Biofilm: this term is frequently used in the wound care space, but biofilm continues to be largely undertreated in wound care. What do the bedside nurse or clinician need to know about biofilm? Should clinicians care less about biofilm on a maintenance or palliative wound versus a wound they are actively trying to heal? Let's address these questions and get to the root of the biofilm in managing complex wound cases.

Biofilm Review

Biofilms, according to an article published in the Journal of Emerging Infectious Diseases, are microorganisms that attach to surfaces and then secrete a polysaccharide coating or "slime," which becomes the substance known as a biofilm.¹ Over 50 years ago, Dr. R.J. Gibbons made some of the first reports about bacterial biofilms while translating his observations into clinical relevance.² Scientific studies have proved that the formation of certain types of biofilm leads to chronically stalled wounds when the biofilm is not addressed. Studies have shown that over 90% of chronically stalled wounds contain biofilm.³ That's too large a percentage to ignore. What are some of the therapeutic methods to control, reduce, or eliminate biofilm, and for which wound types are they indicated?

Biofilm Management Methods

Biofilm must be addressed in an ongoing and repeated manner.³ Wound care clinicians should add tools to their wound healing arsenal that specifically address biofilm. What are these tools? Sharp debridement is an effective way to remove senescent cells, get rid of unwanted wound debris, stimulate growth of new healthy cells, and, of course, remove biofilm. Sharp debridement is an effective option for both a healing wound and a maintenance wound. Combining debridement methods has been found to be an advantage in managing complex wounds and different pathological tissues since 2006.⁴ One common method of combining debridement techniques is using enzymatic debridement first to liquefy the tissue and then following with sharp debridement. Combining debridement methods in this way can ensure that you are removing as much dead tissue from the wound as possible and helping to promote wound healing.

Palliative wounds, however, should get the "double take" when it comes to sharp debridement. With complex palliative wounds, aggressive treatments are not always wanted. Clinicians need to consider the patient's wishes, the care plan goal, and overall comfort. It does not mean that sharp debridement should be completely eliminated as an option, but it does mean having a conversation with the patient in determining appropriate treatment interventions.. Knowing that biofilm becomes resistant to therapeutic maneuvers at 48–96 hours after formation means that clinicians must keep biofilm from reattaching and reforming.³ Tissue cultures performed with next-generation DNA sequencing, if available, can help clinicians target a regimen of antibiotics specific to the bacteria causing the issue, as well as test for genetic markers on the bacteria that show whether these bacteria are developing resistance to an antibiotic.

Clinicians can clear the infection faster using targeted medications while being good stewards of antibiotics. Antibiotics are appropriate for all wound types, including maintenance wounds, palliative wounds, and healable wounds when they are administered topically or orally. Intravenous antibiotics are frequently limited to maintenance and healable wounds. Bacteria and biofilm struggle to exist and proliferate in acidic pH environments; therefore, another strategy to manage, decrease, or eliminate biofilm is to alter the pH of the wound bed to a more acidic environment.⁵ Chronic wounds generally have an alkaline pH of 7.2–8.3.^6,7 Adding a non-cytotoxic acidic biocidal wound cleansing agent to the wound cleansing routine is ideal for healable, maintenance, and palliative wounds.^8,9 Additionally, these wound cleansing agents can often be used with pulse lavage or instill features with negative pressure wound therapy, thereby disrupting biofilm even further. The last item to consider for biofilm management in complex wound care is the wound dressing. Not all wound dressings have a biofilm indication, so clinicians should keep a running list of the dressings that are listed for biofilm management.

Conclusion

Biofilms are present in the majority of complex chronic wounds, and prevent clinicians from reaching goals of safely healing or managing chronically stalled wounds. Biofilms can be the cause of chronically stalled wounds, but there are several different treatment options available for clinicians. Most of the treatment options are great options for all wound types (i.e., healable, maintenance, or palliative).

References

1. Donlan RM. Biofilms: microbial life on surfaces. Emerg Infect Dis. 2002;8(9):881-890.

2. Jefferson KK. What drives bacteria to produce a biofilm? FEMS Microbiol Lett. 2004;236(2):163-173.

3. Attinger C, Wolcott R. Clinically addressing biofilm in chronic wounds. Adv Wound Care. 2012;1(3):127-132.

4. Liu WL, Jiang YL, Wang YQ, Li YX, Liu YX. Combined debridement in chronic wounds: a literature review. Chin Nurs Res. 2017;4(1):5–8. Available at: https://www.sciencedirect.com/science/article/pii/S2095771817300063. Accessed July 24, 2019.

5. Nagoba BS, Suryawanshi NM, Wadher B, Selkar S. Acidic environment and wound healing: a review. Wounds. 2015;27(1):5–11.

6. Sharpe JR, Harris KL, Jubin K, Bainbridge NJ, Jordan NR. The effect of pH in modulating skin cell behaviour. Br J Dermatol. 2009;161(3):671–673.

7. Gethin G. The significance of surface pH in chronic wounds. Wounds UK. 2007;3(3):52–56.

8. Gottardi W, Nagl M. N-chlorotaurine, a natural antiseptic with outstanding tolerability. J Antimicrob Chemother. 2010;6(3):399–409.

9. Corca-Huber D, Ammann CG, Fille M, Hausdorfer J, Nogler, Nagl M. Biocidal activity of N-chlorotaurine against biofilm-forming bacteria grown on metal disks. Antimicrob Agents Chemother. 2014;58(4):2235–2239.