When a number of antimicrobial-impregnated barrier products began generating some industry buzz, Healthcare Purchasing News set out to explore whether they would be long-lasting contributors to a hospital’s infection control practices or flash-in-the-pan headline grabbers that would quickly disappear like Edsels. Do they represent a trend or a fad?

Observed Mary Faith Tamborino, Division Manager, on+qor, a division of All-Pak Inc. (formerly BodyGardz by Performance Textiles), Bridgeville, PA: "I would consider this a trend." On the other hand, Frank Czajka, Senior Product Manager, Medline Inc., Proxima Division, Mundelein, IL, said, "In some applications, use of antimicrobials would be a fad, but not for incise drapes." To cap it off, Gayle Peters, Health Care Communications, 3M Health Care, St. Paul, MN, chimed in that "Ioban antimicrobial incise drapes have been available to help surgeons reduce the risk of infection for about 20 years."

So how do they work?
Curt Koehn, Marketing Director, Drapes and Gowns, Cardinal Health Inc., McGaw Park, IL, explained how the disinfectant in the company’s IsoBac absorbent reinforcement works: "A quaternary amine is impregnated in our cardiovascular and orthopedic drape fenestration reinforcements. The quaternary molecule, Aegis AEM 5700, is bonded to our material. It carries a positive charge, whereas bacteria carry a negative charge. The antimicrobial’s positive charge disrupts the bacteria cell membrane, causing its contents to drain, inactivating the bacterial cell and preventing its reproduction; thus, IsoBac has the ability to suppress growth of microorganisms around the wound site during cases where infection is of greatest risk. It has a greater than 99% bacteriostatic kill rate against antibiotic-resistant microorganisms." The disinfectant in on+qor’s garments works similarly.

Medline’s Acti-Gard line employs an iodine-based antimicrobial. Iodine is the main prep used by most surgical teams, and it’s proven very effective against the most common microorganisms associated with postoperative infection," Czajka said. 3M’s Ioban drapes also are impregnated with iodophor. "It’s in the adhesive," said Peters, "to keep microbial counts low."

Cardinal Health Tiburon drape

Extra protection for high-risk surgery
Koehn explained that antimicrobial barrier products are meant for use during high-risk surgeries and are not intended to be used routinely. Peters added: "A contiguous incise drape helps to provide a sterile surface, isolating the incision site." According to Czajka, "These are specialty products for use in specific cases where infection is a risk and the physician feels the need to have additional control for common bacteria. They’re used in orthopedic surgery, where there’s open bone, and in cardiovascular surgery to kill and keep killing bacteria during the case. They keep the operative site clear." However, Czajka added, "The use of traditional prep and surgical drapes are very effective in maintaining a sterile field. The antimicrobial incise drapes provide an additional measure of security."

Still, some would argue that the combination of sterile surgical drape and skin prep are adequate even for surgery at high risk of infection. William Schaffner, M.D., Chairman of the Department of Preventive Medicine and Professor of Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN, maintains just that. "We try to reduce the risk of infection to an absolute minimum. The issue in surgery is that, at the time of wound closure, you want as few bacteria in the wound as possible. There is bacterial flora on the surgeon, on the patient, and in the room; however, in the United States, our routine cleaning of operating rooms and our scrubbing, gowning, gloving, and masking of surgeons have reduced transmission of bugs from the environment and from the surgical team to the patient to almost zero. It has been demonstrated time and time again that the vast majority of postoperative wound infections are caused by the patient’s own skin flora. That’s not understood by almost anyone, even some surgeons."

"The trick is to reduce the flora," Schaffner continued. "Patients are instructed to take showers or to bathe the night before with chlorhexidine because it reduces skin flora. The surgical wound is highly vulnerable, and skin prep at the time of surgery is so important. That’s why in the immediate perioperative period, starting literally about a half hour before surgery, during surgery, and for a brief period after surgery, we want antimicrobials on board, administered intravenously, so that there are antimicrobial concentrations in the tissue when the wound closes."

Schaffner also said that when cultures are taken from the wound just before closure, "you very frequently will find, no big surprise, a few bacteria in the wound." That’s because, noted Peters, "Skin can be disinfected but not sterilized." Schaffner illustrated: "Aseptic does not mean sterile; we don’t take a blowtorch to the wound; so, during the course of a procedure, usually from the patient’s own flora, a few bugs get in. That’s why perioperative antibiotic prophylaxis works."

