NCLEX: Hematologic and lymphatic disorders

Disseminated intravascular coagulation

DIC is a grave blood coagulation disorder that occurs as a complication of conditions that accelerate clotting. It causes small blood vessel occlusion, organ necrosis, depletion of circulating clotting factors and platelets, and activation of the fibrinolytic (blood-clot promoting) system.


The case of the consumed clotting factors

These processes, in turn, can provoke severe hemorrhage as clotting factors are consumed. Clotting in the microcirculation usually affects the kidneys and extremities, but also may occur in the brain, lungs, pituitary and adrenal glands, and GI mucosa. Although usually acute, DIC may be chronic in cancer patients. Prognosis depends on early detection and treatment, hemorrhage severity, and treatment of the underlying disease.

What causes it
DIC can result from:
• infection, such as gram-negative or gram-positive septicemia; viral, fungal, or rickettsial infection; or protozoal infection (falciparum malaria)
• obstetric complications, such as abruptio placentae, amniotic fluid embolism, or retained dead fetus
• neoplastic disease, such as acute leukemia or metastatic carcinoma
• tissue necrosis from extensive burns or trauma, brain tissue destruction, transplant rejection, or hepatic necrosis. Other possible causes of DIC include cardiac arrest, heatstroke, shock, poisonous snakebite, cirrhosis, fat embolism, incompatible blood transfusions, intraoperative cardiopulmonary bypass, giant hemangioma (a benign vascular tumor), severe venous thrombosis, and purpura fulminans (a severe, rapidly fatal form of nonthrombocytopenic purpura).

Pathophysiology
DIC arises when one of the predisposing conditions listed above activates the coagulation system. Excess fibrin forms (triggered by the action of thrombin, an enzyme) and becomes trapped in the microvasculature along with platelets, causing clots.

Horrific hemorrhaging

Blood flow to the tissues then decreases, resulting in acidemia, blood stasis, and tissue hypoxia. These conditions may lead to organ failure. Both fibrinolysis (fibrin dissolution) and antithrombotic mechanisms induce anticoagulation. Platelets and clotting factors are consumed, and massive hemorrhage may ensue.

What to look for
Abnormal bleeding, without a history of a serious hemorrhagic disorder, can signal DIC. Signs of such bleeding include:
• cutaneous oozing
• petechiae

• ecchymoses
• hematomas
• bleeding from sites of surgical or invasive procedures (such as incisions and I.V. sites)
• GI tract bleeding.

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Assessment add-ons

Also, assess the patient for acrocyanosis (symmetrical cyanosis) and acute tubular necrosis (damage to renal tubule cells, leading to renal failure).
Related symptoms and other possible effects of DIC include:
• nausea and vomiting
• dyspnea
• oliguria (reduced urine output)
• seizures
• coma
• shock
• severe muscle, back, and abdominal pain
• failure of major organ systems.

What tests tell you
• Initial laboratory findings that support a tentative diagnosis of DIC include PT greater than 15 seconds, PTT exceeding 60 seconds, fibrinogen levels below 150 mg/dl, platelet count below 100,000/μl, and fibrin degradation products above 100 mcg/ml.
• Supportive data may include positive fibrin monomers, diminished levels of factors V and VIII, RBC fragmentation, and Hb level below 10 g/dl.
• Assessment of renal status shows urine output below 30 ml/hour, blood urea nitrogen level above 25 mg/dl, and serum creatinine level above 1.3 mg/dl. Additional diagnostic measures may be done to determine the underlying disorder, because other disorders may cause many of the same test results.

How it’s treated
Effective treatment of DIC requires prompt recognition and adequate treatment of the underlying disorder. Treatment may be supportive (for example, when the underlying disorder is selflimiting) or highly specific.
If the patient isn’t actively bleeding, supportive care alone may reverse DIC. But active bleeding may necessitate heparin I.V. and transfusions of blood, fresh frozen plasma, platelets, or packed RBCs to support hemostasis.

Dissension over heparin

Heparin therapy is controversial. It may be used early in DIC to prevent microclotting or as a last resort in an actively bleeding patient. In thrombosis, heparin therapy is usually mandatory. In most cases, it’s given with transfusion therapy.

