Also known as packed cell volume, this is an expression of the fraction of blood volume occupied by the ERYTHROCYTES. It is determined by centrifuging a sample of blood in a capillary tube and measuring the height of the resulting packed cells as a percentage of the total sample height. Normal values: males 42–53 per cent or 0.42–0.53 mL/dL females 32–48 per cent or 0.36–0.48 mL/dL
n. see packed cell volume.
An anticoagulant (see ANTICOAGULANTS), usually given by mouth on a daily basis. The initial dose depends upon the PROTHROMBIN or coagulation time; this should be determined before starting treatment, and then at regular intervals during treatment. It is indicated for the prophylaxis of embolisation (see EMBOLISM) in rheumatic heart disease and atrial ?brillation (see HEART, DISEASES OF); after prosthetic heart-valve insertion; prophylaxis and treatment of venous thrombosis and PULMONARY EMBOLISM; and TRANSIENT ISCHAEMIC ATTACKS OR EPISODES (TIA, TIE). When given in tablet form, its maximum e?ect generally occurs within about 36 hours, wearing o? within 48 hours. Special caution is appropriate in patients with disease of the liver or kidneys or who have had recent surgery. Warfarin is contra-indicated throughout pregnancy (especially the ?rst and third trimesters), and in cases of PEPTIC ULCER, severe HYPERTENSION and bacterial ENDOCARDITIS. The most important adverse e?ect is HAEMORRHAGE. Other reported side-effects include HYPERSENSITIVITY, rash, ALOPECIA, diarrhoea, unexplained drop in HAEMATOCRIT readings, purple toes, skin NECROSIS, JAUNDICE, liver dysfunction, nausea, vomiting and pancreatitis (see PANCREAS, DISEASES OF). (See also COAGULATION.)... warfarin
n. an increase in the *packed cell volume (haematocrit) in the blood. This may be due either to a decrease in the total volume of the plasma (relative polycythaemia) or to an increase in the total volume of the red cells (absolute polycythaemia). The latter may occur as a primary disease (see polycythaemia vera) or as a secondary condition in association with various respiratory or circulatory disorders that cause deficiency of oxygen in the tissues and with certain tumours, such as carcinoma of the kidney.... polycythaemia
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