sterilizing machines

Question 1

Steam Sterilization (AUTOCLAVE)

Answer 1

• Located in SPD
• Uses moist heat under pressure
• Increased pressure, increases temperature
• More effective
• Economical
• Safest
• not all instruments can be steamed
• Time - 15 to 30 mins
• Contact – steam must contact all surfaces
• Temperature (250 - 270F)
• Pressure (15-17psi for gravity sterilizers and 27-30 psi for pre vacuum)
• Moisture – acts as a catalyst
• Coagulates of cell proteins
• Air - Free from air: as it decreases the temperature and the penetration

Autoclave Cycle Buttons:
. Condition
. Exposure phase
. Exhaust
. Drying phase

Question 2

Ultrasonic cleaner

Answer 2

• cleaning machine used in the process that uses ultrasound to agitate a fluid container and its contents
  .Not considered as a disinfecting machine but for cleaning instruments
  . Uses cavitation
  . the formation of an empty space within a solid object or body. (bubbles)

Question 2

Plasma sterilization (STERRAD)

Answer 2

–used for moisture-and heat sensitive devices, such as cameras, scopes and light cords(Sterrad)
- Safer than ETO
- Hydrogen peroxide plasma gas
- Used for heat sensitive materials

Question 3

Frequent methods of sterilization

Answer 3

a) Steam under pressure (Autoclave)
b) Ethylene oxide (EO)
c) Activated glutaraldehyde (Cidex)
d) Plasma (Sterrad)
e) Gravity displacement
f) Pre-vacuum
g) Per acetic acid (Steris)
h) Ionizing radiation
i) Ozone gas
j) Chlorine gas
k) Vapor phase hydrogen peroxide (VPHP)

Question 4

Gravity Displacement Sterilizer

Answer 4

• Relies on gravity to displace air
• Uses steam
• Slower than pre vacuum sterilizer
• 250F / 30 min.

Question 5

Pre vacuum Sterilizer

Answer 5

• Vacuum system removes air reducing total time
• Bowie Dick test (for air entrapment)

Question 6

Flash sterilization (in sub sterile room)

Answer 6

• Sterilizing metal instruments with; wooden handles, plastic parts, rubber tubing, non porous and unwrapped instruments that have been dropped during the procedure
• Items are placed in an instrument tray
• Temp:
  . 270F
  . 3 to 10 mins

Question 7

Ethylene Oxide [EO] (in SPD)

Answer 7

. Gas sterilization used to sterilize heat or moisture sensitive instruments (does not melt items)
. Does not corrode, passes through woven materials
. Residual amount of distilled water should be left in instruments with lumen before sterilizing
. Effective against all microbes and spores
. Spores are hydrated with moisture
. Expensive; highly flammable
. Linked to cancer and reproductive problems
. Lengthy cycle process (16 hrs to 21 days)
. Greatest health exposure risk
* Monitoring of ETO
– Mechanical aeration used to decrease time to
8hrs.
– Chemical
* Tapes
– Biological
* Bacillus subtilis – most resistant to ETO
* Incubated @ 95-98.6C (35-37F)
* Can be read after 24 hrs.
* Use in each load

Question 8

Per acetic Acid

Answer 8

. STERIS Machine
. For endoscopes
. Expensive
. 30 mins.
. Found in the sub sterile room

Question 9

Ionizing Radiation

Answer 9

• Commercially used
• Uses cobalt 60 (radioactive isotope)
• Death of microbes and spores by disrupting their DNA

Question 10

Ozone gas

Question 11

Chlorine gas

Question 12

Vapor phase hydrogen peroxide (VPHP)