QC, Disinfection, Sterilization Flashcards
IQCP
individualized quality control plan
IQCP replaces…
EQC (equivalent quality control) - the standardized approach
IQCP is based on…
- assessment of the unique laboratory testing in use
- patient populations
- other factors (ie. internal quality checks built into new instruments)
IQCP is not required on —– tests
waived
3 parts of IQCP
- Risk assessment
- Quality control plan
- Quality control assessment
5 things IDd in risk assessment phase of IQCP
- how frequently they may occur
- how likely it is they will be detected
- potential severity for patient
- risk prevention/mitigation
- acceptability of residual risk
QCP must include…
numer, type and frequency of QC testing, and acceptable criteria
not eligible to use IQCP
pathology, histology, cytology
IQCP may result in less stringent QC than the standardized method because…
it is risk-based
used to document elements of risk analysis
Failure Modes and Effects Analysis (FMEA) table
2 quality management tools focusing on the pre- and post-analytical phases
Q-probes
Q-tracks
provides a series of cross-sectional quality assurance studies with peer evaluations
Q-probes
provides continuous quality monitors for tracking changes over time
Q-tracks
most variation and highest proportion of errors
preanalytical phase
average time to detect a persistent error
1/2 of the time between control analyses
magnitude of total error that can be tolerated without invalidating the medical usefulness of the result
maximum allowable error (MAE)
control procedure that uses patient data
average of patient (AOP) data
usefulness of mercurials
- toxic, not recommended
usefulness of quaternary ammonium compounds
- active against bacteria, lipid viruses
- inactive against spores
usefulness of phenolic compounds
- active against bacteria, Mycobacterium, fungi, lipid viruses
- less effective against spores
usefulness of chlorine compounds
- active against bacteria, viruses, spores
- corrosive to metals
- must be made fresh
usefulness of iodophores
- active against vegetative bacteria and viruses
- not active against spores
usefulness of alcohols
- general use disinfectant
- not active against spores
usefulness of formaldehyde
- active against bacteria, spores, viruses
- irritating odor, carcinogenic
usefulness of activated glutaraldehyde
- toxic, potential damage to eyes
usefulness of formaldehyde-alcohol
- active against bacteria, spores, viruses
agents useful against spores
- chlorine compounds
- formaldehye solutions
- formaldehyde-alcohol
methods of sterilization
- gas
- dry heat
- chemical
- steam (autoclave)
- filtration
- radiation
used to sterilize items that are easily corroded, such as cutting instruments, and requires longer exposure time
dry heat sterilization
takes hours to sterilize; mainly used for wheelchairs and beds
gas sterilization
gases used for sterilization
- ethylene oxide
- paraformaldehyde
used when a material cannot be autoclaved; uses the same agents as disinfection with longer exposure times
chemical sterilization
autoclave conditions
15 PSI (1 atm)
15 minutes
121° C
useful as a sterilization indicator
Bacillus or Geobacillus spores
most frequent reason for autoclave failing
lack of contact between steam and microorganisms
disinfection
a process that eliminates a defined scope of microbes, including some spores
antiseptics are applied to ——– and do not kill ——–
the skin
spores
factors that influence the degree of killing microbes
- types of organisms
- number of organisms
- concentration of disinfecting agent
- presence of organic material
- nature of surface
- contact time
- temp
- pH
- biofilms
- compatibility of disinfectants and sterilants
why is steam sterilization effective?
heat in water is transferred more readily to a cool body than heat in air
commonly used to sterilize glassware and oils
dry heat
2 methods that achieve disinfection but not sterilization and do not eliminate spores
boiling
pasteurization
pasteurization conditions
72° C
15 seconds
most microbes are retained by a pore size of…
0.45 - 0.80 um
pore size for critical sterilization
0.22 um
Pseudomonas can pass through other pores
HEPA
high efficiency particulate air
HEPA is able to remove microbes larger than…
0.3 um
2 forms of radiation
ionizing (used to sterilize disposable supplies)
nonionizing
all disinfectants regulated by…
sterilizers regulated by…
EPA
FDA
4 means by which chemical agents kill microbes
- react with components of membrane
- denaturation of proteins
- reaction with thiol (-SH) groups of enzymes
- damage of DNA/RNA
denature proteins; make lipids soluble
alcohols
react with NH2, SH, and COOH groups
aldehydes
inactivate proteins
tincture of iodine
reacts with water to form HClO; oxidizer
chlorine
precipitates proteins
silver nitrate
reacts with -SH; lyses membranes
mercuric chloride
disrupts cell membranes
detergents (quaternary ammonium compounds)
aklylating agent
ethylene oxide
sterilize bio-hazardous waste
autoclave if heat stable
sterilize media, liquids, instruments
autoclave
sterilize disposable supplies
ionizing radiation
sterilize antibiotics, vaccines, carbohydrates
filtration
sterilize glassware, oil
dry heat
critical materials
invade sterile tissues or enter vascular system
semicritical materials
come into contact with mucous membranes
noncritical materials
come into contact with skin
autoclave factors that must be monitored
sterilization indicators
culture tests
time, pressure, temp