• Here are the objectives for the presentation•  • At the end of the presentation the student should be able to:•  • 1. Define asepsis and aseptic technique.•  • 2. The importance of caring for equipment and machine.•  • 3. Identify anesthetic equipment and machines used in the

operating room.•  • 4. Have an understanding of various methods of sterilization.•  • 5. Identify sterilization method appropriate for equipment and

supplies used.•  • 6. Have a basic understanding of how to care for the anesthetic

machine•  • 7. Participate in question and answer segment. 

Sterilization falls into the following categories:

High temp /pressure sterilization/ autoclave

Chemical sterilizationRadiation sterilization

Is the safest, oldest , most cost effective method of sterilization.

Steam reaches 121- 1480C (2500 -3000F) at pressure of 15 psi

Sterilization period is dependent on temperature and size of load ranging from 10 – 60 min.

The fastest steam sterilization used is flash sterilization.

It is generally a high speed steam sterilization of unwrapped instrument or devices for 3 – 10 min at 1320 C saturated steam.

This is only intended for use in hospital operating rooms for urgently needed equipment.

In steam autoclave, microorganisms are killed by heat accelerated by the addition of moisture.

Pressure greater than atmospheric pressure is needed to increase the temperature of steam for thermal destruction of microbes.

Any living thing will be killed when exposed to saturated steam at 1200

C (2500 F) longer than 15 minutes.

As temperature increases, exposure time maybe decrease.

Low temperature plasma sterilization was introduced to fill the gap between autoclave (high temperature steam sterilization and EtO gas sterilization - which leaves a toxic residue).

It is a low temperature, nontoxic, but fairly expensive method of sterilization.

Hydrogen peroxide is activated to create a reactive plasma or vapour

The operating temperature ranges from 450 - 500 C.

The cycle time ranges from 450 - 700 C min depending on size of system.

Hydrogen peroxide is a known antimicrobial that is capable of inactivating resisting bacterial spores.

Sterilization occurs in a low moisture environment.

The system is best suited to sterilize heat sensitive medical equipment such as endoscopic equipment (such as fiber optic laryngoscopes).

This is another common, low temperature sterilizing system.

It utilizes peracetic acid a chemical biocidal agent to kill micro-organism.

It is a low temperature system, with temperature ranging from 500 - 560 C.

The peracetic acid is combine with sterile water that flows into the sterilization chamber.

Sterilization time is 12 mins

Repetitive sterile water rinses to complete the process.

The entire process is completely in less than 30 minutes for a standard cycle.

Peracetic acid is an oxidant.

It is acetic acid plus an extra oxygen atom that reacts with most cellular components to destroy cells.

Only immersible instruments can be used with this method , and only a few instruments can be sterilized at any one time.

It is used as a high level disinfectant

Used fro processing heat sensitive supplies and equipment

Provides high level disinfection in 12 minutes at room temperature (200C )

Requires no activation and has minimal odor.

Cidex OPa solution is replacing Cidex and Cidex Plus due to their toxicity

Used on surgical cameras (endoscopes)

The items to be disinfected must be thoroughly cleaned and dried prior to immersion.

Items must be thoroughly rinised with sterile water prior to use.

EtO gas was introduced in the 1950’s

It is an effective, low temperature chemical sterilization method.

It takes longer than steam sterilization, 16 – 18 hrs for a complete cycle.

Temperature reached during the cycle is about 50 – 60 0C

It kills micro-organism including spores.

It must have direct contact with microbes to be sterilized.

It must be used in a n explosion-proof, controlled environment

Wrapped items must be aerated after sterilization.

Aeration time maybe long and is needed to make them non-flammable for use in healthcare facilities.

In general EtO gas is reliable and safe agent for sterilization when handled properly. OSHA also has special handling guideline for EtO.

EtO is used for sterilizing items that are heat of moisture sensitive.

Known disinfectant in the medical industry.

Provides sterilization after 10 hrs of use (but the manufactures has not verified this claim)

It is 3.4% alkaline glutaraldehyde solution (Plus)

It has a reusable life of up to 28 days (we do 2 weeks)

Cidex 2.4% alkaline glutaraldehde solution

It achieves high level disinfection in 45 minutes at 250 C

Has a reusable life of 14 days.

* Cidex products are being withdrawn from the market especially in European market due to its toxic effect and harmful effect to healthcare staff in the hospital

USA market is requiring glutaraldehyde free solution which lead to Cidex OPA solution.

* Cidex products are being withdrawn from the market especially in European market due to its toxic effect and harmful effect to healthcare staff in the hospital

USA market is requiring glutaraldehyde free solution which lead to Cidex OPA solution.

Gamma, Beta Radiation Sterilization

Irradiation is an effective sterilization method

It is limited to commercial use only

The product to be sterilized is exposed to radiation 10 – 20 hrs (sterilization time is 10 – 20 hrs)

Gamma radiation is most commonly used

A dose of 2.5 megarad is generally selected for items

The chemical or thermal energy converted by radiation kills the microorganism by disruption of the DNA molecule

Preventing cellular division hence prevention of life of organism

Cobalt 60 is a radioactive isotope capable of breaking down to produce gamma rays

Cobalt 60 is the most commonly used source for irradiation sterilization.