By the WoundSource Editors

In chronic wounds, debridement can be used to remove dead and necrotic tissue or to remove foreign material. Debridement has repeatedly been shown to expedite healing and is recognized as a critical element in wound care.¹ There are several methods of debridement, some of which may or may not be the best option, depending on the health care setting, so practitioners should follow their individual state licensure boards’ professional scope and practice and the facilities’ policies when considering debridement.

Understanding the role of debridement requires an understanding of the layers of skin and their functions. The deepest layer is the subcutaneous, or hypodermis, which is made up of fat, connective tissue, and blood vessels. Above that is the dermis, which contains the tough connective tissue, hair follicles, nerves, sweat glands, capillaries, and arterioles. The top layer, or epidermis, has no blood vessels and acts as the barrier for the body.²

The Stages of Wound Healing

Wounds are injuries to the skin and, in some cases, the underlying tissue. The wound healing process, or wound healing cascade, goes through several phases in a full-thickness wound, each of which is explained briefly here:³

• Hemostasis: Hemostasis starts within minutes of receiving an injury, and during this phase, blood flow to the dermis layer increases and clot formation begins. Small and superficial wounds typically have a short hemostatic period.
• Inflammatory: The inflammatory period generally lasts one to five days after a wound occurs, and during this time, physiological changes can be present, such as erythema, warmth, and pain. The wound may also experience re-epithelization as new cells begin to grow and activate.
• Proliferative: The proliferative stage occurs only in full-thickness wounds, and during this time, granulation tissue replaces the wounded tissue. This process must be complete before the epithelial covering can occur.
• Maturation/remodeling: This is the final stage in the wound healing cascade for full-thickness wounds, and it is demarcated by the formation of scars. This process may take months or even years to complete and form a mature scar. Initial scar appearance is often red, although this pigmentation fades as the capillaries regress.

Chronic wounds occur when the wound becomes stalled in the inflammation or proliferative phases. The most common cause of delayed healing in chronic wounds is infection. Microbial contamination of wounds can progress to colonization, to localized infection, through to systemic infection, sepsis, multi-organ dysfunction, and subsequent life- and limb-threatening infection. The actual determination of infection can be complicated by the presence of biofilms, not on the surface but deep in wound tissue.⁴ Biofilm presence also contributes extensively to keeping the wound in a state of prolonged inflammation by the stimulation of nitric oxide, inflammatory cytokines, and free radicals.⁵ As a result, one of the best ways to get the wound back on track is effective wound bed preparation beginning with debridement and use of topical antimicrobials. It is important to bear in mind the problem of increased microbial resistance to antibiotics, so using antiseptics, which are less likely to result in resistance, may be a more effective choice.

Wounds often need to be debrided to provide the clinician with an opportunity to assess the wound bed more accurately. The presence of unhealthy tissue can also slow the healing process, increase the risk of infection and sepsis, and provide an environment ideal for bacterial growth. Debridement offers a way to remove this unhealthy tissue.

Methods of Debridement

Treating chronic wounds by using debridement often requires that the proper technique, or method, is used. Ideally, debridement would also remove all of the dead or necrotic tissue at the time of treatment; however, there are often complications, particularly when biofilms repopulate. In this scenario, patients often have to return for additional debridement until the wound heals.⁶ Selecting the proper technique can help to minimize these complications, and potential options include:⁶

• Biological (Biosurgical) debridement involves the introduction of live, sterile bottle fly larvae (Lucilia sericata) into the wounds. This type of debridement provides disinfection of the wound by inhibiting biofilm growth; however, it should be used only on extremities because there can be additional complications in or near body cavities.
• Enzymatic debridement uses enzymes to break down and dissolve necrotic tissue. Although it is generally very safe and easy to use, it can be slow acting and is not suited for injuries that require the elimination of large amounts of necrotic tissue.
• Autolytic debridement uses one’s own body fluids that contain endogenous enzymes to maintain a moist wound environment as non-viable tissue liquifies. There is a higher risk of infection with this method.
• Mechanical debridement removes the unhealthy tissue using abrasive force, generally gauze, soft fiber, wet-to-dry-dressings, or pulse lavage. This technique is inexpensive and can be done in any clinical setting, although it is a very slow process that often causes pain.
• Surgical debridement is the use of a curette, scalpel, scissors, rongeur or other surgical instrument, such as a hydrosurgical system, to remove unhealthy tissue. Wounds that are debrided more frequently can experience a higher rate of healing.⁷