What to do
• Focus patient care on early recognition of the primary signs and symptoms of abnormal bleeding, prompt treatment of the underlying disorder, and prevention of further bleeding.
• To prevent clots from dislodging, don’t scrub bleeding areas.
• Use pressure, cold compresses, and topical hemostatic agents to control bleeding.
• Protect the patient from injury. Enforce complete bed rest during bleeding episodes. If the patient is agitated, pad the side rails.
• Check all I.V. and venipuncture sites frequently.
• Apply pressure to injection sites for at least 10 minutes.
• Monitor fluid intake and output hourly in patients with acute DIC, especially when giving blood products. Watch for transfusion reactions and indications of fluid overload.

• To measure the amount of blood lost, weigh dressings and linens and record drainage.
• Weigh the patient daily, particularly if there’s renal involvement.
• Check the patient for headache, and assess neurologic status periodically.
• Watch for GI and genitourinary tract bleeding. To detect intra-abdominal bleeding, measure the patient’s abdominal girth at least every 4 hours and monitor closely for signs and symptoms of shock. Monitor the results of serial blood studies (especially HCT, Hb levels, and coagulation times).
• Evaluate the patient. With successful treatment, he should be free from bleeding, and tests should show his coagulation parameters and renal status within normal limits.

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Hemophilia

Hemophilia is a hereditary bleeding disorder that results from lack of specific clotting factors. It occurs in two main forms:
• Hemophilia A (classic hemophilia), seen in more than 80% of hemophilia cases, results from deficiency of factor VIII.
• Hemophilia B (Christmas disease), which accounts for roughly 15% of hemophilia cases, results from deficiency of factor IX.

A prettier picture

Treatment advances have greatly improved prognosis, and many hemophiliacs have normal life spans. Surgery can be done safely under a hematologist’s guidance at special hemophilia treatment centers.

What causes it
Hemophilia A and B are inherited as X-linked recessive traits. This means female carriers have a 50% chance of transmitting the gene to each son or daughter. Daughters who receive the gene are carriers; sons who receive it are born with hemophilia.

Nonfunctional factors?

Although traditionally seen as a deficiency of clotting factors, recent evidence suggests that hemophilia may result from nonfunctioning factors VIII and IX.

Pathophysiology
Hemophilia produces abnormal bleeding. Depending on the degree of factor deficiency, the bleeding may be mild, moderate, or severe. Overall prognosis is best in patients with mild hemophilia, which doesn’t cause spontaneous bleeding or joint deformities.

Plugs that preclude clots

After a platelet plug forms at a bleeding site, lack of clotting factors impairs formation of a stable fibrin clot. Delayed bleeding is more common than immediate hemorrhage.

What to look for
Signs and symptoms vary with the severity of hemophilia.
• With mild hemophilia, bleeding doesn’t occur spontaneously or after minor trauma. However, major trauma or surgery typically causes prolonged bleeding.
• With moderate hemophilia, spontaneous bleeding occurs occasionally. Surgery or trauma causes excessive bleeding.
• With severe hemophilia, bleeding occurs spontaneously and may be severe even with minor trauma, leading to large subcutaneous and deep I.M. hematomas.

Bleeding and deformity

Bleeding into joints and muscles also may occur and causes pain, swelling, extreme tenderness and, possibly, permanent deformity.

What tests tell you
Characteristic findings in patients with hemophilia A include:
• factor VIII assay 0% to 30% of normal
• prolonged PTT
• normal platelet count and function, bleeding time, and PT.

Characteristic findings in patients with hemophilia B include:
• deficient factor IX assay
• baseline coagulation results similar to those in hemophilia A, except with normal factor VIII levels.

Three degrees of deficiency

With either hemophilia A or B, the degree of factor deficiency determines the severity of the illness:
• mild hemophilia: factor levels 5% to 40% of normal
• moderate hemophilia: factor levels 1% to 5% of normal
• severe hemophilia: factor levels less than 1% of normal.

How it’s treated
Although hemophilia isn’t curable, treatment can prevent crippling deformities and prolong life expectancy. Correct treatment quickly stops bleeding by increasing plasma levels of deficient clotting factors. This helps prevent disabling deformities that result from repeated bleeding into muscles and joints.

Treatment includes:
• For hemophilia A, cryoprecipitated antihemophilic factor (AHF), lyophilized AHF, or both are given in doses large enough to raise clotting factor levels above 25% of normal to support normal hemostasis. Before surgery, AHF is given to raise clotting factors to hemostatic levels. Levels are then kept within a normal range until the wound has healed. Fresh frozen plasma also can be given.

