Sterilization Techniques and Protocols for Healthcare

Posted on Jul 29, 2025 in Geology

Sterilization: Principles and Importance

Sterilization is the process of killing all types of microorganisms, whether pathogenic or non-pathogenic, including their resistant forms (bacterial spores). Sterilization involves the use of physical or chemical methods for the complete destruction of all microorganisms and spores present on a material. A sterile material is considered aseptic.

Functions of the Sterilization Service

The sterilization service performs several critical functions:

  1. Receives materials and utensils for cleaning and disinfection, proceeding from hospital services.
  2. Prepares materials for sterilization.
  3. Sterilizes materials.
  4. Stores various sterilized materials for a specified time.
  5. Distributes sterilized materials to responsible hospital services.
  6. Controls the expiration date of materials. Sterile controls are performed daily using paper indicators.

Material Preparation for Sterilization

The preparation of materials for sterilization involves several key steps:

  1. Classification
  2. Packaging
  3. Labeling
  4. Sterilization

Packaging

The purpose of packaging is to protect against subsequent contamination and maintain the sterility of the materials. Packaging can be done using different materials, depending on the object to be sterilized. Materials that can be used include:

  • Sterile material
  • Paper
  • Plastic bags
  • Rigid containers

Packaging Requirements

For effective sterilization and maintenance of sterility, packaging materials must meet specific requirements:

  1. The packaging must completely surround the object, covering it entirely.
  2. It must be resistant so that it does not break when bent or sealed with heat.
  3. It must be porous to allow the sterilizing agent to pass through and permit rapid drying at the conclusion of the sterilization process.

Physical and Chemical Sterilization Techniques

A) Physical Methods

  • Dry Heat: Incineration, flaming, Pasteur oven (Poupinel).
  • Moist Heat: Autoclave.
  • Radiation: Ultraviolet radiation.
  • Filtration

B) Chemical Methods

  • Glutaraldehyde: Applied by immersion.
  • Ethylene Oxide: This is a gas used for sterilizing heat-sensitive objects that cannot tolerate water. It is used in special chambers at temperatures not exceeding 60 degrees Celsius, with humidity between 30% and 60% for optimal effect.

Pasteur Oven (Dry Heat)

The Pasteur oven uses hot air for sterilization. Instruments must be clean, dry, and free of organic matter. Paper-based or plastic materials, which are combustible, will burn with dry heat. Once the material is packaged, we seal it with a sterilization indicator. We identify materials and dates. We introduce them into the oven and select the time. We must not open the door until the stipulated final time. Once the sterilization time has elapsed, we open the oven and remove the materials with insulating gloves to avoid burns. We store the material in a safe place to preserve its sterility.

Autoclave (Moist Heat)

The sterilizing agent in an autoclave is pressurized water vapor. It uses metallic recipients where water vapor is maintained at high pressures, remaining above 100°C. The autoclave sterilizes metallic material, glass, plastics, and rubbers. It is important to note that vapor can cause corrosion, oxidation, and loss of sharpness in instruments, so metallic objects used in the autoclave may oxidize over time.

Autoclave Description

Key components of an autoclave include:

  • A cover that seals hermetically.
  • A pressure gauge (indicates internal pressure).
  • A pressure selection control.
  • A safety valve.
  • A timer.
  • A bleed valve (3 positions) with a purge-tube drainage.
  • A grid at the bottom, under which distilled water is heated to generate vapor. This serves to sterilize objects without them coming into direct contact with the water.

Autoclave Procedure

Follow these steps for proper autoclave operation:

  1. Check the water level.
  2. The material must be packaged; avoid stacking layers of packages.
  3. Close the autoclave door.
  4. Turn the valve to position V.
  5. When vapor purges from the valve for 3 minutes, wait for all the air inside to be removed, then turn the valve to position “C”.
  6. Adjust the valve and pressure.
  7. Wait until the safety pressure drops to 0 and the valve is in position V. Never open the autoclave if the pressure has not dropped.
  8. Slowly open the autoclave door, wait for the packages to be cold and dry before storing them.