Haemostasis Health Dictionary

Coagulation of the blood is the process whereby bleeding (or haemorrhage) is normally arrested in the body. Blood starts to clot as soon as the skin (or other tissue) has been cut. Coagulation is part of the process of HAEMOSTASIS which is the arrest of bleeding from an injured or diseased blood vessel. Haemostasis depends on the combined activities of vascular, platelet (see PLATELETS) and PLASMA elements which are o?set by processes to restrict the accumulation of platelets and FIBRIN to the damaged area.

The three-stage process of coagulation is complex, involving many di?erent substances. There are two cascading pathways of biochemical reactions for activating coagulation of blood. The extrinsic pathway is the main physiological mechanism, which is triggered when blood vessels are damaged, usually by trauma or surgery. The intrinsic pathway is activated by internal disruption of the wall of a blood vessel. The basic pattern is broadly the same for both and is summarised simply as follows:

prothrombin + calcium + thromboplastin

thrombin + ?brinogen

?brin

Prothrombin and calcium are normally present in the blood. Thromboplastin is an enzyme which is normally found in the blood platelets and in tissue cells. When bleeding occurs from a blood vessel, there is always some damage to tissue cells and to the blood platelets. As a result of this damage, thromboplastin is released and comes into contact with the prothrombin and calcium in the blood. In the presence of thromboplastin and calcium, prothrombin is converted into thrombin, which in turn interacts with ?brinogen – a protein always present in the blood – to form ?brin. Fibrin consists of needle-shaped crystals which, with the assistance of the blood platelets, form a ?ne network in which the blood corpuscles become enmeshed. This meshwork, or CLOT as it is known, gradually retracts until it forms a tight mass which, unless the tissue injury is very severe or a major artery has been damaged, prevents any further bleeding. It will thus be seen that clotting, or coagulation, does not occur in the healthy blood vessel because there is no thromboplastin present. There is now evidence suggesting that there is an anti-thrombin substance present in the blood in small amounts, and that this substance antagonises any small amounts of thrombin that may be formed as a result of small amounts of thromboplastin being released.

The clotting or coagulation time is the time taken for blood to clot and can be measured under controlled conditions to ensure that it is normal (3–8 minutes). In certain diseases – HAEMOPHILIA, for example – clotting time is greatly extended and the danger of serious haemorrhage enhanced.... coagulation

A group of drugs used to treat bleeding disorders and to control bleeding. Haemostatic preparations that help blood clotting are given to people who have deficiencies of natural clotting factors. For example, factor VIII is used to treat haemophilia. Drugs that prevent the breakdown of fibrin in clots, such as tranexamic acid, can also improve haemostasis.... haemostatic drugs

(blood clotting) the process whereby blood is converted from a liquid to a solid state. The process may be initiated by contact of blood with a foreign surface (intrinsic system) or with damaged tissue (extrinsic system). These systems involve the interaction of a variety of substances (*coagulation factors) and lead to the production of the enzyme thrombin, which converts the soluble blood protein *fibrinogen to the insoluble protein *fibrin, forming the blood clot. Finally, fibrin is broken down by the action of *plasmin. Anticoagulants and tissue plasminogen activators act by inhibiting or activating various pathways in this cascade (see illustration). Blood coagulation is an essential mechanism for the arrest of bleeding (*haemostasis). See also platelet activation.... blood coagulation

n. the production of heat in a part of the body by means of a high-frequency electric current passed between two electrodes. Diathermy is utilized to coagulate tissues and seal off blood vessels, thus effecting *haemostasis. In bipolar diathermy electric current passes between the two electrodes of the instrument. In monopolar diathermy the instrument is one electrode, the other being a large pad applied to another part of the patient’s body. Examples of instruments used to deliver diathermy include diathermy knives, forceps, and scissors. Diathermy snares and needles can be used to destroy unwanted tissue and to remove small superficial neoplasms. See also electrosurgery.... diathermy

combining form denoting stoppage of a flow of liquid; stagnation. Example: haemostasis (of blood).... stasis

Haemorrhage. Bleeding from arteries is bright red, escaping in jerks; from the veins it is darker; steadier from the capillaries. There is an oozing of bright red blood from a cut. In an extravasation blood pours into lax tissues beneath the skin; the part becoming swollen with the appearance of a bruise.

To strengthen veins – Gentian. To enhance resistance – Echinacea. To counter failing strength – Ginseng. To promote granulation – Comfrey. To restore lacerated nerves – St John’s Wort. Nettles are a well-known traditional anti-haemorrhagic.

If bleeding is serious, control with firm finger pressure. Any one of the following may be used in the form of teas, tinctures, powders, etc.

Bowels. Ladies Mantle, Avens, Horsetail, Shepherd’s Purse, Tormentil, Raspberry leaves, Yarrow, Cranesbill, Bilberry.

Gums. Tea. Equal parts: Horsetail, St John’s Wort. (Maria Treben) Or:– Paint gums with Tincture Myrrh, Blood root, Goldenseal or Marigold.

Post-partum. (After child-birth) Goldenseal BHP (1983); Lady’s Mantle BHP (1983).

Lungs. Haemoptysis. Blood spitting. Blood root, Beth root, Lungwort, Mullein, Horsetail, St John’s Wort, Cranesbill. Bur-Marigold. Sage. Mouse Ear, Bugleweed. Nettle tea is a good stand-by.

Post-menopausal bleeding: Internal: Raspberry leaves, Ladies Mantle, Shepherd’s Purse. Plantain tea as an injection. Plugs of cotton wool saturated with Witch Hazel. To be investigated by a competent authority.

Mucous surfaces: tongue, mouth, throat, gullet. Marigold, Yarrow, Rue, Clematis erecta, Life root.

Blood root (tincture: 10-15 drops in water). Ice to suck.

Nose. Witch Hazel. Nettles. Vinegar water: to snuff into nostrils. Apply sponge soaked in cold water to back of the neck. Or: plug nose with Witch Hazel saturated cotton wool.

Hymen. See entry.

Skin. Superficial. Buckwheat, Marigold, Daisy, Tormentil, Witch Hazel, Blood root (tincture),.

Stomach. Haematemesis. The vomit of blood has the appearance of coffee grounds and is a symptom of gastric ulcer. Teas: Avens, Meadowsweet, Yarrow, Bur-Marigold, Cranesbill, Mullein.

Decoctions: Cranesbill root, Beth root, Oak bark.

After Surgery. After tissue excisions, blood clotting or wound-healing disorders for safe haemostasis: Beth root, Cranesbill root, Lady’s Mantle, St John’s Wort.

Blood in the urine. See: HAEMATURIA.

Bleeding of menses: See: MENSTRUATION.

IUD bleeding. Bleeding from intra-uterine devices: Injection: teas – Lady’s Mantle, Cranesbill, Tormentil, Marigold.

Vitamin E supplementation (International Journal of Fertility, Vol 28. 1983) Suggested dose: One 500iu capsule morning and evening.

Retinal haemorrhage. Buckwheat tea. Vitamin C: 1-3g daily. Evening Primrose oil.

Red cell stimulators: Yellow Dock root, Red Clover, Gentian.

White cell stimulators: Liquorice, Ginseng (Siberian) and Korean, Goldenseal, Echinacea.

Vitamins. C. D. K. P.

Minerals. Calcium, Iron, Selenium, Zinc.

Note: Any new episode of bleeding (rectal, gastric, etc) in those 45 and over should be investigated in hospital. Alteration of bowel habit, with bleeding, in young people should lead to referral to a doctor. ... bleeding