Infection Control Flashcards
Defenses Against Infection
Microflora Acidic pH of skin Immune cells Inflammatory response Complement system- release of proteins that promote phagocytosis, the inflammatory response, and disruption of bacterial cell membranes
Microflora
A small number of bacteria and fungi normally reside in skin and digestive tract
Protect the body from pathogenic organisms
Contamination
presence of microbes on wound surface
normal
Colonization
presence of replicating microbes on wound surface
normal
Critical colonization
increasing wound bioburden reaches critical point and begins to adversely affect hos
abnormal
plateau or decline in wound status
Infection
replicating microbes invade viable body tissue
abnormal
decline in wound status
Wound healing =
(number of bacteria x bacterial virulent)+interaction between microbes/host resistance+ modifying factors
Modifying factors:
host’s overall health; presence of underlying pathologies, such as diabetes or peripheral vascular disease; steroid use; presence of nonviable tissue; and proper wound management
Adverse Effects of High Concentrations of Microbes
Compete with host cells for available oxygen and nutrients
Bacterial exotoxins may be cytotoxic
Bacterial endotoxins may activate host inflammatory processes
Wound infections delay and may prevent wound healing
Factors That Increase the Risk of Infection
Host characteristics
Local factors
Host characteristics:
Break in skin integrity Diabetes Malnutrition Obesity Steroid use Immuno-compromise Increased age
Local factors
Ischemia
Necrotic tissue
Wound debris
Chronic wounds
Inflamed Rubor
Well-defined erythemal border
Infected Rubor:
Poorly defined erythemal border
Disproportionate amount of erythema
Possible proximally directed erythemal streaking
Inflamed Calor:
Localized increase in temperature
Infected Calor:
Large localized increase in temperature over wide area
May be febrile
Inflamed Tumor
Small amount of edema
Proportionate to wound
Infected Tumor:
Edema is disproportionate to wound size
Periwound may be indurated
Inflamed Dolor
Pain proportionate to wound size/extent
Infected Dolor:
Increased pain
New-onset pain
Pain disproportionate to wound size/extent
Inflamed Functio Laesa
Temporary decrease in function of affected area
Infected Functio Laesa
Malaise Tachycardia Hypotension Altered mental status Altered function of affected area
Inflamed drainage:
Proportionate to
size/extent of wound
Thin consistency
Serous or serosanguinous
Infected drainage:
Disproportionate to size/extent of wound
Thick, purulent, creamy consistency
May be white, green, blue
May have distinctive odor
Inflamed decline in wound status:
Follows 3 phases of wound healing if treated appropriately
Infected decline in wound status:
Plateau in healing Granulation tissue: Decreased amount Friable Cobblestone-like Color change
Who is at risk for a silent infection?
Patients who are immunocompromised or have inadequate perfusion
Examples of silent infection:
Abscess
Patient with arterial insufficiency and gangrenous toe
Biofilms:
Communities of microorganisms attached to wound surface encased in a glycocalyx
Protected against harsh environments, antiseptics, and antimicrobials
May increase bacterial virulence and resistance
Where are biofilms found?
devitalized tissues, implanted devices, and within gastric mucosa
Gold standard for diagnosing wound infection:
tissue biopsy
Microbe ID Bacteria:
Unicellular Rigid cell wall Lack nuclear membrane Require external medium for growth Reproduce by cellular division
Most common skin and nail fungi
Tinea
Candida
Patients with increased risk
for fungal infection:
On antibiotics
Have immune system diseases
Have diabetes
Have moist, occluded areas of skin
Antimicrobial Agents
Destroy unicellular organisms
Used to treat infection or prophylactically
Antibacterials
Bactericidal
Bacteriostatic
Antifungals
Yeasts
Molds
Types of antimicrobials
penicillins cephalosporins erythromycins amino glycosides tetracycline quinolones sulfonamides
Sensitive
Bacteria unable to grow in the presence of a certain antimicrobial
Resistant
Bacteria that continue to multiply in the presence of a drug
May be natural or acquired
Nosocomial
Increased age Diabetes Immunosuppression Malnutrition Recent surgery Immobility/debility Large burns Prior antimicrobial use
Community Acquired
Prisons
Contact sports teams
Military
People with AIDS
MRSA
Can live hours to days on surfaces Spread by: Nosocomial: environmental contact Community: person to person Can cause cellulitis, osteomyelitis, abcess Rx: mupirocin
VRE
Commonly seen in surgical wounds and UTIs
Rx: ampicillin-amoxicillin
Causes of Resistant Bacteria
Misuse of antimicrobials in humans Prescribed without infection present 50% deemed unnecessary Wrong antimicrobial prescribed Taken incorrectly
Misuse of antimicrobials in animals
24.6 million pounds to livestock/yr in the U.S.
Build muscle faster
Banned in European Union
Adverse reactions:
Mild skin reactions, hives
Difficulty breathing, anaphylactic shock
Photosensitivity, hearing loss, fever
Hepatitis, kidney damage
Delayed sensitivity
Neomycin Gentamycin Bacitracin Lanolin-containing Don’t use for prolonged periods
Topical Antimicrobial Therapy
Types Ointments Creams Solutions Applied to wound surface Reapply every 8–24 hours
Antimicrobial-Impregnated Dressings
Silver, iodine Broad-spectrum antimicrobials Increase cost Overuse may contribute to resistance Must stay in contact with wound bed Lack of scientific evidence
Advantages of topical antimicrobial therapy:
Lower cost than systemic therapies
Reduce bacterial load
Effective in treating where circulation is compromised
Disadvantages of topical antimicrobial therapy:
Higher cost than nonantimicrobial agents
Need for frequent applications
Sensitivity or allergic reaction
Potential for resistance
Antiseptic Agents
Prevent infection by killing microorganisms
Proper uses
Surgical scrub, hand washing, cleansing intact skin
Advantages of systemic antimicrobial therapy:
Reduce bacterial load
Easy to provide
Maybe better adherence
Disadvantages of systemic antimicrobial therapy:
Adverse reactions More frequent/severe Resistance Missed doses Higher cost
Prevent Infections in Open Wounds
Hand washing
Universal precautions/Standard precaution
Avoid strike-through drainage, control excessive moisture (medium for bacteria)
Reduce bioburden
Clean technique
Reduce number of microorganisms present to decrease risk of transmission
Standard
Sterile technique
Only sterile equipment contacts patient’s wound Used for: Surgical debridement Severe burns Immunocompromised patients
Clean
free of gross contamination
Disinfect
to clean a surface with an antimicrobial
Sterile
environment free of microbes
Contamination
presence or anticipated presence of blood, wound fluid, or other potentially infectious waste
Proper Wound Care Procedures
Sequence wound procedures to minimize contamination
If multiple wounds, treat most infected wound last and change gloves in between wounds
Remove gloves and wash hands upon completion
Thoroughly disinfect treatment area after procedures
Properly dispose of infectious waste and sharps
Check expiration dates
Open supplies just prior to use
Seal remaining supplies
Store meds according to JCAHO standards
Keep wounds covered except during examination and procedure
Change dressings if contaminated or ineffective
