porth patho final
Terms in this set (31)
The nurse is assessing lab values of a client with disseminated intravascular coagulation (DIC). The nurse would anticipate the results to include:
Increased prothrombin time (PT)
DIC begins with massive activation of the coagulation sequence as a result of unregulated generation of thrombin, resulting in systemic formation of fibrin. In addition, levels of all the major anticoagulants are reduced
A medical surgical nurse is studying risk factors for the development of secondary thrombocytosis before taking a certification exam. Which of the following situations would the nurse determine would increase a patient's risk? Select all that apply.
• Lung cancer
• Rheumatoid arthritis
• Inflammatory bowel disease
The diseases most likely to cause secondary thrombocytosis would be inflammatory bowel disease due to the damage to the intestinal mucosa, lung cancer due to the tissue factor molecules released by some cancer cells, and rheumatoid arthritis due to chronic inflammation
Which of the following medications are known to interfere with the body's ability to control bleeding? Select all that apply.
• Nonsteroidal anti-inflammatory drugs
Heparin interferes with platelet production, heparin and warfarin interfere with coagulation factors. The use of nonsteroidal anti-inflammatory drugs is the most common cause of impaired platelet function. Hormone replacement therapies and potassium chloride administration have not been connected with impaired hemostasis
Thrombocytosis is used to describe elevations in the platelet count above 1,000,000/μL. It is either a primary or a secondary thrombocytosis. Secondary thrombocytosis can occur as a reactive process due to what?
The common underlying causes of secondary thrombocytosis include tissue damage due to surgery, infection, cancer, and chronic inflammatory conditions such as rheumatoid arthritis and Crohn disease. Lyme disease, caused by a tick bite, does not cause thrombocytosis. Hirschsprung disease and megacolon are the same thing, and they are not inflammatory conditions
A nurse is reviewing the health history and medication list of a client admitted with thrombocytopathia. The nurse determines which of the client's home medications predisposes the client to bleeding? Select all that apply.
Aspirin and salicylates, colchicine, amiodarone and thiazide diuretics interference with coagulation factors.
The spouse of a patient with a history of hepatitis C who is admitted to the hospital with upper gastrointestinal bleeding asks the nurse why these bleeding episodes occur. Having reviewed the patient's laboratory work, and noting a severe vitamin K deficiency, the best response would be that the low vitamin K levels will contribute to which of the following?
Inactive clotting factors
Vitamin K is essential in the synthesis of active clotting factors, and when there is a deficiency, the clotting factors are produced in an inactive form. Sufficient levels of vitamin K is necessary to synthesize factors II, VII, IX, X, and prothrombin.
A client has been admitted for immune thrombocytopenic purpura. The client has not responded to corticosteroid treatment. The priority nursing intervention for this client would include which of the following treatment measures?
Insert an intravenous catheter, so immune globulin can be administered in a timely manner.
The decision to treat ITP is based on the platelet count and the degree of bleeding. Corticosteroids are used as initial therapy; other effective initial treatment includes intravenous immune globulin. However, this treatment is expensive, and the beneficial effect may last only 1 to 2 weeks. Because the spleen is the major site of antibody formation and platelet destruction, splenectomy is the traditional second-line treatment for persons who relapse or do not respond to medications. Isolation is not required; it is not contagious. The client may require a Foley if he does not respond to the immune globulin and must undergo surgery.
A teenage girl, seen in the clinic, is diagnosed with nonthrombocytopenic purpura. The girl states, "You have taken a lot of blood from me. Which of my tests came back abnormal?" How should the nurse respond?
Your CBC with differential showed a normal platelet count.
In persons with bleeding disorders caused by vascular defects, the platelet count and results of other tests for coagulation factors are normal. A shift to the left indicates an infectious or inflammatory process, not a clotting disorder. A lack of iron indicates iron deficiency anemia, not a clotting disorder. A normal hematocrit indicates a normal number of packed red blood cells, not a clotting disorder
A patient has been placed on Bactrim as treatment for community-acquired methicillin-resistant Staphylococcus aureus MRSA for 10 days. After taking the medication for 8 day, the patient comes to the doctor's office complaining of multiple nosebleeds over the past day. Laboratory work shows a platelet count of 80,000/μL. The nurse practitioner suspects which of the following conditions?
