Moist Heat Sterilisation

Question 1

What instrument is moist heat sterilisation carried out in?

Answer 1

An autoclave

Question 2

Autoclaves use __ _______ steam

Answer 2

dry saturated

Question 3

What is saturated steam?

Answer 3

in thermal equilibrium with the water which produced it (steam on phase boundary)

Question 4

What is dry steam?

Answer 4

Water vapour, no liquid water

Question 5

Is superheated steam an efficient sterilising agent?

Answer 5

oh HELL NAWWW!

Question 6

If steam contains air, it will be at a _____ temperature than pure steam

Answer 6

lower

Question 7

Adverse effects of air on steam:

Answer 7

• air can be trapped in porous loads
• air is a poor conductor of heat and inhibits heat flow
• air reduces steam temperature at a given pressure (not saturated)
• the sterilisation temperature will not be achieved

Question 8

Reference conditions for steam sterilisation.

What are other possible conditions?

Answer 8

121 degrees for 15 mins at 15 PSI
126 degrees for 10 mins at 20 PSI
134 degrees for 3 mins at 30 PSI

Question 9

What are the types of autoclaves for non porous and porous loads?

Answer 9

Non-porous: Downward displacement

Porous: High pre-vacuum (HPV) sterilisers

Question 10

What is the process stages for moist heat sterilisation?

Answer 10

• air removal and steam admission
• heating up and sterilisation stage
• drying/ cooling

Question 11

Porous loads requires what kind of autoclave?

Answer 11

high pre-vacuum steriliser

Question 12

What are the conditions for HPV sterilisers?

Answer 12

134 degrees for 3 mins at 30 PSI which requires contact between steam and materials

Question 13

What products can you use HPV sterilisers for?

Answer 13

• dressings
• gowns
• packaging materials permeable to steam and air