1

Chapter 50 and Chapter 51 Assessment of Immune Function

Management of Patients With Immunodeficiency Chapter 70

pp 2474-2484

2

The Immune System

• Immunity: the body’s specific protective response to invading foreign agent or organism

• Immunopathology: the study of diseases that result from dysfunction of the immune system

• Immune disorders: – Autoimmunity– Hypersensitivity– Immune deficiencies: primary and secondary– Infection

3

Central and Peripheral Lymphoid Organs

4

Development of Cells of the Immune System

5

Lymphocytes• B lymphocytes mature in the bone marrow; T lymphocytes mature in

the thymus where they also differentiate into cells with various functions

6

Immune Function• Natural immunity: nonspecific response to any foreign

invader – White blood cell action: release cell mediators such as

histamine, bradykinin, and prostaglandins, and engulf (phagocytize) foreign substances

– Inflammatory response– Physical barriers, such as intact skin, chemical barriers, and

acidic gastric secretions or enzymes in tears and saliva• Acquired immunity: specific against a foreign antigen– Result of prior exposure to an antigen – Active or passive

7

Defenses• Phagocytic immune response

• Humoral/antibody response

• Cellular immune response

• Chemical Response

8

Phagocytic Immune Response• WBC’s (leukocytes) participate in both, natural and

acquired immunity

– Granulocytes (granular leukocytes) release mediators (such as histamine, bradykinin and prostaglandins) and engulf antigen • (include neutrophils, eosinophils and basophils)• Neutrophils- first cells to arrive on scene

– Nongranular leukocytes • Monocytes or macrophages (called Histiocytes

when they enter the tissue spaces)- engulf, ingest and destroy greater number of foreign bodies/toxins that granulocytes do.

9

Humoral/Antibody response

• Humoral is Greek for “blood”• Lymphocytes–Consist of B-cells and T-cells–B lymphocytes: humoral immunity•Produce antibodies or

immunoglobulins• Antibody response

10

Role of Antibodies• Agglutination- (clumping of antigens)

– Helps clear the body of the invading organism by facilitating phagocytosis

• Opsonization- the antigen-antibody molecule is coated with a sticky substance to facilitate phagocytosis

• Promote release of vasoactive substances; activation of complement system and phagocytosis

• Act in concert with other components of the immune system

• Types of immunoglobulins: IgA, IgD, IgE,IgG, and IgM

11

Exposure

12

Cellular immune response• T lymphocytes: cellular immunity– Attack invaders directly, secrete cytokines, and

stimulate immune system responses– Helper T cells– Cytotoxic T cells– Memory cells– Suppressor T cells (suppress immune response)

• T cells help the cells when the cell figures out there is a problem………..(Cells will “hold” the antigen at the surface and wait for the T cells to come get it……)

13

Chemical Immune Response• Histamine- source: basophils, mast cells, platelets – causes vasodilation and vascular permeability

• Kinins- source: precursor factor from clotting system– causes vasodilation and vascular permeability as

well as pain receptors stimulated

• Fibrinopeptides- source: activation of clotting system– vascular permeability and stimulates Chemotaxis

• Prostaglandins/leukotrienes- source: substances synthesized from the phospholipids of cell membranes of most body tissues– vascular permeability and stimulates Chemotaxis

14

Chemical Immune Response– Enhanced Phagocytosis- WBC’s ingest or

engulf any unwanted organism and kill it

– Enhanced Vascular Permeability- allows cells to move back and forth to cells

– Chemotaxis- directional migration of WBC’s along a concentration gradient

– Cell Lysis-breakdown of cell

15

Complement System• Circulating plasma proteins, know as complement, are made in

the liver and are activated when an antibody connects with and antigen.

• Three major physiologic functions– Defending the body against bacterial infection– Bridging natural and acquired immunity– Disposing of immune complexes and the byproducts

associated with inflammation

• The proteins that comprise the complement system interact sequentially

• Three ways to active:– Classic pathway– Alternative pathway– Lectin pathway

16

Autoimmune disorders

• Inability to determine self from non-self

• Lupus Erthematosis, Rheumatoid arthritis

17

Variables That Affect Immune System Function

• Age and gender• Nutrition

• Presence of conditions and disorders: cancer/neoplasm, chronic illness, autoimmune disorders, surgery/trauma

• Allergies• History of infection and immunization• Genetic factors• Lifestyle• Medications and transfusions: see Table 50-6• Pyschoneuroimmunologic factors

18

Tests to Evaluate Immune Function• WBC count and differential– Bone marrow release more neutrophils, may

release “bands” which are immature cells to keep up. “shift to the left” means acute bacteria infection. (mature neutrophils=segmented neutrophils)

• Bone marrow biopsy• Phagocytic cell function test• Complement component tests• Hypersensitivity tests• Specific antigen–antibody tests• HIV infection tests

19

Immunodeficiency Disorders• Primary– Genetic– May affect phagocytic function, B cells

and/or T cells, or the complement system • Secondary– Acquired– HIV/AIDS– Related to underlying disorders, diseases,

toxic substances, or medications

20

Primary Immunodeficiencies

• Usually seen in infants and young children

• Manifestations: vary according to type; severe or recurrent infections; failure to thrive or poor growth; and positive family history

