Sterilisation, Preparation of the Patient and Preparation of the Surgeon Flashcards
Define sterilisation
destruction of all microorganisms on or in an object.
Define disinfection
anything less than sterilisation and may be high-, intermediate- or low-level depending on the range of microorganisms killed.
What pH detergent provides the best material compatibility profile and soil removal?
What is often added to assist in removing organic material?
Neutral
Enzymes (proteases)
What process do ultrasonic cleaning devices use?
Cavitation
(creates minute gas bubbles that implode on contact with surgical instruments, creating a vacuum that removes partical and debris)
What properties should the ideal packaging be? (5)
Permeable to steam
Resistant to heat/physical
Long lasting
Durable
Effective barrier to microorganisms
Can you think of some events that might result in contamination of stored surgical instruments? (8)
Damage to the packaging, such as tears
Packaging becoming wet
Type of packaging material
Storage conditions, i.e. open or closed shelves
Temperature
Humidity
Air movement and traffic
Level of contamination in the environment.
What are the autoclave time and temp for a gravity displacement autoclave?
30 minutes at 121°C
What are the autoclave time and temp for vacuum autoclave?
4 minutes at 132°C
How do Gravity-displacement autoclaves work?
Gravity-displacement autoclaves introduce steam under pressure. Being lighter than air, steam rises and forces air out of a valve at the bottom of the unit. The coldest air is therefore always being forced out of the bottom of the unit and is used to measure the temperature of the autoclave, confirming that sterilisation conditions are being met. The efficacy of sterilisation depends on steam coming into contact with all the items in the autoclave.
What does the efficacy of gravity displacement autoclaves rely on?
steam coming into contact with all the items in the autoclave.
How do pre vacuum autocalves work?
Pre-vacuum autoclaves use a pump to remove air from the chamber prior to the introduction of steam, leading to a rapid and uniform distribution of steam
What detects leaks and inadequate air removal in pre vacuum autoclaves?
A Bowie-Dick test is used to detect air leaks and inadequate air removal. This consists of testing the efficacy of sterilisation of folded cotton towels.
What is ethylene oxide?
colourless and odourless gas,
What is the boiling point of ethylene oxide?
10.5C
How does ethylene oxide sterilise?
It causes alkylation of proteins and nucleic acid, obstructing cell division and reproduction, and is used to sterilise medical equipment that is heat or moisture sensitive
What concentration should ethylene oxide be?
450-1200 mg/l
What temperature should ethylene oxide be?
37-63C
What humidity should ethylene oxide be?
40-80%
What is the exposure time of ethylene oxide?
1-6 hours
What reduces ethylene oxide flammability? (2)
mixed with carbon dioxide or hydrofluorocarbon