Presentation on theme: "Inflammation, Infection, and Immunity"— Presentation transcript:
1Inflammation, Infection, and Immunity Chapter 13Inflammation, Infection, and Immunity
2Learning Objectives Describe physical and chemical barriers. Describe how inflammatory changes act as bodily defense mechanisms.Identify the signs and symptoms of inflammation.Discuss the process of repair and healing.Differentiate infection from inflammation.Discuss the actions of commonly found infectious agents.Describe the ways in which infections are transmitted.Identify the signs and symptoms of infection.Compare community-acquired and nosocomial infections.
3Learning ObjectivesDiscuss the nursing care of patients with infections.Describe the Centers for Disease Control and Prevention (CDC) Standard Precautions guidelines for infection control.Describe the CDC isolation guidelines for Airborne, Droplet, and Contact (Transmission-Based) Precautions.Describe the immune response.Identify the organs involved in immunity.Compare natural and acquired immunity.Differentiate between humoral (antibody-mediated) and cell-mediated immunity.Describe the nursing care of patients with immunodeficiency and of patients with allergies.Describe the process of autoimmunity.
4Skin and Mucous Membranes The body’s first line of defenseProtective covering; secretes substances that inhibit the growth of microorganismsSweat glands secrete lysozyme, an antimicrobial enzymeSebaceous glands secrete sebum, which has antimicrobial and antifungal propertiesAcidic secretions from skin and mucosa of GI and GU systems inhibit growth of many pathogenic organismsSecretions from mammary glands and the respiratory and GI tracts contain immunoglobulin; also clean up phagocytes
5Skin and Mucous Membranes Surfaces colonized by “normal” bacterial flora: prevent pathogens (disease-causing organisms) from entering the bodyCilia in respiratory tract, motility of the GI tract, and sloughing of dead skin distribute and remove microorganisms, preventing their overgrowth and invasion
6Phagocytosis and Inflammation The second line of defenseHelps rid body of invading microorganismsWhite blood cells (leukocytes): colorless cells that are able to phagocytose (ingest) bacteria that can cause infection when they invade the bodyMeasuring the number of these cells indicates severity of infectionWhat are the two types of leukocytes that are especially suited for this purpose?
8The Inflammatory Process A series of cellular changes that signal the body’s response to injury or infectionMay be caused byPhysical agentsExcessive sunlight, x-raysChemical stimuliInsect venom, other chemicalsBiologic agentsBacteria, viruses
10The Inflammatory Process Inflammation: literally “the fire within”This descriptive phrase illustrates the four classic manifestations of inflammationRubor (redness)Calor (heat)Tumor (swelling)Dolor (pain)These signs are the direct result of several related actions that occur when the inflammatory process is initiated.What actions are involved in the inflammatory process?
11Actions in the Inflammatory Process Hemodynamic changesDilation of the capillary bedIncreases blood flow to the areaWarmth and redness at the site of inflammation
12Actions in the Inflammatory Process Increased capillary permeabilityChemical mediators cause leukocytes to line the small blood vessel walls near the inflammatory siteCells pass through the walls; inhabit inflamed areaIngest and carry away bacteria and other foreign substancesPermeability of these vessels causes protein-rich fluid to flow through vessel walls into the interstitial spaceCollection of fluid is responsible for the swellingWhat is pavementing?Swelling may also produce pain.
13Chemical MediatorsThe hemodynamic changes and vascular permeability occur with the help of several chemical mediatorsProstaglandins, histamine, and leukotrienesPowerful substances found in various body tissues; liberated during the inflammatory processCytokines and eicosanoidsCause blood and blood vessel changes
14Kinin SystemProduces bradykinin, which also mediates blood vessel dilation and permeabilityProduces pain, another classic sign of inflammation
15Complement SystemEspecially important in immunologically mediated reactions involving antigen-antibody complexesCauses massive release of histamine and other substances that produce marked vasodilation, vascular permeability, and smooth muscle contractionThese cellular changes produce classic signs of anaphylactic shock: hypotension, swelling, and bronchoconstriction
16Anti-Inflammation Cortisol Hormone produced by the adrenal cortex Anti-inflammatory substance that slows the release of histamine, stabilizes lysosomal membranes, and prevents the influx of leukocytesResult is to impede the inflammatory processProtects body from excessive or prolonged inflammationDrugs (such as corticosteroids) that mimic cortisol often used to treat inflammatory conditions
17Signs and Symptoms of Inflammation Local inflammationProduces the classic signs of heat, swelling, redness, and pain, all of which result in loss of functionSystemic inflammationFever, headache, muscle aches, chills, sweating, and leukocytosisFever is probably caused by pyrogens or by defense mechanisms that are liberated during phagocytosis, or by bacterial endotoxins, antigen-antibody complexes, and certain viruses.What is leukocytosis?