Many drugs have the potential to induced an antigen-antibody response including the formation of immune complexes that target and destroy platelets causing thrombocytopenia, which leads to increased bleeding. Bactrim is a sulfa-containing antibiotic that can cause this reaction. The reaction typically occurs around day 7 with people who have never taken the drug before and on days 2 to 3 for people who have taken the drug before. Thrombocytopenia resolves quickly once the drug is discontinued.
A client is newly diagnosed with impaired platelet function, thrombocytopathia. Which of the following questions is most appropriate for the nurse to ask in order to determine the possible cause of this problem?
"Have you been taking aspirin or any nonsteroidal anti-inflammatory drugs (NSAIDs)?"
The use of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) is the most common cause of impaired platelet function. Aspirin produces irreversible acetylation of platelet cyclooxygenase activity and consequently the synthesis of TXA2, which is required for platelet aggregation. In contrast to the effects of aspirin, the inhibition of cyclooxygenase by other NSAIDs is reversible and lasts only for the duration of drug action.
The school nurse has several children with hemophilia A. After recess, one hemophilia student comes to the school nurse complaining of pain in their knee from falling on the playground. The nurse notes there is swelling in the knee and pain on palpation. The nurse should:
Notify parents to pick up child and possibly administer Factor VIII.
Prevention of trauma is important. ASA and other NSAIDs that affect platelet function should be avoided. Factor VIII replacement therapy administered at home has reduced the typical musculoskeletal damage. Wrapping with a bandage will not prevent damage. Warm compression will extend the bleed.
A 75-year-old patient with a history of heart valve replacement arrives at the outpatient clinic with multiple red pinpoint lesions. The nurse identifies the lesions as being which of the following?
Petechiae are pinpoint red lesions caused by bleeding under the skin and can be noted in the presence of many bleeding disorders, including structural weakening of blood vessels that comes with age
Select the first stage of hemostasis.
Hemostasis is divided into five stages: (1) vessel spasm, (2) formation of the platelet plug, (3) blood coagulation or development of an insoluble fibrin clot, (4) clot retraction, and (5) clot dissolution
A patient in the hospital following a repair of a left hip fracture is refusing to wear the intermittent pneumatic compression stockings ordered by the physician. The nurse explains to the patient that the compression stockings are essential in preventing which of the following?
Pnuematic compression devices assist in preventing deep-vein thrombosis by preventing blood stasis through intermittent compression of the vessels in the legs.
A nursing student asks her instructor, "I don't understand this coagulation system. When we donate blood, what keeps it from clotting in the bag?" The instructor responds:
"Citrate is added to the blood bag, which prevents it from clotting."
The addition of citrate to blood stored for transfusion purposes prevents clotting by chelating ionic calcium. Calcium (factor IV) is required for coagulation to occur, and calcium is supplied by the body for the first two steps. Blood coagulation is regulated by several natural anticoagulants, such as antithrombin III and proteins C and S, which work by inactivating some of the clotting factors. Obviously, if blood not processed but used 24 hours later, it will have clotted.
While being on subcutaneous heparin injections for deep vein thrombosis during her latter pregnancy, a patient begins to experience major side effects. Her OB physician has called in a specialist who thinks the patient is experiencing heparin-induced thrombocytopenia. The nurse should anticipate which of the following orders?
Immediately discontinue the heparin therapy.
The treatment of HIT requires the immediate discontinuation of heparin therapy and the use of alternative anticoagulants to prevent thrombosis recurrence. Decreasing the dose will not stop the HIT. Coumadin is contraindicated in pregnancy. FFP is not called for in this situation.
While taking an exam on disorders of hemostasis, the students were asked to identify endothelial mediators that inhibit platelet aggregation and also vasodilate vessels. Which of the following would be considered a correct answer? Select all that apply.
