Aseptic Technique

presence of pathogens ± toxic products in tissues

Abscnece of patogencic microbes in tissues

Chemical agent that kills or inhibits pathogenic microorganisms - only for agents applied to the body (not into)

Chemical that kills microbes on inanimate objects

Removal of microorganisms but not necessarily spores

Complete elimination of microbial viability, including spores, by physical or chemical means

YES but not infected

• bacteria • local wound environment • local and systemic defence

• 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)

> 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

• 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

• 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

2-3hours after wound exposure/innoculation = decisive period • preventative ABx Tx only beneficial within the 1st 3 hours • after this time outcome decided

1 hour pre surgery - NO difference in infection rate with 5d course of post surgery ABx

Halstead

• surgeon prep • surgical instruments • patient prep • op theatre

• scrub suits, caps, shoes, facemask

• gowns, gloves

Put mask on

• Chlorhexidine (broad spec, variable action v virus, no action v spores, rapid initial kill, persistent residual activity, NOT inactivated by organic material, toxcity not usually a problem unless direct contact with nerves, ears or cornea) • Povidone Iodine (kills bacteria, viruses, funghu, not spores, requires 2 mins contact time, action decreased by organic material and hard water, use on mucosal surfaces and near open wounds, corrodes instruments, acute contact dermatitis and allergies) • Alcohol (ethyl or isopropyl, kills broad spec, enhances action of chlorhexidine and iodine, corrosive to instruments, non-toxic, avoid near open wounds as dissacates) • Sterrillium Alcohol (bactericidal, fungicidal, virucidal, TB, better for skin, no allergies, no scrubbing! v use water. do not mix with other hand creams/disinfectants)

• Open (sterile hands only eg. urinary catheter, central venous line) • Closed (surgical procedures, gloves must cover cuffs)

• chemical - biological (capsule of microbes, attempt to plate and grow after steralisation)

• Antiseptic scrub in prep room for min 5 mins or until no more dirt removed • move to theatre then repeat aseptic preparation and wipe off excess with alcohol • apply final soluation povidone-iodine, PI + alcohol or chlorhexidine + alcohol • sterile gloves applied • sterile single use applicator (chlorhexidine gluconate and isopropyl alcohol)

• Primary draping with single fenestrated or 4 field drapes - 2* draping including skin towels and ahesive drapes