Aseptic surgical technique 2 Flashcards
What is meant by the term disinfectant?
An agent that is lethal to vegetative organisms - not necessarily all of them though
Define the term antiseptic:
agent lethal to vegetative organisms but suitable for use IN living tissue (antiseptic can be a disinfectant but disinfectant is not necessarily an antiseptic)
Define the term bacteristatic:
agent that inhibits or arrests the growth of bacteria
Define the term bactericidal:
an agent that kills bacteria
Define the term cleansing:
removal of visible contamination from surfaces - often employs the use of a detergent
Define the term detergent:
a cleansing agent that acts on surfaces
Define the term sterile:
free from micro-organisms, Absolute term and only possible to attain on inanimate objects
Define the term sterilization:
complete destruction and removal of all forms of micro-organisms by use of physical or chemical agents - physical or chemical
Briefly describe how dry heat versus moist heat result in destruction:
Heat = denaturation or destruction of cellular proteins
Moist/wet heat = coagulation of critical cellular proteins
What is the effect of moisture on the time and temperature required?
Moisture reduces the time and temperature required (hastens denaturation of proteins by coagulating the cellular proteins)
Is boiling water considered to be a form of disinfecting or sterilization?
Destroy most vegetative forms of microbes - not effectively kill spores or microbes protected by dirt
Why is it not advisable to use boiling water for sharped edged instruments?
It will corrode them
What are the time and temperatures that are required for sterilization?
Routine instrument: 15 min at 121
Emergency: 3 min at 131
Linen packs: 30 min at 121
What is the shelf life of the following materials single wrap muslin (2 layer), double wrap muslin (4 layers), single wrap crepe paper, “steripeel:.?
Single wrap - 1 wk, 2d
Double wrap - 7 wk, 3 wk
Single wrap crepe paper - 8 wk, 3 wk
Steripeel - 1 y, 1 y
What is the importance of a sterilization indicator on a pack?
need to know how long ago the package was sterilized
What is a potential disadvantage of using dry heat and for what materials might this be used?
The temperatures and time that are required for penetration are significantly longer.
What is radiation sterilization of used for?
Used to heat sensitive pharmaceuticals, heat sensitive surgical materials (graft implants) and plastic wrapped disposable items (syringes, catheters, needles)
How fast is the effect of alcohol and how much residual effect do they have?
Bactericidal - have a rapid and immediate action however no residual effect
What is the spectrum of activity of alcohols?
Very effective against vegetative bacteria but poor against spores, fungi and viruses
Should alcohols be used on open wounds?
No. Cytotoxic to open wounds
What are some uses of alcohols?
Suitable for skin defatting and preliminary disinfection (rapidly bactericidal)
What is the free component of an iodine solution?
Active component of the iodophor - 10% iodophor solution provides 1% free iodine
What is the spectrum of activity of iodophors?
fungicidal, virucidal but not sporicidal
What is the residual activity of iodophors?
less than one hour
What are the uses for iodophors?
Iodine scrub/solution is effective as a skin disinfectant
Dilute solutions are suitable for wound lavage (high concentrations are known to be cytotoxic) and not as effective as chlorhexidine
What is the spectrum of activity chlorhexidine?
good against bacteria - variable anti-fungal and anti-viral
Outline the effect of the repeated use of chlorhexidine:
Binds to the stratum corneum and is not dislodged by alcohol - increased binding with repeated use - residual activity can last up to 2 days
What is the effect of chlorhexidine on organic matter?
Effectiveness variably affected by presence of blood, pus and organic matter
What is the uses of chlorhexidine?
2% stock solution in bottle
4% stock detergent
Surface disinfectant - diluted 1 in 4 to 0.5% has residual activity for several hours
suitable for wound lavage/tissue irrigation at low concentrations
Rank alcohol, chlorhexidine and povidone-iodine in order of immediate effect:
Alcohol > chlorhexidine > povidone-iodine
Rank alcohol, chlorhexidine and povidone-iodine in order of activity reduced by organic matter:
Alcohol > povidone-iodine > chlorhexidine
Rank alcohol, chlorhexidine and povidone-iodine in order of activity reduced by residual activity:
Chlorhexidine > povidone-iodine > alcohol
What is the activity of QAC’s?
bactericidal activity - fungicidal and protozoa
What is the effect of organic matter on QAC’s?
They are inactivated by the presence of organic matter
Are there any substances that QAC’s are incompatible with?
Inactivated by soaps and anionic compounds
What is the main use of QAC’s?
primarily used for inanimate objects, table, floor cleaners, utensils
What is the spectrum of activity for the aldehydes?
Bactericidal, fungicidal, sporicidal, and virucidal - however exposure times vary for these activities
What is the effect of organic matter on the aldehydes?
These are not affected by organic matter
What is a potential toxicity risk that is associated with the aldehydes?
Inhalation can lead to toxicity if ventilation is poor
How are the aldehydes stored?
The aldehydes are most effective in alkaline environments however their shelf life is greatly reduced at these pHs - hence they come in an acidic solution which is activated to an alkaline at time of use
What is the use of the aldehydes?
surface disinfection and sterilisation of instruments that are not suitable for other methods (e.g. fiberoptic)
What is the spectrum of activity of sodium hypo-chlorinate?
Bactericidal, virucidal and fungicidal - no residual activity
Under what circumstances is sodium hypochlorinate incompatible?
Very low temperatures and presence of ammonium compounds
What are the uses of sodium hypochlorinate?
Dinfection of inanimate objects
What is the spectrum of activity of ethylene oxide?
Excellent spectrum of activity (gram positive and gram negative)
What is the effect of organic matter on ethylene oxide?
Activity is not affected by presence of organic matter
What is incompatible with the use of ethylene oxide?
May damage rubber and plastic objects
Any polyvinyl chloride object previously sterilized by radiation should not be resterilised with ethylene oxide as it can result in formation of a highly toxic carcinogen.
What should ethylene oxide be used on?
almost anything can be sterilised with ethylene oxide - usually reserved for things that are unable to be steam sterilised.
What is the shelf life of things that have been sterilized with ethylene oxide?
one year for plastic packaged items (longer than steam)
What is the spectrum of activity of hydrogen gas plasma?
Effective against broad range of items
What wrapping is required for hydrogen peroxide?
Special Tyvek wrapping is required
What are the two main phases of sterilization required for hydrogen peroxide gas plasma?
- Diffusion - aqueous solution of hydrogen peroxide injected into a chamber
- Gas phase - hydrogen peroxide vapor is broken down into free radicles which then react to kill the micro-organism
What is the effect of organic matter on gas plasma activity?
Activity is not affected by the presence of organic matter although items must be clean for contact
Is their any incompatibilities regarding hydrogen peroxide?
No incompatibilities however items need to be dry
What is the shelf life of something that has been sterilized by hydrogen peroxide gas plasma?
Shelf life of up to one year