18Wound HealingTissue repair and regeneration set in motion from the beginning of the inflammatory processProcess speed depends on type of tissue injured, severity of the wound, presence of infection, and health of the hostMacrophage cells are produced to clean up inflammatory debrisFibroblasts begin repair process by laying down elastin and collagen at the edges of the woundThese substances gradually migrate to the base, forming granulation tissue
19Wound HealingEpithelial cells migrate over the wound and under the scab (usually formed of dried blood and ﬁbroblasts)The scab falls offDamaged cells are replaced by new cells of their own composition by process of regenerationSome tissue regenerates well, other must undergo repair; may involve replacing injured cells with connective tissue that will eventually create a scarThe age and general health of the person affects how rapidly the regeneration and repair process occurs.The healing process can be delayed in the older adult as a result of decreased tissue elasticity and decreased blood supply.What deficiencies may cause a delay in wound healing?
20Wound HealingOccasionally wound becomes infected or ulcerated, resulting in tissue lossGranulation tissue and capillary buds form at wound margins; wound eventually filled with granulation tissueDelayed primary closureSometimes the wound bed is too large for the granulation tissue to fillWound is cleaned and débrided to enhance healingWhen infection is no longer present, wound is sutured closed
21InfectionInvasion by microorganisms, multiplication of invading organisms, and resulting tissue damageInflammation: nonspeciﬁc body reaction to tissue injury; infection: a specific process that causes tissue injuryInfection always results in inflammation, but inflammation may be caused by other processesInflammation precedes infectionUsually the result of the invasion by organismsCaused by a wide variety of microorganisms
22BacteriaOne-celled microorganisms capable of multiplying rapidly within a susceptible hostClassified as gram positive or gram negativeClassified according to shapeRound bacteria: cocciGroups of two: diplococciClusters: staphylococciChains: streptococciRod-shaped organismsFusiform (with tapered ends)Spirochetes (spirals)What may protect the bacteria from phagocytosis?Classification of bacteria as either gram-positive or gram-negative depends on their ability to take up and retain a violet-colored solution called a Gram stain.Gram-positive bacteria retain the stain.Gram-negative bacteria can be decolorized and counterstained pink.
23BacteriaClassified according to their ability to grow in the presence of oxygenAerobesWill grow in the presence of oxygenAnaerobesWill not grow in the presence of oxygenEach classification highlights a characteristic of a microorganism that is considered in the design of an antimicrobial drug to kill or retard the growth of the organismWhat is an example of how a bacteria classification may affect what antimicrobial drug is used?
24VirusesVery small microorganisms that cause significant morbidity (disease) in humansIllnesses range from the common cold to acquired immunodeficiency syndrome (AIDS); childhood illnesses (measles, chickenpox); and several forms of hepatitisVisible only with electron microscopyContain strand of genetic material and surrounded by a protein capsule, but have no cell wallCannot replicate on their own; depend on the resources of the host cell
25VirusesDamage by stimulating antigen-antibody response in tissues that causes inflammation and cell destructionBecause of replication of the virus within the host cell, seldom possible to kill virus without harming the host cellExplains why relatively few antiviral drugs availableCurrent antiviral drugs suppress viral reproduction or growth so that they decrease the severity or duration of the infection, but they are not curativePrevention (immunizations, hygiene) is still the best way to combat viral illness
26Fungi Vegetable-like organisms that exist by feeding on organic matter Many of these infections are superficial skin infections that rarely produce serious illnessSystemic fungal infections caused by Cryptococcus and Aspergillus species; can be life-threateningPatients with compromised immune systems (e.g., HIV) are at especially high risk of acquiring opportunistic fungal infectionsFungal infections are called mycosesWhat are some examples of fungal organisms?Because fungi tend to form spores that are resistant to many antiseptics and disinfectants, they are difficult to treat.Both systemic and topical antimycotic drugs are used to treat fungal infections.
27Protozoa Make up a large group of one-celled organisms Those that produce disease in humans include the Plasmodium species (malaria), Entamoeba histolytica (amoebic dysentery), Giardia lamblia (giardiasis, characterized by diarrhea), and Trypanosoma gambiense (sleeping sickness)Infections often spread by food or water contaminated by human or animal fecesPneumocystis jiroveci is a protozoal infection that was relatively rare before the onset of the HIV/AIDS epidemic.What causes patients with HIV infection to be at risk for pneumocystic pneumonia?