• Potential complications: recurrent, severe, potentially fatal infections; related blood dyscrasias and malignancies

• Treatment: varies by type; treatment of infection; pooled plasma or immunoglobulin; GM-CSF or GCSF; thymus graft, stem cell, or bone marrow transplant

21

Nursing Management

• Monitor for signs and symtoms of infections

– Symptoms of inflammatory response may be blunted

• Monitor lab values

• Promote good nutrition

• Address anxiety, stress, and coping

• Strategies to reduce risk of infection

– Handwashing and strict aseptic technique

– Patient protection and hygiene measures: skin care, promote normal bowel and bladder function, and pulmonary hygiene

22

Patient Teaching • Signs and symptoms of infection

• Medication teaching

• Prevention of infection

– Handwashing

– Avoid crowds and persons with infections

– Hygiene and cleaning

• Nutrition and diet

• Lifestyle modifications to reduce risk

• Follow-up care

23

Colonization, Infection, and Disease

• Colonization: describes microorganisms present without host inference or interaction

• Infection: indicates host interaction with the organism

• Disease: the infected host displays a decline in wellness due to the infection

24

Interpreting the Microbiology Report

• A tool to determine colonization, infection, or disease

• The organism reported may reflect colonization rather than infection

• Mix of cells in smear and stain report may indicate cellular response

• Culture and sensitivity specify the organism and which antibiotic will inhibit growth

• Analyze results in conjunction with the clinical assessment of the patient

25

Isolation Precautions

• Guidelines to prevent the transmission of microorganisms in hospitals

• Standard precautions used for all patients

• The primary strategy for preventing HAIs

• Transmission-based precautions are for patients with known infectious diseases spread by airborne, droplet, or contact routes

26

Elements of Standard Precautions

• Hand hygiene

• Use of gloves and other barriers

• Proper handling of patient care equipment and linen

• Environmental control

• Prevention of injury from sharps and needles

• Patient placement

27

Transmission-Based Precautions

• Airborne precautions– Hospitalized patient should be in negative pressure room with the door

closed; health care providers should wear an N-95 respirator (mask) at all times when in the room

• Droplet precautions– Wear a face mask but door may remain open; transmission is limited to

close contact• Contact precautions

– Use of barriers to prevent transmission; emphasize cautious technique as organism is easily transmitted by contact between the health care worker and the patient

28

Antibiotic –resistant organisms• Nosocomial: Caused by exposure to an organism in the hospital setting • Best way to prevent the spread of infection----good hand washing

(waterless gel, ok)

– Methicillin-resistant Staphylococcus Aureus (MRSA)– Vancomycin-resistant enterococci (VRE)– Penicillin-resistant Streptococcus pneumoniae (PRSP)– C. Difficile

29

Methicillin-resistant Staphylococcus Aureus (MRSA)

• Most prevalent nosocomial pathogen.• Main mode of transmission is via direct contact-especially health care workers

hands.• Staph bacteria and MRSA can be found on the skin and in the nose of people

without causing illness• Can survive on hands for 3 hours if not washed properly• Colonization occurs when the staph bacteria are present on or in the body without

infection (20-30% of the population is colonized in the nose with staph at any given time)

• Infection is when causes disease, typically in a compromised patient.• Contact precautions• Treatment of choice is Vancomyacin

30

Vancomyacin-Resistant Enterococcus• Major source of transmission is health care workers hands. • Can survive on environmental surfaces for weeks without proper

disinfectants.• Contact precautions with a special disinfectants• Treatment includes Beta-lactam and aminoglycoside antibiotics

31

Clostridium difficile• occurs when the normal intestinal flora is altered, allowing C. difficile to

flourish in the intestinal tract and produce a toxin that causes a watery diarrhea.

• Spores can survive up to 70 days in the environment and can be transported on the hands of health care personnel who have direct contact with infected patients

• Symptoms:– Watery diarrhea– Cramps– Fever– Abd pain

• Treatment: related to Cause

32

Infectious Terrorism• Biologic agents of terrorism– Anthrax– Plague– Tularemia– Botulism-treat with antitoxin– Small pox-vaccination– Hemorrhagic fever-no established treatment

33

Nursing Process—Assessment of the Patient With an Infectious Disease

• Health history: investigate the likelihood and probable source of infection, associated pathology, and symptoms

• Administer a physical exam

• Vital Signs

34

Nursing Process—Diagnosis of the Patient With an Infectious Disease

• Risk for infection transmission

• Deficient knowledge

• Risk for ineffective thermoregulation

35

Collaborative Problems/Potential Complications

• Septicemia, bacteremia, or sepsis• Septic shock• Dehydration• Abscess formation• Endocarditis• Infectious disease-related cancers• Infertility• Congenital abnormalities

36

Nursing Process—Planning the Care of the Patient With an Infectious Disease

• Major goals include prevention of the spread of infection, increased knowledge about the infection and its treatment, control of fever and related discomforts, and absence of complications

37

Interventions

• Prevent the spread of infection

– Perform handwashing

– Exercise Standard Precautions

– Recognize mode of transmission and establish Transmission-Based Precautions as indicated

• Teach about infectious process and the prevention of the spread of infections

• Assess and treat fever

– Increases metabolic rate by 7% each 1 degree above normal