bone marrow aspiration and trephine

Bone marrow is a blood like substance that is found in the larger bones of the human body. It is the main site for the production and storage of blood cells before they enter the circulatory system. Blood cells in the bone marrow comprise of ‘stem cells’ (blood cells at their earliest stage of development), red cells, white cells and platelets. In an adult the production of blood cells is dependent upon the body’s need. All blood cells have a very important function in the body including fighting infection, transporting oxygen and helping to prevent bleeding.

A bone marrow aspiration involves taking a sample of bone marrow, usually from the back of the large pelvic bone. This involves the insertion of a special needle into the marrow of the bone after local anaesthetic has been used to numb the tissues surrounding it. Approximately 2-10mls of blood like fluid from the bone marrow will be withdrawn into a syringe depending upon the tests required.

A bone marrow trephine investigation is usually carried out at the same time although involves the use of a second special needle inserted into the same area to take a small sample of the ‘spongy’ bone marrow tissue.

There are many different reasons for undergoing a bone marrow aspiration or trephine. Your doctor will explain the reason for your test before going ahead and will also gain your consent to do so.

The actual procedure itself will take approximately 20 minutes. You should however allow longer as some recovery time may be required or other tests such as peripheral blood samples.

A specialist haematology doctor or the haematology advanced nurse practitioner will carry out the procedure and if required with the assistance of a specialist trained health care professional.

The procedure is uncomfortable but enough local anaesthesia is used to numb the tissues around the pelvic area, although you will feel some pressure and for a short time possibly a ‘pulling’ sensation down one of your legs. We can provide ‘Entonox,’ (gas and air), for those patients who are anxious about the procedure.

If this is something that you think you would like, please ask a nurse on your arrival to the department. There is no prior preparation required for the use of Entonox.

No, you can come alone, although you will have to wait in the department for approximately 20 minutes following the procedure if you choose to have Entonox.