Medline Aurora gown

The importance of published data
Schaffner summarized the importance of scientists’ submitting studies they’ve conducted for publication so that others can make use of the data. "We’re in the era of evidence-based medicine. You can’t just come up with a good idea or a neat concept. You’ve got to demonstrate that a product actually performs the way it’s said to perform," he said. "As one of my friends likes to say, ‘We trust in God; all others must provide data.’ We are obliged, as we introduce new products and other innovations, to have the kind of objective information that will help us to make decisions."

A search on MEDLINE (http://www.ncbi.nlm.nih.gov/
entrez/query.fcgi), brought 10 studies on antimicrobial drapes for human use1-10. All but two were published in the 1980s.

Of the 10 studies concerning drapes impregnated with a disinfectant, results were mixed. It was sometimes difficult to compare results, because the studies didn’t all use the same methods or have the same objectives; consequently, how the drapes’ performance was evaluated varied. A few studies found reductions in numbers of potential pathogens or in wound infection rates when antimicrobial drapes were present.1,6,9 Other studies pointed out that, even though the survival rate of bacteria may have been reduced by using antimicrobial drapes, it represented little or no difference in wound infection rates when compared to conventional preparations.3,5,7,8

Medline Industries Acti-Gard

Is any benefit gained?
"Would there be some additional protection provided by drapes that have antimicrobials in them?" posed Schaffner. "That’s a good question, a question that you could test. You could test in animal surgery. It could be tested prospectively with a randomized, controlled trial in humans. I would anticipate that, if there is any benefit, it is going to be marginal. By doing everything correctly in simple, clean surgery, the infection rate is less than 2% anyway. In some types of surgery, the infection rate is even lower; for example, joint-replacement surgery has a stupendously low rate, less than 1%. To show that, in addition to everything else we do already, you have an additional benefit from antimicrobial-impregnated drapes, you’d have to do very large studies, because you start out with a tiny infection rate."

A matter of choice
Should we conclude that vendors who sell these products are out to make a fast buck? Not at all, said Schaffner. "Give the companies the benefit of the doubt. Let’s think that they have good intentions and that there are people in the company who think the way a lot of doctors still think, that the more you use antimicrobials the better it is. They may be convinced by their own logic that they have a product that is useful and benefits patients, but," the doctor avows, "we’re interested in evidence-based medicine."

Koehn agreed that there is no wealth of studies definitively proving benefits of using antimicrobial drapes, but he said, "As long as our customers feel the value is there and ask for it, we’ll make it available in our Tiburon and Optima lines."

References

1.Conn J Jr, Bornhoeft JW, Almgren C, Mucha DP, Olderman J, Patel K, et al. In vivo study of an antimicrobial drape system. J Clin Microbiol 1986;24:803-808.

2.Lewis DA, Leaper DJ, Speller DC. Prevention of bacterial colonization of wounds at operation: comparison of iodine-impregnated (‘Ioban’) drapes with conventional methods. J Hosp Infect 1984;5:431-437.

3.Ritter MA, Campbell ED. Retrospective evaluation of an iodophor-incorporated antimicrobial plastic adhesive wound drape. Clin Orthop 1988;228:307-308.

4.Alexander JW, Aerni S, Plettner JP. Development of a safe and effective one-minute preoperative skin preparation. Arch Surg 1985;120:1357-1361.

5.Manncke K, Heeg P. Experimental and clinical studies of the efficacy of an antimicrobial incision drape. [Article in German]. Chirurg 1984;55:515-518.

6.Yoshimura Y, Kubo S, Hirohashi K, Ogawa M, Morimoto K, Shirata K, et al. Plastic iodophor drape during liver surgery: operative use of the iodophor-impregnated adhesive drape to prevent wound infection during high risk surgery. World J Surg 2003;27:685-688.

7.Dewan PA, Van Rij AM, Robinson RG, Skeggs GB, Fergus M. The use of an iodophor-impregnated plastic incise drape in abdominal surgery: a controlled clinical trial. Aust N Z J Surg 1987;5:859-863.

8.Hagen KS, Treston-Aurand J. A comparison of two skin preps used in cardiac surgical procedures. AORN J 1995;62:393-402.

9.Fairclough JA, Johnson D, Mackie I. The prevention of wound contamination by skin organisms by the pre-operative application of an iodophor impregnated plastic adhesive drape. J Int Med Res 1986;14:105-109.

10.Geelhoed GW, Sharpe K, Simon GL. A comparative study of surgical skin preparation methods. Surg Gynecol Obstet 1983;157:265-268.