Pertinent Insights On Antimicrobial Dressings And Infection Control

These expert panelists debate the use of antimicrobial dressings versus regular wound dressings, the efficacy of antiseptics and whether sterile gloves are useful in reducing the risk of infection.

Q:

Do you use any antiseptic, such as alcohol, hydrogen peroxide, Dakin’s solution or povidone-iodine solution for wounds?

A:

Although he notes that the above listed antiseptics are toxic to wounds and prevent wound healing, Khurram Khan, DPM, says their judicious use may be required as necessary on infected wounds. With infected wounds, he says his first concern is resolving infection. Once the infection has resolved, Dr. Khan shifts his attention to wound healing.

   Dr. Khan uses alcohol sparingly around wounds to clean the area and employs hydrogen peroxide around the wound to cleanse any bleeding/dry blood. He will use Dakin’s solution sparingly for severely infected wounds but only for one or two days until the infection resolves. As for povidone-iodine, he will use this in wounds as needed until any infection and cellulitis resolves, especially in the hospital setting. Dr. Khan also uses povidone-iodine in wounds that are macerated to help in the drying process and when splinting is required.

   Once cellulitis resolves, Dr. Khan switches the dressing to a less toxic dressing that will help with the wound healing process. He also uses Hibiclens quite a bit when scrubbing a wound, and cites research showing that H2O2 and iodine decrease migration of fibroblasts whereas chlorhexidine and silver enhance growth at low doses.1 Therefore, he says using a chlorhexidine scrub for one minute with a saline rinse will not destroy the wound healing potential and research has shown this to inhibit bacterial growth on skin for up to eight hours.1

   Kazu Suzuki, DPM, CWS, does not see a good reason to recommend alcohol or hydrogen peroxide for wound irrigation, either at home or in the clinic. He also avoids using Dakin’s solution (diluted bleach solution), which is often recommended for packing infected wounds.

   “Those aseptic solutions are terribly irritating and toxic to the granulation tissues in the wound bed,” he says. “Unfortunately, we do encounter many of our wound care patients, coming in for the first visit, using these antiseptic solutions to ‘clean’ the wounds and we have to teach them that ‘you should not put any liquid in your wounds that you wouldn’t put in your eyes.’”

   Thanh Dinh, DPM, does not routinely use antiseptic solutions for cleansing wounds. In addition to demonstrating little benefit over saline irrigation, antiseptic solutions are more likely to cause cellular toxicity to healing wounds, according to Dr. Dinh. Furthermore, she notes limited data on systemic absorption of these solutions and limited evidence for effective prevention of infection.

   Similarly, Ryan Fitzgerald, DPM, stresses the importance of managing the potential for wound colonization and infection, noting this often includes the use of antiseptic wound cleansers and dressings. However, he urges clinicians to be careful when selecting an antiseptic as many can be too caustic to the fragile wound environment.

   Dr. Suzuki only uses an antiseptic solution when using a Betadine solution for dry gangrenous wounds to “temporize” those wounds. Theoretically, he says Betadine will dehydrate the gangrenous wounds and make them less likely to turn into “wet” gangrene. This also provides time to schedule for surgical or auto-amputation, according to Dr. Suzuki. However, he notes such an effect is anecdotal and he is unaware of any good study tracking the natural history of gangrenous wounds and the effect of Betadine use.

   For an antiseptic, Dr. Fitzgerald often utilizes Dakin’s solution in significantly contaminated wounds. In those patients with suspected Pseudomonas infection, he frequently uses an acetic acid in conjunction with standard of care modalities to promote wound progression toward healing.

   Dr. Suzuki is participating in a trial on a hypochlorous acid solution (Vashe Wound Therapy, Puricore) for wound irrigation and as an ultrasound debridement medium. As he notes, hypochlorous acid (weak acid, HClO) smells like a bleach but it is a tissue-friendly solution that is naturally synthesized within human neutrophils to kill bacteria. Since it is pH-balanced for human use, he says Vashe is not irritating or toxic to granulation tissues or mucosal membranes. He calls Vashe Wound Therapy “a neat method to add another layer of attack to combat wound surface bacteria and biofilms.”

