Their objective? To minimize the risk of surgical site infections by destroying all microorganisms on the devices before they are reused.
Hospitals’ sterile processing departments play the important role of helping to combat hospital acquired infections (HAIs) by putting reusable surgical devices through a rigorous “reprocessing” procedure – a detailed, multistep process to clean and sterilize the instruments.
Adequate reprocessing of reusable medical devices is vital to protecting patient safety, says the FDA. And sterilization is a fundamental step in a hospital’s effort to keep HAIs in check. By killing germs, sterilization ensures no harmful pathogens that can cause infections are transferred from one patient to another.
But it’s not a one-size-fits-all process – different medical devices have different procedures that need to be followed. Devices made of stainless steel are heat stable and can withstand high-temperature steam sterilization. On the other hand, heat- and moisture-sensitive items – including flexible endoscopes and catheters – require the use of a low-temperature sterilization technology, like ethylene oxide and hydrogen peroxide.
No matter which sterilization method is used, sterile processing teams need to be certain that any microorganisms contaminating instruments are killed.
But how do they know for sure?
Biological indicators (BIs) are an integral part of the sterilization quality control process. They provide direct evidence that the sterilization process conditions are sufficient to kill the most resistant bacteria. Here’s how they work:
BIs contain bacterial spores – a form of bacteria that have thick outer walls, which help them survive in hostile environments. Not all microorganisms form spores, but in the spore state, the organism is much more resistant to sterilization.
A large population of these resistant spores get encapsulated into a self-contained BI device – or a capped plastic sleeve – which is added to the sterilization cycle along with the surgical instruments.
The theory behind the BI? If the sterilization process is effective enough to kill a large population of highly resistant spores, it also will kill a lower number of less resistant organisms on the medical devices. And that’s the proof needed to know whether the sterilization cycle was successful.
Today, sterile processing teams are able to get results in under an hour. But that certainly has not always been the case.
Microbiologist Bill Foltz has dedicated his 40-year career to helping sterilization teams in hospitals get results as quickly as possible.
When 3M first entered into the BI arena in the 1970s, readout times for sterilization loads took between five and seven days. And since there’s a limited number of medical devices in circulation in any given hospital, that meant equipment was being sent into surgeries without proof of sterilization. And non-sterile equipment potentially was being used on patients.
“Back then, there wasn’t a whole lot of incentive for hospitals to monitor the loads more than once a week,” Bill recalls, “because it took so long to get the results back.”
Bill and his team knew the incredible impact they could have on patient safety if they could reduce readout times.
So, they built upon the innovations their colleague Robert Nelson had pioneered in the early-1970s, including the first self-contained BI with an easy-to-read design and a small desktop incubator, which had decreased readout times from between five and seven days to 48 hours.
By the early 1980s, their goal was to reduce the readout times even further – decreasing them from two days down to eight hours. That way, sterilization technicians would be able to monitor loads within a work shift – which would be a huge boon for the industry. They enlisted the help of a few good friends to make it happen.
Bill’s team collaborated with other high-level 3M scientists from a variety of backgrounds to take on the challenge of getting readouts down to less than eight hours. He called the group the “Blue Sky Club,” because “we were in pursuit of visionary creative thinking to make this happen,” says Bill. One idea was to genetically modify the indicator organisms to overproduce an enzyme to detect a sterilization failure. But genetic modification of the organisms had its challenges and concerns for use in the hospital setting.
“I thought, maybe we could utilize an enzyme that was naturally produced by the organism and able to be detected by an incubator, thus eliminating the problems with genetic modification,” says Bill. “So, I ordered a bunch of enzyme substrates – which are indicators that detect specific enzymes – and started screening them with our indicator organisms.”
He found a couple that worked, and that was the basis of the proprietary ‘rapid readout’ science that allowed his team to decrease the readout times from as long as 48 hours to one hour for steam sterilization.
This was a significant step change for the industry – but the team kept pushing. Just six years ago, they utilized the same enzyme detection technology to decrease that time even further to just 30 minutes for certain steam sterilization cycles.
Following their pioneering work for steam sterilization, the team saw a similar need to reduce BI result time for low temperature vaporized hydrogen peroxide – or VH2O2 – sterilization. Use of the VH2O2 sterilization process was growing as medical instruments became increasingly complex and more delicate; requiring low temperature sterilization instead of steam. However, sterile processing teams still faced a 24-hour wait for BI results, as that is all that was available for this sensitive sterilization modality. In 2016, Bill and his team introduced a four-hour rapid-readout system for VH2O2 sterilization.
Yet again, they wanted to push it even faster, since the low temperatures used in this type of sterilization didn’t require extra cool-down time for the processed load items. So in July of 2017, the team announced a 24-minute vaporized hydrogen peroxide BI readout system.
Faster BI results can have an enormous impact on hospitals – from reducing the expense of having to purchase additional sets of equipment to have on hand for surgeries; to helping ensure sterilized items get to the OR on time, meaning surgeries are more likely to proceed without delay. But the biggest impact is on patient safety: The use of biological indicators to monitor every load can reduce the risk of sterilization failures and help improve the standard of patient care.
“It really is remarkable when you think of the number of lives that have been touched by this technology,” says Ericka Lutz, 3M Global Marketing Manager. “Health care facilities in more than 60 countries around the world depend on the science and solutions that Bill and his team created to help reduce the risk of surgical site infections.”
Bill is the first to admit that it takes a village to get innovations like these out the door and continue to find ways to help improve patient outcomes decade after decade.
“I think we’ve helped make our hospital customers’ lives a lot easier and allowed them to do a much better job in helping to ensure patient safety,” he says. “As a scientist, you can’t ask for much more than that.”