It might be tempting to eyeball a surgical instrument and declare it clean, but guidelines call for quantitative assessments of apparatuses after they undergo sterile processing. Is the payoff—presumably, improved patient safety—worth the effort? If you ask Lauren Fitts, MPH, an infection preventionist at Missouri Baptist Medical Center in St. Louis, Missouri, the answer is clear: Of course.
She should know. As an intern, Fitts and her colleagues examined the cleanliness of tough-to-sterilize instruments used in hip, spinal fusion, and colon procedures. They used 3M’s Clean-Trace ATP System in a 450-bed community hospital to collect and analyze bioluminescence data. The research team ultimately found that 43 of 44 (97.7%) tested instruments logged an acceptable relative light unit (RLU) score, meaning they were deemed clean, according to the findings of the study, published recently in the American Journal of Infection Control.1
“I can understand why people would say that it’s not necessary to perform these quantitative assessments. We got great results,” Fitts told Infection Control Today. “But when you have one wrong turn, especially with an instrument or an invasive device, that can cost someone their life, money, and quality of life.”
Targeting Bioluminescence Data
Knowing that mere visual inspections had been proven insufficient, investigators set out to collect baseline adenosine triphosphate (ATP) testing data for surgical instruments. They hoped to bolster quality improvement programs and to develop a process in compliance with existing standards. Fitts and her colleagues zeroed in on a hospital with 23 operating rooms that performed roughly 60 surgical procedures per day, inspecting the most challenging instruments: Kerrisons, laparoscopic Metzenbaum scissors, Ochsners, and large Rongeurs.
During the course of the investigation, which ran for roughly 1 month in spring 2018, workers processed the instruments per Association for the Advancement of Medical Instrumentation guidelines and manufacturer instructions. This process included spraying the instruments with Steris Pre-Klenz, visual inspections, tagging and tracking, swabbing, manual wash, and a standard 24-minute machine wash.
But to assess the sanitization of each instrument, Fitts and her team turned to a relatively new method. Using bioluminescence, they measured ATP levels, which provided insights into the level of bioburden on a surface, potentially hinting at degree of cleanliness or contamination. The test relies on a swab and a reacting agent for a machine to determine how many RLUs, the unit for measuring ATPs, an instrument contains.
“ATP is the least labor-intensive, most cost-effective kind of biological test,” Fitts noted.
As per instructions from the test manufacturer, investigators defined cleanliness as an instrument with a readout of 151 or fewer RLUs. The mean RLU number after the machine wash was just 47, according to the findings.
Overall, the examination suggested that the community hospital’s central sterile processing department had done its job. That confirmation could provide peace of mind when things are running properly, but it could also serve as the sounding of an alarm if a breakdown in sterile processing were to occur, Fitts said.
“To get this process started, it ends up being like any other thing in a hospital, where you’re checking, you’re double-checking, and 9 times out of 10, everything’s great,” she said. “But you want to be sure that you catch that one time before it really has a negative impact.”
A Win for Central Sterile Processing
As an early-career infection preventionist, Fitts appreciated the opportunity to shine a light on the often-overlooked central sterile processing department. She said she hopes her findings—and their implication that, at least in one hospital, the unit had executed well—would further underscore sterile processing’s crucial role.
“That’s a really critical part of the patient experience,” Fitts added, “and I think it needs to be treated with attention.”
Fitts LN, Yegge J, Goris A, Vinson S, Dubberke E. How clean is clean enough? An observational pilot study to assess central sterilization processing efficacy with adenosine triphosphate levels. Am J Infect Control. 2019 Sep 10. pii: S0196- 6553(19)30750-3. doi: 10.1016/j.ajic.2019.08.006.