Patho Chapter 12 (Disorders of Hemostasis) Prep U

The father of a 2-year-old boy recently diagnosed with hemophilia A asks the nurse how to prevent complications for his son. The best response would be:

"Avoid administering aspirin and nonsteroidal anti-inflammatory drugs." Explanation: The prevention of trauma is important in persons with hemophilia, and aspirin and nonsteroidal anti-inflammatory drugs should be avoided. Children with hemophilia should not be prevented from interaction with other children. Hemophilia will not be resolved with a blood transfusion. All bleeds require medical attention.

A client is newly diagnosed with impaired platelet function, thrombocytopathia. Which question 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)?" Explanation: 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 the drug action.

A woman who has given birth 12 hours ago is displaying signs and symptoms of disseminated intravascular coagulation (DIC). The client's husband is confused as to why a disease of excessive coagulation can result in bleeding. Which of the nurse's explanations best characterizes DIC?

"So much clotting takes place that there are no available clotting components left and bleeding ensues." Explanation: DIC hemorrhage results from an insufficiency of clotting proteins after large scale coagulation. It is not a result of physical irritation, organ overload, or bacteria and hormones.

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." Explanation: 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.

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." Explanation: 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.

A neonatal nurse is caring for a newborn that has been prescribed an injection of vitamin K to prevent possible bleeding. Lack of which physiologic finding in a newborn makes it necessary for the neonate to be given vitamin K?

Intestinal bacteria Explanation: The main source of vitamin K is from intestinal bacteria synthesis; infants are born with a lack of intestinal flora and are therefore at risk for vitamin K deficiency.

In which client would diagnostic investigations be least likely to reveal increased thrombopoietin production?

A 21-year-old woman awaiting bone marrow transplant for myelogenous leukemia Explanation: Diseases such as myelogenous leukemia and other cases of primary thrombocytosis result in abnormalities in the thrombopoietin receptor and platelet binding. Cases of secondary thrombocytosis have an etiology rooted in increased thrombopoietin production. 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.

A client with a diagnosis of hemophilia A has been admitted with bilateral knee pain. The nurse should anticipate performing what intervention during the client's treatment?

Administration of factor VIII and implementation of fall prevention measures. Explanation: Clients with hemophilia have a deficit in factor VIII. Administration of vitamin K, platelets, or DDAVP is ineffective because of the absence of this clotting factor. Injury prevention is paramount in the care of a client with a bleeding disorder.

Anticoagulant drugs prevent thromboembolic disorders. How does warfarin, one of the anticoagulant drugs, act on the body?

Alters vitamin K, reducing its ability to participate in the coagulation of the blood Explanation: The anticoagulant drugs warfarin and heparin are used to prevent thromboembolic disorders, such as deep vein thrombosis and pulmonary embolism. Warfarin acts by decreasing prothrombin and other procoagulation factors. It alters vitamin K in a manner that reduces its ability to participate in synthesis of the vitamin K-dependent coagulation factors in the liver.

How does low-dose aspirin therapy impact clot formation?

Aspirin is a platelet aggregation inhibitor. Explanation: Low-dose aspirin therapy inhibits prostaglandin synthesis, thus interfering with platelet aggregation. The other options do not accurately describe the effect that aspirin has on the formation of clots.

A 57-year-old man is diagnosed with thrombocytopenia. The nurse knows that thrombocytopenia refers to a decrease in the number of circulating platelets. The nurse also knows that thrombocytopenia can result from what?

Decreased platelet production Explanation: A reduction in platelet number, also referred to as thrombocytopenia, is an important cause of generalized bleeding. Thrombocytopenia usually refers to a decrease in the number of circulating platelets to a level less than 100,000/μL. The greater the decrease in the platelet count, the greater the risk of bleeding. Thrombocytopenia can result from a decrease in platelet production, increased sequestration of platelets in the spleen, or decreased platelet survival.

A nurse working in an ambulatory care unit is working with a client who has recently been diagnosed with a V Leiden mutation. The nurse tells the client the importance of smoking cessation to avoid:

Deep vein thrombosis (DVT) Explanation: Factor V Leiden mutation increases the risk of DVT because physiologic anticoagulants have an increased difficulty inactivation of the mutated factor V gene. The inability to inactivate the factor V Leiden gene contributes to an increase in thrombotic complications, including DVT.

A newborn has a clotting disorder that results in the body being unable to produce fibrin. Which of the following could be the cause?

Deficiency of fibrinogen Explanation: Fibrinogen is a soluble protein that polymerizes to form the insoluble protein fibrin during blood clotting.

A client is admitted to the hospital with a diagnosis of deep vein thrombosis and started on intravenous heparin therapy. Seven days later, the client's lab values identify a rapid decrease in platelets. The health care provider recognizes this as:

Drug-induced thrombocytopenia Explanation: Drug-associated thrombocytopenia presents with a rapid fall in the platelet count within 2 to 3 days of resuming a drug or 7 or more days after initiating a drug for the first time. The platelet count rises rapidly after the drug is discontinued. Heparin is one of the drugs that can cause this problem. Immune thrombocytopenic purpura (ITP) is an autoimmune disorder that results in platelet antibody formation and excess destruction of platelets. Thrombotic thrombocytopenic purpura (TTP) and hemolytic-uremic syndrome (HUS) are thrombotic microangiopathies.

