Exam 2 Flashcards
classification of hyper sensitivity reactions
source of antigen, time (immediate or delayed), immunological mechanism causing tissue injury
types 1 2 and 3 sensitivities are
immediate, humoral immunity, and mediated by antibodies
type 4 sensitivity is
delayed, cell mediated immunity, and are mediated by T-cells and don’t involve antibodies
type 1 immune responce
IgE mediated reaction, from exposure to allergen, person becomes sensitized to allergen, IgE attaches to mast cells and basophils (chemical mediators of inflammation are released on second exposure), plasma cells produce the antibodies
type 1 reactions local
skin wheal localized (pale w/ fluid surrounded by reddened area) ex. mosquito bite
type 1 reactions systemic
anaphylaxis, occurs in minutes, can lead to airway obstruction and vascular collapse, initial itching and edema at site of exposure
manifestations of anaphylaxis
watery red eyes, bronchial edema (wheezing), dilated pupils, weak thread pulse, angioedema, cyanosis (first in finger tips and lips) shortness of breath
treatment of anaphylaxis
epinephrine, diphenhydramine (Benadryl), hydrocortisone, O2, IV fluids, H2 receptor blocker
type 1 atopic reactions
inherited tendency to become sensitized to environmental allergens, ex. allergic rhinitis asthma urticaria (hives) angioedema, atopic dermatitis
allergic rhinitis
hay fever, can be year round (dust mold animal dander), can be seasonal (pollen from grass weeds or trees), affects the eyes and respiratory tract (rhinorrhea= runny nose, lacrimation, mucosal swelling w/ airway obstruction, pruritus= itching)
atopic dermatitis
chronic skin disorder, increase IgE levels, skin lesions more generalized then wheal, blood vessels dilate and cause tissue edema
urticaria
cutaneous reaction to allergens, wheals (pink raised edematous pruritic), vary in shape/size, spread over body, after exposure to allergen, may last minutes or hours, hives
angioedema
localized skin lesions, like hives but deeper, effects eyelids lips tongue larynx hands/feet GI tract and genitalia
lab tests for type 1
eosinophil level elevated, eosinophils in sputum nasal and bronchial secretions, elevated IgE levels, ELISA test for IgE antibodies to allergens when skin cant be tested
type 2 immune response (examples and categories)
cytotoxic (cell toxic) and cytolytic (cell breakdown), Examples: hemolytic transfusion reaction, goodpasture syndrome, immune thrombocytopenic purpura, graves disease, RH incompatibility reaction, autoimmune and drug related hemolytic anemia
type 2 reactions (how it works)
tissue specific IgG/ IgM mediated, immunoglobulins attach to antigen on cell surface, mistakenly identifies normal cell as foreign and destroys target cell (normally WBC RBC or platelets), this antigen-antibody complex activates the complement system (results in cytolysis or phagocytosis)
type A blood is compatible with
type A or O
type B blood is compatible with
type B or O
type AB blood is compatible with
type A, B, AB, or O
type O blood is compatible with
only type O
Type O is the
universal donor
Type AB is the
Universal recipient
Incompatibility reaction (acute hemolytic reaction)
antibodies coat the foreign blood cells causing agglutination, this causes small blood vessels to be blocked which uses up clotting factors which can cause bleeding, within hours neutrophils and macrophages phagocytize the clumped cells
hemolytic transfusion reactions
as the cell dies it releases hemoglobin into the urine and plasma
manifestations of transfusion reaction
chills/fever, backache/ headache, flushing, apprehension, chest pain, increased pulse and RR, dyspnea, hypotension, hemoglobinuria, jaundice, dark urine, bleeding, acute kidney injury (increase BUN creatinine), shock, cardiac arrest
delayed hemolytic reaction
more than 24 hours after transfusion to 14 days after, fever chills mild jaundice and decreased hemoglobin, no acute treatment needed, may need another transfusion
febrile blood transfusion reaction
leucocytes incompatibility, occurs in minutes to hours, fever chills Nausea flushing tachycardia anxiety
bacterial infection from blood transfusion
caused by contaminated blood products, occurs in minutes to less than 24 hours, tachycardia hypotension fever chills and shock
allergic reaction from blood transfusion
