Interventions for Clients with Hematologic Problems - PowerPoint PPT Presentation

About This Presentation
Title:

Interventions for Clients with Hematologic Problems

Description:

Interventions for Clients with Hematologic Problems RED BLOOD CELL DISORDERS Disorders of the hematologic system can occur as a result of problems in the production ... – PowerPoint PPT presentation

Number of Views:358
Avg rating:3.0/5.0
Slides: 54
Provided by: intranetT9
Category:

less

Transcript and Presenter's Notes

Title: Interventions for Clients with Hematologic Problems


1
Interventions for Clients with Hematologic
Problems
  • RED BLOOD CELL DISORDERS

2
  • Disorders of the hematologic system can occur as
    a result of problems in the production, function,
    or normal destruction of any type of blood cell.
  • The type and severity of the specific disorder
    determine the degree of threat to the client's
    well-being

3
RED BLOOD CELL DISORDERS
  • The major cellular population of the blood
    consists of red blood cells (RBCs), or
    erythrocytes.
  • Adequate tissue oxygenation depends on
    maintaining the circulating number of RBCs within
    the normal range for the person's age and gender
    and ensuring that the cells can perform their
    normal functions. RBC disorders include problems
    in production, function, and destruction.
  • These problems may result in an insufficient
    number or insufficient function of RBCs (anemia)
    or an excess of RBCs (polycythemia).

4
RED BLOOD CELL DISORDERS
  • Anemia is a reduction in either the number of
    RBCs, the quantity of hemoglobin, or the
    hematocrit (percentage of packed RBCs per
    deciliter of blood).
  • Anemia is a clinical sign, not a diagnosis,
    because it is a manifestation of a number of
    abnormal conditions.
  • Despite the many causes of anemia, the effects of
    anemia on the client and the corresponding
    nursing care are similar for all types of anemia

5
(No Transcript)
6
(No Transcript)
7
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • Sickle cell disease is a condition in which
    chronic anemia is one of many problems causing
    pain, disability, increased risk for disease, and
    early death.
  • Once considered a childhood disorder, clients
    with sickle cell disease who receive appropriate
    supportive care may live into their 30s and 40s.
  • In addition, there is great variation among
    clients in the severity of the disease and the
    onset of complications.

8
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • Pathophysiology
  • Hereditary disorder - formation of abnormal beta
    chains in the hemoglobin molecule.
  • The normal hemoglobin molecule of adults is
    composed partially of the globin protein,
    consisting of two alpha chains and two beta
    chains of amino acids (hemoglobin A (HbA)). The
    total hemoglobin of normal healthy adults is
    usually 98 to 99 HbA, with a small percentage
    of a fetal form of hemoglobin (HbF).
  • In sickle cell disease, at least 40 of the total
    hemoglobin contains an abnormality of the beta
    chains, known as hemoglobin S (HbS).

9
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • HbS is sensitive to changes in the oxygen content
    of the RBC. When RBCs containing large amounts of
    HbS are exposed to conditions of decreased
    oxygen, the abnormal beta chains contract and
    pile together within the cell, distorting the
    overall shape of the RBC.
  • These cells assume a sickle shape, become rigid,
    clump together, and form clusters that block
    capillary blood flow.
  • Capillary obstruction leads to further tissue
    hypoxia (reduced oxygen supply) and more
    sickling, causing blood vessel obstructions and
    infarctions in the locally affected tissues.
  • Situations that lead to sickling include hypoxia,
    dehydration, infections, vascular stasis, low
    environmental or body temperatures, acidosis,
    strenuous exercise, and anesthesia

10
Red blood cell actions under conditions of low
tissue oxygenation. (HbS, Hemoglobin S HbA,
hemoglobin A.)
11
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • Usually, sickled cells resume a normal shape when
    the precipitating condition is removed and proper
    oxygenation occurs.
  • The membranes of the cells become damaged over
    time, and cells become irreversibly sickled.
  • The membranes of cells with HbS are more fragile
    and more easily destroyed in the spleen and in
    other organs that have long, twisted capillary
    pathways. The average life span of an RBC
    containing 40 or more of HbS is approximately 20
    days. This reduced life span is responsible for
    hemolytic (blood cell-destroying) anemia in
    clients with sickle cell disease.

