sleeves. Only the front of the gown is considered sterile.
Sterilization refers to the complete destruction of all living organisms, including bacterial spores and viruses. The word sterile means free from or the absence of all living organisms. Any item to be sterilized must be thoroughly cleaned mechanically or by hand, using soap or detergent and water. When cleaning by hand, apply friction to the item by using a brush. After cleaning, thoroughly rinse the items with clean, running water before sterilization. The appropriate sterilization method is determined according to how the item will be used, the material of which the item is made, and the sterilization methods available. Physical methods of sterilization comprise moist heat and dry heat. Chemical methods include gas and liquid solutions.
PHYSICAL METHODS. Steam under pressure (autoclave) is the most dependable and economical method of sterilization. It is the method of choice for metalware, glassware, most rubber goods, and dry goods. All articles must be correctly wrapped or packaged so that the steam will come in contact with all surfaces of the article. Similar items should be sterilized together, especially those requiring the same time and temperature exposure. Articles that will collect water must be placed so the water will drain out of the article during the sterilization cycle. A sterilizer should be loaded in a manner that will allow the free flow of steam in and around all articles. Each item sterilized must be dated with the expiration of sterility. Sterilization indicators must be used in each load that is put through the sterilization process. This verifies proper steam and temperature penetration.
The operating instructions for a steam sterilizer will vary according to the type and manufacturer. There are a number of manufacturers, but there are only two types of steam under pressure sterilizers. They are the downward displacement and the prevacuum, high-temperature autoclave.
In the downward (gravity) displacement autoclave, air in the chamber is forced downward and out of the bottom discharge outlet as pressurized steam enters from the top of the chamber. The temperature in the sterilizer gradually increases as the steam heats the chamber and its contents. The actual timing does not begin until the temperature is above 245°F (118°C).
The prevacuum, high-temperature autoclave is the most modern and economical to operate and requires the least time to sterilize a single load. By use of a vacuum pump, air is extracted from the chamber before admitting steam. This prevacuum process permits instant steam penetration to all articles and through all cotton or linen dry goods. The sterilization time is reduced to 4 minutes. The temperature in the chamber is rapidly raised and held at 274°F (134°C). Timing the cycle is done automatically.
If the temperature is increased, the sterilization time may be decreased. The following are some practical sterilization time periods:
All operating rooms are equipped with highspeed (flash) sterilizers. Wrapped, uncovered, opened instruments placed in perforated trays are