Bone marrow is located within cancellous bone and long-bone cavities. It consists of a pattern of vessels and nerves, differentiated and undifferentiated hematopoietic cells, reticuloendothelial cells, and fatty tissue. All of these are encased by endosteum, the membrane lining the bone marrow cavity. After proliferation and maturation have occurred in the marrow, blood cells gain entrance to the blood through or between the endothelial cells of the sinus wall.

A bone marrow specimen is obtained through aspiration or biopsy or needle biopsy aspiration. A bone marrow examination is important in the evaluation of a number of hematologic disorders and infectious diseases. The presence or suspicion of a blood disorder is not always an indication for bone marrow studies. A decision to use this procedure is made on an individual basis.

Sometimes, the bone marrow aspirate does not contain hematopoietic cells. This is known as a dry tap, which occurs when hematopoietic activity is so sparse that there are no cells to be withdrawn or when the marrow contains so many tightly packed cells that they cannot be suctioned out of the marrow. In such cases, a bone marrow biopsy would be advantageous. Before the bone marrow procedure is started, a peripheral blood smear should be obtained from the patient and a differential leukocyte count done.

See Table 2.1.

1. Assess the patient for fear or anxiety related to the procedure. Provide education, reassurance, and a supportive presence.

2. Follow standard precautions. Check for latex allergy; if allergy is present, do not use latex-containing products. Position the patient on the back or side according to site selected. The posterior iliac crest is the preferred site in all patients older than 12–18 months. Alternate sites include the anterior iliac crest, sternum, spinous vertebral processes T10 through L4, ribs, and tibia in children. The sternum is not generally used in children because the bone cavity is too shallow, the risk for mediastinal and cardiac perforation is too great, and the child may be uncooperative.

3. Clip hair if necessary and cleanse and drape the site as for any minor surgical procedure.

4. Inject a local anesthetic (procaine or lidocaine). This may cause a burning sensation. At this time, a skin incision of 3 mm is often made.

5. The healthcare provider introduces a short, rigid, sharp-pointed needle with stylet through the periosteum into the marrow cavity.

6. Pass the needle–stylet combination through the incision, subcutaneous tissue, and bone cortex. The stylet is removed, and 1–3 mL of marrow fluid is aspirated. Alert the patient that when the stylet needle enters the marrow, they may experience a feeling of pressure. The patient may also feel moderate discomfort as aspiration is done, especially in the iliac crest. Use a Jamshidi needle for biopsy, although you can also use the Westerman-Jensen modification of the Vim-Silverman needle.

7. Remove the stylet and advance the biopsy needle with a twisting motion toward the anterosuperior iliac spine.

8. Rotate or “rock” the needle in several directions several times after adequate penetration of the base (3 cm) has been achieved. This frees up the specimen. Slowly withdraw the needle once this is done.

9. Push the biopsy specimen out backward from the needle. Use the specimen to make touch preparations or immediately place in fixative. Make slide smears at the bedside.

10. Apply pressure to the puncture site until bleeding ceases. Apply a sterile dressing to the site.

11. Label the specimen with the patient’s name, date and time of collection, and test(s) ordered.

1. A specific and diagnostic bone marrow picture provides clues to many diseases. The presence, absence, and ratio of cells are characteristic of the suspected disease.

2. Bone marrow examination may reveal the following abnormal cell patterns:

   1. Multiple myeloma, plasma cell myeloma, macroglobulinemia

   2. Chronic or acute leukemias

   3. Anemia, including megaloblastic, macrocytic, and normocytic anemias

   4. Toxic states that produce bone marrow depression or destruction

   5. Neoplastic diseases in which the marrow is invaded by tumor cells (metastatic carcinoma, myeloproliferative and lymphoproliferative diseases)

   6. Agranulocytosis, which occurs when bone marrow activity is severely depressed, usually is a result of radiation therapy or chemotherapeutic drugs.

   7. Platelet dysfunction

   8. Some types of infectious diseases, especially histoplasmosis and tuberculosis

   9. Deficiency of body iron stores, microcytic anemia

   10. Lipid or glycogen storage disease

   11. Myelodysplastic syndrome is the name of a group of conditions that occur when blood-forming cells in the bone marrow are damaged.

Pretest Patient Care

1. Observe standard precautions.

2. Instruct the patient about test procedure, purpose, benefits, and risks.

3. Ensure that an informed consent form is properly signed and witnessed. Bone marrow aspiration is usually contraindicated in the presence of hemophilia and other bleeding dyscrasias.

4. Reassure the patient that analgesic agents will be available if needed. Administer moderate sedation and analgesia, if ordered. Use an oxygen monitor to evaluate breathing effectiveness.

5. Bone marrow biopsies or aspirations can be uncomfortable. Tell the patient that squeezing a pillow may be helpful as a distraction technique. Offer emotional support.

6. Sites used for bone marrow aspiration or biopsy affect pretest, intratest, and posttest care. Sites used include the posterior superior iliac crest, anterior iliac crest (if the patient is very obese), sternum (not used as often with children because cavity is too shallow, danger of mediastinal and cardiac perforation is too great, and observation of procedure is associated with apprehension and lack of cooperation), vertebral spinous processes T10 through L4 and ribs, tibia (often in children), and ribs. Position the patient according to the site selected.

7. Explain to the patient the importance of remaining still during the procedure.

8. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.