12
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • The client with sickle cell disease experiences
    periodic episodes of extensive cellular sickling,
    or crises.
  • Repeated occlusions of progressively larger blood
    vessels have long-term negative effects on
    tissues and organs. Most effects are thought to
    occur as a result of capillary and blood vessel
    occlusion leading to tissue hypoxia, anoxia,
    ischemia, and cell death.
  • Tissues and organs begin to have small infarcted
    areas that eventually destroy all healthy cells
    and lead to organ failure.
  • Tissues and organs most commonly affected in this
    way are the spleen, liver, heart, kidney, brain,
    bones, and retina

13
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • Etiology
  • Sickle cell disease is a genetic disorder with an
    autosomal recessive pattern of inheritance.
  • The formation of the beta chains of the
    hemoglobin molecule is dependent on a pair of
    genes.
  • When the client inherits one abnormal gene of
    this pair, the condition is called sickle cell
    trait.
  • When the client inherits two abnormal genes, the
    condition is called sickle cell disease (formerly
    sickle cell anemia), and the client has severe
    manifestations of the disease even under
    relatively mild precipitating conditions. In
    addition, if the client has children, each child
    will inherit one of the two abnormal genes and at
    least have sickle cell trait

14
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • Cultural considerations
  • Sickle cell disease occurs most often in African
    Americans, as well as in African, Mediterranean,
    Caribbean, Middle Eastern, and Central American
    populations.
  • Approximately 1 of every 12 African Americans has
    the sickle cell trait.
  • One of every 345 African-American infants
    inherits two abnormal genes (one from each
    parent) and has overt sickle cell disease

15
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • History
  • An adult with sickle cell disease has a
    long-standing diagnosis of the disorder.
  • The nurse asks the client about previous crises,
    including precipitating events, severity, and
    usual treatments.
  • Recent activities and situations are explored to
    determine the probable precipitating condition or
    event.
  • The nurse also reviews all activities and events
    during the previous 24 hours, including food and
    fluid intake, exposure to temperature extremes,
    types of clothing worn, medications taken,
    exercise, trauma, stress, and ingestion of
    alcohol or other recreational drugs. This
    activity review provides important information
    about fatigue, activity tolerance, and
    participation in activities of daily living
    (ADLs).

16
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • The client is asked about changes in sleep and
    rest patterns, ability to climb stairs, and any
    activity that induces shortness of breath.
  • Obtaining a subjective baseline assessment of the
    client's perceived energy level using a scale
    ranging from 0 to 10 (0 not tired with plenty
    of energy 10 total exhaustion) can be useful
    in evaluating the degree of fatigue and the
    effectiveness of later treatments

17
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • Physical assessment/clinical manifestations
  • Pain is the most common symptom experienced
    during sickle cell crisis.
  • Jaundice may also be present as a result of
    increased red blood cell (RBC) destruction and
    release of bilirubin.
  • Other clinical manifestations vary with the site
    of tissue damage.
  • Cardiovascular assessment
  • Compare peripheral pulses, temperature, and
    capillary refill in all extremities
  • Extremities distal to blood vessel occlusion are
    cool to the touch with slow capillary refill and
    may have diminished or absent pulses.
  • The heart rate may be rapid and the blood
    pressure low to average, with a decreased pulse
    pressure because breakage of RBCs leads to anemia

18
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • Integumentary assessment
  • The skin may be pale or cyanotic as a result of
    decreased perfusion and anemia. The nurse
    examines the lips, tongue, nail beds,
    conjunctivae, palms, and soles at regular
    intervals for subtle color changes. With
    cyanosis, the lips and tongue are gray, and the
    palms, soles, conjunctivae, and nail beds have a
    bluish tinge.
  • Jaundice. The nurse assesses for jaundice in
    clients with darker skin by inspecting the oral
    mucosa, especially the hard palate, for yellow
    discoloration. Inspection of the conjunctivae and
    adjacent sclera may be misleading because of
    normal deposits of subconjunctival fat that
    produce a yellowish hue when seen in contrast to
    the dark periorbital skin. Therefore the nurse
    examines the sclera closest to the cornea to
    diagnose jaundice more accurately. Jaundice from
    excessive bilirubin may also cause intense
    itching.

