Therapeutic Plasma Exchange: Core Curriculum 2008

Relation of volume exchanged, estimated plasma volume (EPV), and percentage of decrease in initial concentration for large-molecular-weight substances removed during therapeutic plasma exchange (TPE). For example, if the volume exchanged (Ve) is equal to the patient's EPV, Ve/EPV will equal 1 and pretreatment values will be decreased by 63%. If the plasma exchanged is equal to 1.4 times the EPV, pretreatment levels will be decreased by 75%. As shown in the figure, increasingly voluminous exchanges during a single treatment yield a progressively smaller decrease in pretreatment levels. For most indications, each treatment should provide an exchange volume equal to 1 to 1.4 times the EPV. (Reproduced from Kaplan AA: A Practical Guide to Therapeutic Plasma Exchange, copyright Andre Kaplan)

Progressive decrease in immunoglobulin G (IgG) levels after 3 consecutive therapeutic plasma exchange (TPE) treatments equaling 1 plasma volume each. Intertreatment increases between treatments represent a combination of extravascular to intravascular reequilibration and a variable amount of new IgG synthesis. (Reproduced from Kaplan AA: A Practical Guide to Therapeutic Plasma Exchange, copyright Andre Kaplan)