Commonly used sterilization methods in operating rooms

Disinfection must be done during surgery, because in many cases, it is precisely because of the lack of disinfection that wound infection or even infection of internal organs after surgery are the main factors that may lead to problems in the effect. In fact, surgery is a commonly used sterilization method, such as burning, cauterization, and dry baking, etc., which include different techniques and plans.

There are five commonly used

(I) Thermal sterilization

Heat can destroy the proteins and nucleic acids of microorganisms, causing the proteins to denature and coagulate and the nucleic acids to melt and break, thus leading to their death.

1. Dry heat sterilization commonly uses methods such as incineration, cauterization and dry baking.

(1) Incineration and burning Incineration is only used for discarded items contaminated by pathogenic microorganisms, garbage, human and animal carcasses, etc. Cauterization is used to sterilize inoculating loops, metal instruments, test tube mouths, bottle mouths, etc. in microbiology laboratories.

(2) Dry baking: Use a dry oven for sterilization, which generally needs to be heated to 160℃~170℃ for 2h to achieve the purpose of sterilization. Suitable for sterilization of glassware, porcelain, metal items, etc.

2. Moist heat disinfection and sterilization

(1) Pasteurization is named after the French scholar Pasteur who invented it. It mainly kills pathogens or specific microorganisms at a lower temperature while leaving the heat-sensitive components in the items intact. There are two methods: one method is to heat at 61.1℃～62.8℃ for 30min; the other method is to heat at 71.7℃ for 15～30s. Nowadays, people often use the latter method to sterilize milk.

(2) Boiling method: Boiling at 100℃ for 5 to 10 minutes can kill bacterial vegetative cells. Spores need to be boiled for 1 to 2 hours. Commonly used for disinfection of syringes, tableware and drinking water.

(3) The circulating steam method uses an Arnold steamer or ordinary steamer and heats at 100°C for 15 to 30 minutes to kill bacterial vegetative bodies. If the sterilized items are placed in an incubator at 37°C to allow the spores to develop into reproductive bodies, and then steamed again the next day, and this is repeated more than three times, the sterilization effect can be achieved. This method is called intermittent sterilization. It is often used for sterilizing items that are not resistant to high temperatures, such as sugars, serum and egg culture medium.

(4) High-pressure steam sterilization is a rapid and effective sterilization method. High-pressure steam sterilizers use heating to generate steam. As the steam pressure continues to increase, the temperature rises accordingly. Usually, when the pressure is 103.4kPa (equivalent to the old 15 pounds per square inch or 1.05kg/cm2), the temperature inside the device can reach 121.3℃ and maintain for 15 to 30 minutes, which can kill all microorganisms including spores. This method is often used to sterilize moisture-resistant and high-temperature resistant items such as general culture media, physiological saline, surgical instruments and dressings.