Infection Flashcards
What is nosocomial infection?
Infection acquired after admission to a health care facility that was not present or incubating at the time of admission
What is in the first line of defense?
Nonspecific Defenses
Skin, mouth, eye, respiratory tract, urinary tract, GI, vagina
Normal flow out unless normal flora disrupted.
What is an infection?
- Invasion of body tissue by a microorganism and its subsequent proliferation there
- causes damage to host tissue
What are ex of third line of defense?
- Lymphocytes
- antibodies
What are ex of second line of defense?
- phagocytic wt blood cells
- antimicrobial proteins
- inflammatory response
What are ex of first line of defense?
- skin
- mucous membranes
- secretions of skin and mucous membranes
What are 2 body defenses against infection?
- Nonspecific defenses: protect prs againt all microorganisms regardless of prior exposure
- Specific defenses: r/t immune sys. Respond to foreign protein in the body called antigens
Tissue injury caused by physical/chemical agent effects?
- Capillary widening => increased blood flow => heat
- Increased permeability => fluid release into tissues => redness
=> swelling - Attraction of leukocytes => extravasation of leukocytes to site of injury => tenderness
- systemic response => fever and proliferation of leukocytes => pain
What initiates inflammatory response?
Damage to host cells => first response to injury
=> local response
What are three phases of nonspecific defenses?
- Vascular and cellular responses
- Exudate production
- Reparative phase
What is the vascular and cellular responses?
- Damaged cells release chemical
- Fluid and WBCs (phagocytes) leak into tissues (edema and elevated WBCs)
What are the chemicals released in phase 1?
Histamine, bradykinin, prostaglandins
- b.v. to dilate
- more blood flow to injured area => redness, heat
What causes pain in phase 1?
- Pressure of accumulating fluid on local nerve endings
- Stimulation of nociceptors by prostaglandins
What consists of inflammatory exudate?
Inflammatory exudate => fluid escaped from b.v., dead and live phagocytic cells, dead bacteria, dead tissue cells
What are the exudate production?
- Serous
- Serousanguinous
- Sanguinous
- Purelent.
What happens in phase three?
Repair injured tissues
- Scar tissue formation and remodeling (
What is collagen synthesis?
Ongoing to strengthen tissue
What are clinical signs of inflammation?
- erythema/redness
- heat
- edema/swelling
- pain or tenderness
- exudate production (maybe
- loss of fct (if severe)
What ex could cause loss of fct?
Edema or mucus production in airway => alter gas exchange => hypoxia
What are the specific defenses?
Immune sys recognizes and respond to foreign proteins (antigens) in body
How immune sys fct?
- Macrophages swallow dead, dying cells or bacteria
- leave behind parts of invading bacteria (antigens)
- Body attacks antigens
- B-lymphocytes (defensive WBCs) => make antibodies to attack
- T-lymphocytes (memory cells) go into action quickly if body encounter same bacteria.
- When antigens detect, B-lymphocyte produce antibodies
What is active immunity?
Body make own antibodies in response to antigen
What is natural active immunity?
From contact with the disease => dev of the disease
- Lifelong
What is artificial active immunity?
Vaccination introduce disease => make antigen => stimualte immune sys => T-lymphocytes + antibodies but not produce disease
What is passive (acquired) immunity?
Provides temporary protection against disease-producing antigens
- Antibodies from one source transferred to host
What is natural immunity?
Antibodies from the immune mother through placenta or in colostrum
- Last 6 m to 1 y
What is artificial immunity?
Admin of antibodies from animal or other prs by injection
- Immune serum used as preventative measure after pathogen exposure to stop illness dev (rabies, hepatitis A)
- Last 2-3+ wks
What is a local infection?
- Not affect whole body
- Not in bloodstream
- Limited to outer surface of body (ex: infected wound)
- may be internal (pneumonia, UTI)
What is systemic infection?
Affect entire body of single organ or part
- Affect bloodstream
- Symptoms => whole body (pathogen thorughout whole body rather than concentrated in one area)
- may dev after failed treatment localized infection
- can be fatal
What is bacteremia?
Culture of prs blood => bacteria
Sepsis?
Bacteremia => systemic symptoms
What are clinical manifestations of local infection?
*inflammation & acute infection BUT inflammation not mean infection
- erythema/redness
- heat
- edema / swelling
- pain/tenderness
- may have exudate (purulent, pus)
- severe => loss of fct
- fever: only systemic symptom caused by local infection
What are clinical manifestations of systemic infection?
- Fever
- Fatigue
- Body aches
- Tachycardia and tachypnea
- N&V
- Anorexia
- Weakness, decreased energy
- Lymph nodes that drain the area of infection often become enlarged, swollen, and tender during palpation
What does infection in older adult entail?
- typical symptoms not present sometimes: fever, pain and swelling
Atypical: change in behaviour (new/increased confusion, incontinence or agitation)
Often dx when infection advanced