Sterilization Monitoring: A Critical Step in Infection Prevention and Patient Safety

Having proper sterilization processes in place is crucial in preventing the transmission of infection. Monitoring the sterilization process ensures that it is effective. The methods used to monitor sterilization are physical (mechanical) monitoring, chemical indicators, and biologic monitoring. Mechanical and chemical indicators don’t guarantee sterilization; however, they are the first indicator that something may be wrong with the process. Biological indicators are the best assurance that sterilization has been achieved.

Monitoring the sterilization equipment, procedures, and recordkeeping are essential to ensure patient safety. The monitoring results must be documented and kept according to local and state regulations. Several regulatory agencies, including the Joint Commission and Centers for Medicare and Medicaid mandate documentation.

Mechanical/physical monitoring

Mechanical, or physical, monitoring consists of observing the cycle time, temperature, and pressure of each load. The sterilizer gauges or displays are observed for each of these parameters and those results are documented. Some sterilizers have a recording device or printout that can be used for documentation. If these parameters have not been met during the process, this could be the first indication of a problem. Documentation of these parameters should be maintained for a certain duration according to your state’s regulations.

Chemical monitoring

Chemical monitoring uses sensitive chemicals or inks that change colors when exposed to temperatures or a combination of time and temperature. Chemical monitoring consists of indicator tape, strips, tabs, or markings on packaging materials. These indicators measure time and temperature parameters. They also measure pressure in autoclaves.

Chemical indicators

Chemical indicators are placed on the inside of each package to ensure the sterilizing agent has reached the instruments inside the package. If the indicator is not seen from the outside, place an additional indicator on the outside of the package. The indicators validate the sterilant penetrated the packaging material.

These indicators show that the item has been exposed to the sterilization process, but they do not prove sterilization. There are different classes of these indicators based on their ability to monitor one or multiple sterilization parameters (time, temperature, pressure). Inspect the indicators at the end of the sterilization cycle. If they don’t turn colors or suggest inadequate processing, the item should not be used.

Biological monitoring/spore testing

Biological monitoring, also known as spore testing, is the only way to prove sterilization. This method includes placing a strip or vial of spores in the sterilizer to ensure those spores are killed. If the spores are killed, the sterilization process is successful. There are mail-in test strips or in-house vials of spores used with an incubator. Spore testing should be performed at least weekly and with each implantable device. Spore testing may need to be performed more frequently if the sterilizer is used multiple times throughout the day. This would allow for early detection of equipment malfunctions or procedure errors. In turn, this would minimize the extent of instrument retrieval and possible patient surveillance.

The Center for Disease Control (CDC) and the Association of Perioperative Registered Nurses (AORN) have steps to follow in the event a spore testing is positive. Following positive spore testing from steam sterilization, the sterilizer should be removed from service. Once this is done, sterilization logs should be reviewed, and procedures to determine any potential reason for the failed test should be implemented. If the logs show that physical and chemical monitoring was met, there is no need at this point to retrieve instruments for re-sterilization. However, any implantable device should be retrieved and not used until they are shown to be sterile. The sterilizer should then be retested, using the same type of spore testing that failed and the same cycle. If the additional spore test is negative, the sterilizer can be returned to service.

If the repeat spore test is positive, remove the sterilizer from service and have it inspected or repaired. Retrieve instruments, insofar as possible, from the last negative spore test and re-sterilize.

After the sterilizer is repaired, perform spore testing until three consecutive negative testing is achieved. Once spore testing results are favorable, put the sterilizer back into service.

If using a method of sterilization that is not steam, and having a single positive spore test, treat all instruments as nonsterile. All instruments should be retrieved and reprocessed.

Sterilization monitoring and documentation are important aspects of an effective infection prevention and control program. If you have questions or need help with infection control, reach out to us at Total Medical Compliance. We will be happy to tell you about our NEW infection control, sterilization, and disinfection program.