What is Myelosuppression?
Myelosuppression otherwise known as bone marrow suppression is a reduction in the capacity of the bone marrow to generate blood cells. Bone marrow suppression results in decreased numbers of circulating leukocytes (leukopenia), erythrocytes (erythrocytopenia), and platelets (thrombocytopenia). Decreased leukocyte numbers cause immunosuppression. Decreased erythrocytes and platelets cause hypoxia, fatigue, and increased bleeding tendency. Myelosuppression can be mild to severe (fatal) based on the number of cells produced.
Most chemotherapeutic agents suppress bone marrow function to some degree. The agents associated with severe bone marrow suppression include busulfan, cyclophosphamide, cytosine arabinoside, dactinomycin, doxorubicin, daunorubicn, etoposide, mitomycin C, nitrogen mustard, and triethylenethiophosphoramide. Immunosuppression, which places the client at extreme risk for infection, is the major dose-limiting side-effect of cancer chemotherapy. Suppression of immune function is the main life-threatening side-effect and presents the nurse with serious challenge of providing the client with understanding, environment, and support to withstand this potentially devastating Complication.
Myelosuppression Symptoms & Signs
The signs and symptoms of myelosuppression are largely related to the decrease in the levels of the blood components. Manifestations of myelosuppression include the following:
- Fever as a sign of infection
- The patient have bleeding tendencies and bruises (excessive bleeding) because of thrombocytopenia
- Increased risks of having infections because of leukopenia
- Symptoms of having an infection
- Fatigue because of anemia
Myelosuppression can result in diminished production of red blood cells, white blood cells and platelets. When the number of red blood cells decreases the patient may have anemia and easy fatigability. On the other hand, decrease production of white blood cells may cause leukopenia or neutropenia (decrease in the number of neutrophils), and when this happens the patient will be more prone to infection especially that neutrophils combat bacteria. The patient will be immunocompromised and his body will have a hard time combating infections. While when the platelets start to lessen it may cause thrombocytopenia and will result in bleeding tendencies and bruising.
Myelosuppression Causes & Risk factors
Causes and Risk factors for bone marrow suppression include:
Majority in all the cases the cause of myelosuppression is chemotherapy and other cancer treatments. This is because a lot of the medicines used in chemotherapy momentarily repress the bone marrow.
These are also devastating when it reaches the bone marrow. The radiation combats the function of the bone marrow in producing RBC, WBCs and platelets when given in large proportions in increased frequency.
The cancer cells themselves can also lead to myelosuppression. A number of cancers attack the bone marrow and squeeze out the cells usually residing there. However, there are others that can suppress the bone marrow without attacking them directly such as deficiencies in nutrition, which is very frequent in people who suffer from cancer, gradually slow production of the blood cells as well as viral infections and several non-chemotherapeutic medications.
The condition more often than not initiates more than a week following damage to the bone marrow. Nevertheless, the bone marrow usually goes back to normal throughout the next several weeks. Not as much of, increasing injury can be brought about by infrequently, permanent damage that causes irreversible myelosuppression. Extremely rigorous radiation, chemotherapy or other cancer treatments have the ability to demolish every one of the cells in the bone marrow.
Myelosuppression Diagnostic Tests
Laboratory tests employed for the diagnosis of myelosuppression include the following:
Blood Count Tests
Having the blood extracted is a common practice among cancer patients. Especially that myelosuppression is one of the side-effects of the chemotherapy, it is important for a routine blood test to de done in a regular way. A significant decrease in red blood cells, white blood cells and platelets should be reported to the doctor immediately. There are many lab tests to be done to find the red blood cell count, leukocyte and neutrophil count and platelet count and clotting function examinations. Anemia may initially be noticed using a Complete Blood Count (CBC). It is a usual test that calculates the number and relation of the proportion of every dissimilar kind of cells in your blood stream.
Bone Marrow Biopsy
When CBC is not that efficient the doctor may suggest bone marrow biopsy. This test also determines the presence of cancer cells in the bone marrow as a result of leukemia or other malignancies involving the bone marrow. This test is done by aspirating bone marrow cells on the ischium part of the pelvis. The aspiration is extremely painful so patient support is needed throughout the procedure.
Management of myelosuppresion includes treatments aimed to reduce the cause of myelosuppression as well as symptomatic management. A mild case of myelosuppression is not constantly managed.
Limiting Cancer Therapy
If the case is caused by chemotherapy or radiation therapy, the cancer treatments may be suggested stopping, lessening or postponing them. This is done to reduce the damage or to give the patient’s bone marrow a time to improve. The full dose of the cancer treatment should not be given.
Meanwhile, the red blood cells and platelets can be simply replaced by blood transfusions (packed RBC’s or platelets). This will give a short-term solution to the problem and the bad news is the treatment may need to be done over and over because the transfused cells live only for a short period of time. There is also small risk of having a transfusion reaction and infection if the blood that is being transfused is contaminated by virus. In addition, sad to say, but transfusions of WBCs’ are not that effective and infrequently given by the doctors.
Growth Factor Therapy
Growth factor injections may be successful. Growth factors are defined as natural substances that can be found in the human body. This growth factor promotes blood cell production of the bone marrow. There are specific types of growth factor for certain blood cells, these are the examples:
- Erythropoietin injections
- granulocyte colony-stimulating factor
- granulocyte-macrophage colony-stimulating factor
- interleukin 11
The growth factor injections can lessen the need for blood transfusion and to make the life better for cancer patients. However, this has several side-effects if the kidneys are healthy and may not be successful if the body is producing enough erythropoietin. Other side-effects include pain in the bones, rashes, muscle soreness, nausea, and fever, retention of fluid, tachycardia, reddish eyes and dyspnea.
Bone Marrow Transplant
Bone marrow transplant is required if the bone marrow has permanent and severe damage. Bone marrows are taken from compatible donors.
Complications of myelosuppression may include:
- Sepsis- Presence of severe infection as a result of very low white blood cells may eventually to systemic infection.
- Hemorrhage- The presence of thrombocytopenia or low platelet count results in poor platelet aggregation. This will eventually lead to profuse bleeding in all areas of the body including nose bleeding, hematochezia (bright red blood in the stool), severe bruising and the like.
- Severe anemia- Unmanaged bone marrow suppression often leads to severe reduction in RBCs. This condition results in excessive weakness, fatigability, difficulty of breathing and hypoxia.
Prevention of bone marrow suppression depends on limiting or avoiding the cause such as:
- Exercising caution in administering chemotherapeutic agents.
- Avoiding exposure to high doses of radiation.
- Increasing the immune system by means of healthy diet, exercise and vitamin supplementation.