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Inflammation, Infection, Immunity Vocabulary • • • • • • • • • Allergen Antibodies Antigen Autoimmunity Bacteria Contamination Colonization Fungi lysozyme • • • • • • • • • Nosocomial Immunity Infection Inflammation Medical asepsis Sebum Surgical asepsis Virus Rickettsiae Protection • Natural barriers – Skin and mucous membranes – Sweat glands- lysozyme – Sebaceous glands—sebum – Immunoglobulin – Phagocytes – Cilia – Acidic gastric secretions – Normal bacterial flora First line of Defense • Intact skin provides a physical barrier against “foreign” invaders Second Line of Defense • Phagocytosis – Neutrophils – Monocytes • Inflammation Circulating phagocytes move toward vessel walls and begin to adhere to the vessel walls (pavementing). Through a process called diapedesis, they squeeze through intercellular junctions becoming part of the exudate and migrate to inflammatory lesions. 4 steps of Phagocytosis 1. Recognition of the target and its adherence to the phagocyte 2. Engulfment 3. Fusion with lysosomes within the phagocyte 4. Destruction of the target by lysosomal enzymes. Leukocytes – Three kinds of granulocytes • neutrophils • eosinophils • basophils – Two kinds of leukocytes without granules in their cytoplasm • lymphocytes • monocytes • Other important cells • Basophils –act similarly to mast cells • Platelets—stop bleeding if vascular injury has occurred • Mast cells– activate inflammatory response through degranulation and synthesis of mediators in response to stimuli The Inflammatory Process • Series of cellular changes that signal the body’s response to injury or infection. • Most of the essential components of the process are found in the circulation • Most of the early mediators of inflammation increase movement of plasma and blood cells from the circulation into the tissues surrounding the injury • These substances are collectively called “exudate.” • Superficial hallmarks of inflammation are: – Redness (rubor) – Swelling (tumor) – Heat (calor) – Pain (dolor) – Loss of function Actions in the Inflammatory Process Cellular injury--Trauma, mechanical injury Oxygen or nutrient deprevation Chemical agent Thermal injury Radiation • Hemodynamic changes – Vascular changes are immediate – Arterioles at injury site constrict briefly – Followed by dilation, increasing blood flow to the area – Increased pressure in microcirculation causes exudation of plasma and blood cells into the tissues leading to edema and swelling. – Blood remaining in circulation becomes more sluggish and viscous • WBC’s migrate to vessel walls and stick there (pavementing). • Biochemical mediators stimulate endothelial cells lining the capillaries, causing them to retract, leaving spaces between cell junctions • Leukocytes squeeze out • Vascular permeability continues throughout inflammatory process Chemical Mediators • Cytokines – Secreted by cells participating in the immune response – Function as messengers • Eicosanoids • Prostaglandins – Any of a large group of biologically active unsaturated fatty acids produced by the metabolism of arachidonic acids through the cyclooxygenase pathway. Local short-range hormones that are formed rapidly, act immediately and they decay or are destroyed. – Influence vasodilation, vascular permeability, bronchoconstriction, inhibition of gastric secretions, stimulation of neural receptors for pain curing tissue damage. – NSAIDS block the production of prostaglandins • Histamine – Substance produced from the amino acid histadine which causes dilation of blood vessels, increased secretion of acid by the stomach, smooth muscle constriction, mucus production, and itching. The release of histamine from the mast cells is a major component of type I hypersensitivity reactions, including asthma. • Leukotrienes – Any of a group of arachidonic acid metabolites that functions as a chemical mediator of inflammation. Synthesized in the cells in response to inflammation or tissue injury. Extremely powerful bronchoconstrictors and vasodilators and mediate the adverse vascular and broncial effects of systemic anaphylaxis. • Cortisol – Hormone produced by the adrenal cortex. – Anti-inflammatory – Slows the release of histamine, stabilized lysosomal membranes and prevents the influx of leukocytes, thus impeding the inflammatory process. Local vs Systemic Inflammation • Local – – – – – Heat Swelling Redness Pain Loss of function • Systemic – – – – – – Fever Headache Muscle aches Chills Sweating Leukocytosis SIRS • Systemic Inflammatory Response Syndrome – – – – – – – – Generalized inflammation occurs Threatens vital organs Damage endothelial lining of vessels Increases capillary permeability Hypotension Microemboli Blood shunting compromises organ perfusion Hypermetabolic state • Increased serum glucose – Termed Sepsis when confirmed infection diagnosed – MODS Wound Healing • End result of inflammation • Time dependent on severity, presence of infection, health of patient • Vitamin C, zinc protein and other deficiencies delay healing Inflammatory Phase • A) Immediate to 2-5 days • B) Hemostasis – Vasoconstriction – Platelet aggregation – Thromboplastin makes clot • C) Inflammation – Vasodilation – Phagocytosis Proliferative Phase • A) 2 days to 3 weeks • B) Granulation – Fibroblasts lay bed of collagen – Fills defect and produces new capillaries • C) Contraction – Wound edges pull together to reduce defect • D) Epithelialization – Crosses moist surface – Cell travel about 3 cm from point of origin in all directions Remodeling Phase • A) 3 weeks to 2 years • B) New collagen forms which increases tensile strength to wounds • C) Scar tissue is only 80 percent as strong as original tissue Healing by Intention • Primary – Clean surgical wounds • Secondary – Contaminated or infected wounds • Tertiary – Delayed primary closure Infection • A process involving invasion of body by micro-organisms that leads to tissue damage • Different from inflammation which is a nonspecific reaction to tissue injury • Specific process that causes injury • Infection leads to inflammation Infectious Agents Bacteria • One celled organisms • Rigid cell wall and gelatinous capsule protect from phagocytosis • Classified by shape, ability to take up stain, need for oxygen Bacteria cocci Bacilli • Rod shaped – Fusiform – spirochetes Bacteria • • • • • • • • • • • Staphylococcus - normally found on the skin, but can cause boils and pimples. Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for many serious infections that are sometimes fatal. Escherichia coli - normal inhabitant of the colon, hence called "coliform" bacteria E. coli O157:H7 is a virulent strain that produces toxins that can cause diarrhea, abdominal pain, and even kidney failure. Chlamydia - a sexually transmitted disease (STD) caused by the bacterium Chlamydia trachomatis. Over one million cases of chlamydia were reported in the United States in 2006.. Salmonella - frequent cause of food poisoning Vibrio cholerae - causes cholera, an infection of the small intestine characterized by watery diarrhea Treponema pallidum - a spiral-shaped (spirochete) bacteria that causes syphilis Neisseria gonorrhoeae - a Gram-negative coccus that causes gonorrhea, one of the most common sexually transmitted diseases Borrelia - a spirochete transmitted by ticks that causes Lyme disease (borreliosis). Mycobacterium tuberculosis - the cause of tuberculosis Yersinia pestis - causes bubonic plague, transferred by flea bites Bacillus anthracis - the organism that causes anthrax, characterized by black lesions. Viruses • Very small, cannot be seen with microscope • Cause significant disease in humans • Needs the host cells to replicate • Seldom possible to kill virus without harming host • Prevention via immunizations and hygiene Viral Illnesses • • • • • • • • • • • • • Common Cold is caused by a rhinovirus Influenza (Flu) Dengue fever is transmitted by bites from mosquitoes mainly in Southeast Asia and South America Acquired Immunodeficiency Syndrome (AIDS) is caused by the Human Immunodeficiency Virus (HIV). It is transmitted by sexual contact with an infected person or by sharing needles or syringes for drug injection. Hepatitis (inflammation of the liver, jaundice) Herpes (cold sores, and genital herpes) Rabies (transmitted by bites from infected bats, raccoons, dogs) Polio (may cause paralysis) Smallpox (eradicated from the world in 1977 through vaccination) Mumps Yellow Fever is a viral hemorrhagic fever transmitted by infected mosquitoes. Measles or rubella Warts caused by a virus may be treated at home with solutions and patches containing salicylic acid over several weeks, or in the doctor's office by freezing Fungi • Fungi include one-celled yeasts slightly bigger than bacteria, and multi-celled mushrooms and molds. Fungi do not have chlorophyll to make their own food, so