Mrs. Mahdia Samaha Alkony

Haemostatic mechanisms  The bleeding vessel constricts  Platelets aggregate at the site, forming an unstable hemostatic plug.  Coagulation factors are activated on the surface of these aggregated platelets, forming fibrin, which anchors the platelet plug to the site of injury.

Path physiology The failure of normal hemostatic mechanisms can result in bleeding. Causes of bleeding :  Trauma  It can occur spontaneously.  Vascular abnormalities  Some patients have defects in more than one hemostatic mechanism. The site of spontaneous bleeding can be anywhere in the body.

When bleeding occur:  The bone marrow may be stimulated to increase platelet production (thrombopoiesis).  Sometimes,the increase in platelets does not result from increased production but from a loss in platelet pooling within the spleen.  The spleen holds about one third of the circulating platelets at any time. If the spleen is lost (eg, splenectomy), the platelet reservoir is also lost, and an abnormally high amount of platelets enter the circulation.

Clinical Manifestations  Local bleeding, usually into the skin.  If platelet defects develop: o Petechiae, often in clusters on the skin and mucous membranes. o Bleeding can be severe. If bleeding is not severe it can be stopped when local pressure is applied

Clinical Manifestations  Coagulation factor defects bleeding occurs deeper within the body: 1. subcutaneous or intramuscular hematomas 2. hemorrhage into joint spaces).

Medical Management  If bleeding is significant; transfusions of blood products.  If fibrinolysis is excessive; hemostatic agents such as aminocaproic acid (Amicar) can be used.

Nursing Management  Observe the pt. carefully for bleeding.  The pt. needs to understand the importance of avoiding activities that increase the risk of bleeding.  The skin is observed for petechiae and ecchymoses (bruises) and the nose and gums for bleeding Hospitalized patients may be monitored for bleeding by testing (feces, urine, emesis, and gastric drainage) for occult as well as obvious blood.

THROMBOCYTOPENIA

Etiology  Thrombocytopenia (low platelet level) can result from various factors: 1. decreased production of platelets within the bone marrow 2. increased destruction of platelets 3. increased consumption of platelets.

Decreased Production  Hematologic malignancy, especially acute leukemias  Myelodysplastic syndromes (MDS): metastatic involvement of bone marrow from solid tumors  Aplastic anemia  Megaloblastic anemia  Toxins  Medications  Infection (esp. septicemia, viral infection, tuberculosis)  Alcohol  Chemotherapy

MANAGEMENT  Treat leukemia; platelet transfusion  Treat MDS; platelet transfusion  Treat solid tumor  Treat underlying condition  Treat underlying anemia  Remove toxin  Stop medication  Treat infection  Refrain from alcohol consumption

Increased Destruction  Due to Antibodies  Idiopathic thrombocytopenic purpura  Lupus erythematosus  Malignant lymphoma  Chronic lymphocytic leukemia (CLL)  Medications  Due to Infection; Bacteremia, Postviral infection  Sequestration of platelets in an enlarged spleen

Increased Consumption  Disseminated intravascular coagulation (DIC

Clinical Manifestations  Bleeding and petechiae with platelet counts less than 50,000/mm3  When the platelet count drops below20,000/mm3: 1. petechiae 2. nose and gingival bleeding 3. excessive menstrual bleeding 4. excessive bleeding after surgery or dental extractions.  When the platelet count is less than 5000/mm3, spontaneous, potentially fatal central nervous system or gastrointestinal hemorrhage can occur.

Assessment and Diagnostic Findings  Bone marrow aspiration and biopsy  Enlarged spleen results in increased sequestration of platelets.

Medical Management  Treatment of the underlying disease.  If platelet production is impaired, platelet transfusions  Splenectomy

IDIOPATHIC THROMBOCYTOPENIC PURPURA (ITP)

 ITP affects people of all ages  more common among children and young women. There are two forms of ITP: 1. The acute form occurs in children, often appears 1 to 6 weeks after a viral illness.This form is self- limited; remission often occurs spontaneously within 6 months. Occasionally, corticosteroids are needed for a brief time. 2. Chronic ITP is often diagnosed by exclusion of other causes of thrombocytopenia.

Pathophysiology  Unknown cause,  viral infections precede ITP in children.  medications such as sulfa drugs can induce ITP.  Systemic lupus erythematosus (SLE)  Pregnancy.  Anti-platelet autoantibodies that bind to the patient’s platelets are found in the blood of patients with ITP.  When the platelets are bound by the antibodies, the RES or tissue macrophage system ingests the platelets, destroying them.

 The body attempts to compensate for this destruction by increasing platelet production within the marrow.

Clinical Manifestations  Many patients have no symptoms  low platelet count (often less than 20,000/mm3.  easy bruising, heavy menses, and petechiae on the extremities or trunk.  Dry purpura:simple bruising or petechiae  Wet purpura: gastrointestinal tract bleeding (including the mouth) and pulmonary system (eg, hemoptysis), which is termed.  Patients with wet purpura have a greater risk for intracranial bleeding than do those with dry purpura.

