Bone Marrow Aspiration

Bone marrow refers to the spongy tissue that is found inside the larger bones such as spine, breast bone, hips, ribs, legs and skull. Marrow has two parts – both solid and liquid. If the solid portion of the bone is sampled, it is called biopsy. Aspiration procedure is used to collect the liquid part of the marrow.

Both the procedures show whether the bone marrow is healthy and making normal amounts of blood cells. This procedure is normally used by doctors to diagnose and monitor blood and marrow diseases, including cancer. In bone marrow aspiration, the doctor uses a needle to draw a sample of the fluid portion. For a biopsy, a larger needle is used to take the sample of the solid part.

Most often bone marrow aspiration and bone biopsy is done at once. Together, they make the bone marrow examination. Although they are different procedures, they offer complementary information about bone marrow cells.

Why is it done?

Bone marrow aspiration and biopsy offer detailed information about the condition of the bone marrow and blood cells. In case the blood tests indicate that cell counts are abnormal, and information is not sufficient about a suspected problem, this is done. The doctor may perform bone marrow exam to diagnose a disease condition involving the bone marrow or blood cells:

• To determine a disease progression
  
• To check the iron levels and metabolism and
  
• To monitor treatment of a disease.

Pre bone marrow aspiration procedure

It is imperative to inform the doctor about any medications and supplements the patient is consuming. This can increase the risk of bleeding after a bone marrow aspiration. In case of anxiety or worry, better talk to the health care provider so that a sedative medication could be given before the aspiration in addition to a numbing agent through local anesthesia at the site where the needle is inserted.

Bone marrow aspiration is done in a hospital, a clinic or in a doctor's room. A specialist in blood disorders – a hematologist – or an oncologist, who is a specialist in cancer does the procedure with a nurse and a trained technologist. It usually takes about half an hour for the exam and if any intravenous sedation is given, extra time is taken for pre and post procedure care.

The patient's blood pressure and heart rate are checked. Some form of anesthesia is administered before the bone marrow aspiration as it can be painful. For many, local anesthesia is sufficient. You will be fully awake during the aspiration, but the site is numbed to reduce pain. If you are quite anxious, intravenous IV sedation is given before the marrow procedure.

Bone marrow aspiration procedure

The area for inserting the biopsy needle is marked and cleaned. The bone marrow fluid (aspirate) is usually collected from the top ridge of the back of the hipbone, and if it is done from the breast bone or the front of the hip near the groin. In young children and kids, the sample is taken from the lower leg bone, just below the knee. The patient will be made to lie down on the abdomen or side.

The bone marrow aspiration is usually done before the biopsy. A small incision is made to insert the needle easier. A hollow needle is inserted through the bone and into the bone marrow. Several samples are taken and aspiration takes only a few minutes. While the health care team ensures that sufficient quantity of sample is drawn, sometimes a 'dry tap' may occur, that is fluid cannot be withdrawn. The needle is moved for another attempt.

Post aspiration procedure

After the bone marrow exam, pressure is applied to the where the needle was inserted to stop the bleeding. A smaller bandage is placed on the site. If local anesthesia had been administered the patient is asked to lie back for 10-15 minutes and apply pressure on the biopsy site. In case, IV sedation had been given, you are taken into a recovery area as sedatives may cause impaired judgment, memory lapses or slowed response.

Tenderness may be felt for a week or more after the bone marrow exam, and the doctor administers pain reliever. You need to keep the bandage dry for 24 hours and not shower or bathe, or swim or use the hot tub. It is okay to get the aspiration site wet after 24 hours. In case bleeding soaks through the bandage, or does not stop even with direct pressure, consult the doctor. The doctor also needs to be contacted if there is persistent fever, worsening pain, swelling at the procedure site and increasing redness or drainage at the procedure site. Also it is advised to avoid rigorous activity for a couple of days to minimize bleeding and discomfort.

Results from bone marrow aspiration

The sample is sent to a laboratory for analysis. The results are available in a few days. The pathologist or hematologist evaluates the samples to check the health of the marrow and if it has enough healthy blood cells and also for abnormal cells. The doctor confirms or rules out a diagnosis and how advanced the disease is or if the treatment is working. Sometimes, follow-up tests are done.

Risks of bone marrow examination

This is a safe procedure and complications are rare. But some complications include:

Excessive bleeding which can happen in people with low platelet count.
Infection in those with weakened immune systems.
Discomfort that could be long lasting in the biopsy site.
Heart and lung problems can be caused due to penetration of the breastbone.
Sedation can cause allergic reaction, nausea and irregular heartbeats in some.

Uses of bone marrow exams

These are used for many conditions including:

• Anemia
  
• Bone marrow disorders which include myelodysplastic syndrome and myelofibrosis.
  
• Blood cell conditions such as Leukopenia, leukocytosis, thrombocytopenia, thrombocytosis, pancytopenia and polycythemia – which produce too few or too many of certain types of blood.
  
• Cancers of the bone marrow or of blood including leukemia, lymphomas and multiple myeloma.
  
• Cancers that have spread to other areas including breast.
  
• Hemochromatosis and
  
• Infections.

While problems with bone marrow can create lasting and serious health problems, bone marrow exams, such as aspiration and biopsy are important to help determine the status and extent of problems in the cells to evaluate and determine further treatment and management.

Aspiration Pneumonia

Aspiration pneumonia occurs when gastric contents, vomit or food distillate into the lungs and cause inflammation of the lungs and bronchial tubes. The aspirated material is responsible for introducing bacteria that is not normally found in the lungs. Pus forms as a result of this infection. The infection can then spread to the blood and other areas of the body. It can bring on shock and acute respiratory distress syndrome.

Sometimes it can cause pus to collect in the lungs. The severity of aspiration pneumonia depends on the volume and acidity of the aspirated contents. The effects of aspiration pneumonia can range from mechanical obstruction of airways to acute respiratory distress. Older persons or persons with altered mental status are more likely to face this emergency situation. Aspiration pneumonia is also a coincident risk of head trauma, acute stroke or metabolic derangement. Elderly hospitalized patients and those suffering from neurological diseases or gastroesophageal reflux are at increased risk of aspiration pneumonia.

Symptoms of aspiration pneumonia are fever and cough with foul-smelling or blood-stained mucus. Patients experience shortness of breath and chest pain. Increased heart rate and wheezing is also noticed. Aspiration pneumonia can be fatal if not attended to in time. Hospitalization may be required for management of the illness. Treatment measures vary depending on the severity of the pneumonia. Chest x-ray, blood culture and sputum culture can aid diagnosis and treatment. Swallowing studies are conducted on the patient to assess the swallowing function. Intravenous antibiotic medications are used to treat aspiration pneumonia. Articial breathing apparatus is used to aid the patient and keep the airways open. Oxygen therapy is also resorted to.

Thoracentesis

Thoracentesis or pleural fluid aspiration is a procedure that involves removal of fluid from the space between the lining of the pleura and the chest wall. Fluid is withdrawn with the aid of a needle passed through the skin of the chest wall into the pleural space. An analysis of the pleural effusion can indicate pulmonary embolism, hemothorax, Pancreatitis, pneumonia, heart failure or thyroid disease. Thoracentesis can aid in relieving pressure caused by accumulation of excess pleural fluid. A chest x-ray is taken before and after the Thoracentesis process. Do not move or cough while the diagnostic test is being conducted. Patients who have had lung surgery or lung disease such as emphysema may have difficulty with Thoracentesis. Pneumothorax, pulmonary edema or respiratory distress are rare complications associated with thoracentesis. It is essential to keep the doctor posted of any medications such as blood thinners or known allergies.