Infection Control Today - 09/2002: Instrumental Knowledge

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Testing Instruments and Making the Grade

By Michelle Gardner

Testing medical instruments and devices is important for patient safety and infection control practices, and there are a number of testing options: biological, failure analysis, packaging, repair and maintenance, and new product development, just to name a few.

The Association for the Advancement of Medical Instrumentation (AAMI) offers publications for standards and recommended practices addressing sterilization and biological evaluation of medical devices. For example, the former contains information on sterility assurance, safe and effective reprocessing of medical and dental devices, recommended practices for disinfection, and steam, dry heat and chemical sterilization.

As the leader in the administration and coordination of the U.S. voluntary consensus standards and conformity assessment system, the American National Standards Institute (ANSI) helps U.S. businesses, organizations, government agencies and consumer groups effectively participate in national and international standards development activities.

Among its multitudes of standards and agreements for technical specifications, the International Organization for Standardization (ISO) publishes a guide to the development and inclusion of safety aspects for medical devices.

Finding information about testing standards and recommended practices is not the hard part, but interpreting the requirements may be a challenge.

One function of Nelson Laboratories in Salt Lake City is to know and understand the requirements of various standards organizations.

"The Food and Drug Administration (FDA) has overview documents, the European community has its overview documents and we have ISO standards that (explain how) you should perform and validate the sterilization process," says Jerry Nelson, PhD, the company's director. "There are published, committee-reviewed and routinely updated documents that establish how you should do radiation, ethylene oxide, steam and any other process. Keeping current with the standards is a huge issue. We have one employee whose job it is to maintain the library and standards lists."

Representatives of Nelson Laboratories serve on AAMI, American Society for Testing and Materials (ASTM) and PDA committees. (PDA is a non-profit international association of more than 10,000 scientists involved in the development, manufacture, quality control and regulation of pharmaceuticals and related products.) "We try to have representation so we can be involved with how the standard should be written. We often influence the standard process," says Nelson.

Within its range of product tests, Nelson Laboratories provides laboratory service for the medical device and pharmaceutical industries that need to comply with control limits on microorganisms.

"We help them get products registered through the regulatory process and do routine quality assurance tests after their products are registered," explains Nelson. "We design sterilization cycles to assist companies in monitoring and controlling bioburden and monitor the environments in which the products are made. We do analyses on products and packaging, which can include integrity and physical performance of the packaging. We determine if the sterilization process was properly delivered and if the product is sterile."

More than 99 percent of Nelson Labs' work is on behalf of the product manufacturer. For example, study directors obtain cleaning information for a manufacturer's reusable device and soil it to determine the effectiveness of the cleaning procedure.

"If the company does provide a cleaning procedure, we help develop one," says Nelson. "We verify that the instructions for use (IFUs) clearly explain to hospital staff how to clean the instrument. When the product gets to the hospital, there can be some deviation (in the cleaning process). Hospitals have sterilizers set a certain way and instruments might be put in a cycle that runs a four-minute process when it needs a 10-minute process. We have to be conservative in our processes, realizing the variability that might exist in a hospital. Our standard practice is to determine the cycle that kills a specific challenge, then the time is doubled."

Continuing Education

Spectrum Surgical Instruments in Stow, Ohio repairs medical instruments, which is where most of its testing comes in to play.

"Every instrument that is repaired, whether it be a scissor that is sharpened or a $400 laminectomy punch, is tested for sharpness [according to] protocols," says Alex Vrancich, operations manager. "The same types of materials, protocols, tests and guidelines that are used in Germany during the manufacturing process, we put in to place for testing. Just as they are tested before they come to Spectrum, we test them before they go out to the customer."

When Spectrum sharpens a scissor, it uses a latex material that is a skin simulator. "There are varying degrees of thickness in this material," explains Vrancich. "For a microscissor that would be used in an eye tray or for a heart procedure, we may use the thinner yellow material. The standard is to cut through it three times. If it cuts through clean, without any snags or burrs impeding the cutting, it is approved and OK'd by us."

When all is said and done, the most important test is the surgeon's reaction to the instruments. "We have protocols in place, but the surgeon is the final test control," says Vrancich. "If he or she says it is sharp, we know we have done our job. Our repair process involves finding instrument sets that have the most complaints from surgeons. Those are what we concentrate on and we work with the surgeon, the nurse manager or whoever is responsible for the instruments."

All scissors go dull, all needle holder jaws wear out and anything with an edge that is used frequently is going to need upkeep and maintenance. "I compare it to tires on our car," says Vrancich. "If you are driving, you are wearing out the rubber on your tires and sooner or later, you are going to need them replaced. The same holds true for instruments. If they are being used, they are going to need maintenance."

Spectrum understands the importance of getting medical equipment on a preventive maintenance schedule to head problems off at the pass.

"Preventive maintenance includes training," says Vrancich. "Our programs are approved for continuing education units for nurses and technicians through IAHCSMM and ASHCSP. We train in a lecture setting and our technicians do hands-on training at the hospital."

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