Medical Management  Patients whose counts exceed 30,000 to 50,000/mm3 may be carefully observed without additional intervention.  If the count is lower than 20,000/mm3, or if bleeding occurs, the goal is to improve the patient’s platelet count, rather than to cure the disease.  If the patient is taking a medication that is known to cause ITP, medication must be stopped immediately.  immunosuppressive agents block the binding receptors on macrophages so that the platelets are not destroyed.

 Corticosteroid therapy  Intravenous gamma globulin (IVIG) is also commonly used to treat ITP  Splenectomy is an alternative treatment  Chemotherapy agent  anti-D in patients who are Rh(D)-positive.  platelet transfusions are usually avoided

Nursing Management  Determine the risk of bleeding from activity.  Detailed history  Avoid intramuscular injections or rectal medications and rectal temperature measurements  Observe the pt. for S.E. of corticosteroid including osteoporosis, proximal muscle wasting, cataract formation, and dental caries

Patient education about  should avoid constipation  avoid Valsalva maneuver  avoid flossing of the teeth.  Electric razors should be used for shaving  soft-bristled toothbrushes should replace stiff- bristled ones.  Patients should also be counseled to refrain from vigorous sexual intercourse when the platelet count is less than 10,000/mm3

Acquired Coagulation Disorders

LIVER DISEASE  Most blood coagulation factors are synthesized in the liver. Therefore, hepatic dysfunction can result in diminished amounts of the factors needed to maintain coagulation and hemostasis.  Prolongation of the PT  Minor bleeding is common (eg, ecchymoses),  Risk for significant bleeding, related especially to trauma or surgery.

LIVER DISEASE  Transfusion of fresh frozen plasma may be required  Patients may also have life-threatening hemorrhage from peptic ulcers or esophageal varices.  In these cases, replacement with fresh frozen plasma, PRBCs, and platelets is usually required.

VITAMIN K DEFICIENCY  The synthesis of many coagulation factors depends on vitamin K. Causes:  malnourishement  some antibiotics decrease the intestinal flora that produce vitamin K Treatment:  Administration of vitamin K either orally or as a subcutaneous injection)  adequate synthesis of coagulation factors is reflected by normalization of the PT.-

COMPLICATIONS OF ANTICOAGULANT THERAPY  These agents, particularly warfarin or heparin, can result in bleeding. If the PT or PTT is longer than desired and bleeding has not occurred, the medication can be stopped or the dose decreased.  Vitamin K is administered for warfarin toxicity.  Protamine sulfate is rarely needed for heparin toxicity, because the half-life of heparin is very short. With significant bleeding, fresh frozen plasma replaces the vitamin K–dependent coagulation factors.

DISSEMINATED INTRAVASCULAR COAGULATION (DIC)  DIC is not a disease but a sign of an underlying condition.  DIC may be triggered by sepsis, trauma, cancer, shock, abruptio placentae, toxins, or allergic reactions  It is potentially life-threatening.

Pathophysiology  In DIC, the normal hemostatic mechanisms are altered so that a massive amount of tiny clots forms in the microcirculation.  Initially, the coagulation time is normal.  as the platelets and clotting factors are consumed to form the microthrombi, coagulation fails.  the result of excessive clotting is bleeding.  The clinical manifestations of DIC are reflected in the organs, which are affected either by excessive clot formation (with resultant ischemia to all or part of the organ) or by bleeding. The bleeding is characterized by low platelet and fibrinogen levels; prolonged PT, PTT, and thrombin time; and elevated fibrin degradation products (D-dimers)

Pathophysiology  The mortality rate can exceed 80% Identification of patients who are at risk for DIC and recognition of the early clinical manifestations of this syndrome can  result in earlier medical intervention, which may improve the prognosis.

Medical Management  Treating the underlying cause of the DIC.  Correct the secondary effects of tissue ischemia by: 1. improving oxygenation 2. replacing fluids 3. Correcting electrolyte imbalances 4. Administering vasopressor medications.

 Transfusion of blood and blood products: 1. Cryoprecipitate is given to replace fibrinogen and factors V and VII 2. fresh frozen plasma is administered to replace other coagulation factors

 Heparin may inhibit the formation of microthrombi and thus permit perfusion of the organs (skin, kidneys, or brain) to resume.  Heparin is typically reserved for the patient in whom thrombotic manifestations predominate or in whom extensive blood component replacement fails to halt the hemorrhage or increase fibrinogen and other clotting levels.  When heparin is administered, bleeding may actually worsen initially until the thrombotic process is interrupted. The effectiveness of heparin can best be determined by observing for normalization of the plasma fibrinogen concentration and diminishing signs of bleeding.