• Prostaglandin I2
• Nitric oxide
If platelets are activated, they are inhibited from adhering to the surrounding uninjured endothelium by endothelial prostacyclin (prostaglandin I2 [PGI2]) and nitric oxide. Both of these mediators are potent vasodilators and inhibitors of platelet aggregation. Endothelial cells also elaborate an enzyme called adenosine diphosphatase that degrades ADP and further inhibits platelet aggregation. The plasma also contains a plasma protein called plasminogen that gets activated and converted to plasmin, an enzyme capable of digesting the fibrin strands of the clot. Release of the vasoconstrictor TXA2 is responsible for much of the vessel spasm. Dense granules mainly contain adenosine diphosphate (ADP), ATP, ionized calcium, serotonin, and histamine, which facilitate platelet adhesion and vasoconstriction at the site of vessel injury.
A client with von Willebrand disease is admitted to the hospital for an elective surgical procedure. The nurse caring for this client will review which of the following labs to monitor the client's coagulation?
Clinical manifestations of von Willebrand disease include spontaneous bleeding from the nose, mouth, and gastrointestinal tract, excessive menstrual flow, and a prolonged bleeding time in the presence of a normal platelet count.
A patient with chronic idiopathic thrombocytopenia purpura (ITP) asks the nurse at the doctor's office what causes all the nosebleeds that have been occurring. The nurse's best response would be the presence of which of the following?
Immune cells that destroy the platelets
ITP is an autoimmune disorder that causes the destruction of platelets by antiplatelet antibodies that attack the platelet membrane glycoproteins, platelet phagocytosis caused by the antibodies, and no elevation in thrombopoietin, which stimulates growth and development of megakaryocytes.
A nurse is assessing a child brought to the clinic with multiple petechiae and excessive bruising covering his body. Laboratory tests reveal a low platelet count. The nurse is aware that these clinical manifestations are caused due to of which of the following pathological processes?
Platelets function to form the platelet plug to help control bleeding after injury. Without enough platelets, the blood cannot clot properly and bleeding occurs.
Thrombocytes, or platelets, are circulating cell fragments of the large megakaryocytes that are derived from the myeloid stem cell. Platelets function to form the platelet plug to help control bleeding after injury to a vessel wall. Their cytoplasmic granules release mediators required for the blood coagulation process. Without enough platelets, the blood cannot clot properly and bleeding occurs. Bleeding and easy bruising may also arise from dysfunctional platelets.
To form a platelet plug, platelets must adhere to the vessel inner layer. For this to occur, which protein molecule is required?
Von Willebrand factor
Platelet adhesion requires a protein molecule called von Willebrand factor (vWF). This factor is produced by both megakaryocytes and endothelial cells and circulates in the blood as a carrier protein for coagulation factor VIII. The plasma also contains a plasma protein called plasminogen, which gets activated and converted to plasmin, an enzyme capable of digesting the fibrin strands of the clot. The extrinsic pathway of coagulation, which is a much faster process, begins with trauma to the blood vessel or surrounding tissues and with the release of an adhesive lipoprotein called tissue factor (also known as thromboplastin or factor III) from the subendothelial cells. Thromboxane A2 (TXA2) is released during platelet aggregation, the step after adhesion.
In a client with DIC, microemboli form, causing obstruction of blood vessels and tissue hypoxia. Common clinical signs may be due to what? (Select all that apply.)
• Circulatory failure
• Renal failure
• Respiratory failure
In DIC, microemboli may obstruct blood vessels and cause tissue hypoxia and necrotic damage to organ structures, such as the kidneys, heart, lungs, and brain. As a result, common clinical signs may be due to renal, circulatory, or respiratory failure; acute bleeding ulcers or convulsions; and coma. A form of hemolytic anemia may develop as red cells are damaged as they pass through vessels partially blocked by thrombus.
A medical student is familiarizing herself with recent overnight admissions to an acute medical unit of a university hospital. Which of the following patients would the student recognize as least likely to have a diagnosis of antiphospholipid syndrome in his or her medical history?
A 21-year-old male with a diagnosis of cellulitis and suspected endocarditis secondary to intravenous drug use.
