Wound Infection Flashcards
What is an Acute Wound?
A wound with an aetiology that occurs suddenly, but then heals in a timely manner
What is a Chronic wound?
A wound that has a slow progression through the wound healing stages due to intrinsic or extrinsic factors
Which stages of wound healing are the main points of disruption for chronic wounds?
- Inflammation
- Proliferation
True or false: Chronic wounds occur most with primary intention wounds.
False - Secondary Intention
What Intrinsic Factors influence wound healing?
- Nutrition - Calories / Nutrients needed for cell proliferation
- Concurrent Disease
- PAD
- Age
- Immunosuppresion / Drugs
- Systemic Infection
- Substance Abuse
- Hydration - resulting in imbalance of electrolytes which impairs cell function
What extrinsic factors influence wound healing?
- Pressure / Mechanical Stress
- Micro-environment
- Bacterial burden / Foreign bodies
- Size of wound
- Presence of necrotic tissue / slough
What main nutrients are important for wound healing?
- Protein
- Vitamin A
- Zinc
- Iron
Why is Protein important for wound healing?
Protein deficiency inhibits normal protein synthesis and wound healing. Immune response is diminished and matrix formation is delayed
Why is Vitamin A important for wound healing?
Promotes epithelialisation and granulation of healing wounds
Why is Zinc important for wound healing?
Plays an important role in the synthesis of collagen formatoin, epithelialisation ann cell proliferation
Why is Iron important for wound healing?
- Essential for collagen formation
- Anaemia results in decreased transportation of oxygen to damaged tissue
What is Hyperglycaemia?
High levels of sugar or glucose in the blood
How can Hyperglycaemia affect wound healing?
- Impairs cell wall rigidity, meaning decreased blood flow through vessels, meaning less nutrients and oxygen are transported to wound site
- This leads to prolonged inflammatory stage due to delayed macrophage introduction, and diminished leukocyte migration to wound.
How does infection of a wound delay the healing process?
- Prolonged inflammatory stage
- Depleting the components of the complement cascade
- Disrupting the clotting mechanism
What are the five stages of the Wound Infection Continuum?
- Contamination
- Colonisation
- Local Infection
- Spreading Infection
- Systemic Infection
What is the Contamination stage of wound infection?
- Open wound is contaminated with non-proliferating microbes
What is the Colonisation stage of wound infection?
- Limited Proliferation of microbes within the wound
- Host defence keeps these in check - no harm done
What is the Local Infection stage of wound healing?
- Proliferation of microbes increases to extent that host defences cannot tolerate the bioburden
What is the Spreading Infection stage of wound infection?
- Microbes have proliferated and spread to surrounding tissue outside of the wound
What is the Systemic Infection stage of wound infection?
- Microbes have spread throughout the body via the vascular or lymphatic systems
Through what stages of the Wound Infection Continuum would a biofilm occur?
- Local Infection -> Systemic Infection
What is a Biofilm?
- Structured clusters of bacterial cells enclosed in a matrix attached to the surface of a wound
- Appear to facilitate the survival of bacterial pathogens - there is an increasing tolerance to antibiotics
Are Biofilms visible to the naked eye?
No
What types or organisms are from the Gram Positive cocci Pathogen?
- Staphylococci Aureus / MRSA
- Beta Haemolytic Streptococci
- Enterococci Corynebacterium
What types of organisms are from the Gram Negative Aerobic rods Pathogen?
- Pseudomonas
- Aeruginosa
What types of organisms are from the Gram Negative Facultative rods Pathogen?
- Escherichia Coli
- Enterobacter Species
- Proteus Species
What types are organisms are from the Anaerobes pathogen?
- Bacteroides
- Clostridium
What types of organisms are from the Fungi pathogen?
- Yeasts
- Aspergillus
What types of bacteria are normally present of wounds?
- A flora of Gram +ve and -ve aerobic, or anaerobic bacteria
What bacteria is found in higher percentage of wounds under a month old?
Gram +ve bacteria
What bacteria is found in higher percentages in wounds older than a month old?
Gram -ve and anaerobes
Golden-yellow purulent discharge is a clinical sympton of which bacteria?
Staphylococcus aureus
Beefy red, friable and painful wounds are a clinical symptom of which type of bacteria?
- Streptococcus
Bright green wound with strong sweet malodour is a clinical symtom of which bacteria?
- Pseudomonas aeruginosa
How are wound infections diagnosed?
- Clinical Observations / Presentation of wound
- Swab only to be used to determine TYPE of infection to determine treatment - NOT FOR ASSESSING WHETHER INFECTION IS PRESENT
What are the classic signs and symptoms of Infection?
- Erythema
- Local warmth
- Swelling
- Purulent discharge
- New / Increasing pain
- Increasing malodour
- Delayed wound healing beyond normal expectations
What are signs of spreading infections?
- Patient attitude - change in appetite, focus etc.
- Sepsis
- Cellulitis
- Osteomyelitis
What is Cellulitis?
- Bacteria (or their products) have invaded surrounding tissue to a wound causing acute, diffuse inflammation and infection of skin and underlying subcutaneous tissue
What is Osteomyelitis?
- Bone infection
- Clinical presentation usually ‘sausage toe’
What factors need to be taken into account for Infection Control?
- ANTT is essential
- Regular and effective hand hygeine
- Appropriate use of sterile / non-sterile gloves
- PPE
- Clean Environment
- Effective waste / sharp disposal
How are wound infections best managed?
- Minimising factors that increase infection risk
- Infection control procedures
- Improve bed/margins of the wound (managing exudate, removal of slough/necrotic tissue)
- Provide education to patient / carers
- Regular re-assessment
What are the key anti-microbial dressings used for dressing infected wounds?
- Iodene
- Silver
- Honey
- PMBH (Polyhexamethylene biguanide
