Chapter 11 Sterilization Flashcards
MOA of iodine/iodophors
Oxidation/substitution by free iodine denatures proteins
MOA of steam sterilization
Kills through coagulation and denaturation of proteins with moist heat
MOA of ethylene oxide
Alkylation of proteins and nucleic acids obstructing cell metabolism and reproduction
MOA of plasma sterilization
Use electromagnetic energy to create plasma phase from vapor of H2O2, oxygen, or peracetic acid mixture. Plasma has free radicals that deactivate cellular processes
MOA of chlorhexidine
Disrupts the cell membrane
Time and temp for steam sterilization
Typically 121 degrees Celsius for 30 minutes in a gravity displacement sterilizer (more common) with 15-30 minutes drying time
132 degrees celsius for 4 minutes in a prevacuum unit with 15-30 minutes drying time
Prevacuum unit is used in which type of sterilization
Steam
Benefits of steam sterilization
Allows for lower temps to be used
efficacious against spores
What is true in regards to bowls in steam sterilizers
Bowls will trap cool air if open facing up and will not sterilize appropriately
What material should not be used in ethylene oxide sterilization
Glass - it resists penetration
Which sterilization method and material combination will cause toxicity if not aerated?
Ethylene oxide is absorbed by rubbers and plastics. Aeration is needed.
Benefits of plasma sterilization
Lack of toxic residues - Since using H2O2 does not require aeration
useful for moisture and heat sensitive items
Short cycle time
Which materials should not be used in plasma sterilization
Linens, wood, or liquids
Storage of heat-sealed plastic wrap for ethylene oxide
one year
Storage of paper wrapping with ethylene oxide
30-60 days
Cloth wrapping with ethylene oxide
15-30 days
How long can instruments be stored for when sealed in plastic wrap with tape after being sterilized with EtO
90-100 days
Disadvantages of ethylene oxide sterilization
flammable so usually mixed with CO2 or hydrochlorofluorocarbon
Glass resists penetration
Absorbed by rubber and plastics - aeration needed
Time - 2-5 hours
What are the three types of sterilization indicators
Physical - Print outs or graphs verifying temp and time
Chemical - Class 1-6
Biologic - Check viability of bacterial colonies on a culture after processing
What are class 5 and class 6 indicators
Class 5 - react to all parameters that are important to a given type of sterilizer
Class 6 - react to more specific guidelines to combat prion infection
Describe class 5 indicators
React to all parameters that are important to a given type of sterilization (except prions)
Describe class 6 indicators
React to more specific guidelines to combat prion infection
Which of the following has the most residual activity? Triclosan, Alcohol, Iodine, or Chlorhexidine
Chlorhexidine
Alcohol has none
Triclosan an intermediate amount
Iodine a moderate amount
What are the advantages of Povidone-iodine?
safe in the ears, mouth and eyes
Bactericidal/-static status of chlorhexidine
Bactericidal at high concentrations
Bacteriostatic at low concentrations
What percentage of chlorhexidine solution can be used in wounds?
<0.05%
Spore activity of chlorhexidine
Poor against spores unless at high temperatures
Is chlorhexidine ototoxic in the middle ear?
yes