Q:

Do you use sterile gloves when you take care of lower extremity wounds?

A:

Drs. Suzuki and Khan see no reason to use sterilized gloves. Noting that human skin is never sterile and lower extremity wounds are inherently contaminated with bacteria, Dr. Suzuki says sterile gloves are also “vastly more expensive” in comparison to regular rubber gloves.

   Dr. Khan cites studies demonstrating no difference in infection rate in wounds using sterile versus non-sterile gloves, sterile versus non-sterile dressings or sterile saline versus tap water.2-4 He recognizes the goal is to stay as clean as possible and one can prevent cross-contamination by frequent switching of gloves after debridement of the wound, cleansing and application of a new dressing.

   Dr. Khan often switches gloves three or four times during a single dressing change as does Dr. Suzuki.

   Dr. Dinh and Dr. Fitzgerald do not use sterile gloves for ulcer debridement or application of clean (not sterile) dressings in the office or inpatient hospital setting. However, both will use sterile gloves to apply bioengineered alternative tissues. Dr. Fitzgerald also uses sterile gloves when performing procedures such as a percutaneous tendo-Achilles lengthening.

Q:

What kind of antimicrobial dressings do you use?

A:

Dr. Suzuki routinely uses silver-containing antimicrobial dressings in the shape of foams (Mepilex Ag, Molnlycke) and calcium alginate or hydrofiber (Silvercel, Systagenix and Aquacel Ag, Convatec). Thus far, he has only seen one case of possible allergic reaction to silver dressings and he believes such allergies are pretty rare. Dr. Suzuki also uses medical-grade sterile honey gel (Medihoney, Derma Sciences), an antimicrobial and osmotic debriding agent.

   Dr. Suzuki has also started using a new product, Cutimed Sorbact WCL (BSN Medical), a non-adherent contact layer dressing coated with dialkyl carbamoyl chloride, a fatty acid derivative that binds to bacteria cell walls and prevents bacterial growth. He notes the product is not metallic, is inexpensive and it is not linked to any allergic reaction or bacterial resistance.

   For Dr. Fitzgerald, the use of antimicrobial dressings depends somewhat on the wound type and location. In the context of a potentially infected or colonized wound, he will often utilize some sort of silver-impregnated dressing in conjunction with other modalities such as alginates, depending on the degree of drainage.

   Dr. Dinh uses antimicrobial dressings in certain clinical situations. These include reducing the bioburden in preparation for applying an advanced bioengineered skin substitute or in the infected ischemic wound in which systemic antibiotics may not provide adequate tissue concentrations as a result of poor tissue perfusion. In those instances, she usually selects silver containing dressings, povidone-iodine or cadexomer-iodine preparations. In addition to decreasing the bacterial bioburden, she says such dressings have demonstrated effectiveness against methicillin resistant Staphylococcus aureus in vitro.

   Dr. Khan notes “very little evidence” for dressings in regard to preventing infection or slowing the progression of biofilm. He uses antimicrobial dressings more as a convenience factor. The seven-day dressings that release silver are mainstays for him as they allow the patient to keep a dressing on for seven days (under an Unna boot or a total contact cast). Dr. Khan says he will also employ these dressings if the patient doesn’t qualify for home health.

   “Otherwise, the goal is to maintain a moist wound healing environment and whichever dressing of the month you choose to obtain will be fine,” he says.

   Although Dr. Suzuki is a “big fan” of medical maggots (Monarch Labs), he does not use them routinely because of the acquisition cost, which patients must pay out of pocket.

Q:

What is your thought process in choosing antimicrobial dressings versus conventional dressings?

