As blood cells normally
wear out, they are constantly being replaced by the bone marrow. Following chemotherapy,
as these cells wear out, they are not replaced as they would be normally, and
the blood cell levels begin to drop. The decrease in blood cell counts does
not occur immediately after chemotherapy because the drugs do not destroy the
cells already circulating in the bloodstream. Instead, the drugs temporarily
prevent formation of new blood cells by the bone marrow stem cells. Normally,
white blood cells have an approximate 6-hour life span, platelets live for about
10 days, and red blood cells have a life span of 120 days.
The lowest count that blood cell levels fall to is called the nadir. The nadir for each blood cell type will occur at different times but usually WBCs and platelets reach their nadir or lowest point within 7-14 days. It is at this point in time that patients are most susceptible to infection and bleeding. RBCs live longer and will not reach a nadir for several weeks.
Red blood cells or erythrocytes
carry oxygen from the lungs to the tissues and transport carbon dioxide back
to the lungs. There are normally between 4 and 6 million red blood cells per
milliliter of blood. The hematocrit is a measurement of the percentage of total
blood volume occupied by red blood cells. A normal hematocrit ranges between
36-42%. Hemoglobin is the red pigment in RBCs; it's function is to carry
oxygen. An average hemoglobin is between 12 to 16 grams per deciliter. A lower
than normal amount of red blood cells is referred to as anemia. Signs and symptoms
of anemia include a fall in the red blood cell count, decreased hemoglobin and
hematocrit levels, fatigue, hypotension, shortness of breath, tachypnea, tachycardia,
headaches, dizziness, and irritability.
Anemia caused by chemotherapy
is temporary. If the patients hematocrit and hemoglobin fall too low,
transfusions of packed red blood cells may be needed until the bone marrow has
recovered its normal ability to produce more blood cells. Because blood
transfusions have some risks, this procedure is used only if there are serious
anemia symptoms. A newer option for treating anemia caused by chemotherapy is
giving erythropoietin, a naturally occurring growth factor that stimulates RBC
production by bone marrow cells. Erythropoetin can relieve symptoms of anemia
and reduce the need for blood transfusions.
Management strategies for
a. Obtaining a baseline complete blood count and monitoring the number of red blood cells during and after chemotherapy.
b. Encouraging the patient to eat foods that are rich in iron, vitamins and minerals.
c. Teaching the patient to report signs and symptoms of anemia such as fatigue, dizziness, headaches, irritability, shortness of breath, an increase in heart rate or rate of breathing or both.
d. Encouraging the patient to modify and pace activities to get sufficient sleep and rest.
e. Giving transfusions of packed red blood cells or human erythropoetin as ordered.
White blood cells help the
body resist infection. Bacteria can invade many areas of the body, including
the skin, respiratory tract, oral cavity, sinuses, and perianal area. A normal
white blood cell (WBC) count ranges between 4,000 and 10,000 per milliliter
of blood. An overall decrease in the total white blood cell count is known as
leukopenia. WBCs are divided into 2 main categories: granulocytes, which
contain granules in the cytoplasm of the cell, and agranulocytes, which have
no cellular granules. Granulocytes include neutrophils, eosinophils, and basophils.
Lymphocytes and monocytes are agranulocytes.
Granulocytes, especially neutrophils, provide an important defense against infections and are the most numerous type of WBC. The normal range of neutrophils is between 2,500 and 6,000 cells per milliliter. A lower than normal number of neutrophils is referred to as neutropenia. Neutropenia is the most common factor that puts people with cancer at risk of potentially life-threatening infection. A patient with an absolute neutrophil count of 1,000 or less is considered to be neutropenic. Patients with a neutrophil count of 500 or less are severely neutropenic and at high risk of infection.
The type, dose, schedule,
and mode of administration of a drug help predict its myelosuppressive effects.
Neutropenia is most severe with the use of cell cycle-specific drugs, particularly
those that are active in the S and M phases. However, cell cycle nonspecific
drugs can have a delayed and prolonged effect on the bone marrow. The use of
high-dose or combination regimens can cause persistent nadirs because of intense
damage to the stem cell population. If WBC counts are very low, the patient
may be given antibiotics as a preventative measure. In the cancer patient with
neutropenia, a fever is usually treated with broad-spectrum antibiotics and
colony stimulating factors.
