Also known as plasmapheresis. The removal of the circulating PLASMA from the patient. It is done by removing blood from a patient and returning the red cells with a plasma expander. The plasma exchange is carried out through an in-dwelling CANNULA in the femoral vein, and the red cells and plasma are separated by a hemonetics separator. Usually a sequence of three or four sessions is undertaken, at each of which 2–3 litres of plasma are removed. The lost plasma can either be replaced by human serum albumin (see ALBUMINS) or a plasma expander.
In autoimmune disorders, disease is due to damage wrought by circulating ANTIBODIES or sensitised lymphocytes (see LYMPHOCYTE). If the disease is due to circulating humoral antibodies, removal of these antibodies from the body should theoretically relieve the disorder. This is the principle on which plasma exchange was used in the management of autoimmune diseases due to circulating antibodies. Such disorders include Goodpasture’s syndrome, SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) and MYASTHENIA GRAVIS. One of the problems in the use of plasma exchange in the treatment of such diseases is that the body responds to the removal of an antibody from the circulation by enhanced production of that antibody by the immune system. It is therefore necessary to suppress this homeostatic response with cytotoxic drugs such as AZATHIOPRINE. Nevertheless, remissions can be achieved in autoimmune diseases due to circulating antibodies by the process of plasma exchange.
The name applied to the straw-coloured ?uid portion of the BLOOD composed of a solution of various inorganic salts of sodium, potassium, calcium, etc., as well as SERUM and ?brinogen, the material which produces clotting (see COAGULATION). When the plasma is clotted, the thinner ?uid separating from the clot is the serum.... plasma
These are cells that produce ANTIBODIES and occur in bone-forming tissue as well as the lining of the gastrointestinal tract and the lungs. The cells develop in LYMPH NODES, SPLEEN and BONE MARROW when T-lymphocytes (see IMMUNITY) are stimulated by antigens (see ANTIGEN) to produce the precursor cells from which plasma cells originate.... plasma cells
Synthetic organic substances, capable of exchanging ions – cationic or anionic – from the contents of the intestine. Originally used in the prevention of OEDEMA, they have been superseded in this role by the modern DIURETICS, and are now used chie?y in the treatment of HYPERKALAEMIA. They are usually taken by mouth or as an ENEMA.... ion exchange resins
complex insoluble chemical compounds that may be administered with the diet to alter the *electrolyte balance of the body in the treatment of heart, kidney, and metabolic disorders. For example, in patients on a strict low-sodium diet such resins combine with sodium in the food so that it cannot be absorbed and passes out in the faeces.... cation-exchange resins
a type of *electrocoagulation used to arrest haemorrhage or destroy abnormal tissue. A stream of inert gas, such as argon or helium, is ionized, thereby carrying electrical energy to adjacent tissue; there is no physical contact between the plasma coagulation apparatus and the tissue.... plasma coagulation
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