Sterlization is the process by which an object is freed from micro-organism. Sterlizaton is the process that eliminates, remove, kill or deactivate all forms of life from a particular surface, object or fluid such as food or biological culture media.
OBJECTIVES
- Providing infection-free supply / article
- Doing complete destruction of micro organism.
- Sterlize the instruments and equipment used in surgical practice.
- Keep the article ready in ready to use condition so that they can be used at any time.
- For safety from infection of the patient.
METHODS OF STERLIZATION
NATURAL METHOD OF STERLIZATION
This method is used for contaminated linen and bedpans. Direct sunlight can kill acid-fast bacteria. For this, linen and badpans are kept in direct sunlight for 6 hours for two consecutive days.
PHYSICAL METHOD OF STERLIZATION
All types of bacteria can be killed in this method. Heat is the most common used and safest agent for sterlization in hospitals. The heat for sterlization can be used as follows.
Boiling (Moist Method)
Keeping an instrument or article in boiling water (100 ℃) for 10 minutes can kill most of the pathogens present. For this, the article surface should be very clean, and the article should be completely immersed in water.
The lid of the sterlizer should be tightly closed. The article is kept closed in a sterlizer for 7 to 10 minutes. After sterlization, the article is removed from the sterlizer by chittle foreceps.
The article should not remove the sterlizer in the middle of the boiling process. Sharp instruments such as scissors, knives, needles etc. should not be boiled as they can become blunt due to boiling.
ADVANTAGE
Boiling can be used in the home environment.
It is an economic method of sterlization.
DISADVANTAGE
Some bacteria and viruses and all types of spores are not killed by boiling, meaning they are heat resistent.
This process cannot be used for articles that are destroyed by moisture and heat.
AUTOCLAVING
Autoclaving is the most commonly used method for sterlization of surgical instruments. It is the best, safe and effective method for sterlization. This spore forming can destroy micro-organism.
In autoclaving, sterlization is performed by steam at high pressure. In autoclaving water is boiled and sterlization is carried out with the help of its steam.
When the pressure increases in a closed vessel, its temperature also increases. When this steam comes in contact with a cooler surface, its condensation converts it into water and gives this surface this steam latent heat, which has a temperature of 121 ℃. For this, the article is kept in autoclave for 15-45 minutes. In this, surgical instruments, syrings tatha needles, linen, masks, abdominal swabs and dressing etc. can be sterlized.
HOT AIR OVEN
In this process, sterlization is done by hot air at 160 ℃. It can sterlize glassware, forceps, scissors, scalpels, syringes, liquid parafins and dusting powder. All types of spores, micro-organisms can be destroyed by this method. This is a safe but costly method of sterlization. The glassware is dried before placing in it.
CHEMICAL METHOD OF STERLIZATION
This is called cold sterlization or disinfection by disinfectants method. In this, the chemical disinfectant is used which either coagulation of bacterial protein or change the chemical composition of the protein. Phenol, Lysol, Formalin, Dettol or alcohol are commonly used disinfectants.
This method is used to sterlize the instruments which may be damaged by heat or their corrosion may occur. Sopre cannot be destroyed by this, and it can cause injury to the skin and articles. The disinfectants are kept in correct strength. The article is fully submerged in it.
RADIATION METHOD OF STERLIZATION
In this, non-ionizing and ionizing radiation are used for sterlization. Infra red, ultra violet radiation is used as non-ionizing radiation, and x-rays and gamma-rays are used as ionizing radiaiton. By this diposable syringe, catheters, sharp instruments which cannot bear heat are sterlized.
GAS STERLIZATION
For this ethylene oxide (oxirane) gas is used for sterlization. Its special chambers are made, whose temperature and humidity are controlled. Before sterlization it is removed from the air and the articles are kept in these chambers for 3 to 6 hours. Gases like formaldehyde and betapropiolatone etc. are also used for sterlization.