Stroke, transient ischemic attacks, deep vein thrombosis, and pulmonary emboli are all common manifestation of the hypercoagulability associated with antiphospholipid syndrome. Cellulitis, endocarditis, and other infectious processes would be less likely to correlate with antiphospholipid syndrome.
A 42-year-old male client recently diagnosed with liver cancer is noted as at high risk for bleeding abnormalities. The nurse recognizes this risk as a result of:
The reduction of clotting factors synthesized in the liver
In liver disease, synthesis of clotting factors is reduced and bleeding may result. Vitamin K would not be produced in large amounts of active form in a diseased liver. Vitamin C deficiency in the diet would not contribute to increased bleeding.
A nurse is caring for a client in the intensive care unit who has sustained severe trauma and now has developed disseminated intravascular coagulation (DIC). The nurse is aware that the client is experiencing:
Widespread coagulation and bleeding in the vascular compartment
DIC begins with massive activation of the coagulation sequence, which leads to fibrin deposition and formation of thrombi in the microcirculation of the body. DIC and its acute manifestations are related to the bleeding problems that occur.
A nurse is assisting a client with self-care and observes the following:
Thrombocytopenia refers to a decrease in the number of circulating platelets to a level less than 100,000/µL. Cutaneous bleeding is seen as purple areas of bruising (purpura) and pinpoint hemorrhages (petechiae) in dependent areas where the capillary pressure is higher. Leukopenia is a decrease in white blood cells. Neutropenia is a decrease in neutrophils, and thrombocytosis describe elevations in the platelet count
A nurse orienting to the surgical suite is studying medications that affect platelet function and notes that the most common medications are which of the following?
Nonsteroidal anti-inflammatory drugs (NSAIDs) and aspirin
Both aspirin and NSAIDs interfere with platelet function by decreasing the ability of platelets to aggregate. The effect of NSAIDs lasts only as long as the drug is active; aspirin's effect lasts the life of the platelets.
A client tells the nurse that he has recently begun to take over-the-counter (OTC) calcium supplements to ensure that his blood will clot. The best response by the nurse would be:
"This is not necessary, unless it has been prescribed by your health care provider."
The body usually has sufficient amounts of calcium for these reactions. Most of the coagulation factors are proteins synthesized in the liver. Vitamin K is necessary for the synthesis of factors VII, IX, and X; prothrombin (factor II); and proteins C and S. Calcium (factor IV) is required in all but the first two steps of the clotting process. Unless prescribed, excessive calcium can contribute to electrolyte imbalance and complications
Heparin is an anticoagulant given by injection to prevent the formation of blood clots. How does heparin work?
Promotes the inactivation of clotting factors
Heparin binds to antithrombin III, causing a conformational change that increases the ability of antithrombin III to inactivate thrombin, factor Xa, and other clotting factors. By promoting the inactivation of clotting factors, heparin ultimately suppresses the formation of fibrin. Heparin does not bind to factors X and Xa. Heparin does not inactivate factor VIII.
Disseminated intravascular coagulation is a grave coagulopathy resulting from the overstimulation of clotting and anticlotting processes in response to what?
Disease or injury
Disseminated intravascular coagulation is a paradox in the hemostatic sequence and is characterized by widespread coagulation and bleeding in the vascular compartment. It is not a primary disease but occurs as a complication of a wide variety of conditions such as disease or injury, such as septicemia, acute hypotension, poisonous snake bites, neoplasms, obstetric emergencies, severe trauma, extensive surgery, and hemorrhage.
A client refuses to take the 81 mg of aspirin ordered by the physician, stating, "I do not have any pain." The best response by the nurse would be:
"The 81 mg of aspirin daily will help protect you from a stroke or a heart attack."
A low dose of aspirin (81 mg) can be used to prevent platelet aggregation and clot formation in persons who are at risk for myocardial infarction, stroke, or peripheral artery disease. This dose of aspirin will not be therapeutic for preventing pain in most clients and will not prevent increased bleeding. Aspirin will not dissolve a blood clot.