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Chapter 33

Chapter 33. Immunologic Disorders. Anatomy and Physiology of the Immune System. Anatomic Structures and Components. Bone marrow Lymph, lymphatics, and lymph nodes Spleen Thymus Stem cells White blood cells (leukocytes)

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Chapter 33

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  1. Chapter 33 Immunologic Disorders

  2. Anatomy and Physiology of the Immune System

  3. Anatomic Structures and Components Bone marrow Lymph, lymphatics, and lymph nodes Spleen Thymus Stem cells White blood cells (leukocytes) Neutrophils, monocytes and macrophages, eosinophils, basophils, mast cells, B lymphocytes (B cells), T lymphocytes (T cells) Cytokines Eicosanoids

  4. Figure 33-1

  5. Physiologic Functions: Innate Immunity Operational at all times, whether or not a pathogen is present At birth, are immediately functional Include anatomic and physiologic barriers, inflammatory response, and the ability of certain cells to phagocytose foreign invaders

  6. Physiologic Functions: Barriers Skin and mucous membranes: a protective covering; secretes substances that inhibit pathogen growth Sweat glands secrete lysozyme, antimicrobial enzyme Acidic GI and GU systems inhibit growth of pathogenic organisms Secretions from the respiratory and gastrointestinal tracts contain the antibody IgA, as well as phagocytes Surfaces colonized by normal bacterial flora; prevents pathogens from attaching/gaining access to the body Coughing and sneezing, peristalsis in the GI tract, emptying the bladder, and sloughing of dead skin cells: remove microorganisms from the body, thus preventing their invasion and overgrowth

  7. Physiologic Functions: Inflammation Body initially responds to an injury or infection by dilating the capillary bed and increasing the capillary permeability of the affected area Brings white blood cells to the site; allows them to enter the tissue to attack microorganisms This multistep process is called inflammation and is recognized by rubor (redness), tumor (swelling), calor (heat), and dolor (pain) at the site of injury or infection

  8. Physiologic Functions: Phagocytosis The process of ingesting and digesting invading pathogens, dead cells, and cellular debris

  9. Physiologic Functions: Acquired Immunity Specific to particular pathogen: activated only when needed Antibody mediated Initiated when IgM immunoglobulins on B lymphocytes detect a foreign antigen Active: person synthesizes own antibodies in response to pathogen Passive: antibody produced by person or animal is transferred to another person

  10. Physiologic Functions: Acquired Immunity Cell mediated Aimed at intracellular defects caused by viruses and cancer Responsible for delayed hypersensitivity reactions and rejection of transplanted tissue

  11. Figure 33-2

  12. Physiologic Functions: Tolerance Immune system must recognize its own proteins Autoimmune diseases occur when there is a breakdown of tolerance; immune system identifies its own proteins as foreign and mounts a response to destroy these self-proteins Examples: idiopathic thrombocytopenic purpura (ITP), thrombotic thrombocytopenic purpura (TTP), acute rheumatic fever, type 1 diabetes mellitus, systemic lupus erythematosus, rheumatoid arthritis, Graves’ disease, and Hashimoto’s thyroiditis

  13. Age-Related Changes Bone marrow becomes less productive Lymphatic tissue shrinks, resulting in fewer and smaller lymph nodes Immunologic function not affected unless a person is unusually stressed by trauma, a chronic infection, or treatment for cancer

  14. Nursing Assessment of the Immune System

  15. Chief Complaint and History of Present Illness Frequent or persistent infections, bleeds for a long time when cut, bruises easily, or has chronic fatigue

  16. Past Medical History Cancer or prior treatment for cancer, HIV infection, history of splenectomy, or an indwelling venous access device, indicating that the patient needed long-term venous access Medications patient is using or a recent change in medication may suggest an underlying immunologic problem Ask about recent changes in medications and recent immunizations

  17. Family History Note family history of immunologic disorders such as cancer Death of a family member at a young age for reasons other than trauma may indicate a genetic immunologic disorder

  18. Review of Systems Reddened, swollen, painful, warm areas Ask about fever, chills, or night sweats Breaks in the skin, ulcers, lesions, or enlarged lymph nodes Assess for weakness, lethargy, malaise, restlessness, apprehension, or headache Ask about sinus pain, dyspnea, or cough Pain or burning with urination

