Sterilization Indicators

Why do we use sterilization indicators?

- Confirming the probability of absence of microorganisms on medical devices
- Detecting and verifying sterilization failures as soon as possible
- Preventing the use of medical devices that have not been adequately sterilized
- Improving patient outcome and safety

What are physical monitors used for?

To verify that the parameters of a sterilization cycle met the manufacturer's guidelines

What are physical monitors?

Unit specific devices:
- Recording charts
- Printout
- Gauges or digital displays

What are chemical indicators?

- Usually either heat or chemical sensitive inks that change color
- Sensitive to one or more of the critical variables required for successful sterilization (time, temp, steam)

What are the critical variables for steam sterilization?

- Time
- Temp
- Moisture

What do chemical indicators demonstrate?

- Only that items have been exposed to physical conditions within a sterilizing chamber

What are Biological indicators?

Devices used to monitor the effectiveness of sterilization processes, in terms of whether these processes effectively destroy microorganisms and spores.

How do biological indicators work?

- Contain spores of a resistant microorganism (Bacillus stearothermophilus)

- Growth of organisms within the indicator is demonstrated by a color change (yellowish color)

Biological indicators are used for ______________ not as ____________

quality control, routine sterilization indicator

Define critical variables

Parameters identified as being essential to the sterilization process

Define stated value

Value or range of values of a critical parameter, to which the indicator is designed to react

What information should be included in the packaging of sterilization indicators?

- Class of the chemical indicator
- Sterilization process (steam, ETO, radiation)
- Intended use for which the indicator is designed
- The critical variables to which the indicator will respond and where applicable, their stated values

What is the practical application of class 1 indicators?

Indicator tapes, indicator labels, load cards

What is the practical application of class 2 indicators?

Bowie-dick type tests for equipment control to evaluate the efficacy of air removal and steam penetration

What are single variable indicators used for?

Designed to react to one critical variable and will indicate exposure to a sterilization process at a stated value (SV) of the chosen variable

What is a practical application of class 3 indicators?

A temperature tube that contains a chemical pellet that melts at a specific temperature

What is the practical application of Multiple variable indicators?

Usually used for pack control monitoring. Usually paper strips printed w/ color changing chemical indicator

What are Integrating indicators used for?

- Designed to react to all critical variables
- Have stated values equivalent to or exceeding the performance requirements requirements for biological indicators

What are practical applications of integrating indicators?

Used as an internal chemical indicator for pack control monitoring

What are emulating indicators used for?

Cycle verification indicators designed to react to all critical variables for specified sterilization cycles

What are the 3 types of sterilization indicators

- Physical monitors
- Chemical indicators
- Biological indicators

What are the 2 types of chemical indicators

- External
- Internal

What are external chemical indicators used for?

To differentiate between processed and unprocessed units

What are internal chemical indicators used for?

Indicate whether sterilization conditions were met within a package

Where should internal indicators be placed?

Inside the pack where the sterilant may have most difficulty penetrating

What is the only way you can determine with certainty that a sterilizer is destroying microbes?

Biological indicators

What is autoclave tape an example of?

External chemical indicator

How long must biological indicators be incubated to rule out a color change?

8-24 hours

What is the most accurate sterilization indicator?

Biological indicators

Define endpoint

Point of the observed changes as defined by the manufacturer occurring after the indicator has been exposed to specific stated values

Class 1 Indicator

Process indicator

What are process indicators used for?

Indicate an individual unit has been directly exposed to the sterilization process

Where should process indicators be placed?

Affixed to or printed on each package except if internal chemical indicator visible

Class 2 sterilization indicators

Indicators used for specific tests

Class 3 sterilization indicators

Singe variable indicators

Class 4 indicators

Multiple variable indicators

What are multiple variable indicators used for?

Designed to react to two or more critical variables and will indicate exposure to a sterilization process at a stated value of the chosen variables.

Class 5 sterilization indicators

Integrating Indicators

Class 6 chemical indicators

Emulating Indicators

What is the practical application of emulating indicators?

Could be used as an internal chemical indicator for pack control monitoring for the cycle for which they are labeled