Haemostatics

Ajuga chia (Labiatas). In this haemostatic drug the presence of alkaloids has been recorded by Aliev. (Farmatsiya, 1946, 9, 21 Chem. Abstr., 1948, 42, 287.)... 

Small-volume oily injections 7 Absorbable haemostats... 

The reduction of blood loss during or after surgical procedures where suturing or hgature is either impractical or impossible can often be accomphshed by the use of sterile, absorbable haemostats. These consist of a soft pad of sohd material packed around and over the wound which can be left in situ, being absorbed by body tissues over a period of time, usually up to 6 weeks. The principal mechanism of action of these is the ability to encourage platelet fiacture because of their fibrous or rough surfaces, and to act as a... 

This is an insoluble gelatin foam produced by whisking warm gelatin solution to a uniform foam, wtiieh is then dried. It ean be cut into suitable shapes, paeked in metal or paper containers and sterilized by dry heat (150°C for 1 hour). Moist heat destroys the physical properties of the material. Immediately before use, it ean be moistened with normal saline eontaining thrombin. It behaves as a meehanieal haemostat providing the ftamewoik on wtiieh blood elotting ean oeeur. 

This is composed of the sodium and ealeium salts of alginic add formed into a powder or fibrous material and sterilized by autoelaving. It aids clotting by forming a sodium-caldum alginate complex in contact with tissue fluids, acting principally as a mechanical haemostat. It is relatively slowly absorbed and some residues may occasionally remain in the tissues. 

Blood plays various vital roles within the body and it is not surprising that a number of processes have evolved capable of effectively maintaining haemostasis (the rapid arrest of blood loss upon vascular damage, in order to maintain a relatively constant blood volume). In humans, three main mechanisms underline the haemostatic process ... 

Figure 12.4 Terminal steps of a blood clot (haemostatic plug) cross-linked fibrin molecules bind together platelets and red blood cells congregated at the site of damage, thus preventing loss of any more blood...

Table 12.4 Some substances isolated from bloodsucking parasites which inhibit their host s haemostatic mechanisms. All are polypeptides of relatively low molecular mass...

Polypeptide Molecular mass (Da) Producer Haemostatic effect disrupted... 

On the other hand, it should be noted that with some pyridazine derivatives, haemostatic activity has been observed [273-275], Thus for instance, sulphon-ylpyridazinones of type (73, R = HO, NH2NH, Me2N(CH2)3NH) have been reported to shorten the bleeding time in mice to an extent comparable to carbazochrom sodium sulphonate [275]. 

The prevention of excessive blood loss through breaches of the vascular barrier is important to maintain oxygen delivery and blood volume. A fall in blood volume would cause a drop in blood pressure and the metabolism of all of the major organs would be badly affected. Failures of the haemostatic mechanisms can lead to haemorrhage (bleeding disorders) or thrombosis (hypercoagulation disorders). 

Plasminogen activator inhibitor-1 (PAI-1) Systemic Haemostatic system Inhibits fibrinolysis... 

Pathophysiologically, primary haemostatic defects, characteristically due to malfunction of vascular endothelial or platelets, are exemplified by von Willebrand disease and agents such as aspirin and non-steriodal anti-inflammatory drugs (NSAID) where there is a prolonged bleeding time or abnormality in closure using the laboratory equivalent of platelet function analyse the PEA-100. In contrast, secondary bleeding, follows a period of haemostasis... 

Sanders TAB, Dean TS, Grainger D, Miller GJ, Wiseman H. Moderate intakes of soy isoflavones increase HDL but do not influence transforming growth factor p concentrations and haemostatic risk factors for coronary heart disease in healthy subjects. Am. J. Clin. Nutr. 76, 373-377, 2002. 

It exerts its haemostatic action by reducing capillary fragility, and is indicated in epistaxis, haematuria, retinal... 

It is a local haemostatic and antiseptic agent. The haemostatic effect of feracrylum is based on the formation of synthetic complex consisting of its adduct with plasma proteins principally albumin. Like other biodegradable polymers, the feracrylum-albumin complex formed gets broken down over a period of time. 

It is indicated as adjunct to conventional haemostatic procedures in capillary and venule oozing in various surgical and diagnostic procedures, dental extraction and oral surgeries. 

Astringents act by precipitating proteins in superficial layers of cells and are used to diminish the excretion or exudation of superficial cells. They are also used as local haemostatics and mummifying agents (discussed elsewhere). The different types of astringents used in dentistry are ... 

It has an astringent, antiseptic and haemostatic properties and used in 1-2% concentration to harden the gum or for inflamed and ulcerated gums. 

Certain systemic haemostatics e.g. tranexamic acid, ethamsylate etc. are also used in the prevention and treatment of capillary bleeding in epistaxis, haematuria and after tooth extraction. 

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