19
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • Abdominal assessment
  • Abdominal organs are usually the first to be
    damaged as a result of multiple episodes of
    hypoxia and ischemia. The nurse inspects the
    abdomen for asymmetry or bulging areas, gently
    palpating it. Affected organs, such as the liver
    or spleen, may be firm and enlarged with a
    nodular texture in later stages of the disease
  • Musculoskeletal assessment
  • Extremities are a common site of vascular
    occlusion among clients who have sickle cell
    disease. In addition, joints may be damaged from
    frequent hypoxic episodes and undergo necrotic
    degeneration.
  • The nurse inspects the extremities for symmetry
    and records any areas of swelling or color
    difference. Clients are asked to move all joints,
    and the nurse notes the range of motion and any
    accompanying pain

20
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • Central nervous system assessment
  • During crises, clients may have a low-grade
    fever. If the CNS sustains infarcts or repeated
    episodes of hypoxia, they may have seizure
    activity or clinical manifestations of a stroke.
    Hand grasps are assessed bilaterally. The nurse
    assesses gait and coordination in those clients
    who are permitted to walk.
  • Laboratory assessment
  • Large percentage of hemoglobin S (HbS) present on
    electrophoresis. A person who has sickle cell
    trait usually expresses less than 40 HbS, and
    the client with sickle cell disease may express
    85 to 95 HbS. This percentage does not change
    during crises.
  • Another indicator of sickle cell disease is the
    percentage of RBCs showing irreversible sickling.
    This value is less than 1 among people who do
    not have sickle cell disease, is 5 to 50 among
    people with sickle cell trait, and may exceed 90
    among clients with sickle cell disease

21
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • The hematocrit of clients with sickle cell
    disease is usually low (between 20 and 30).
    This value decreases even more dramatically
    during vascular occlusive crises, or aplastic
    crises, when the bone marrow temporarily fails to
    produce cells during stressful periods (such as
    infection).
  • The reticulocyte count is elevated, indicating
    anemia of long duration. Often the mean
    corpuscular hemoglobin concentration (MCHC) and
    total bilirubin level are elevated in the client
    who has sickle cell disease.
  • The total white blood cell (WBC) count is usually
    above normal among clients who have sickle cell
    disease. It is thought that this elevation is
    related to chronic inflammation resulting from
    tissue hypoxia and ischemia

22
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • Radiographic assessment
  • Bone changes occur as a result of chronically
    stimulated marrow and hypoxic bone tissue. The
    skull may show radiographic changes resulting
    from chronic bone surface resorption and
    regeneration, giving the skull a "crew cut"
    appearance. Joint necrosis and degeneration also
    are obvious on x-ray examination.
  • Other diagnostic assessment
  • Electrocardiographic (ECG) changes document
    cardiac infarcts and tissue damage.
  • Ultra-sonography, computed tomography (CT),
    positron emission tomography (PET), and magnetic
    resonance imaging (MRI) may reveal soft-tissue
    and organ degenerative changes resulting from
    inadequate oxygenation and chronic inflammation

23
(No Transcript)
24
(No Transcript)
25
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • Interventions
  • PAIN DRUG THERAPY. Clients in acute sickle cell
    crisis often require at least 48 hours of
    parenteral analgesics.
  • Morphine and hydromorphone (Dilaudid) are the
    medications of choice
  • For sickle cell crisis, these agents should be
    administered intravenously on a routine schedule.
    Once relief is obtained, the intravenous (IV)
    dose can be tapered and then administered orally
  • Meperidine (Demerol) is also used for sickle cell
    crisis, but long-term use of this agent can cause
    neurologic symptoms, including anxiety and
    seizures
  • Intramuscular (IM) injections are avoided because
    frequent injections lead to sclerosing of tissue
    (and absorption may be impaired by poor
    circulation).
  • Moderate pain may be treated with oral doses of
    codeine, morphine sulfate, or nonsteroidal
    antiinflammatory drugs (NSAIDs)

26
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • Complementary therapies and other
    nonpharmacologic measures, such as keeping the
    room warm, using distraction and relaxation
    techniques, proper positioning with support for
    painful areas, aroma therapy, therapeutic touch,
    and warm soaks or compresses, have all been
    useful in decreasing pain.
  • The nurse must not assume, however, that these
    methods alone will provide adequate pain relief.
    Analgesics are required to treat sickle cell pain

