What are the different modalities of the plasmapheresis procedure?
Plasma exchange involves the withdrawal of blood from the circulation and its separation into cellular and plasma fractions by centrifugal separation or perfusion of a synthetic filter. In both methods, the cellular components are returned to the patient and the plasma is removed.
Double filtration plasmapheresis uses two filters with different pore sizes to separate toxic substances from plasma; the second filtration step is to separate useful substances that are returned to the circulation from higher-molecular-weight pathogenic substances that are removed.
Plasma adsorption procedure involves plasma exchange followed by delivery to an adsorption column to which pathogenic substances bind and are then removed from circulation.