hypersensitivity to plasma proteins in donors blood, occurs immediately or within 24 hours, mild urticaria itching flushing, can progress to anaphylaxis (hypotension, dyspnea, decreased O2 sat, flushing)
transfusion related acute lung injury TRALI reaction
reaction between transfused anti-leukocyte antibodies and recipients leukocytes leading to pulmonary inflammation and edema, can cause fever hypotension tachypnea dyspnea decreased O2 sat and frothy pinky sputum
circulatory overload reaction
fluid given faster than pt can tolerate, slow administration to pts at risk, administer furosemide (lasixs) between units, signs & symptoms include: cough dyspnea adventitious breath sounds, h/a, HPTN, increased HR and JVD
type 3 immune complex reactions
antigens combine w/ antibodies that are deposited in tissue or small blood vessels, they cause release of chemotactic factors that lead to inflammation and destruction of the involved tissues, can be local or systemic (immediate or delayed), common sites are kidneys skin joints blood vessels and lungs, associated with acute glomerular nephritis SLE and RA
type 4 hypersensitivity reaction
delayed reaction (contact dermatitis-tb test, microbial hypersensitivity reactions, transplant rejection), cell-mediated immune response, sensitized t lymphocytes attack antigens and release cytokines, 24- 48 hours for response to occur
signs and symptoms of contact dermatitis
inflamed red vascular lesions, itching, burning, stinging, scratching causes spread
latex allergies
can come into contact directly or through air, cross sensitivity to some foods (bananas kiwi avocados chestnuts potatoes tomatoes grapes hazelnuts peaches apricots), can be either type 1 or type 4 reaction, greater risk with multiple exposure family history hay fever asthma
autoimmunity
immune response against self, could be inherited tendency, typically starts with a trigger, if a person has one autoimmune disease they are more likely to have another
Microorganisms and Human Relationships
Mutual (Normal flora, relationship can be breeched by injury) and Opportunistic microorganisms
Pathogens cause disease in human host cells by:
Direct destruction of host cell by pathogen, interference with the host cell’s metabolic function, and rendering a cell dysfunctional by accumulation of pathogenic substances and toxins
Infection
A state of tissue destruction resulting from invasion of microorganisms
Pathogenicity
Virulence, Infectivity, Toxigenicity, Antigenicity, Antigenic Variability, Pathogenic Defense Mechanism, Coinfection, Superinfection
Type of Pathogens
Obligate- requires the host for metabolism and reproduction
Faculative- live on the host, but can survive independently EX: worms
Classes of Infectious Microorganisms
Bacteria, Viruses, Rickettsiae, Micoplasms, chlamydiae, Fungi, and Protozoa
Bacteria Class
Cocci, Bacilli, Spirochetes, Gram Stain
Positive Gram Stain
No decolorization with alcohol, infection of respiratory tract and soft tissues Ex: Steptococcus Pneumoniae
Negative Gram Stain
Decolorization with alcohol, infections of Genitourinary and GI tract Ex: E. Coli
Bacterial Resistance to Lines of Defense
Production of thick capsules of carbs or proteins, Exotoxins (proteins released during bacterial growth), and Endotoxins (released during lysis or destruction of the bacteria)
Complications of Infection
Septicemia (when microoganisms gain access to the blood and circulate throughout the body), Bacteremia (when septicemia is caused by bacteria), Septic Shock (process of systematic vasodilation due to severe infection, usually gram -, decreased BP, decreased O2 delivery)
Viral Disease
Requires a host cell, 6 phase of replication, latency (cold sores), not sensitive to antibiotics or normal defense mechanisms
Fungal Disease
large thick walled microoganisms, yeast/mold, mycoses-(diseases caused by fungi), Dermatophytes- (fungi that invades skin, hair, or nails)
Yeast- opportunistic, candida albicans
Modes of Transmission
direct contact, droplet transmission, airborne transmission, vector transmission
Local Manifestations of Infection
heat, incapacitation, pain, edema, redness, lymphadenitis, purulent exudate
Systemic Manifestations of Infection
Fever, weakness, headache, malaise, anorexia, nausea
Counter measures against Pathogenic Defenses