they get their nutrition as parasites or by breaking down remains of dead plants or animals. Some fungi are poisonous (e.g., Amanita mushrooms), but some have beneficial uses. For example, Penicillium notatum produces the antibiotic penicillin and Saccharomyces cerevisiae is the yeast used to make bread rise and to brew beer. Fungal diseases are called mycoses Mycoses • Aspergillosis - infection of sinuses and lungs • Blastomycosis - skin and pulmonary infections • Candidiasis - cutaneous and vaginal infections. Candida albicans is the most common cause of vaginal yeast infections. • Coccidioidomycosis - may cause cough, chest pain, shortness of breath • Cryptococcosis - may be transmitted in pigeon droppings Fungi Protozoa • One celled organisms • More complex than bacteria • May form cysts that can protect them from harsh environments, allowing them to live outside a host for prolonged periods Protozoal diseases • • • • • • • • Malaria (transmitted by mosquitos) is most prevalent in Sub-Saharan Africa Leishmaniasis (transmitted by sandflies which are about one-third the size of mosquitoes) African trypanosomiasis (sleeping sickness transmitted by the tsetse fly) Amoebic dysentery Coccidiosis Cryptosporidiosis Giardial enteritis Toxoplasmosis Rickettsiae • • • • Between a virus and bacteria in size May be rods, cocci or pleomorphic Mulitply in the cells of host animals Transmitted to humans through bites of fleas and ticks • Diseases more prevalent in areas of poor sanitation and high rodent and insect populations Helminths • • • • • • Worms Found in soil and water Transmitted hand to mouth Infections generally in GI tract Pinworms most common, esp. in children Tapeworms in GI tract lead to weight loss and abdominal pain with bloating • Hookworms enter through soles of feet Pin worm • Hook worm larvae tracts Transmission of Infection 6 requirements of transmission of infection 1) Infectious agent 2) Reservoir 3) Portal of exit 4) Mode of transfer 5) Portal of entry 6) Susceptible host Signs and Symptoms of Infection • Local: Local signs of inflammation • Generalized: Pain, swollen lymph nodes, fever, elevated WBC • Infected individuals may be more infectious before symptoms arise. • Asymptomatic carriers may spread disease Types of Infection • Community acquired– – From day to day contact with society – Increased incidence with poverty, poor sanitation, overcrowding, resistant strains – Food borne • Salmonella, Hepatitis A, – STDs Community Acquired • Prevention – Hygiene – Immunization – Food handling laws – Screening – Cooking – Isolation – Vector control Hospital Acquired • Nosocomial– increased rates of morbidity and mortality • Prevention, prevention, prevention! • At risk patients – Anyone with non-intact skin – Anyone with tubes or catheters – Immune compromised – Weakened or in poor health – Poor nutritional status Precautions • Standard – Used with all patients – Wash hands before and after contact – Wear gloves when handling any body fluid • Table 2-1. Standard Precautions: Key Components • Handwashing (or using an antiseptic handrub) � After touching blood, body fluids, secretions, excretions and contaminated items Immediately after removing gloves Between patient contact Gloves � For contact with blood, body fluids, secretions and contaminated items � For contact with mucous membranes and nonintact skin Masks, goggles, face masks � Protect mucous membranes of eyes, nose and mouth when contact with blood and body fluids is likely • Gowns �Protect skin from blood or body fluid contact Prevent soiling of clothing during procedures that may involve contact with blood or body fluids Linen Handle soiled linen to prevent touching skin or mucous membranes �� Do not pre-rinse soiled linens in patient care areas Patient care equipment �� Handle soiled equipment in a manner to prevent contact with skin or mucous membranes and to prevent contamination of clothing or the environment �� Clean reusable equipment prior to reuse Environmental cleaning �� Routinely care, clean and disinfect equipment and furnishings in patient care areas Sharps �� Avoid recapping used needles �� Avoid removing used needles from disposable syringes �� Avoid bending, breaking or manipulating used needles by hand �� Place used sharps in puncture-resistant containers Patient resuscitation �� Use mouthpieces, resuscitation bags or other ventilation devices to avoid mouth-tomouth resuscitation