Tammy Wright
MILWAUKEE—An independent study that researchers spent two years designing and conducting has linked non-viable and microbial contamination found in operating rooms (ORs) to the use of disposable garments and high personnel traffic during surgical procedures.
Charles Edmiston, Jr., Ph.D., CIC, an associate professor of surgery at the Medical College of Wisconsin and director of hospital epidemiology at Froedtert Memorial Lutheran Hospital (Milwaukee), began the project so he could analyze the density of lint released during intraoperative surgeries. Similar studies in the past, he says, have focused on static environmental sampling techniques, collecting data when the fewest number of personnel are present in the operating room.
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Edmiston: Research was completed during surgery.
'The key to my study is that research was completed during surgery,” he adds, noting that using a busy OR provides hospital personnel with informative statistics they can use to make procedural improvements.
With funding from Kimberly-Clark Corp. (Roswell, GA) and the Surgical Microbiology Laboratory Research Fund/Medical College of Wisconsin, Dr. Edmiston and a team of researchers employed a personal cascade impactor sampling device to take real-time aerosol samples from areas where disposable fabrics constructed from wood pulp polyester and 100 percent polypropylene were present. Two devices were located in the immediate operative environment near the patients, while two other devices were placed in the periphery of the room.
Samples from the two groups of fabrics were collected on Mylar substrates, which were then subjected to scanning electron microscopy (SEM) to identify the predominant fibers recovered. Researchers also used a modified personal cascade impactor to obtain intraoperative airborne samples for microbial analysis from both study groups.
'We found wood pulp polyester in virtually every [group] sample, whereas in the 100 percent polypropylene group, out of 31 prep touch samples taken from inert surfaces, we found only three with one or two strands [of material],” Dr. Edmiston says. 'Of 88 airborne samples, we found only two that contained a few strands of 100 percent polypropylene.”
Dr. Edmiston claims these findings demonstrate that the use of disposable gowns, scrubs and surgical draping made of wood pulp polyester is associated with significant linting when compared to items made of 100 percent polypropylene. The study also found a significant microbial burden present in the busy OR compared to a control or unoccupied environment.
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He says the high levels of non-viable and viable airborne particles detected throughout the OR during the intraoperative period suggests that the cause of the non-viable particles is related to the use and movement of disposable materials, and that the increased bacterial recovery associated with the occupancy of the surgical suite can be related to shedding from personnel in the room.
'This study provides good information and shows that there is a material available with good barrier properties and superior linting and flammability properties,” Jay Sommers, Ph.D., director of Clinical and Scientific Documentation at Kimberly-Clark says, referring to 100 percent polypropylene or the spun bond-melt blown-spun bond (SMS) fabrics used by Kimberly-Clark to manufacture its garments.
Sommers says customers have been surprised by the study's findings. 'They didn't realize there was so much linting in operating rooms,” he notes. 'To date, we've done five lint analyses for customers with problems and one-millionth of the fibers we've found were 100 percent polypropylene, and the rest were wood pulp polyester.”
Those results, according to Sommers, have helped maintain or gain business for Kimberly-Clark.
The major findings of the study, however, are not rocket science to traditional members of the cleanroom industry, according to Brad Whitsel, president of Whitsel Associates, a cleanroom consultancy in Chambersburg, PA.
'To me, hospitals are a riddle and a mystery wrapped up in an enigma,” he says, ' in that they don't use all the tools available to manage or control particles and microorganisms. It's a huge opportunity for businesses that service cleanrooms if hospitals ever start operating like real cleanrooms, which they should have been doing 20 years ago.”
As an example, Whitsel says there are woven continuous filament fabrics on the market today that were designed specifically for use in hospitals with high-density barrier properties that are inherently static dissipative, antimicrobial and liquid repellent for wearer safety, making them superior to disposable garments in many applications.
'There are a lot of things in use in cleanrooms that could be applied to the hospital industry,” he explains, citing air handling systems, wipes and swabs as examples of other products that could help control contamination in operating rooms. 'If you use every tool you can to manage human-sourced particles then you're also controlling microorganisms. However, it seems hospitals would rather deal with infection.”
From a hospital's perspective, Dr. Edmiston's study—which has been the subject of poster sessions at two major medical conferences and published in the Association of Operating Room Nurses (AORN) Journal has other far-reaching consequences.
'The study didn't really bring about closure. It proved to me that [non-viable and viable contamination] is a far flung problem that requires a multi-disciplinary approach,” he says, 'and it opened up a lot of possibilities for future research.”
For instance, Dr. Edmiston, believes it wouldn't take a major leap of faith to examine the potential for lint itself to be a vehicle for the distribution of nosocomial pathogens or hospital-acquired infections in the intraoperative environment.
He says the clinical relevance of his findings poses other questions as well, including:
- does the presence of airborne microbial populations effect the surgical site infection rate?
- can data such as this influence current practice patterns as the presence of personnel and activity level increases particle burden in the OR?
- does the traditional surgical mask play a role in helping disseminate nosocomial pathogens in the OR?
'For certain high-risk patients like those receiving biomaterial devices, the study showed it's possible for the devices to become contaminated by airborne exposure, with infection usually showing after implantation into the host,” explains Dr. Edmiston, who finds this issue to be particularly important given his infection control experience. He also serves as the chairman of the Food and Drug Administration's General Hospital & Personal Use Device Panel.
'To answer these pending questions, I'm currently looking at the issue of surgical masks,” Dr. Edmiston acknowledges. 'I hope to look at the other two issues in the near future.”