By Kelly M. Pyrek
While absolute perfection in manufacturing can be difficult to come by, efforts are being made by healthcare-product manufacturers to ensure that the impervious gowns and surgical drapes that healthcare workers count on are indeed providing the anticipated level of barrier protection.
In September, the Association for the Advancement of Medical Instrumentation (AAMI) announced it had updated a standard with an additional measure that one expert says can help ensure that subpar healthcare gowns and drapes don’t find their way into operating rooms. The revised standard is ANSI/AAMI PB70:2012, "Liquid barrier performance and classification of protective apparel and drapes intended for use in healthcare facilities."
The change to PB70 is “going to tighten the standard up as to what is acceptable and can take to market,” says Donna Swenson, BS, CSPDM, CRCST, CHL, co-chair of AAMI’s Protective Barrier Committee, which updated the document.
The standard includes the requirements for testing how well drapes and gowns used in surgeries protect the wearer from potentially infectious body fluids. It classifies the products into four levels based on the amount of protection they offer. While the standard is primarily for manufacturers, healthcare providers also find it helpful, Swenson says. The standard helps users understand when they pull a particular product off the shelf what kind of protection they can except to get from it.
Sharon Van Wicklin, MSN, RN, CNOR/CRNFA, CPSN, PLNC, perioperative nursing specialist with the Association of periOperative Registered Nurses (AORN), a member of AAMI's Protective Barrier Committee, notes, "Surgical gowns and drape products are used to establish a barrier that provides protection for both the patient and the perioperative team member by minimizing the passage of microorganisms, body fluids, and particulate matter between sterile and unsterile areas during surgical and other invasive procedures. This newly revised ANSI/AAMI standard provides information on the performance tests that are used to classify surgical gowns and drape products. Knowledge of these defined classifications will help perioperative team members be better informed when selecting gowns and drapes, and to choose the product that will provide the most appropriate level of protection for the procedure."
Swenson explains that the revision focuses on the acceptance criteria for a product lot. The standard adds what is called a rejectable quality level (RQL) to help determine if the test results are acceptable and if the product can be released. The previous version of PB70 recommended manufacturers use only an acceptable quality level (AQL) to set the criteria. Now it recommends manufacturers use both AQL and RQL.
“RQL is generally defined as that level of quality that the sampling plan will accept 10 percent of the time,” Swenson says. “This means lots at or worse than the RQL are accepted—at most—10 percent of the time. In other words, they are rejected at least 90 percent of the time. Using both AQL and RQL criteria will provide a high probability that the consumer will only receive unacceptable product a very small percentage of the time.”
The impact of the revised standard on most manufacturers will be minimal, as they already are doing everything right. "A majority of the manufacturers have been conducting stringent testing to ensure they were in compliance with the acceptable quality level in the first place; now we have added the rejectable quality level component, basically looking at it from the users' standpoint," Swenson says. "The additional testing does prevent manufacturers from reducing the amount of sampling that they do, which is sometimes done in industry when you have a long history with a product."
That miniscule chance of getting a subpar gown or drape is nothing to be concerned about, Swenson emphasizes. "I don't think people need to be worried because nothing is 100 percent and our standards are not to 100 percent either," she says. "The testing that would be required to get a product near 100 percent would be so cost-prohibitive that no one could do it. So we must be realistic while ensuring that healthcare professionals are getting the level of protection they need for the type of procedure they are doing. Many of the gown and drape manufacturers are not going to have any problems adding this to their criteria at all, and in fact they already may be doing more than what is necessary."
Swenson continues, "A representative from a manufacturer contacted me with a question about how frequently they should be doing the RQL requirement. I responded based on what the FDA normally requires, and the goal is to keep manufacturers from performing reduced sampling. The manufacturer was getting questions from their customers and sales force as to whether they were compliant and it appears they were more than compliant. In statistics, once you build a body of knowledge, it can be acceptable to reduce the amount of times you do quality checks on product lots. What AAMI has done is say 'No, you have to do RQL testing too, so you are not going to be able to reduce your sampling at the plant.' So this is ensuring that you are going to get the same type of testing all of the time. It increases your probability of getting a good quality product just a little bit more. Statistically, if I run a lot of 1,000 but I do it 10 times, I have a certain level of probability that I am going to meet a certain quality level. If I run it 5,000 times and I get the same results, my probability gets tighter. But if I say I run it 5,000 times and everything has been good and I cut back on my testing, long-term, my probability could drop a little because I might miss some things that might have changed in my process. Revising the standard says you can't do that."
At most the revised standard could have the greatest impact for small companies and those new to the marketplace. "The big manufacturers have been doing the testing all along, so the change in the standard is partially for new players in the marketplace and new products," Swenson says. There has been a lot of emphasis on isolation gowns these days and we wanted to be clear as to what our expectations were if manufacturers wanted to claim certain levels of protection. They need to ensure their production processes are consistent and they are conducting both AQL and RQL checks."
Swenson adds, "Regarding new technology, statistically you need to do a high level of testing for quality because you haven't proven anything yet. The best example I can give is when I validate my sterilization process. When I start, I do quarterly validation because I have no body of knowledge -- the fact that it worked once doesn't mean it's going to work again and again. So I start doing quarterly validation, and even when I get to where I am doing annual validation, I wait until I get to that point before I go to parametric release -- it's like I don't jump into parametric release suddenly, even though my initial testing shows everything is okay and I should be able to rely on parameters. People in quality tend to be very cautious, so they look closely at levels of confidence with processes. Until they really feel comfortable with a process, they won't go to the next level. The RQL requirement is adding an additional level of confidence to show we are looking at it from the manufacturing and the user side."
Because a number of representatives from manufacturers and testing labs are members of the AAMI’s Protective Barrier Committee that was tasked with revising the standard, there was strong manufacturer and industrial representation, according to Swenson.
In fact, the idea for revising the standard originated from the manufacturing side. "Manufacturers felt we needed to look at quality from both standpoints -- the manufacturer and the end user," Swenson says. "They thought that tightening the standard a bit more was needed, thereby ensuring the end user of the gown or drape is going to get the barrier protection they assume they are getting."
"We suggested and promoted testing multiple lots for initial classification to ensure product consistency," explains Joe Palomo, senior principal engineer in research and development at Cardinal Health. "The testing of multiple lots, as opposed to a single lot, assures a more precise characterization of the product and accurate AAMI barrier rating.
As for the RQL requirement's impact on Cardinal Health’s product sampling processes, Palomo says, "Cardinal Health was already pulling a large sample, so we don’t expect much impact. However, the use of the RQL requires all manufacturers to pull a larger sample than was initially allowable. As with the testing of multiple lots, the larger sample driven by the RQ enables a more precise characterization of the product and accurate AAMI barrier rating. The effect of both changes is to provide a more uniform evaluation approach for manufacturers and, for end users, a higher degree of assurance that the rating claimed is accurate."
The standard also includes a change that gives manufacturers greater latitude when testing their products, Swenson says. When manufacturers test their fabric, they place a blotter paper underneath it and then spray the fabric with water. The blotter paper absorbs whatever water goes through the fabric. The amount of water on the paper determines the product’s level of protection, Swenson says.
For years, manufacturers have used a test from the American Association of Textile Chemists and Colorists (AATCC), but the blotter paper employed in that test is no longer being manufactured, although some test houses still have a supply. The standard now allows manufacturers to use a test called WSP80.3, which does not require the use of any specific paper, but allows the use of any blotter paper that meets the specifications in PB70. “It is a similar test that should give equivalent results,” Swenson says. “It is just giving manufacturers a little bit of flexibility, but maintaining the same standard.”