Aseptic surgical technique

Question 1

What is meant by the term disinfectant?

Answer 1

an agent that is lethal to vegetative organisms

Question 2

What is meant by the term antiseptic?

Answer 2

an agent that is lethal to vegetative organisms but is suitable for use within living tissue

Question 3

What is meant by the term bacteristatic?

Answer 3

agent that inhibits or arrests the growth of bacteria

Question 4

What is meant by a bactericidal?

Answer 4

an agent that kills bacteria

Question 5

What is cleansing?

Answer 5

removal of visible contaminant from surfaces - it often employs the use of a detergent

Question 6

What is a detergent?

Answer 6

a cleansing agent that acts upon surfaces

Question 7

What is the meaning of sterile?

Answer 7

free from micro-organisms and only possible to attain on inanimate surfaces

Question 8

What is meant by the term sterilisation?

Answer 8

free from microorganisms - absolute term and only possible on inanimate objects

Question 9

Are spores more resistant to a dry heat or a wet heat?

Answer 9

Spores are more resistant to a dry heat than a wet heat

Question 10

Is boiling water an effective means of sterilisation?

Answer 10

It is considered to be a form of disinfectant rather than a method of sterilisation.

Question 11

Steam under pressure is able to sterilise, why is this?

Answer 11

Boiling water will not sterilise due to its relatively low temperature -saturated steam under pressure is able to produce the greater temperatures that are required for sterilisation

Question 12

Briefly describe the temperature and time in the autoclave for routine instrument sterilisation, emergency (flash) and linen packs:

Answer 12

Routine instrument - 15 min @ 121 degrees
Emergency flash - 3 min @ 134 degrees
Linen packs - 30 min @ 121 degrees

Question 13

How does dry heat kills organisms?

Answer 13

Kills organisms by oxidation and removal of water

Question 14

What is a disadvantage of using dry heat?

Answer 14

Temperature and time required are significantly higher and longer than those required for moist heat sterilisation

Question 15

When would radiation be useful as a technique for sterilisation?

Answer 15

Useful for heat sensitive pharmaceuticals, heat sensitive surgical materials (graft implants) and plastic wrapped disposable items (syringes, catheters)

Question 16

Briefly describe the activity of alcohols:

Answer 16

Bactericidal, rapid and immediate effect bu no residual. They are very effective against bacteria but poor against spores, fungi and viruses

Question 17

The effect of alcohols on organic material:

Answer 17

They are affected by the presence of proteinaceous material

Question 18

Provide some potential uses for alcohols:

Answer 18

Suitable for skin defatting and preliminary disinfection (rapidly bactericidal)

Question 19

Briefly describe the activity of the Iodophors:

Answer 19

They are rapidly bactericidal in their actions and have residual activity of about an hour. They are fungicidal and virucidal at high concentration but not sporicidal

Question 20

Does organic matter impact upon the effectiveness of iodophors?

Answer 20

yes the activity of them is reduced by the presence of organic matter

Question 21

What are some potential uses for iodophors?

Answer 21

Iodine scrub/solution is effective as a skin disinfectant. Dilute solutions 0.01-1% (higher concentrations are cytotoxic) can be used for wound lavage

Question 22

Briefly describe the activity of chlorhexidine:

Answer 22

Good broad spectrum bactericidal (only sporadical at 1%) and has a greater initial reduction in numbers than the iodophors.

Question 23

What is the effect of increased organic matter on Chlorhexidine?

Answer 23

Increased organic matter reduces the effectiveness of chlorhexidine

Question 24

What are some potential uses for chlorhexidine?

Answer 24

Surgical scrub - comes as a stock 4% detergent

Comes as a 2% stock solution in a bottle

Question 25

Rank the disinfectants (alcohol, chlorhexidine and povidone-iodine) in order of greatest immediate effect, activity reduced by organic matter and residual activity:

Answer 25

Greatest immediate effect: alcohol > chlorhexidine > povidone-iodine

Activity reduced by organic matter: alcohol > povidone-iodine > chlorhexidine

Residual activity: Chlorhexidine > povidone-iodine > alcohol