A plasmapheresis treatment takes several hours and can be done on an outpatient basis. It can be uncomfortable but is normally not painful. The number of treatments needed varies greatly depending on the particular disease and the person's general condition. An average course of plasma exchanges is six to 10 treatments over two to 10 weeks. In some centers, treatments are performed once a week, while in others, more than one weekly treatment is done.
Plasmapheresis removes the fluid part of the blood, the plasma, from blood cells.
The cells are returned to the person undergoing treatment, while the plasma is discarded. The procedure takes several hours and can be uncomfortable, although it is normally not painful. A person undergoing plasmapheresis can lie in bed or sit in a reclining chair. Blood is taken to the separator from one tube, while the separated blood cells, combined with replacement fluids, are returned to the patient through the other tube. The amount of blood outside the body at any one time is much less than the amount ordinarily donated in a blood bank.