The bone marrow harvest is associated with some discomfort. Patients may complain of slight pain or tenderness in the harvested areas. Pain is usually well controlled by paracetamol. Patients are frequently discharged from hospital later the same day. During a Peripheral blood stem cell harvest in the pheresis unit , a patient is connected to a cell separation machine via a needle inserted into each arm.
Blood is withdrawn from one arm and circulated through the machine which separates the stem cells.
The remaining cells are returned to the blood circulation through the needle in the opposite arm. Several collection runs are required to harvest an adequate number of stem cells. Each session may last for a couple of hours. The procedure is painless, but patients occasionally suffer from light-headedness, coldness, numbness around the lips or cramping in the hands during the harvest. After each session the cells are frozen until needed for the transplant.