Combined debridement uses more than one method of debridement and is particularly successful when used on complex wounds.⁸ However, there are certain conditions in which debridement should not be used, such as:⁶

• Ischemic wounds of the extremities with critically compromised blood flow
• Dry, stable eschars of the heel without signs of edema, fluctuance, or drainage
• Calciphylaxis wounds with expanding tissue necrosis and a violaceous border
• Pyoderma gangrenosum when there is a prominent and raised, active border

Why Debride

Chen and Wang studied chronic pressure ulcers that were described as dry, hard, black, crusting eschar.⁹ Conservative sharp debridement was performed using an eye vascular clamp to separate necrotic tissue from the wound bed. The necrotic tissue was then cut or trimmed with sterile scissors, and 5mm thick hydrogel was then applied to promote autolysis. Results – All wounds healed.⁹

Reuven Gurfinkel et al. studied burns with eschar.¹⁰ Both wounds were of the dry and liquefied necrosis type. Combined methods used were ultrasonic and enzymatic debridement. Anesthetic gel (esracaine 2%) was applied, followed by combined ultrasonic and enzymatic debridement in flap perforation within two to five minutes. Result – This combined approach was more rapid and effective than either method alone.¹⁰

Conclusion

Knowing and understanding when debridement is necessary and which method is most appropriate are essential for clinicians who treat chronic or complex wounds. Ultimately, debridement should lead to better healing, and identifying the most appropriate method can promote optimization of the healing process and more favorable patient outcomes.

References
1. Frykberg RG, Banks J. Challenges in the treatment of chronic wounds. Adv Wound Care. 2015;4(9):560–82.
2. Takeo M, Lee W, Ito M. Wound healing and skin regeneration. Cold Spring Harb Perspect Med. 2015;5(5):1–12.
3. Sorg H, Tilkorn DJ, Hager S, Hauser J, Mirastschijski U. Skin wound healing: an update on the current knowledge and concepts. Eur Surg Res. 2017;58(1–2):81–94.
4. Gould L, Abadir P, Brem H, et al. Chronic wound repair and healing in older adults: current status and future research. Wound Repair Regen. 2015;23(1):1–13. doi: 10.1111/wrr.12245. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4414710/. Accessed April 13, 2019.
5. Leaper D, Assadian O, Edmiston CE. Approach to chronic wound infections. Br J Dermatol. 2015;173(2):351–8. doi: 10.1111/bjd.13677. Available at: https://www.ncbi.nlm.nih.gov/pubmed/25772951. Accessed March 13, 2019.
6. Carpenter S, Shaffett TP. Choosing the best debridement modality to ‘battle’ necrotic tissue: pros and cons. Today’s Wound Clinic. 2017;11(7).
7. Wickline S. Wounds heal better when debrided often. MedPageToday. 2013. www.medpagetoday.com/dermatology/generaldermatology/40692. Accessed on February 21, 2019.
8. Liu W, Jiang Y, Wang Y, Li Y, Liu Y. Combined debridement in chronic wounds: a literature review. Chin Nurs Res. 2017;4(1):5–8.
9. Chen MH, Wang YM. The treatment and nursing care methods of combined debridement in pressure ulcer. J Nurs Train. 2010;25:478–9.
10. Gurfinkel R, Lavon I, Cagnano E, et al. Combined ultrasonic and enzymatic debridement of necrotic eschars in an animal model. J Burn Care Res, 2009;30:505–13.

The views and opinions expressed in this blog are solely those of the author, and do not represent the views of WoundSource, Kestrel Health Information, Inc., its affiliates, or subsidiary companies.