  19. Functional Assessment Occupation and hobbies Self-concept Activity and exercise Sleep and rest Nutrition Interpersonal relationships Coping and stress Perception of health

  20. Physical Examination General survey Responsiveness, mood, expression, posture Carefully inspect and describe reddened, swollen, or painful areas Skin Note general color, texture, turgor, temperature, and integrity of the skin Palpate for swollen or painful areas

  21. Physical Examination Head and neck Enlarged, swollen, or draining areas Thorax The examiner with advanced skills may palpate the axilla for enlarged lymph nodes Lungs Document respiratory rate and effort; auscultate for wheezing, crackles, or rhonchi

  22. Physical Examination Heart and vascular system Heart rate and blood pressure Abdomen The examiner with advanced skills may palpate the abdomen for tenderness Palpate the groin for enlarged lymph nodes

  23. Diagnostic Tests and Procedures Blood tests Complete blood cell (CBC) count Antinuclear antibody test Enzyme-linked immunosorbent assay and Western blot tests Cultures of blood, urine, sputum, and stool Detect infections in blood, sputum, urine, stool Skin tests

  24. Nursing Actions for the Patient at Risk for Injury from Infection The lower a patient’s white blood cell count, in particular the lower the neutrophil count, the greater the patient’s risk of infection See Box 33-2, p. 599

  25. Bone Marrow Transplant and Peripheral Blood Stem Cell Transplant Restore hematologic and immunologic systems in patients with malignancies who have received extremely high doses of chemotherapy and radiation therapy Allogeneic bone marrow transplant Autologous bone marrow transplant Peripheral blood stem cell transplant

  26. White Blood Cell Disorders of the Immune System: Neutropenia Total number of neutrophils abnormally low, increasing risk of infection Caused by decreased bone marrow production, chemotherapy, radiation therapy, certain drugs or an autoimmune reaction Also by increased neutrophil utilization because of overwhelming infection

  27. White Blood Cell Disorders of the Immune System: Neutropenia Common sites of infection: lung, blood, skin, urinary tract, gastrointestinal tract Goal of antibiotic therapy: support patient until patient’s own white blood cells are available to fight the infection Important to minimize patient’s exposure to infectious agents by instituting compromised host precautions

  28. Leukemia Cancer of the white blood cells: bone marrow produces too many immature white blood cells Immature white blood cells leave patient at great risk for life-threatening infections Factors: exposure to large doses of ionizing radiation or exposure to certain chemicals such as benzene, a compound found in gasoline Two main types—myelogenous and lymphocytic Each type can be either chronic or acute

  29. Leukemia Signs and symptoms of acute leukemia Fevers and night sweats Fatigue, paleness, tachycardia, and tachypnea Petechiae or purpura, epistaxis, gingival bleeding, melena, or menorrhagia Weight loss and swollen lymph nodes

  30. Leukemia Medical diagnosis of acute leukemia CBC with extremely high white blood cell count Bone marrow biopsy Medical treatment of acute leukemia Chemotherapy Antibiotics and blood transfusions

  31. Leukemia Assessment Signs or symptoms of infection Complete vital signs every 4 hours If sputum, note the amount and color Skin for reddened, swollen, painful, or draining areas Inspect the mouth and pharynx for reddened, swollen, painful, or draining areas Assess for any evidence of bleeding Petechiae, purpura, or ecchymoses Perform a guaiac test

  32. Leukemia Interventions Risk for Injury Fatigue Impaired Oral Mucous Membranes Imbalanced Nutrition: Less Than Body Requirements Anxiety Ineffective Therapeutic Regimen Management

  33. Hypersensitivity Reactions Exaggerated immune responses that can be uncomfortable and harmful to the patient Four types of hypersensitivity reactions, classified according to the time between exposure and reaction, immune mechanism involved, and site of reaction

  34. Hypersensitivity Reactions Type I Immediate hypersensitivity reactions are mediated by IgE reacting to common allergens, such as dust, pollen, animal dander, insect stings, or various drugs Either local, resulting in local swelling and discomfort, or systemic, resulting in anaphylaxis and possible death if not recognized and treated promptly

  35. Hypersensitivity Reactions Type II Immediate hypersensitivity reactions are mediated by antibody reactions Can occur with a mismatched blood transfusion or as response to various drugs