Live Virus (attenuated), Inactivated (killed), toxoid- purified toxins that have been chemically detoxified w/o loss of immunogenicity
Community-associated infections
An infection that is acquired by a person who has not been hospitalized or had a medical procedure within the past year
Healthcare-associated infections
Contracted in a hospital or institutional setting, were not present or incubating in the pt on admission, more difficult to treat because is often drug resistant, MRSA most common, prevent by using disinfectants and antiseptics
Pneumonia types
can be community required pneumonia, hospital acquired pneumonia, pneumococcal pneumonia, and viral pneumonia
pneumonia pathophysiology
infectious process, respiratory droplet spread, causes inflammation in the lungs, occurs commonly in the bronchioles interstitial lung tissues and/or the alveoli
pneumonia clinical manifestations
fever, chills, cough, sputum production, fatigue, loss of appetite, hemoptysis (cough up blood), dyspnea, tachypnea tachycardia, pleuritic pain, crackles in lungs
acute bronchitis
acute infection or inflammation of airways or bronchi, commonly follows viral illness, can hear wheezes or crackles in upper airways
treatment: aspirin humidity and cough suppression
anti-infective
any medication effective against pathogens, classified by susceptible organisms chemical structure and mechanism of action
empirically
to treat known or suspected infection by a particular organism
prophylactically
to prevent infection (ex. before surgery)
list beta lactam antibiotics
penicillins, cephalosporins, carbapenems, monobactams
list non-beta lactam antibiotics
macrolides, quinolones, aminoglycosides, tetracyclines, sulfonamides
drugs that inhibit cell wall synthesis
Penicillin, Cephalosporins, Carbapenems, Monobactams, and Vancomycin
drugs that inhibit protein synthesis
Macrolides, Ketolides, Tetracyclines, Aminoglycosides
drugs that inhibit bacterial DNA replication
Fluroquinolones and miscellaneous antibacterials (bacitracin, metronidazole (Flagyl), polylmyxin, rifampin, telithromycin)
drugs that inhibit folic acid production
sulfonamides
drugs that disrupt the fungal cell membrane
azoles
Methicillin-resistant Staphylococcus aureus (MRSA)
Resistant to certain antibiotics, At least 60% of MRSA infections resistant to penicillin, Most often acquired in hospital, Usually occurs in patients with weakened immune systems, Still sensitive to vancomycin, Ones that are resistant to vancomycin may have susceptibility to linezolid (Zyvox)
Vancomycin-resistant Enterococci (VRE)
Enterococci found in GI tract female genital tract wounds and pressure ulcers,Therapy options are limited: vancomycin is only antibiotic effective against multidrug-resistant VRE strains, Newer antibiotics are being used when resistant to vancomycin
natural penicillins
penicillin G (IM or IV) and penicillin V (PO use)
subgroups of penicillins
Aminopenicillins (amoxicillin, ampicillin), Extended-spectrum (eg. Ticarcillin IM or IV, piperacillin, ticarcillin, carbenicillin), Penicillinase-Resistant (cloxacillin, dicloxacillin, nafcillin, oxacillin)
chemicals that inhibit beta-lactamase
Clavulanic acid, Tazobactam, Sulbactam
These chemicals bind with beta-lactamase and prevent the enzyme from breaking down the penicillin, thus making the drug more effective
Penicillin–beta-lactamase inhibitor combination drugs
Ampicillin + sulbactam = Unasyn
Amoxicillin + clavulanic acid = Augmentin
Ticarcillin + clavulanic acid = Timentin
Piperacillin + tazobactam = Zosyn
penicillin indications
used to treat or prevent infections from gram + bacteria
penicillin adverse effects
risk for allergic reaction, cross sensitivity to other beta lactams, can cause N/v diarrhea bone marrow suppression and abdominal pain
penicillin interactions
NSAIDS, Oral contraceptives, warfarin
Cephalosporins
Similar to penicillin, Assess if there is an allergy to penicillin (cross-sensitivity), Five groups or generations,Well absorbed from the GI tract Metabolized in the liver excreted in the urine, Adverse Effects:
mild diarrhea abdominal cramps rash pruritus redness edema, Drug-to-Drug Interactions: Aminoglycosides oral anticoagulants ETOH (alcohol)
Cephalosporins: First generation
Good gram-positive coverage
Parenteral and PO forms
Examples: Cefazolin (Ancef), Cephalexin (Keflex)