Patient placement �� Place patients who contaminate the environment or cannot maintain appropriate hygiene in private rooms Airborne Precautions • • Airborne precautions include: Standard Precautions PLUS • Personal respiratory protection – • or – • N95 respirator Prior fit-testing that must be repeated annually and fit-check / seal-check prior to each use. Powered Air-Purifying Respirator (PAPR) Airborne Infection Isolation Room (AIIR) – At a minimum, AIIR rooms must: • • • • Provide negative pressure room with a minimum of 6 air exchanges per hour Exhaust directly to the outside or through HEPA (High Efficiency Particulate Air) filtration Airborne precautions apply to patients known or suspected to be infected with microorganisms transmitted by airborne droplet nuclei. • • Airborne Precautions • Airborne precautions are required to protect against airborne transmission of infectious agents. • Diseases requiring airborne precautions include, but are not limited to: Measles, Severe Acute Respiratory Syndrome (SARS), Varicella (chickenpox), and Mycobacterium tuberculosis. • Preventing airborne transmission requires personal respiratory protection and special ventilation and air handling. • How airborne transmission occurs: • Airborne transmission occurs through the dissemination of either: • airborne droplet nuclei (small-particles [5 micrograms or smaller] of evaporated droplets containing microorganisms that remain suspended in the air for long periods of time) or • dust particles that contain an infectious agent • Microorganisms carried by the airborne route can be widely dispersed by air currents and may become inhaled by a susceptible host in the same room or over a long distance form the source patient – depending on environmental factors such as temperature and ventilation • In addition to Standard Precautions, Droplet Precautions are required for patients known or suspected to have the following illnesses transmitted by large particle droplets. Common organisms/diseases which require Droplet Precautions include: Bacterial: • Invasive Hemophilus influenzae disease: meningitis, pneumonia (in infants and small children), epiglottitis. Invasive Neisseria meningitidis disease: meningitis, pneumonia, and bacteremia. Mycoplasma pneumonia Group A Streptococcal pharyngitis, pneumonia, or scarlet fever in infants and young children Viral • Influenza Adenovirus (requires Contact Precautions in addition) Mumps Parvovirus B19 Rubella Droplet precautions • • • • Private room Mask when less than 3 feet from patient Door may be open No special ventilation required Contact Precautions • Direct contact transmission involves skin to skin contact and physical transfer of microorganisms to a susceptible host from an infected or colonized person, such as occurs when personnel turn patients, bathe patients or perform other patient care activities that require physical contact. Direct contact can also occur between patients that may have physical contact with each other. • Contact Precautions are required if: • A patient is colonized and/or infected with multidrug-resistant organism. A multidrugresistant organism is an organism that is resistant to treatment with standard firstline antibiotics. A particular organism is identified as being potentially hazardous to others and/or to the ecology of the hospital environment because of its antibiogram, pathogenicity, virulence, or epidemiologic characteristics (i.e., VRE, MRSA). Contact precautions • Private room • Strict barrier precautions Asepsis • Medical – Clean technique – Hand hygiene • Surgical – Sterile technique Immunocompromised Patients • Decreased immunity to infection – AIDS – Transplant – Chemotherapy – Leukemia and aplastic anemia Immunity • Immune system body’s defense network • Provides adequate protection from most infections and diseases • Factors that compromise immunity: – Aging – Stress – Congenital defects – Therapeutic interventions – Malnourishment Innate vs Acquired Immunity • Innate – Present at birth – Not dependant on previous exposure – Non-specific defense mechanisms – Inflammatory response • Acquired – Develops after birth – Response to specific antigens – Depends on proper development and functioning of B and T lymphocytes Non-specific defenses • • • • Innate Physical and chemical Inflammation and phagocytosis Complement – A series of proteins that inhance inflammation and immunity • Pyrogen—released in