Week 2 Cardiac - Student

ALTERATIONS IN PERFUSION (LEWIS 12TH EDITION CHAPTERS 34, 37-39)

  • Overview of perfusion alterations in medical-surgical nursing.

COMPONENTS OF BLOOD

  • Red Blood Cells (Erythrocytes): Carry oxygen.

  • White Blood Cells (Leukocytes): Key players in the immune response.

  • Platelets: Essential for blood clotting, preventing excessive bleeding.

  • Plasma: Contains nutrients (e.g., amino acids, glucose) and water, serving as the medium for transporting cells and other substances.

THROMBOCYTOPENIA (LEWIS 12TH EDITION CHAPTER 34)

  • Definition: A condition characterized by low platelet counts, leading to increased risk of bleeding.

NORMAL HEMOSTASIS

  • Involves:

    • Vascular endothelium

    • Platelets

    • Coagulation factors

  • All components must function together to prevent hemorrhage and repair vascular injuries.

  • Disruption in any element may result in bleeding or thrombosis.

ETIOLOGY AND PATHOPHYSIOLOGY

  • Defined as a reduction of platelets below normal levels (normal range not specified).

  • Leads to:

    • Abnormal hemostasis

    • Prolonged or spontaneous bleeding

  • Commonly acquired from high doses of particular medications.

CLINICAL MANIFESTATIONS

  • Patients may be asymptomatic until platelet counts drop below 50,000/μL.

  • Symptoms include:

    • Mucosal or cutaneous bleeding

    • Petechiae: Microhemorrhages

    • Purpura: Bruising from multiple petechiae

    • Ecchymosis: Larger areas of hemorrhage

  • Prolonged bleeding may occur after routine procedures.

  • Possible internal bleeding symptoms: Weakness, fainting, dizziness, tachycardia, abdominal pain, hypotension.

    • Notable concern for hemorrhage, which may be acute or gradual.

CAUSES OF THROMBOCYTOPENIA

  • Acquired Causes:

    • Immune thrombocytopenic purpura (ITP)

    • Thrombotic thrombocytopenic purpura (TTP)

    • Heparin-induced thrombocytopenia (HIT)

IMMUNE THROMBOCYTOPENIC PURPURA (ITP)

  • Description: Most common acquired thrombocytopenia; results from abnormal platelet production and destruction.

  • Associated with autoimmune disorders (like Lupus), infections (H. pylori, HIV).

  • Platelets become coated with antibodies, leading to their destruction in the spleen.

DIAGNOSTIC STUDIES

  • Reduced platelet count (<150,000/μL).

    • Testing includes peripheral blood smear, ITP antigen-specific assay, medical history evaluation, clinical examination.

TREATMENTS FOR ITP

  • Interprofessional Care: Begins if platelet counts drop below 30,000/μL or if symptomatic.

  • Initial Treatment: Corticosteroids (e.g., prednisone, methylprednisolone).

  • Advanced Treatments:

    • Romiplostim (Nplate)

    • Eltrombopag (Promacta) - can cause liver damage and ineffective with high-calcium foods.

    • High doses of IV immunoglobulin (IVIG) compete with antiplatelet antibodies.

    • Rituximab (Rituxan) targets B cells.

PLATELET TRANSFUSIONS

  • Indicated: For life-threatening hemorrhages or when platelet count is very low (<10,000/μL).

  • Not used prophylactically due to possible antibody formation.

SPLENECTOMY

  • Performed in non-responsive cases or for chronic conditions; it may compromise immunity.

THROMBOTIC THROMBOCYTOPENIC PURPURA (TTP)

  • Description: Uncommon syndrome encompassing hemolytic anemia, thrombocytopenia, and various systemic symptoms.

  • Microthrombi formation in small vessels leads to complications (notably kidney injury).

CAUSES AND RISK FACTORS

  • Deficiency of plasma enzyme ADAMTS13, autoimmune disorders, drug toxicities, pregnancy, infections.

INTERPROFESSIONAL CARE

  • Treat underlying conditions; urgent plasmapheresis may be necessary to reverse platelet consumption.

  • Corticosteroids and immunosuppressant therapies are sometimes indicated.

HEPARIN-INDUCED THROMBOCYTOPENIA (HIT)

  • A serious immune reaction that occurs in some patients after the administration of heparin.

  • Symptoms include:

    • Significant drop in platelet counts (≥50%) within 5-10 days of heparin therapy initiation.

    • Major concern for venous and arterial thromboembolic events.

INTERPROFESSIONAL CARE

  • Immediate cessation of all heparin; critical notes in medical records.

  • Warfarin usage should start only when platelets are stable above 150,000/μL.

  • Other treatments for severe cases include plasmapheresis and thrombolytic therapy.

THROMBOCYTOPENIC NURSING MANAGEMENT

  • Prevent Hemorrhage: Vigilantly monitor for bleeding and provide safety measures; avoid IM injections when possible.

  • Encourage patient education on safety measures to reduce bleeding risks.

  • Monitor platelet counts and educate on menstrual blood loss management.

ANGINA AND MYOCARDIAL INFARCTION (ACS)

  • Overview: Angina represents ischemia; myocardial infarction indicates irreversibility leading to tissue necrosis.

STABLE ANGINA

  • Caused by increased oxygen demand; often linked to underlying atherosclerosis.

UNSTABLE ANGINA & NSTEMI

  • New or changing chest pain indicates cardiac ischemia, potential transition to an MI.

STEMI

  • Resulting from complete blood vessel occlusion, leading to significant tissue death.

NURSING MANAGEMENT FOR ACS

  • Important to assess and provide rapid care during chest pain episodes:

    • Position upright, apply oxygen, monitor VS, conduct ECG, and administer medications as required.

LABORATORY TESTS

  • Cardiac Enzymes: Troponin and CK-MB levels used in diagnosis; troponin is particularly sensitive.

HEART FAILURE

  • Definition: The heart's incapacity to provide adequate blood to meet physiological demands, leading to systemic complications.

PATHOPHYSIOLOGY OF HF

  • Associated with cardiac output issues; dysfunction can arise from left- or right-sided failure, or both.

RISK FACTORS

  • Key contributors include hypertension, coronary artery disease, diabetes, and lifestyle factors.

CLINICAL MANIFESTATIONS

  • Symptoms such as dyspnea, fatigue, and changes in vital signs indicate worsening heart failure.

NURSING MANAGEMENT

  • Constantly monitor respiratory status, administer necessary medications, and educate patients on dietary restrictions.