A client has been placed on sulfamethoxazole/trimethoprim as treatment for community-acquired methicillin-resistant Staphylococcus aureus (MRSA) for 10 days. After taking the medication for 8 days, the client comes to the health care provider'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 condition?

Drug-induced thrombocytopenia Explanation: 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. Sulfamethoxazole/trimethoprim 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 pregnant woman contacts her physician because she has developed sudden, severe pain and swelling in her left lower leg. The physician explains to her that her past medical includes an inherited defect in factor V Leiden, which predisposes her to the development of:

Excessive clotting Explanation: Factor V Leiden is an inherited clotting disorder. The normal factor V gene is replaced by the factor V Leiden gene, which is harder for normal anticoagulants to inactivate. The inability to inactivate factor V Leiden predisposes a person to developing blood clots, and the prothrombic situation that occurs with pregnancy increases the risk of thrombosis.

A client has been diagnosed with inherited hypercoagulability. Select the most likely cause.

Factor V gene mutation Explanation: Of the inherited causes of hypercoagulability, mutations in the factor V gene and prothrombin gene are the most common. Among the acquired or secondary factors that lead to increased coagulation and thrombosis are venous stasis due to prolonged bed rest and immobility, myocardial infarction, cancer, hyperestrogenic states, and use of oral contraceptives.

A client with hemophilia type A comes to the emergency department with severe pain and swelling in the right knee. To reduce musculoskeletal damage, the nurse anticipates the administration of:

Factor VIII replacement therapy Explanation: Factor VIII replacement therapy administered at home has reduced the typical musculoskeletal damage. It is initiated when bleeding occurs or as prophylaxis with repeated bleeding episodes for clients with hemophilia A.

The nurse is studying hemostasis. She knows that which statements are true? Select all that apply.

Hemostasis refers to the body's ability to control bleeding. Vessel constriction or spasm is a factor in effective hemostasis. Hemostasis results in the formation of a platelet plug. Hemostasis occurs in established stages. Explanation: Hemostasis, which refers to the stoppage of blood flow, is divided into stages which include vessel vasoconstriction and formation of the platelet plug. The development of a blood clot is a part of the coagulation process.

A nurse is caring for a client receiving heparin therapy. Five days after the start of therapy the nurse notices a sudden decrease in the platelet count. Which complication of heparin therapy can cause platelets to decrease?

Heparin-induced thrombocytopenia Explanation: In persons with drug-associated thrombocytopenia, there is a rapid fall in the platelet count within 2 to 3 days of resuming a drug or 7 or more days after starting a drug for the first time. The platelet count rises rapidly after the drug is discontinued. The anticoagulant drug heparin has been increasingly implicated in thrombocytopenia and, paradoxically, in thrombosis. The complications typically occur 5 days after the start of therapy and result from heparin-dependent antiplatelet antibodies that cause aggregation of platelets and their removal from the circulation. The antibodies often bind to vessel walls, causing complications such as deep vein thrombosis, pulmonary embolism, myocardial infarction, and stroke. The treatment of heparin-induced thrombocytopenia requires the immediate discontinuation of heparin therapy and the use of alternative anticoagulants to prevent thrombosis recurrence.

A nurse is preparing a presentation on factors that lead to increased coagulation and thrombosis. Which factors should be included in the teaching plan? Select all that apply.

Inflammatory bowel disease Steroid therapy Oral contraception Smoking Explanation: Factors that promote thrombotic effects are inflammation, steroid therapy, hospitalization, oral contraception, deficiency in B vitamins and folate, smoking, and use of central intravenous catheters. Heart failure also contributes to venous congestion and thrombosis. Deformed red blood cells in sickle cell disease, use of oral contraceptives, smoking, pregnancy, and cancer also predispose clients to venous thrombosis.

The nurse is planning care for a 70-year-old client who has lived with severe hemophilia since childhood. For what complications of hemophilia should the nurse prioritize assessing? Select all that apply.

Hepatitis Arthritis Cardiovascular disease Explanation: The client would have received blood component transfusion when younger, which carries a risk for viral hepatitis. Arthropathy would manifest as pain and inflammation of the joint (arthritis) and is common due to past episodes of hemarthrosis. While a history of hemophilia does not place the client at risk for cardiovascular disease on its own, the client is at an age when preventive measures related to cardiovascular disease (e.g., prophylactic aspirin) would be recommended—but which would be contraindicated in this client. Being aware of the cardiovascular risk allows for alternative reduction of risk to be considered. The client would not be at risk for increased clotting (thrombosis) or hypertension.

A 40-year-old client has been admitted to the cardiac intensive care unit after having an anterior wall myocardial infarction (MI). The nurse is reviewing modifiable risk factors with the client to avoid the redevelopment of thromboembolic complications, possibly leading to a second MI. Which of the following increases this risk?