27
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • POTENTIAL FOR SEPSIS. The client with sickle cell
    disease is more susceptible to bloodborne
    infections and infection by encapsulated
    microorganisms, such as Streptococcus pneumoniae
    and Haemophilus influenzae, as a result of
    decreased spleen function. Interventions aim at
    preventing or halting the process of infection,
    controlling infection, and initiating early,
    effective treatment regimens for specific
    infections.
  • PREVENTION/EARLY DETECTION. Frequent, thorough
    handwashing is of the utmost importance. Any
    person with an upper respiratory tract infection
    who must enter the client's room wears a mask.
    Strict aseptic technique is used for all invasive
    procedures.
  • The nurse continually assesses the client for the
    presence of infection and monitors a daily
    complete blood count (CBC) with differential WBC
    count. The oral mucosa is inspected during every
    nursing shift for lesions indicating fungal or
    viral infection. The lungs are auscultated every
    8 hours for crackles, wheezes, or diminished
    breath sounds. Each time the client voids,
    assistive nursing personnel inspect the urine for
    odor and cloudiness, and the client is asked
    about any sensation of urgency, burning, or pain
    during urination. Vital signs are taken at least
    every 4 hours to assess for fever

28
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • DRUG THERAPY. Prophylactic therapy with
    twice-daily administration of oral penicillin in
    the penicillin-tolerant client has resulted in
    dramatic reductions in the number of pneumonia
    and other streptococcal infections. Agents used
    depend on the sensitivity of the specific
    organism causing the infection, as well as the
    extent of the infection

29
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLS Sickle Cell Disease
  • POTENTIAL FOR MULTIPLE ORGAN DYSFUNCTION
  • The client in sickle cell crisis is admitted to
    the acute care hospital. The nurse assesses for
    adequacy of circulation to all body areas.
    Restrictive clothing is removed, and the client
    is instructed to avoid keeping the hips or knees
    in a flexed position.
  • Dehydration perpetuates cell sickling and must be
    avoided. Nursing personnel assist the client in
    maintaining an adequate hydration status. The
    client in crisis requires an oral or parenteral
    intake of at least 200 mL/hr.
  • Oxygen is ordered, and the nurse ensures that
    oxygen therapy is delivered appropriately,
    including nebulization to prevent dehydration.
  • Transfusion therapy has been used to decrease the
    incidence of organ dysfunction and stroke. RBC
    transfusions are therapeutic because levels of
    hemoglobin A (HbA) are sustained, whereas levels
    of hemoglobin S (HbS) are diluted. Transfusions
    also suppress erythropoiesis, thereby decreasing
    the production of sickle cells. Transfusions may
    be administered in either the acute care or
    clinic setting by a registered nurse. The nurse
    monitors the client closely for complications of
    transfusion therapy
  • In some treatment centers, bone marrow
    transplantation is being performed to correct
    abnormal hemoglobin permanently. Because bone
    marrow transplantation is expensive and may
    result in chronic and life-threatening
    complications, its risks and benefits need to be
    seriously considered for each client

30
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLSGlucose-6-Phosphate Dehydrogenase
Deficiency Anemia
  • Overview
  • Many forms of congenital hemolytic (blood
    cell-destroying) anemia result from defects or
    deficiencies of one or more enzymes within the
    red blood cell (RBC). More than 200 such
    disorders have been identified. Most of these
    enzymes are needed to complete some critical step
    in cellular energy production. The most common
    type of congenital hemolytic anemia is associated
    with a deficiency of the enzyme
    glucose-6-phosphate dehydrogenase (G6PD). This
    disease is inherited as an X-linked recessive
    disorder and affects about 10 of all African
    Americans.
  • G6PD stimulates critical reactions in the
    glycolytic pathway. RBCs contain no mitochondria,
    so active glycolysis is essential for energy
    metabolism. Newly produced RBCs from clients with
    G6PD deficiency have relatively sufficient
    quantities of G6PD however, as the cells age,
    the concentration diminishes drastically. Cells
    that have reduced amounts of G6PD are more
    susceptible to breaking during exposure to
    specific drugs (e.g., phenacetin, sulfonamides,
    aspirin acetylsalicylic acid, quinine
    derivatives, thiazide diuretics, and vitamin K
    derivatives) and toxins.
  • After exposure to any of these agents, clients
    experience acute intravascular hemolysis lasting
    from 7 to 12 days. During this acute phase,
    anemia and jaundice develop. The hemolytic
    reaction is self-limited because only older
    erythrocytes, containing less G6PD, are destroyed