Multiple risks

• Inhibitors to factor VIII develop after multiple transfusions in 10% to 20% of patients with severe hemophilia, causing resistance to factor VIII infusions. Desmopressin (DDAVP) may be given to stimulate release of stored factor VIII, raising the blood level of this factor. In hemophilia B, administering factor IX concentrate during bleeding episodes increases factor IX levels.
• A patient who undergoes surgery needs careful management by a hematologist experienced in caring for hemophiliacs. The deficient factor must be replaced before and after surgery (possibly even minor surgery such as dental extractions). Aminocaproic acid (Amicar) is commonly used for oral bleeding, to inhibit the active fibrinolytic system in the oral mucosa. Human immunodeficiency virus screening reduces the risk of acquired immunodeficiency syndrome from transfusion.

What to do
• During bleeding episodes, administer the deficient clotting factor or plasma as ordered. The body uses up AHF in 48 to 72 hours, so repeat the infusion, as ordered, until bleeding stops.
• Apply cold compresses or ice bags, and elevate the injured part.
• To prevent recurrent bleeding, restrict the patient’s activity for 48 hours after bleeding is under control.
• If bleeding into a joint occurs, immediately elevate the affected joint.
• Control pain with an analgesic, such as acetaminophen (Tylenol), codeine, or meperidine (Demerol) as ordered.
• Know that aspirin and aspirin-containing medications are contraindicated because they decrease platelet adherence and may worsen bleeding.
• Avoid I.M. injections because of possible hematoma formation at the injection site.
• After bleeding episodes and surgery, watch closely for signs and symptoms of further bleeding, such as increased pain and swelling, fever, or indications of shock. Closely monitor PTT.
• To restore mobility in an affected joint, begin range-of-motion exercises, if ordered, at least 48 hours after bleeding is controlled. Tell the patient to avoid bearing weight on the joint until bleeding stops and swelling subsides.

• Evaluate the patient. He should be free from bleeding; he should understand how to minimize bleeding risks and know what to do if bleeding occurs.

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Sickle cell anemia

A type of congenital hemolytic anemia (shortened RBC survival and inability of bone marrow to compensate for decreased RBC life span), sickle cell anemia occurs mainly in African-Americans. It results from a defective Hb molecule (HbS), which causes RBCs to roughen and become sickle shaped and more fragile.

Renegade RBCs

The abnormal RBCs impair circulation, resulting in chronic ill health, periodic crises, long-term complications, and premature death.

What causes it
Sickle cell anemia may stem from homozygous inheritance of the HbS–producing gene, which causes the amino acid valine to replace glutamic acid in the Hb beta chain.

Pathophysiology
Blood vessel obstruction by rigid, tangled RBCs causes tissue oxygen starvation and possible necrosis. These conditions, in turn, lead to painful vaso-occlusive crisis, a hallmark of the disease. Bone marrow depression results in aplastic (megaloblastic) crisis.

Crises and their causes

Factors that predispose a patient to sickle cell crisis include deoxygenation (as from pneumonia, hypoxia, or scuba diving), cold exposure, acidosis, and infection.

What to look for
Signs and symptoms of sickle cell anemia include:
• aching bones
• cardiomegaly (heart enlargement)
• chest pain
• chronic fatigue
• diastolic and systolic murmurs or tachycardia
• exertional or unexplained dyspnea
• hepatomegaly (liver enlargement) or jaundice
• increased susceptibility to infection
• ischemic leg ulcers (especially on the ankles)
• joint swelling
• pallor.

Crisis components

During a painful vaso-occlusive crisis, the patient may experience:
• severe abdominal, thoracic, muscular, or bone pain
• low-grade fever
• possible increased jaundice and dark urine
• diminished spleen size in chronic disease.

What tests tell you
• Stained blood smear showing sickle-shaped RBCs and Hb electrophoresis showing HbS confirm the diagnosis.
• CBC shows low RBC and elevated WBC and platelet counts. Hb levels may be low or normal.
• Erythrocyte sedimentation rate and RBC survival time are decreased; serum iron levels and reticulocyte counts are increased.

How it’s treated
Although sickle cell anemia can’t be cured, treatment can ease symptoms and prevent painful crises. Treatment includes:
• Polyvalent pneumococcal and Haemophilus influenzae B vaccinations; anti-infectives, such as low-dose oral penicillin; and chelating agents, such as deferoxamine (Desferal), help minimize complications.
• Analgesics can relieve the pain of vaso-occlusive crisis.
• An iron supplement may be given if folic acid levels are low.
• An antisickling agent may be given. However, the most commonly used agent, sodium cyanate, has many adverse effects.
• During an acute sequestration crisis, treatment may include sedation, analgesia, blood transfusions, oxygen therapy, and large amounts of oral or I.V. fluids.