  36. Hypersensitivity Reactions Type III Immediate hypersensitivity reactions result in tissue damage resulting from precipitation of antigen-antibody immune complexes Can occur with autoimmune reactions, some occupational diseases, or as response to various drugs

  37. Hypersensitivity Reactions Type IV Delayed hypersensitivity reactions result from immune cells migrating to the site of exposure days after the exposure to the antigen Can occur with contact dermatitis, measles rash, tuberculin skin testing, or various drugs

  38. Idiopathic Thrombocytopenic Purpura (ITP) IgG mistakenly helps destroy patient’s platelets Drugs that induce ITP: sulfonamides, thiazide diuretics, chlorpropamide, quinidine, and gold. Patients with HIV are at increased risk for developing ITP Treatment: steroids and intravenous immune globulin (IVIG)

  39. Thrombotic Thrombocytopenic Purpura (TTP) Exaggerated immunologic response to vessel injury that results in extensive clot formation and decreased blood flow to the site Patients critically ill; develop fever, thrombocytopenia, hemolytic anemia, renal impairment, and neurologic symptoms The main treatment is plasmapheresis Others: steroids, antiplatelet agents (e.g., aspirin, dipyridamole, Persantine), splenectomy, or all three

  40. Systemic Lupus Erythematosus Autoimmune disease: immune system unable to recognize itself; mounts an immune response against its own proteins Damage from antibodies and immune complexes directed against one/many organs The cause is unknown Cause of death: infection and disease of the cardiovascular, renal, pulmonary, and central nervous systems

  41. Systemic Lupus Erythematosus Signs and symptoms Fatigue, malaise, fever, anorexia, nausea, and weight loss Arthralgias and myalgias Joints often swollen, tender, stiff, and painful Rash and photosensitivity Butterfly-shaped rash across the bridge of the nose and the cheeks Inflammation of the retina can result in sudden-onset blindness

  42. Systemic Lupus Erythematosus Diagnosis No one test confirms the diagnosis of SLE Based on constellation of symptoms If any four of the following symptoms: SLE Characteristic rash Photosensitivity with exposure to sunlight Oral ulcers Arthritis Pleuritis or pericarditis Renal, neurologic, hematologic, or immunologic disorder Positive ANA

  43. Systemic Lupus Erythematosus Medical treatment There is no cure Treatment: symptomatic and aimed at minimizing symptoms, preventing organ damage, and maintaining quality of life Analgesics, nonsteroidal anti-inflammatory drugs (NSAIDs), antimalarials, corticosteroids Cytotoxic agents suppress the abnormal immune response

  44. Systemic Lupus Erythematosus Assessment Thorough health history and physical examination Complete functional assessment: determine the effects of the symptoms on the activities of daily living

  45. Systemic Lupus Erythematosus Interventions Fatigue Acute Pain Disturbed Body Image Ineffective Coping Ineffective Therapeutic Regimen Management

  46. Human Immunodeficiency Virus (HIV) A retrovirus that infects cells expressing CD4 on their cell membranes, primarily TH cells

  47. Transplant Rejection Patients who undergo kidney, heart, liver, or other organ transplantation risk that their healthy immune system will recognize the transplanted organ as foreign and try to destroy it

  48. Transplant Rejection Rejections occur because T lymphocytes can directly attack the allograft, resulting in acute transplant rejection within hours of the transplant B lymphocytes can make antibodies against the allograft Fibrin accumulates on the transplanted tissue, causing ischemia

  49. Transplant Rejection Donor-recipient tissue matching minimizes recipient’s immune system attacking allograft Drug combinations suppress recipient’s immune system and minimize the immune response to the allograft Drugs suppress the patient’s ability to fight bacteria, viruses, fungi, and parasites, putting at risk for infection Combinations of the steroids cyclosporine and azathioprine chronically suppress the immune system after an organ transplant

  50. Transplant Rejection Several newer drugs target the T cells while preserving B cell function and thus more of the patient’s immune function Tacrolimus (Prograf), antilymphocyte globulin, antithymocyte globulin, and murine monoclonal antibody to CD3 (OKT3) Patients who have undergone organ transplantation must take immunosuppressive therapy the rest of their lives to preserve the allograft

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