Disinfection and sterilization

• How many surgical procedures are performed each year in the United States?

  Approximately 46.5 million
• How many GI endoscopies are performed annually?

  At least 10 million
• What is a major risk associated with surgical and invasive procedures?

  The introduction of infection
• What can result from failure to properly disinfect or sterilize equipment?

  Infection transmission and outbreaks
• What are the two types of pathogen transmission risks mentioned?

  Person-to-person transmission and environmental pathogen transmission
• Why is it essential to achieve disinfection and sterilization?

  To prevent the transmission of infectious pathogens to patients
• What should health care policies identify regarding cleaning, disinfection, or sterilization?

  They should be based on the items' intended use
• What has been documented in multiple studies regarding disinfection and sterilization?

  Lack of compliance with established guidelines
• What does the focus of sterilization and disinfection strategies include?

  Medical equipment, non-sterile items, and environmental surfaces
• What is the definition of sterilization?

  • Complete elimination or destruction of all forms of microbial life
  • Accomplished by physical or chemical processes
  • Principal sterilizing agents include steam, dry heat, ethylene oxide, H2O2 gas plasma, ozone, and liquid chemicals
• What is disinfection?

  • Process that eliminates many or all pathogenic microorganisms on inanimate objects
  • Does not eliminate bacterial spores
  • Usually accomplished with liquid chemicals or wet pasteurization
• What factors limit the efficacy of disinfection?

  Prior cleaning, organic/inorganic load, microbial contamination, germicide concentration, exposure time, object nature, biofilms, temperature, pH, and humidity
• What are the classifications of chemical disinfectants?

  • High-level disinfectants: Kill all microorganisms except many bacterial spores (e.g., glutaraldehyde, peracetic acid)
  • Intermediate-level disinfectants: Kill mycobacteria, vegetative bacteria, enveloped viruses, and most fungi (e.g., chlorine compounds, alcohols)
  • Low-level disinfectants: Kill vegetative bacteria and enveloped viruses but not spores (e.g., QACs, phenols, iodophores)
• What is cleaning in the context of disinfection and sterilization?

  The removal of visible soil from objects and surfaces
• What is decontamination?

  A procedure that removes pathogenic microorganisms from objects
• What is a germicide?

  An agent that can kill microorganisms, particularly pathogenic organisms
• What is Earle H. Spaulding's classification scheme for disinfection and sterilization?

  • Critical items: High risk of infection, must be sterile (e.g., surgical instruments)
  • Semi-critical items: Contact with mucous membranes, require high-level disinfection (e.g., endoscopes)
  • Noncritical items: Contact with intact skin, require low-level disinfection (e.g., bedpans)
• Why are critical items considered high risk?

  Because contamination can lead to disease dissemination
• What are examples of critical items?

  Surgical instruments, catheters, implants
• What is required for semi-critical items?

  High-level disinfection with chemical disinfectants
• What are examples of semi-critical items?

  Respiratory therapy equipment, endoscopes, laryngoscope blades
• What is the risk associated with noncritical items?

  Virtually no documented risk of transmitting infectious agents
• What is required for noncritical items?

  Low-level disinfection
• What are the properties of an ideal antiseptic or disinfectant?

  • Wide spectrum of activity
  • Effective in the presence of organic matter
  • Stable with a long shelf life
  • Non-toxic and non-irritative
  • Fast-acting and high penetrating power
  • Should not leave residue or stain
• What factors affect the level of disinfection achieved?

  Contact time, temperature, concentration of active ingredient, presence of organic matter, and microbial load
• What are some examples of chemical disinfectants?

  • Alcohol
  • Chlorine compounds
  • Glutaraldehyde
  • Hydrogen peroxide
  • Iodophors
  • Phenolics
  • Quaternary ammonium compounds
• What concentration of ethyl and isopropyl alcohol is considered an intermediate-level disinfectant?

  70%
• What is the mode of action of alcohols as disinfectants?

  They dehydrate cells, disrupt membranes, and coagulate proteins
• Why are alcohols not recommended for sterilizing medical materials?

  They lack sporicidal action and cannot penetrate protein-rich materials
• What are hypochlorites commonly used for in healthcare?

  Disinfecting tonometer heads and spot disinfection of surfaces
• What is the recommended dilution of household bleach for decontaminating blood spills?

  A 1:10 to 1:100 dilution
• What is the main disadvantage of hypochlorites?

  Inactivation in the presence of organic matter
• What is glutaraldehyde used for?

  Disinfection or sterilization of endoscopes and surgical equipment
• What is the contact time necessary for high-level disinfection with glutaraldehyde?

  20 to 90 minutes
• What is the main limitation of formaldehyde as a disinfectant?

  Its carcinogenic potential and irritating fumes
• What is peracetic acid effective against?

  Sporicidal, virucidal, fungicidal, and tuberculocidal
• How does hydrogen peroxide act as a disinfectant?

  By producing hydroxyl free radicals that destroy cell components
• What is the main use of hydrogen peroxide in hospitals?

  As both a disinfectant and an antiseptic
• What must be done if a pure hydrogen peroxide formulation is used?

  All equipment must be thoroughly rinsed
• What is the definition of a germicide?

  An agent that can kill microorganisms, particularly pathogenic organisms