Sterilisation, preparation of the patient and preparation of the surgeon

Question 1

Define aseptic technique

Answer 1

A collection of mechanisms by which the surgeon strives to reduce the number of microorganisms present in the surgical wound, the overall aim being to reduce the incidence of surgical site infections

Question 2

Define sterilisation

Answer 2

The destruction of all microorganisms in or on an object

Question 3

Define disinfection

Answer 3

Anything less than sterilisation and may be high, intermediate or low level depending on the range of microorganism killed

Question 4

Describe the appropriate sterilisation for critical, semi-critical and non-critical items

Answer 4

Critical e.g. surgical instruments and implants = sterilised
Semi-critical = sterilised or high-disinfection
Non-critical = disinfected

Question 5

What is the sterility assurance level (SAL)?

Answer 5

The probability of a single viable microorganism occurring on an instrument after sterilisation i.e. an estimation of the lethality of the sterilisation process

Question 6

What value SAL is used for surgical instruments?

Answer 6

10-6 (one in a million chance of microbe survival)

Question 7

What pH detergent provides the best material compatibility profile and soil removal?

Answer 7

Neutral

Question 8

Which enzymes are often added to cleaning material to assist in removing organic material?

Answer 8

Proteases

Question 9

Name some features of ideal packaging material

Answer 9

• permeable to steam or gas
• resistant to heat and physical damage
• long-lasting
• durable
• an effective barrier to microorganisms

Question 10

What type of packaging are commonly used in practice?

Answer 10

Paper-plastic (ideally double wrapped)
non-woven polypropylene (good for large instruments or boxes)

Question 11

What are the benefits of instrument sterilisation boxes?

Answer 11

-robust
- allow a greater number of instruments to be stored in a single kit

Question 12

What ensures sterilisation boxes haven’t previously been opened after sterilisation?

Answer 12

Single-use plastic seals are clipped over the handles which need to be broken to open the box

Question 13

What may cause contamination of a sterilised instrument?

Answer 13

• damage to packaging
• packaging becoming wet
• type of packaging material
• storage conditions e.g. open vs closed shelves
• temperature
• humidity
• air movement and traffic
• level of environmental contamination
  (Time, although there is evidence to suggest that sterility is not lost over time)