inflammation and causes fever • Interferon—produced in viral infections Active Immunity • Acquired after direct contact with antigen – May be through illness or vaccination • Antibodies develop to the specific antigen • Antibodies retain memory • Quickly react when exposed later to same antigen Passive Immunity • From injection with immunglobulin or antiserum • Antibodies were produced by another individual • Temporary • Newborns have passive acquired immunity via breastmilk Organs of Immunity Antibody Mediated Immunity • Immediate • Initiated when antigen binds and interacts with antibody receptors on the surface of a mature B cell • B-cell is triggered into a sequence of cell division and differentiation steps • Result is the production of – Immunglobulin secreting plasma cells – Long-lived memory cells Antigens • Almost any biochemical • React with antibody or T-cell • Diverse ability to induce an immune response • Proteins and complex carbohydrates are very immunogenic • Nucleic acids and lipids poor immunogens • Some very small molecules are are not immunogenic—called haptens Antibodies Immunglobulins are serum glycproteins produced by plasma cells in response to a challenge by antigens. Antibodies—immunglobulins with specificity for a particular antigen Classes of Immunoglobulins • IgA—predominant antibody in normal body secretions • IgG—most abundant, crosses placental barrier to provide passive immunity to infant • IgM—largest immunoglobulin; first antibody produced during initial response to antigen • IgE—allergic reactions and parasitic infections; least common • IgD—located on surfaces of developing B lymphocytes. Antibodies • Neutralize bacterial toxins • Neutralize viruses • Opsonize bacteria to promote phagocytosis • Activate components of the inflammatory response Cell Mediated Immunity • Varieties of mature T cells – Memory cells- induce secondary immune response – Lymphokine-producing cells- transfer delayed hypersensitivity and secrete proteins that activate other cells such as macrophages – Cytotoxic cells- attack antigens directly and destroy cells that bear foreign antigens – Regulatory cells, primarily helper T—control cell mediated and humoral immune response – Suppressor cells- turn off the immune response when danger is past Cellular Immunity • Fights most viral and bacterial infections • Hinders growth of malignant cells • Responsible for rejection of transplanted organs Immunodefciency • Can be congenital or acquired • Result from problems with any phase of immunity: humoral, cell-mediated, vital mediators, problems with phagocytosis • Causes of Acquired Immune Deficiency: – Infection – Malignancy – Autoimmunity (e.g. SLE, RA) – Chronic disease (DM, renal dz) – Drugs – Aging – Stress – Malnutrition Nursing Care of the Immunocompromised Patient • • • • • • • • Prevent infection Small changes in body temp may be significant Avoid rectal thermometers Encourage adequate nutrition/hydration Hygiene TC&DB Protective Isolation when needed Patient and family education Allergies • • • • • • Hypersensitivity Atypical immune response Causative antigen called an allergen Inflammatory cascade Release of histamine Local manifestations vary according to allergen: urticaria, pruritus, conjuctivitis, rhinitis, laryngeal edema, GI cramps and malabsorption, angioedema. Nursing Care of the Patient with Allergies • • • • • Know the allergies Know allergic response Know current medications Pt education Avoid allergens Anaphylaxis • Life threatening • Histamine release – – – – Bronchospasm Vasodilation Increased capillary permeability Hypovolemic shock • Signs and symptoms – – – – – Increased anxiety Wheezing, dyspnea, cyanosis Hives, facial edema Arthralgia Hypotension Autoimmune Diseases • Poorly understood etiology • Ability to distinguish self from non-self hampered • Immune system attacks own tissue • Cause injury by – Effect of antibodies on cell surfaces – Deposition of antigen-antibody complexes – Action of sensitized T cells • Multiple Sclerosis—myelin sheath destruction • Rheumatoid arthritis– lining of joints • Diabetes type I—insulin secreting cells of pancreas • Grave’s disease—Thyroid • Systemic lupus erythematosus—multiple tissues Nursing Care • Medical interventions depend on the specific disease • Steroids and NSAIDS • Nursing Diagnoses – Risk for activity intolerance – Impaired skin integrity – Knowledge deficit – Chronic pain – Imbalanced nutrition risk