31
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLSGlucose-6-Phosphate Dehydrogenase
Deficiency Anemia
  • Collaborative management
  • It is critical that the precipitating drug or the
    agent responsible for the hemolytic reaction be
    identified and totally removed. People should be
    screened for this deficiency before donating
    blood, because administration of cells deficient
    in G6PD can be hazardous for the recipient.
  • During and immediately after an episode of
    hemolysis, adequate hydration is essential to
    prevent precipitation of cellular debris and
    hemoglobin in the kidney tubules, which can lead
    to acute tubular necrosis. Osmotic diuretics,
    such as mannitol (Osmitrol), may assist in
    preventing this complication. Transfusion therapy
    is indicated when anemia is present and kidney
    function is normal

32
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLSImmunohemolytic Anemia
  • Overview
  • Increased RBC destruction through hemolysis can
    occur in response to many situations, including
    trauma, infection (especially malarial
    infections), and autoimmune reactions. All
    increase the rate at which RBCs are destroyed by
    causing lysis (breakage) of the RBC membrane.
  • In immunohemolytic anemia, immune system
    components attack a person's own RBCs. The exact
    mechanism that causes immune components to no
    longer recognize blood cells as self and to
    initiate destructive processes against RBCs is
    not known. Some hemolytic anemias are present
    with other autoimmune disorders (such as systemic
    lupus erythematosus) or lymphoproliferative
    disorders. Regardless of the cause, RBCs are
    viewed as non-self by the immune system and are
    destroyed.

33
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLSImmunohemolytic Anemia
  • There are two types of immunohemolytic anemia
    warm antibody anemia and cold antibody anemia.
  • Warm antibody anemia is usually associated with
    immunoglobulin G (IgG) antibody excess. These
    antibodies are most active at 98 F (37 C) and
    may be stimulated by drugs, chemicals, or other
    autoimmune problems.
  • Cold antibody anemia is associated with fixation
    of complement proteins on immunoglobulin M (IgM)
    and occurs best at 86 F (30 C). This problem is
    commonly associated with a Raynaud-like response
    in which the arteries in the distal extremities
    constrict profoundly in response to cold
    temperatures or stress

34
ANEMIAS RESULTING FROM INCREASED DESTRUCTION OF
RED BLOOD CELLSImmunohemolytic Anemia
  • Collaborative management
  • Treatment depends on clinical severity. Steroid
    therapy for mild to moderate immunosuppression is
    the first line of treatment and is temporarily
    effective in most clients. Splenectomy and more
    intensive immunosuppressive therapy with
    cyclophosphamide (Cytoxan, Procytox) and
    azathioprine (Imuran) may be instituted if
    steroid therapy fails. Plasma exchange therapy to
    remove attacking antibodies is effective for
    clients who do not respond to immunosuppressive
    therapy

35
Indications for treatment with blood components
36
ANEMIAS RESULTING FROM DECREASEDPRODUCTION OF
RED BLOOD CELLSIron Deficiency Anemia
  • Overview
  • The adult body contains between 2 and 6 g of
    iron, depending on the size of the person and the
    amount of hemoglobin in the cells.
  • Approximately two thirds of this iron is
    contained in hemoglobin the other third is
    stored in the bone marrow, spleen, liver, and
    muscle.
  • If a person has an iron deficiency, the iron
    stores are depleted first, followed by the
    hemoglobin stores. As a result, RBCs are small
    (microcytic), and the client has relatively mild
    manifestations of anemia, including weakness and
    pallor. In iron deficiency anemia, serum ferritin
    values are less than 12 g/L.
  • Iron deficiency anemia is the most common type of
    anemia and can result from blood loss, increased
    energy demands, gastrointestinal malabsorption,
    and dietary inadequacy.
  • The basic problem of iron deficiency anemia is a
    decreased supply of iron for the developing RBC.
    Iron deficiency anemia can occur at any age but
    is more frequent in women, older adults, and
    people with poor diets

