Aseptic Technique Flashcards
Define sepsis
presence of pathogens ± toxic products in tissues
Define asepsis
Abscnece of patogencic microbes in tissues
Define antiseptic
Chemical agent that kills or inhibits pathogenic microorganisms - only for agents applied to the body (not into)
Define disinfectant
Chemical that kills microbes on inanimate objects
Define disinfection
Removal of microorganisms but not necessarily spores
Define steralisation
Complete elimination of microbial viability, including spores, by physical or chemical means
Do all surgical wounds become contaminated?
YES but not infected
What are the 3 factors that affect surgical wound infection?
- bacteria
- local wound environment
- local and systemic defence
Give some bacterial factors that affect wound infection
- presence and growth
- no. of bacteria (>10^5/g = “infection”)
- type and virulence (capsules, toxins)
- duration of exposure
- timing of exposure (hot defences lowest within 1st 3 hours wound)
Give some surgical factors that affect wound infection
> surgical procuedure - duration (>90 mins = 2x risk of infection, GA time >60 mins every minute extra = 0.5% ^ risk) - patient and surgeon prep - type of surgery > surgical wound - dead space and seroma - foreign material - blood clots - devilatlised tissue
Give some patient factors that affect wound infection
- age (old >8yrs or young)
- nutrition +/-
- disease conditions (DM, renal failure, endocrinopathy, cancer, hypoalbumenaemia, trauma, inflam, immunodeficiency)
- therapy (anaesthetic agents, corticosteroids, chemo, radiotherapy, blood tranfusion, vasoconstrictors, surgery
How may wounds be contaminated? Give examples of surgeries that fall into each category
- Clean (non-traumatic, elective Sx, no inflam, no break in aseptic technique, NO entering GIT/resp/repro tract)
- cat/dog castrate
- bitch spey
- thyroidectomy
- lump removal - Clean-contaminated (GI/resp tract entered with no spillage, urogen/biliary tract enetered with no infection, minor aseptic technique breach)
- cat castrate
- clean Sx with minor aseptic technique breach
- gastrotomy/eneterotomy
- cystotomy - Contaminated (Gross GIT spillage, entracne to urogen/biliary tract if infected, fresh traumatic wound 4hrs)
- abscess, FB, rtaumatic wound, surgical extraction
What is the decisive period?
2-3hours after wound exposure/innoculation = decisive period
- preventative ABx Tx only beneficial within the 1st 3 hours
- after this time outcome decided
When is the optimum time to give preventative ABx?
1 hour pre surgery
- NO difference in infection rate with 5d course of post surgery ABx
Who came up with the principles of good surgical technique?
Halstead