Oral contraceptives Explanation: The best answer is oral contraceptives. Modifiable risk factors for the development of thrombosis include oral contraceptives, prolonged bed rest, smoking, and obesity. Nonmodifiable risk factors include Factor V Leiden mutation, myocardial infarction, coronary artery disease, and cancer.

A 75-year-old client with a history of heart valve replacement arrives at the outpatient clinic with multiple red pinpoint lesions. The nurse identifies the lesions as:

Petechiae Explanation: 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.

A young man has been diagnosed with hemophilia, and the nurse is planning his discharge teaching. The nurse knows to include what in the discharge teaching?

Prevent trauma to the body. Explanation: Hemophilia A is an X-linked recessive disorder that primarily affects males. Approximately 90% of persons with hemophilia produce insufficient quantities of the factor VIII. The prevention of trauma is important in persons with hemophilia.

A client has an impaired platelet function that may have developed from inheritance, drugs, disease, or extracorporeal circulation. The health care provider would document this as:

Thrombocytopathia Explanation: Thrombocytopathia results from inherited disorders of adhesion and/or acquired defects such as drugs, disease process, or extracorporeal circulation. Plasmapheresis is the process of removal of plasma from withdrawn blood and replacement with fresh frozen plasma. Fibrinolysis is the process in which a blood clot is dissolved.

A nurse is treating a client with aplastic anemia. Due to the replacement of normal bone marrow with malignant cells, the nurse teaches the client to prevent scratches, scrapes, and cuts. What root cause likely underlies the client's increased risk for hemorrhage?

Thrombocytopenia Explanation: Thrombocytopenia results from a decrease in megakaryocytes due to overcrowding of the bone marrow. With fewer megakaryocytes the client will have fewer circulating platelets and will be at risk for bleeding. Polycythemia is an overproduction of red blood cells. Neutrophilia results from stimulation of the inflammatory system. DIC does not result from aplastic anemia.

A client diagnosed with autosomal dominant von Willebrand factor disease (vWF) is experiencing mild to moderate bleeding. The health care provider would classify the diagnosis as:

Type 2 Explanation: Type 2 vWF is an autosomal dominant disorder that is characterized by defects in vWF and results in mild to moderate bleeding. Types 1 and 3 are associated with reduced levels of vWF. There is no type 4.

A 44-year-old female client presents to the emergency department with abnormal bleeding and abdominal pain that is later attributed to gallbladder disease. Which diagnosis would the medical team be most justified in suspecting as a cause of the client's bleeding?

Vitamin K deficiency Explanation: Factors VII, IX, and X and prothrombin require the presence of vitamin K for normal activity. Vitamin K deficiency may result from impaired fat absorption caused by liver or gallbladder disease. Calcium, factors X and V, and platelet phospholipids combine to form prothrombin activator, which then converts prothrombin to thrombin. Excess calcium could result in increased formation of blood clots. Hemophilia B is a hereditary disorder. Half of the cases of ITP occur as an acute disorder in children; ITP in adults is a chronic disorder with insidious onset.

A nurse is caring for a client who has sustained severe trauma and has developed disseminated intravascular coagulation (DIC). The nurse will explain this complication to the family based on which physiologic principle?

Widespread coagulation and bleeding in the vascular compartment Explanation: DIC is a paradox in the hemostatic sequence and is characterized by widespread coagulation and bleeding in the vascular compartment. It 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 10-month-old infant has begun to take his first steps and his mother has brought him for assessment because of swelling in his ankles and knees. The mother also states that he was eager to walk but has now regressed and cries when she tries to encourage it. The clinician should:

assess the child for signs and symptoms of hemophilia A. Explanation: The child's presentation is characteristic of hemophilia A, not DIC or von Willebrand disease. Vitamin K does not affect the physiology of hemophilia.

A young woman diagnosed with prostacyclin deficiency is admitted to the hospital with recurrent deep vein thrombosis and an ovarian infarction asks the nurse why she keeps having these problems. Understanding the role of prostacyclin in hemostasis, the nurse explains that prostacyclin enables:

blood vessel vasodilation and inhibition of platelet aggregation Explanation: Prostacyclin is a prostaglandin released by the endothelial cells, which is responsible for limiting the vasoconstriction and platelet aggregation that is initiated by endothelial injury. Deficiency of this hormone increases the risk of inappropriate platelet aggregation in areas other than areas with endothelial damage, which can contribute to thrombosis in uninjured vessels.

The school nurse has several children with hemophilia A. After recess, one hemophilia student comes to the school nurse complaining of pain in the 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 the child and possibly administer Factor VIII. Explanation: 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 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. Explanation: 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.

Many different proteins, enzymes, and hormones are involved in maintaining hemostasis. Which protein is required for platelet adhesion?

von Willebrand factor Explanation: Platelet adhesion requires a protein molecule called von Willebrand factor. This factor is produced by the endothelial cells of blood vessels and circulates in the blood as a carrier protein for coagulation factor VIII. The release of growth factors results in the proliferation and growth of vascular endothelial cells, smooth muscle cells, and fibroblasts and is important in vessel repair. Ionized calcium contributes to vasoconstriction. Platelet factor 4 is a heparin-binding chemokine.