37
ANEMIAS RESULTING FROM DECREASEDPRODUCTION OF
RED BLOOD CELLSIron Deficiency Anemia
  • Collaborative management
  • The primary treatment of clients with iron
    deficiency anemia is to increase the oral intake
    of iron from common food sources.
  • An adequate diet supplies a person with about 10
    to 15 mg of iron per day, of which only 5 to 10
    is absorbed in the stomach, duodenum, and upper
    jejunum. This amount is sufficient to meet the
    needs of healthy men and healthy women after
    childbearing age but is not sufficient to supply
    the greater needs of menstruating women and
    adolescents during growth spurts.
  • Fortunately, if iron intake is inadequate, or if
    bleeding or pregnancy occurs, the
    gastrointestinal tract is capable of increasing
    the absorption of iron to about 20 to 30 of the
    total daily intake.
  • When iron deficiency anemia is severe, iron
    preparations can be administered intramuscularly.
    Such preparations are administered using the
    Z-track best practice method

38
Common food sources of iron, vitamin b12, and
folic acid
39
ANEMIAS RESULTING FROM DECREASEDPRODUCTION OF
RED BLOOD CELLSVitamin B12 Deficiency Anemia
  • Overview
  • Proper production of RBCs depends on adequate
    desoxyribonucleic acid (DNA) synthesis in the
    precursor cells so that cell division and
    maturation into functional RBCs can occur.
  • All DNA synthesis requires adequate amounts of
    folik acid to ensure the availability of the
    nucleotide thymidine, which stimulates DNA
    synthesis. One function of vitamin B12 is to
    serve as a cofactor to activate the enzyme system
    responsible for transporting folic acid into the
    cell, where DNA synthesis occurs.
  • Thus a deficiency of vitamin B12 indirectly
    causes anemia by inhibiting folic acid
    transportation and limiting DNA synthesis in RBC
    precursor cells.
  • These precursor cells then undergo improper DNA
    synthesis and increase in size. Only a few are
    released from the bone marrow. This type of
    anemia is called megaloblastic (macrocytic)
    because of the large size of these abnormal
    cells.

40
ANEMIAS RESULTING FROM DECREASEDPRODUCTION OF
RED BLOOD CELLSVitamin B12 Deficiency Anemia
  • Vitamin B12 deficiency can result from inadequate
    intake (dietary deficiency). This can occur with
    strict vegetarian diets or diets lacking
    sufficient dairy products.
  • Conditions such as small bowel resection,
    diverticula, tapeworm, or overgrowth of
    intestinal bacteria can lead to poor absorption
    of vitamin B12 from the intestinal tract.
  • Anemia caused by failure to absorb vitamin B12
    (pernicious anemia) can also result from a
    deficiency of intrinsic factor (a substance
    normally secreted by the gastric mucosa), which
    is necessary for intestinal absorption of vitamin
    B12.
  • Vitamin B12 deficiency anemia may be mild or
    severe, usually develops slowly, and produces few
    symptoms. Clients usually have pallor and
    jaundice, as well as glossitis (a smooth,
    beefy-red tongue), fatigue, and weight loss.
  • Because vitamin B12 also is necessary for normal
    nervous system functioning, especially of the
    peripheral nerves, clients with pernicious anemia
    may also have neurologic abnormalities, such as
    paresthesias (abnormal sensations) in the feet
    and hands and disturbances of balance and gait.

41
ANEMIAS RESULTING FROM DECREASEDPRODUCTION OF
RED BLOOD CELLSVitamin B12 Deficiency Anemia
  • Collaborative management
  • When anemia is caused by a dietary deficiency,
    the client must increase the intake of foods rich
    in vitamin B12 (animal proteins, eggs, dairy
    products).
  • Vitamin supplements may be prescribed when anemia
    is severe. For clients who have anemia as a
    result of a deficiency of intrinsic factor,
    vitamin B12 must be administered parenterally on
    a regular schedule (usually weekly for initial
    treatment, then monthly for maintenance).