28Rickettsiae Between bacteria and viruses in size Rods, cocci, or pleomorphic (varied) shapesMultiply in cells of animal hosts (e.g., rats and squirrels); transmitted to humans through flea and tick bitesRocky Mountain spotted fever and typhusDiseases caused by rickettsiae tend to be more prevalent in areas in which sanitation is poor and rodent and insect populations are not well controlled
29HelminthsParasites (worms) are found in soil and water and are generally transmitted from hand to mouthInfections occur commonly in the gastrointestinal tract and may produce mild abdominal pain and bloating, or they may be asymptomaticExamples: pinworms, tapeworms, and hookwormsWhat are the symptoms of pinworms? Tapeworms? Hookworms?Tapeworms can be found in the gastrointestinal tract.Hookworms often enter an individual through the soles of the feet and migrate throughout the body.
30MycoplasmasGram-negative, multishaped organisms without cell walls that are responsible for several infections in humansResponsible for primary atypical pneumonia and have been linked to Reiter’s syndromeInfections usually found in the upper respiratory tract and most often affect children and young adultsRespond well to erythromycinReiter’s syndrome is a multisystem inﬂammatory disease that may be associated with urethritis, conjunctivitis, and pharyngitis.What are pleuropneumonis-like organisms?
31Transmission of Infection Chain of InfectionInfection possible only when factors occur in sequence1. Causative agent2. Reservoir3. Portal of exit4. Mode of transfer5. Portal of entry6. Susceptible hostCausative agents are the microorganisms that are present in sufficient number and virulence to damage human tissue.Areas in which organisms can pool and reproduce are called reservoirs.Portal of exit refers to the route by which the infectious agent leaves one host and travels to another.Mode of transfer refers to the means by which a microorganism is transported to a host.Portals of entry are the doorways or pathways into the host.Microorganisms must become implanted into a susceptible host.What are examples of each of these factors?
32Signs and Symptoms of Infection Localized infectionsRedness, pain, warmth, swelling, and pusGeneralized infectionsMay not show all signs apparent in localized infectionsPain may be mild to severe depending on its locationWarmth is generally expressed as feverMalaiseAnorexiaProstrationOnce an individual becomes infected with a pathogen, symptoms may or may not be apparent.What is a subclinical infection?Asymptomatic carriers may inadvertently infect others.
33Types of Infection Community-acquired infection Acquired in day-to-day contact with the publicChildhood illnesses, tuberculosis, HIV/AIDS, food-borne illness, sexually transmitted infectionsPrevention and controlImmunizations, educating food handlers, screening and early treatment, isolation of infected person, control vectors, personal measures (condom use, proper hygiene, especially hand washing)Many viral infections are pervasive in society and occur at predictable times of the year.When are common childhood illnesses most prevalent? Food-borne illnesses?Poverty, low immunization rates, overcrowding, unsanitary living conditions, and resistant strains of pathogens are at least partially responsible for the increase in infectious diseases that were once well controlled.
34Types of Infection Hospital-acquired (nosocomial) infection Occur within a health care facility; may affect patient as well as health care workerStrains of bacteria in hospital usually more virulent and often resistant to antibioticsSome pathogenic bacteria that are no longer susceptible to previously effective antibiotics are found in hospital patientsVancomycin-resistant enterococcus (VRE) is one example; the incidence of vancomycin resistance in patients with a nosocomial enterococcal infection is rapidly increasing.What measures may prevent the spread of VRE?Iatrogenic infections are caused by the treatment given the patient.
35Medical Asepsis Limit spread of microorganisms Often called clean techniqueChange bed linen, sanitize bedpans, use individual medication cups for each patient and for each administration, frequent hand washingHand washingMost effective method to prevent cross-contaminationSoiled hands main transmission of nosocomial infectionsWhat three things should be used for good hand washing?The use of antimicrobial soaps is also recommended when working with patients who are more susceptible to infection, such as premature infants or immunocompromised patients.
37Surgical Asepsis, or Sterile Technique Eliminate microorganisms from any object that comes into contact with the patientIncludes care techniques that prevent unsterile surfaces from coming into contact with the patient, such as during dressing changes
38Standard PrecautionsInfection control guidelines for hospitals and other health care agencies from Hospital Infection Control Practices Advisory Committee (HICPAC) and CDCFor all patients in hospitals regardless of their isolation statusUse when you will have contact with a patient’s blood, bodily fluids, secretions (except sweat), excretions, broken skin, and mucous membranesUse when you have contact with materials that are soiled or contaminated with bodily fluids or bloodThe current guidelines, called standard precautions, combine the major features of universal precautions and body substance isolation precautions.Use standard precautions with all patients, no matter what their diagnosis or infectious status may be.What are the guidelines for the use of standard precautions?
