Infection Flashcards
What are the three things required for establishment of a wound infection?
- Sufficient dose of pathogenic microorganisms
- A suitable microbial nutrient medium
- Impairment of natural host defenses
What is asepsis?
Prevention of wound contamination
What is antisepsis?
Killing bacteria that are already present
What harm does surgery do?
- A surgical incision is a wound: tissue trauma
- Surgery must be performed in such a way as to minimise trauma
Can can trauma manifest into?
- Haemorrhage
- Infection
- Swelling
- Loss of function
What may infection be due to?
- Pre-existing tissue contamination
- Surgical exposure of tissues to contamination
- Relative or absolute immunodeficiency
What are some predisposing factors to surgical wound infection?
- Systemically compromised patient
- Tissue hypoxia
- Tissue trauma
- Inadequate debridement
- Prolonged tissue exposure to the environment
- Foreign material in the wound
- Haematoma ( inadequate haemostasis + dead space)
- Presence of resistant organisms in the environment
Where can the source of self infection/ cross infection come from?
- Operative area
- Operative personnel
- Airbourne
- Equipment
- Post-op area
What factors influence the battle between contaminants and the host’s defences?
- Patient Factors
- Surgeon Factors
- Environmental Factors
Describe what patient factors are…
Who we do it to:
- Age
- Health status
- Low body weight - can become hypothermic
- Dermatitis at site
- Propensity to lick and scratch wounds
- Lack of compliance with dressings
- Obesity
- Chemotherapy
- Corticosteroids
Describe what surgeon factors are…
How we do it
- Disruption of local blood flow
- Tissue trauma
- Blood clots act as growth medium
- Foreign material e.g. sutures
- Electrocautery
- Creation of dead space
- Wicking of bacteria by multifilament sutures
- Long anaesthetic periods
- Drying of tissues
- Thermal damage from drills etc.
Describe what environmental factors are…
Where we do it
- Theatre cleanliness
- Theatre air flow
- Theatre traffic
- Hospital and ward cleanliness
- Skin clipping
- Skin disinfection
- Instrument sterility
- Draping
- Gowning and gloving
- Nosocomial infection
- Sink water sterility
When should prophylactic antibiotics be given?
- Long surgeries
- Implant surgeries
- Contaminated/ dirty surgeries
How should prophylactic antibiotics be given?
- High dose IV
- First generation cephalosporin or penicillin G
- At induction, blood levels are high at surgery
- Repeat after 90 minutes