42
ANEMIAS RESULTING FROM DECREASEDPRODUCTION OF
RED BLOOD CELLSFolic Acid Deficiency Anemia
  • Overview
  • Primary folic acid deficiency can also cause
    megaloblastic anemia. Clinical manifestations are
    similar to those of vitamin B12 deficiency
    without the accompanying nervous system
    manifestations, because folic acid does not
    appear to affect nerve function.
  • The absence of neurologic problems is an
    important diagnostic finding to differentiate
    folic acid deficiency from vitamin B12
    deficiency. The disease develops slowly, and
    symptoms may be attributed to other problems or
    diseases.
  • The three common causes of folic acid deficiency
    are poor nutrition, malabsorption, and drugs.
    Poor nutrition, especially a diet lacking green
    leafy vegetables, liver, yeast, citrus fruits,
    dried beans, and nuts, is the most common cause.
    Chronic alcohol abuse and parenteral alimentation
    without folic acid supplementation are other
    dietary causes.
  • Malabsorption syndromes, such as Crohn's disease,
    are the second most common cause.
  • Specific drugs impede the absorption and
    conversion of folic acid to its active form and
    can also lead to folic acid deficiency and
    anemia. Such drugs include methotrexate, some
    anticonvulsants, and oral contraceptives

43
ANEMIAS RESULTING FROM DECREASEDPRODUCTION OF
RED BLOOD CELLSFolic Acid Deficiency Anemia
  • Collaborative management
  • Prevention of folic acid deficiency anemia is
    aimed at identifying high-risk clients, such as
    older, debilitated clients with alcoholism
    clients prone to malnutrition and those with
    increased folic acid requirements.
  • A diet high in folic acid and vitamin B12
    prevents a deficiency.
  • By routinely including assessment of dietary
    habits in a health history, the nurse can
    determine which clients are at risk for
    diet-induced anemias and provide appropriate
    follow-up.
  • For the client diagnosed with this type of
    anemia, management includes oral folic acid 1 mg
    daily or intramuscular administration of folic
    acid for clients with absorption problems.

44
ANEMIAS RESULTING FROM DECREASEDPRODUCTION OF
RED BLOOD CELLSAplastic Anemia
  • Overview
  • Aplastic anemia is a deficiency of circulating
    erythrocytes resulting from arrested development
    of RBCs within the bone marrow. It is caused by
    an injury to the hematopoietic precursor cell,
    the pluripotent stem cell.
  • Although aplastic anemia sometimes occurs alone,
    it is usually accompanied by agranulocytopenia (a
    reduction in leukocytes) and thrombocytopenia (a
    reduction in platelets).
  • These three problems occur at the same time
    because the bone marrow produces not only RBCs
    but also white blood cells (WBCs) and platelets.
  • Consequently, if the bone marrow is abnormal for
    any reason or if it has been exposed to a toxic
    substance that can damage bone marrow cells,
    production of erythrocytes, leukocytes, and
    thrombocytes slows greatly. Pancytopenia (a
    deficiency of all three cell types) is common in
    aplastic anemia.

45
ANEMIAS RESULTING FROM DECREASEDPRODUCTION OF
RED BLOOD CELLSAplastic Anemia
  • The onset of aplastic anemia may be insidious or
    rapid.
  • The development of aplastic anemia, although
    relatively rare, is associated with chronic
    exposure to several toxic agents. In about 50 of
    cases, the cause of aplastic anemia is unknown.
    Aplastic anemia may occur as an aftermath of
    viral infection, but the mechanism of bone marrow
    damage is unknown

46
ANEMIAS RESULTING FROM DECREASEDPRODUCTION OF
RED BLOOD CELLSAplastic Anemia
  • Collaborative management
  • Blood transfusions are the mainstay of treatment
    for clients with aplastic anemia.
  • Transfusion is indicated only when the anemia
    causes real disability or when bleeding is life
    threatening because of thrombocytopenia.
  • Unnecessary transfusion, however, increases the
    opportunity for the development of immune
    reactions to platelets, shortens the life span of
    the transfused cell, and may increase the rate of
    rejection of transplanted marrow cells. Thus
    transfusions are discontinued as soon as the bone
    marrow begins to produce RBCs.

