CMA Chapter 6: sterilization

• Medical asepsis prevents microbes from spreading to or from patients
• Surgical asepsis is the absence of microorganisms, infection, and infectious material on instruments, equipment, and supplies
• Responsibilities to manage assisting with minor surgical procedures

  1. Become familiar with surgical instruments

  2. Understand principles and practices of surgical asepsis

  3. Understand and use disinfection and sterilization techniques

  4. Use equipment designed for sterilization, treatment, and diagnostic purposes

  5. Maintain accurate records and inventory of purchases related to surgical equipment and supplies
• Attention to detail and professional integrity during surgical aseptic procedures is essential in preventing serious patient complications
• The goal of surgical asepsis is to free an item or area from all microorganisms, including pathogens and other microorganisms
• Items, once sterilized, are not considered sterile indefinitely
• Cindy knows items are sterile through various sterilization procedures, including those involving the autoclave
• Responsibilities in a medical office may include assisting with minor surgical procedures while maintaining surgical asepsis
• The difference between medical asepsis and surgical asepsis is explained in this chapter
• Breaks in sterile technique can lead to infections that the body cannot fight, delaying recovery and being costly to the patient
• Surgical asepsis, also known as sterile technique, should be used during any office surgical procedure, handling sterile instruments for incisions and excisions, and changing wound dressings
• Surgical Asepsis

  • Destroys microorganisms before they enter the body
  • Prevents entry of microbes into the body during invasive procedures
  • During contact with a normally sterile part of the body
  • Hands and forearms are washed for 5-10 minutes with a brush
• Sanitation and disinfection are adequate for maintaining medical asepsis in the medical office
• Sanitation and disinfection

  Not sufficient to process instruments and equipment used during sterile procedures
• Sterilization procedure

  Steam under pressure, dry heat, ethylene oxide gas, and liquid chemicals are principal sterilizing agents
• Sterilization

  The complete elimination or destruction of all forms of microbial life, including spore forms
• Methods of sterilization

  • Heat
  • Moist heat (steam under pressure)
  • Boiling
  • Dry heat
  • Liquids
  • Glutaraldehyde
  • Formaldehyde
  • Gas
• The Right to Know requires all companies, including medical offices, using hazardous materials to have safety data sheets available to their employees
• Sterilization equipment is used in clinics and medical offices
• Clinical medical assistants are responsible for following manufacturer's recommendations or OSHA requirements and guidelines for sterilization equipment
• The autoclave has two chambers, an outer one where pressure builds and an inner one where sterilization occurs
• Objects requiring surgical asepsis

  Must be sanitized first and sterilized by either a physical or chemical process
• Manufacturer's recommendations for processing instruments according to the purposes for which the items will be used

  Determine the appropriate level of asepsis
• Method of sterilization

  Depends on the nature of the material to be sterilized and the type of microorganism to be destroyed
• Clinical medical assistants are responsible for becoming familiar with the uses and operation of each piece of sterilization equipment
• Safety data sheets are prepared by the chemical manufacturer and clearly state how to handle and dispose of the chemicals
• Sanitation and disinfection


  Adequate for maintaining medical asepsis in the medical office
• Occupational Safety and Health Administration (OSHA) and state regulations have defined a specific law to protect from hazardous materials called The Right to Know
• Distilled water is converted to steam in the autoclave to reach the required temperature for sterilization
• The autoclave is the most frequently used piece of equipment for sterilizing instruments today
• Sterilization indicators are used to ensure proper pressure, temperature, and time in the autoclave for destruction of all microbial life
• Sterilization process in an autoclave

  Distilled water is added to a reservoir, converted to steam when a preset temperature is reached. The steam is forced into the inner chamber, increasing pressure and raising the temperature to 250°F or higher, allowing for destruction of all microorganisms, including viruses and spores
• Sterilization is required for surgical instruments and equipment that will come into contact with internal body tissues or cavities
• Automatic autoclaves

  • Can be set to vent, time, turn off, and exhaust at preset times and levels. Some steps may need to be done manually. Manufacturers provide instructions for operating the machine and recommendations for sterilizing different types of loads
• Instruments or equipment subject to damage by water should not be sterilized in the autoclave. They can be sterilized with gas methods or cold-sterilized in a liquid such as glutaraldehyde or formaldehyde
• Items sterilized in an autoclave

  • Minor surgical instruments, surgical storage trays and containers, some surgical equipment like bowls for holding sterile solutions
• Air exhaust in an autoclave

  Air in the chamber is pushed out and replaced by pressurized steam. When no air is present, the chamber seals and the temperature gauge begins to rise
• Improper wrapping, loading, or operation of the autoclave may prevent the indicator from registering properly, and the sterility of the contents cannot be assured
• Always follow the manufacturer's recommendations for sterilizing instruments or equipment and for using any chemical products for sterilization
• Operating the Autoclave

  1. All components of autoclaving - temperature, pressure, steam, and time - must be correct for the items to reach sterility

  2. Follow the instruction manual carefully

  3. The autoclave has a reservoir tank that should be filled with distilled water only

  4. When filling the internal chamber of the autoclave with distilled water from the reservoir, ensure the water level is at the fill line

  5. The temperature, pressure, and time required vary with the items being sterilized

  6. Solid or metal loads take slightly less time than soft, bulky loads

  7. Some microorganisms, such as spores, are killed only if exposed to high enough temperature for a specific amount of time

  8. When the items have been in the autoclave at the right temperature for enough time, the timer will sound, indicating that the cycle is finished

  9. Be sure to vent the autoclave to allow the pressure to drop safely

  10. After the pressure has dropped to a safe level, open the door of the autoclave slightly to allow the temperature to drop and the load to cool and dry

  11. Never handle or remove items from the autoclave until they are dry because bacteria from your hands would be drawn through the moist coverings and contaminate the items inside