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What to do
• Advise the patient to avoid tight clothing that restricts circulation.
• Emphasize the need for prompt treatment of infection.
• Evaluate the patient. He should be free from pain and infection. He and his family should understand what steps to take to avoid exacerbating the disease.

Thrombocytopenia

The most common hemorrhagic disorder, thrombocytopenia is characterized by a deficiency of circulating platelets. Because platelets play a vital role in blood clotting, this disorder seriously threatens hemostasis.

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Predicting recovery

Drug-induced thrombocytopenia carries an excellent prognosis if the causative drug is withdrawn; recovery may be immediate. Otherwise, prognosis depends on the patient’s response to treatment of the underlying cause.

What causes it
Thrombocytopenia may be congenital or acquired (more common). In either case, it usually results from:
• decreased or defective platelet production in the bone marrow
• increased platelet destruction outside the marrow, caused by an underlying disorder (such as cirrhosis of the liver, DIC, or severe infection)
• sequestration (as in hypothermia or increased RBC destruction in the spleen) or platelet loss.

An acquired affliction

Acquired thrombocytopenia may result from such drugs as nonsteroidal anti-inflammatory agents, sulfonamides, histamine blockers, heparin, alkylating agents, or antibiotic chemotherapeutic agents.

Fleeting forms

In children, thrombocytopenia of unknown cause (idiopathic thrombocytopenia) is common. Transient thrombocytopenia may follow a viral infection, such as Epstein-Barr or infectious mononucleosis.

Pathophysiology
In thrombocytopenia, lack of platelets may cause inadequate hemostasis. The four responsible mechanisms include:
• decreased platelet production
• decreased platelet survival
• pooling of blood in the spleen
• intravascular dilution of circulating platelets.

Minding megakaryocytes

Platelet production falls when the number of megakaryocytes decreases or when platelet production becomes dysfunctional.

What to look for
Watch for these signs and symptoms:
• abnormal bleeding (typically of a sudden onset, with skin petechiae or ecchymoses, or bleeding into mucous membranes)
• malaise and fatigue
• general weakness and lethargy
• large, blood-filled bullae (elevations) in the mouth.

What tests tell you
• Coagulation tests show diminished platelet count with prolonged bleeding time.
• Bone marrow studies may reveal increased megakaryocytes and shortened platelet survival.

How it’s treated
The underlying cause must be treated. In drug-induced thrombocytopenia, the offending drug is withdrawn.

Outlining the options

Treatment may include:
• splenectomy for hypersplenism
• chemotherapy for acute or chronic leukemia
• steroids, danazol, or I.V. immune globulin for idiopathic thrombocytopenia
• platelet transfusions (to reduce the risk of spontaneous bleeding) if the platelet count falls below 20,000/μl.

What to do
• Take every possible precaution against bleeding, including guarding the patient from trauma. Keep the bed side rails up and pad them, if possible. Instruct him to use an electric razor and a soft toothbrush. Avoid all invasive procedures, such as venipuncture or urinary catheterization, if possible. When venipuncture is unavoidable, exert pressure on the puncture site for at least 20 minutes or until bleeding stops.
• Monitor platelet counts daily. Test stools for occult blood, and test urine and vomitus for blood. Watch for signs of bleeding (including petechiae, ecchymoses, surgical or GI bleeding, and menorrhagia).
• When the patient is bleeding, enforce strict bed rest if n ecessary.
• When giving platelet concentrate, remember that platelets are extremely fragile. Infuse them quickly, using the administration set recommended by the blood bank. During platelet transfusion, monitor the patient for febrile reaction (flushing, chills, fever, headache, tachycardia, and hypertension).
• Be aware that HLA–typed platelets may be ordered when the patient no longer responds to pooled platelets (because of antibody development). WBC–depleted platelets may be ordered to reduce the risk of febrile reactions. A patient with a history of minor reactions may benefit from acetaminophen and diphenhydramine (Benadryl) before the transfusion.
• During steroid therapy, monitor the patient’s fluid and electrolyte balance and blood glucose level. Watch for infection, pathologic fractures, and mood changes.
• Evaluate the patient. He should lack signs and symptoms of gross and microscopic bleeding. He and his family should know how to reduce bleeding risks.

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