39Transmission-Based (Isolation) Precautions Airborne precautionsUsed with diseases that are spread through the airDroplet precautionsUsed with infections that are spread by droplets or dust particles containing the infectious agentContact precautionsUsed when caring for patients who are infected by microorganisms that are transmitted by direct (skin-to-skin) or indirect contact with contaminated equipmentWhat are examples of disease spread through the air? Droplets? Contact?Surgical masks filter expired air; respirators such as the HEPA filter respirator and the N95 respirator filter inspired air.Droplets are spread primarily during coughing, sneezing, or talking and during certain procedures such as suctioning and bronchoscopy.Needles, dressings, stethoscopes, bed rails, and doorknobs may become contaminated and cause the spread of microorganisms by contact.
40BioterrorismThe intentional use of microorganisms to cause death or diseaseMethods used to spread agents of bioterrorism are varied and might include powders, aerosols, or contamination of food or water.What are some agents that may be used in bioterrorism?Nurses should be aware of their employing agency’s plans for dealing with public exposure to bioterrrorism agents, including decontamination procedures and personal protective equipment and procedures.
41Immunocompromised Patients Decreased immunity to infection; are at increased risk for bacterial, fungal, parasitic, and viral infectionsPatients receiving chemotherapy and other patients with low white blood cell counts are at increased risk of infection.What diseases may cause a patient to be immunocompromised?The use of standard precautions for all patients and of transmission-based precautions for specific situations should reduce the risk of acquiring infections from other persons and from the environment.
42Nursing Care of Patients with Infections Urge the patient to consume adequate fluidsEncourage to consume high-protein, high-vitamin dietIsolation, if requiredLaboratory testsWhite blood cell count with differential; erythrocyte sedimentation rate; iron level; cultures of urine, blood, wound, sputum, and throatAdminister antibiotic drug therapyHyperbaric oxygen therapyFluid intake is important in the transportation of nutrients to the cells to fight infection.How much fluid intake should a patient have each day?Examples of nursing diagnoses for patients with infections or for patients who are vulnerable to infections include Risk for Infection, Risk for Injury, Impaired Tissue Integrity, Social Isolation, and Disturbed Body Image.Caution patients not to stop taking the medication when they start feeling better.
43ImmunityProvides resistance to invading organisms; enables body to fight off invaders once they have gained accessAntigenAny substance capable of stimulating a response from the immune systemUsually foreign; body recognizes it because it’s differentAntibodiesAlso known as immunoglobulinsProteins are created in response to specific antigensIf the immune system is intact and functioning properly, it is able to provide adequate protection from most infections and diseases in a healthy individual.What are some factors that may compromise the immune system?Once the body recognizes a substance as an antigen, natural and acquired defenses are put into action to destroy the invader and prevent disease.
44Immunity Innate (natural) immunity Acquired immunity Present at birth; not dependent on a specific immune response or previous contact with an infectious agentAcquired immunityDevelops after birth as a result of the body’s natural immune responses to antigensDepends on the proper development and functioning of B and T lymphocytesDeveloped after direct contact with an antigen through illness or vaccinationWhat factors may influence innate immunity?Nonspecific defense mechanisms, including physical and chemical barriers to infection, phagocytosis and the inflammatory process, contribute to natural immunity.Once the body has been exposed to an antigen through illness or vaccination, antibodies develop and retain memory for the antigen.If the body is exposed to the same antigen later, the antibodies can react quickly to fight off disease.
45Immunity Leukocytes (white blood cells) Thymus and bone marrow Key role in immune responses to infectious organisms and other antigensGranulocytes and nongranulocytesThymus and bone marrowParticipate in the formation and maturation of immune system cells
46Immunity Lymph nodes Spleen Liver Attack antigens and debris in the interstitial fluid and produce and circulate lymphocytesSpleenFilter dead cells, debris, and foreign molecules from bloodLiverFilters blood and plays a part in the production of specific immunoglobulins and other chemicals involved in the immune response
48Nonspecific Defenses Against Infection Innate (natural) immunityPresent at birth; physical and chemical barriers to invasion of the body as well as substances that protect and repair tissues and stimulate the body to fight off diseasePhysical and chemical barriers, inflammation, and phagocytosis are nonspeciﬁc defenses against infectionOther nonspecific defenses against infection that protect the body include complement, pyrogen, and interferon.How do complement, pyrogen and interferon assist with defense against infections?
