Infection Control Today - 09/2002: Instrumental Knowledge

Testing Instruments and Making the Grade

By Michelle Gardner

Testingmedical instruments and devices is important for patient safety and infectioncontrol practices, and there are a number of testing options: biological,failure analysis, packaging, repair and maintenance, and new productdevelopment, just to name a few.

The Association for the Advancement of Medical Instrumentation (AAMI) offerspublications for standards and recommended practices addressing sterilizationand biological evaluation of medical devices. For example, the former containsinformation on sterility assurance, safe and effective reprocessing of medicaland dental devices, recommended practices for disinfection, and steam, dry heatand chemical sterilization.

As the leader in the administration and coordination of the U.S. voluntaryconsensus standards and conformity assessment system, the American NationalStandards Institute (ANSI) helps U.S. businesses, organizations, governmentagencies and consumer groups effectively participate in national andinternational standards development activities.

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

Finding information about testing standards and recommended practices is notthe hard part, but interpreting the requirements may be a challenge.

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

"The Food and Drug Administration (FDA) has overview documents, theEuropean 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 shoulddo radiation, ethylene oxide, steam and any other process. Keeping current withthe standards is a huge issue. We have one employee whose job it is to maintainthe library and standards lists."

Representatives of Nelson Laboratories serve on AAMI, American Society forTesting and Materials (ASTM) and PDA committees. (PDA is a non-profitinternational association of more than 10,000 scientists involved in thedevelopment, manufacture, quality control and regulation of pharmaceuticals andrelated products.) "We try to have representation so we can be involvedwith how the standard should be written. We often influence the standardprocess," says Nelson.

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

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

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

"If the company does provide a cleaning procedure, we help developone," says Nelson. "We verify that the instructions for use (IFUs)clearly explain to hospital staff how to clean the instrument. When the productgets 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 acycle that runs a four-minute process when it needs a 10-minute process. We haveto be conservative in our processes, realizing the variability that might existin a hospital. Our standard practice is to determine the cycle that kills aspecific 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 issharpened or a $400 laminectomy punch, is tested for sharpness [according to]protocols," says Alex Vrancich, operations manager. "The same types ofmaterials, protocols, tests and guidelines that are used in Germany during themanufacturing process, we put in to place for testing. Just as they are testedbefore they come to Spectrum, we test them before they go out to thecustomer."

When Spectrum sharpens a scissor, it uses a latex material that is a skinsimulator. "There are varying degrees of thickness in this material,"explains Vrancich. "For a microscissor that would be used in an eye tray orfor a heart procedure, we may use the thinner yellow material. The standard isto cut through it three times. If it cuts through clean, without any snags orburrs 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 reactionto the instruments. "We have protocols in place, but the surgeon is thefinal test control," says Vrancich. "If he or she says it is sharp, weknow we have done our job. Our repair process involves finding instrument setsthat have the most complaints from surgeons. Those are what we concentrate onand we work with the surgeon, the nurse manager or whoever is responsible forthe instruments."

All scissors go dull, all needle holder jaws wear out and anything with anedge that is used frequently is going to need upkeep and maintenance. "Icompare 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 goingto need them replaced. The same holds true for instruments. If they are beingused, they are going to need maintenance."

Spectrum understands the importance of getting medical equipment on apreventive 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 andtechnicians through IAHCSMM and ASHCSP. We train in a lecture setting and ourtechnicians do hands-on training at the hospital."