A:

Dr. Dinh cites “a great deal of confusion” regarding the role of antimicrobial dressings in treating and preventing infection in wounds. She notes that studies evaluating the use of such dressings are not standardized and the supportive evidence is meager. However, Dr. Dinh notes the use of these dressings may be appropriate in certain clinical situations.

   Dr. Suzuki also notes a lack of in-vivo clinical evidence to suggest that antimicrobial dressings reduce wound infection rates. However, he has witnessed many patients who developed wound infection after they switched from antimicrobial dressings (for example, Mepilex Ag) to a conventional dressing (regular Mepilex).

   Since one cannot completely sterilize any open wounds and since there are so many Staphylococcus aureus carriers among patients with wounds, he theorizes that it does make sense to use antimicrobial dressings. Although the cost of purchasing antimicrobial dressings can be an issue, Dr. Suzuki notes one might be able to justify a few dollars of additional cost per dressing, given that sepsis in the older patient populations can be devastating.

   Dr. Dinh says one must balance the benefits of antibacterial activity against the potential cellular toxicity to the healing host tissues. When deciding on an antimicrobial dressing, she advises considering the patient’s risk status, wound bioburden and the presence of biofilm. In patients who are immunocompromised, ischemic or have a history of resistant organisms, Dr. Dinh notes the use of antimicrobial dressings may be more important to reduce the risk of infection. Additionally, the degree of bioburden and the presence of a biofilm in chronic wounds can significantly delay the healing rates, and she says one should use antimicrobial dressings to promote wound closure.

   If a wound is colonized or infected, Dr. Fitzgerald will proceed with an antimicrobial dressing over a more conventional dressing to address this component of wound healing. He also uses these types of dressings in situations in which he believes the potential for contamination is significant.

   Dr. Khan notes that cost and the ability to obtain dressings play large roles in what he can use in the inner city clinics. He tries to obtain antimicrobial dressings to help patients keep dressings on longer and reduce the overall time and costs associated with daily dressing changes by nurses, but he says it has become an issue of availability. If Dr. Khan can trust the patient to use a conventional dressing or if he or she qualifies for home health, he will ask for daily dressing changes to maintain a moist wound healing environment.

   “Either way, the old adage of ‘It’s not what you put onto a wound but what you take off the wound’ will allow it to heal,” says Dr. Khan.

   Dr. Dinh is an Assistant Professor of Surgery at Harvard Medical School and is affiliated with the Beth Israel Deaconess Medical Center in Boston. She is a Fellow of the American College of Foot and Ankle Surgeons.

   Dr. Fitzgerald is in private practice at Hess Orthopaedics and Sports Medicine in Harrisonburg, Va. He is an Associate of the American College of Foot and Ankle Surgeons.

   Dr. Khan is an Associate Professor at the New York College of Podiatric Medicine. He is an attending in the Surgery Department at Metropolitan Hospital in New York City. He is an Associate of the American College of Foot and Ankle Surgeons.

   Dr. Suzuki is the Medical Director of the Tower Wound Care Center at the Cedars-Sinai Medical Towers. He is also on the medical staff of the Cedars-Sinai Medical Center in Los Angeles and is a Visiting Professor at the Tokyo Medical and Dental University in Tokyo.

References

1. Thomas GW, Rael LT, Bar-Or R, et al. Mechanisms of delayed wound healing by commonly used antiseptics. J Trauma. 2009; 66(1):82-90.
2. Slotts NA, Barbour S, Griggs K, et al. Sterile versus clean technique in postoperative wound care with open surgical wounds: a pilot study. J Wound Ostomy Continence Nurs. 1997; 24(1):10-18.
3. Alqahtani M, Lalonde DH. Sterile versus nonsterile clean dressings. Can J Plast Surg. 2006; 14(1):25-27.
4. Fernandez R, Griffiths R.Water for wound cleansing. Cochrane Database Syst Rev. 2008 Jan 23;(1):CD003861.

   For further reading, see “Minimizing The Risk Of Perioperative Infections In Patients With Wounds” in the March 2012 issue of Podiatry Today.