Question

Using your book and outside sources research various sterilization process discussed in chapter 10. Write a 5 page paper about steam sterilization (both gravity displacement and pre vacuum) and ONE additional process used to sterilize instruments. Be sure to discuss advantages and disadvantages of both steam sterilization and process you have chosen. Also, be sure to compare and contrast your chosen process and steam sterilization.
Must be APA format, be sure to include references as well as in text citations

Surgical Technology program

Answer 1

A steam steriliser, also known as 'autoclave' is a decontamination method in which Sterilization is achieved by exposing products to saturated steam at high temperatures (121°C to 134°C). Product(s) are placed in a device called the autoclave and heated through pressurized steam to kill all microorganisms including spores.

Types of autoclave

Autoclaves function primarily through either gravity or vacuum-induced or pre-vacuum (pre vac) sterilization methods, though some types of autoclaves combine both methods to sterilize. Though both types of autoclaves sterilize through high-temperature steam and use pressure as a means to allow steam to displace ambient air in the chamber to penetrate sterilization media, how these mechanisms occur differ and thus, are more conducive to certain types of media over others.

Gravity displacement autoclave:

Description: The most basic sterilization cycle. Steam displaces air in the chamber by gravity (i.e. without mechanical assistance) through a drain port.

Typical application: Glassware, unwrapped goods, waste, utensils, redbags.

Gravity autoclaving, also known as gravity displacement autoclaving is the most basic form and is suitable for sterilizing the most common laboratory media, including steel utensils, glassware, and bio-hazardous waste. Gravity-induced autoclaving involves pumping steam into the autoclave chamber, which displaces the ambient air and forces it out of exhaust valves so that the remaining steam can sterilize the contents.

ADVANTAGE

This mechanism is advantageous in the simplicity of its design and lack of dependency on peripheral mechanisms to displace ambient air with steam, making these types of autoclaves more affordable and dependable. The majority of autoclave media or items to be sterilized are simple in design and do not contain spaces or obstacles for steam to penetrate within, thus the steam displacement function is ample for proper sterilization. It is for these reasons that gravity autoclaves are the most common types of autoclaves in the market and are usually the recommended type of autoclave for most uses.

DISADVANTAGE: The disadvantages of a gravity-displacement process are the length of time required for sterilization and the dependence on gravity to remove air

Pre-vacuum autoclave:

Air is mechanically removed from the chamber and load through a series of vacuum and pressure pulses. This allows the steam to penetrate porous areas of the load that couldn’t otherwise be reached with simple gravity displacement.

Typical application: Wrapped goods, packs, animal cage bedding, cages, porous materials, redbags.

Vacuum autoclaving, also known as pre-vacuum autoclaving or sterilizing is more suited in cases where air cannot be easily removed from sterilization media. This may include large or porous items such as animal cages and bedding sterilization as well as wrapped surgical kits. The vacuum function in these autoclaves allows deeper sterilization of the contents, as it completely evacuates the ambient air within, allowing high-temperature steam to penetrate and sterilize areas that would normally be occupied by ambient air, and can be more efficient at sterilizing certain items with hard-to-reach areas within.

Another process of sterilization is Ethylene Oxide (EtO) sterilization

Ethylene Oxide (EtO) is a common gas used for low temperature sterilization. It is a colorless, poisonous gas that attacks the cellular proteins and nucleic acids of microorganisms. It is most commonly used to sterilize instruments with long lumens such as endoscopes and all materials that have to be sterilized but cannot withstand higher temperature. EtO process temperatures from 25 - 55°C are used. A lower temperature results in a less efficient process which leads to a longer exposure time.

Advantages of EtO are:

Ø Low temperature

Ø High efficiency – destroys microorganisms including resistant spores

Ø Large sterilizing volume/ chamber capacity

Ø Non corrosive to: plastic, metal and rubber materials

Disadvantages are:

Ø Excessively Long cycle

Ø Safety concerns - carcinogenic to humans

Ø Toxicity issues - toxic residues on surgical instruments and tubing

Ø Not recommended for flexible scope

Ø EtO is flammable

Ø Requires special room conditions, safety equipment and separate ventilation system

Ø Relatively high annual costs for maintenance, servicing and consumables