49Specific Defenses Against Infection—The Immune Response Antibody-mediated immunityFirst-line defense: B lymphocytes and the production of antibodies in response to specific antigensHumoral immune response initiated when an antigen binds to a special receptor on a B lymphocyteResults in antibodies that seek out and “stick to” specific antigens in the bodyForms antigen-antibody complexes, which are then targeted for cleanup by neutrophils and macrophagesFormation of these complexes activates complement and intensifies T-lymphocyte activityWhat are the five classes of antibodies (immunoglobulins)?
50Specific Defenses Against Infection—The Immune Response Cell-mediated immunityA delayed response to injury or infection because of time needed for migration of T cells and production of substances that enhance the immune response and influence the destruction of antigensFights most viral or bacterial infections and hinders the growth of malignant cellsThis process also launches an attack on transplanted tissue or organs in the bodyWhat three types of cells do T cells include?
51Immunodeficiency Etiology and risk factors Medical treatment Body unable to launch an adequate immune response and is at great risk for infectionCan be congenital or, more commonly, acquiredMedical treatmentCongenital immunodeficiency treated with replacement therapy of the immune componentAcquired immunodeficiency is treated by correcting the underlying conditionWhat is the primary clinical clue to immunodeficiency?Stress, whether physical or emotional, alters the body’s response to disease.
52Immunodeficiency Nursing care Prevent infection Encourage adequate nutritional intakePerform good skin, mouth, perineal, wound, and IV site care; assess for signs of infectionEncourage patients to turn, cough, and breathe deeplyProtective (compromised host) isolation may be necessaryPatient education on risks and signs of infectionWhat is the single most important measure in prevention?A small increase in body temperature in these patients can be significant and should be reported.
54Hypersensitivity and Allergy Medical treatmentAntihistamines, bronchodilators, corticosteroids, topical lotions and ointmentsTesting to determine specific allergensDesensitizationWhat are the side effects of antihistamines?Testing is performed by injecting small amounts of allergen under the skin (intradermally) or by pricking the surface of the patient’s skin and monitoring for the degree of wheal-and-flare reaction.Desensitization is aimed at increasing tolerance to the offending agent and decreasing the severity of the allergic response.
55Hypersensitivity and Allergy Nursing careDocument all allergies, symptoms they cause, and any treatment currently usedEducation is important for all patients with allergiesSpecific allergens, limiting exposure to or avoiding allergens, the proper use of medications such as inhaled bronchodilators, and the actions and side effects of drugsNever administer any drug to which the patient reports a previous allergic reaction.Where should patient allergies be posted?Patients who are at risk for life-threatening (anaphylactic) reactions should wear a medical alert bracelet that identifies their allergy.Individuals with insect sting allergies should obtain an emergency sting kit and be taught how to self-inject epinephrine.
56Anaphylaxis Etiology and risk factors Life-threatening; can quickly deteriorate into shock, coma, and deathHistamine released causes bronchospasm, vasodilation, and increased capillary permeability, which causes fluid to leave the circulation and enter the tissues, causing shock from hypovolemiaSigns and symptoms of anaphylaxis include anxiety, wheezing and difficulty breathing, cyanosis, hives, facial edema, arthralgia, and hypotensionAnaphylaxis is an emergency situation, and the patient’s life depends on rapid intervention.What is the most common cause of anaphylaxis?
57Anaphylaxis Medical treatment Oxygen, intravenous epinephrine, aminophylline, diphenhydramine, and corticosteroidsDopamine to raise blood pressure; nebulized bronchodilator to relax bronchi and improve ventilationNursing careAdminister prescribed drugs, including oxygen, and monitor intravenous fluidsMonitor respirations, color, heart rate, and oxygen saturation until the patient is fully recoveredThe best care is to prevent anaphylaxis whenever possible by obtaining a history of allergies and taking precautions to protect the patient from substances (often drugs) that may trigger this reaction.
58Autoimmune Diseases Etiology and risk factors Immune system reacts against and destroys its own tissuesInitiated when tissue injury, infection, or malignancyGenetic factor: autoimmune diseases tend to be familialCan involve any tissue or organ systemCauses injury in three waysThe effect of antibodies on cell surfacesThrough the deposit of antigen-antibody complexesThrough the action of sensitized T cellsThe exact causes and pathology of most autoimmune diseases are poorly understood, but many of these disorders cause severe illness and death.What are examples of autoimmune diseases?
59Autoimmune Diseases Medical treatment Nursing care Corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs) are used to treat inflammationImmunosuppressive therapies may be tried to moderate the autoimmune responseNursing careAdequate rest, maintenance of optimal hydration and nutritional status, and prevention of infectionSupportive atmosphere important to enhance the patient’s coping skills and promote emotional health