Several naturally occurring
hematopoietic growth factors may stimulate the production of various types of
blood cells. These growth factors are also called colony-stimulating factors.
The 2 growth factors that stimulate production of WBCs are granulocyte-macrophage
colony stimulating factor and granulocyte colony stimulating factor. These drugs
may be given the day after chemotherapy. In some situations, doctors may prescribe
growth factors in order to prevent the WBC from falling too low, so that chemotherapy
can be given on schedule.
Management strategies for
a. Obtaining baseline data before chemotherapy begins, particularly the absolute neutrophil count.
b. Monitoring the neutrophil count during and after chemotherapy.
c. Assessing the patient for signs and symptoms of infection.
d. Teaching the patient about signs of infection such as fever, sore throat, new cough or shortness of breath, nasal congestion, burning during urination, shaking chills, redness, swelling, and warmth at the site of an injury.
e. Giving antibiotics or colony stimulating factors as ordered.
f. Instructing the patient to maintain a safe and clean environment to prevent infection.
g. Advising the patient to avoid people who have colds or any communicable diseases.
h. Advising the patient to avoid eating raw fruits and vegetables, handling fresh flowers or plants, or handling pet excrement due to the possibility of acquiring a fungal or bacterial infection.
i. Emphasizing the importance of meticulous personal hygiene. To avoid infection, the patient should be advised to bathe daily, perform oral care every 4 hours or more often, empty the bladder at least every 4 hours, and avoid using rectal suppositories or enemas. Female patients should be instructed to avoid douching or using tampons that can serve as reservoirs for infection.
j. Instructing the patient in good hand washing technique.
k. Encouraging the patient to maintain good nutrition by eating a high-protein, high-carbohydrate diet, and drinking at least 8 glasses of fluid daily.
The Oncology Nursing Society is an excellent resource for clinical practice matters for nurses.
For example, click here for information about management and prevention of neutropenia.
Look for the answer to this question
What are 2 drugs that are given to stimulate production of white blood cells?
Thrombocytes or platelets
are critical for maintaining homeostasis, by being able to form blood clots
when needed. The normal range for platelet counts is between 150,000 and 450,00
per milliliter of blood. The term for a low platelet count is thrombocytopenia.
Symptoms of thrombocytopenia include easy bruising, bleeding longer than usual
after minor cuts or scrapes, bleeding gums or nose bleeds, development of ecchymoses
(large bruises) and petechiae (multiple small bruises). Sites of bleeding can
include the skin, mucous membranes, gastrointestinal system, genitourinary system,
respiratory system, and the brain. Chemotherapy can depress the platelet count
and drugs containing acetylsalicylic acid (aspirin) or nonsteroidal anti-inflammatory
agents (NSAIDS) can worsen the potential for thrombocytopenia.
Although low platelet counts resulting from chemotherapy are temporary, they can cause serious and potentially life-threatening blood loss from injury or bleeding that can damage internal organs. If platelet counts are very low (below 10,000), or if a person with moderately low counts has greater than normal bleeding, platelet transfusions may be given. Transfused platelets last only a few days, and some people who have received multiple platelet transfusions can develop an immune reaction that destroys donor platelets. A platelet growth factor may be given to people with severe thrombocytopenia to decrease the need for platelet transfusions.
Management strategies for thrombocytopenia include:
a. Monitoring the patients platelet count closely.
b. Assessing for superficial or internal signs of bleeding such as petechiae, epistaxis (nose bleeds), easy bruising, prolonged bleeding time, coffee ground emesis and hematuria.
c. Testing the stool and urine for blood.
d. Teaching the patient to maintain a safe environment to prevent falls or trauma.
e. Using stool softeners to avoid straining, which can cause rectal tearing and bleeding, and eating a high fiber diet and drinking plenty of fluids to avoid constipation.
f. Postponing, if possible, any invasive medical or surgical procedures, including dental extractions, multiple venipunctures, or injections.
g. Avoiding using sharp instruments such as razors or scissors for grooming.
h. Avoiding medications that may prolong or exacerbate bleeding, such as steroids or over-the-counter drugs containing aspirin.
i. Using a soft toothbrush and avoiding flossing.
j. Using a water-soluble lubricant for sexual activity.
k. Giving platelet transfusions as ordered.