47
ANEMIAS RESULTING FROM DECREASEDPRODUCTION OF
RED BLOOD CELLSAplastic Anemia
  • Because clients with some types of aplastic
    anemia have a disease course similar to that of
    autoimmune problems, immunosuppressive therapy
    may be helpful. Agents that selectively suppress
    lymphocyte activity, such as antilymphocyte
    globulin (ALG), antithymocyte globulin (ATG), and
    cyclosporine (Sandimmune), have brought about
    partial or complete remissions. In more severe
    cases, general immunosuppressive agents, such as
    prednisone and cyclophosphamide (Cytoxan,
    Procytox), have been effective.
  • Splenectomy (removal of the spleen) is considered
    in clients with an enlarged spleen that is either
    destroying normal RBCs or suppressing their
    development.
  • Bone marrow transplantation, which replaces
    defective stem cells, has also resulted in a cure
    for some clients. Cost, availability, and
    complications limit this technique for treatment
    of aplastic anemia, however

48
POLYCYTHEMIA
  • In polycythemia, the number of red blood cells
    (RBCs) in whole blood is greater than normal.
  • The blood of a client with polycythemia is
    hyperviscous (thicker than normal blood).
  • The problem may be temporary (occurring as a
    result of other conditions) or chronic. One type
    of polycythemia, polycythemia vera, is fatal if
    left untreated.

49
Polycythemia Vera
  • Overview
  • Polycythemia vera (PV) is characterized by a
    sustained increase in blood hemoglobin
    concentration to 18 g/dL, an RBC count of 6
    million/mm3, or a hematocrit increase to 55 or
    greater.
  • PV is a cancer of the RBCs with three major hall
    marks continuous production of massive numbers
    of RBCs, excessive leukocyte production, and
    overproduction of thrombocytes. Extreme
    hypercellularity (cell excess) of the peripheral
    blood occurs in people with PV
  • The skin, especially facial, and mucous membranes
    have a dark, flushed (plethoric) appearance.
    These areas may appear purplish or cyanotic
    because the blood in these tissues is
    incompletely oxygenated. Most clients experience
    intense itching related to vasodilation and
    variation in tissue oxygenation.

50
Polycythemia Vera
  • Blood viscosity is also greatly increased,
    causing a corresponding increase in peripheral
    resistance.
  • Superficial veins are visibly distended. Blood
    moves more slowly through all tissues and thus
    places increased demands on the pumping action of
    the heart, resulting in hypertension. In some
    highly vascular areas, blood flow may become so
    slow that vascular stasis occurs. Vascular stasis
    causes thrombosis (clot formation) within the
    smaller vessels to the extent that the vessels
    are occluded and the surrounding tissues
    experience hypoxia, progressing to anoxia and
    further to infarction and necrosis. Tissues most
    prone to this complication are the heart, spleen,
    and kidneys, although infarction with loss of
    tissue and organ function can occur in any organ
    or tissue

51
Polycythemia Vera
  • Because the actual number of cells in the blood
    is greatly increased and the cells are not
    completely normal, individual cell life spans are
    shorter. The shorter life spans, coupled with
    increased cell production, result in a rapid
    turnover of peripheral blood cells. This rapid
    turnover increases the amount of intracellular
    products (released when cells die) in the blood,
    adding to the general "sludging" of the blood.
    These products include uric acid and potassium,
    which cause the symptoms of gout and hyperkalemia
    (elevated serum potassium level).
  • Later clinical manifestations of PV are related
    to abnormal blood cells. Even though the number
    of circulating erythrocytes is greatly increased,
    their oxygencarrying capacity is impaired, and
    clients experience severe generalized hypoxia. In
    spite of the RBC excess, most clients with PV are
    susceptible to bleeding problems because of an
    associated platelet dysfunction

52
(No Transcript)
53
Polycythemia Vera
  • Collaborative management
  • Polycythemia vera is a malignant disease that
    progresses in severity over time. If left
    untreated, few people with PV live longer than 2
    years.
  • Conservative management with repeated
    phlebotomies (two to five times per week) can
    prolong life for 5 to 10 years. (Phlebotomy is
    the collection of the client's RBCs to decrease
    the number of RBCs and diminish blood viscosity.)
  • Maintaining adequate hydration and promoting
    venous return are essential to prevent thrombus
    formation. Therapy aims to prevent clot formation
    and includes the use of anticoagulants
  • As the disease progresses, clients need more
    intensive therapies that suppress bone marrow
    activity, including oral alkylating agents and/or
    irradiation with injections of radioactive
    phosphorus.
  • Bone marrow transplantation, an experimental
    treatment, is promising, but the results are too
    limited to determine its application to PV
Write a Comment
User Comments (0)
About PowerShow.com