their distinct anticoagulant properties. 

Epidural/Intrathecal- Presence of infection at the injection microinfusion site concomitant anticoagulant therapy uncontrolled bleeding diathesis parenterally administered corticosteroids within a 2-week period, other concomitant drug therapy or medical condition that would contraindicate the technique of epidural or intrathecal analgesia acute bronchial asthma upper airway obstruction. 

Dispersed Powders. The principal use of dispersed powders is in pad—dry—chemical pad—steam dyeing techniques. They are normally made from press cake by ball or bead milling to microparticle size in the presence of dispersing agents. The drying is stricdy controlled and is carried out in the presence of anticoagulants to prevent aggregation of the dispersed dye particles. 

Sialic acid -m acid glycoprotein [BIOPOLYMERS - ANALYTICAL TECHNIQUES] (V ol 4) -m Factor V [BLOOD, COAGULANTS AND ANTICOAGULANTS] (Vol 4)... 

With annuloplasty procedures heparin and endocarditis prophylaxis should be administered before the procedures. When the edge-to-edge technique is performed, heparin should not be administered until the transseptal puncture has been performed. Regular follow-up examination, anticoagulation, and endocarditis prophylaxis are recommended after mitral repair procedures. 

Earlier data (3) obtained with tests in cones and chemical determination suggested that the anticoagulant effect of heparin introduced on the wall was greater than that to be expected if all the heparin were dissolved in the plasma. This conclusion requires checking with more uniform heparin layers and improved coagulation test techniques on flat surfaces. It is known that some heparin goes into solution in plasma from GBH or PVPyrH surfaces, as prepared by us, and it seems probable that this is generally true for any adsorbed heparin system in which the... 

The following atomic absorption spechophoto-metric technique is applicable to blood, and involves atomisation in a graphite furnace assembly. Blood samples should be anticoagulated with dipotassiiun edetate. If heparin is used, a blank containing heparin of the same batch should be carried throu the preparative and assay procedures. 

Pacifici and Viani, commenting on comparisons among results from different methods applied to protein binding, warn that methods for drug binding need to be standardized. Currently, results depend greatly on technique and interpretation of results thus, experimental details such as anticoagulant used, type of dialysis or filtration membrane, buffer characteristics, duration of experiment, and temperature should be taken into account. 

However, charcoal hemoperfusion is now regarded as the recommended method for rapid reduction of serum theophylhne concentrations, if necessary, although access to this technique is limited in most hospitals. Venovenous hemofiltration, which is readily avaUable in many hospitals, appears to be a reaUstic and practical alternative to charcoal hemoperfusion, in combination with oral activated charcoal, particularly in the hemodynamically unstable patient with severe theophylhne toxicity without anticoagulation (40,41). A higher extraction ratio in neonates than in adults has also been described (41). 

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