Assessing Debridement Options For Diabetic Wounds

Author(s): 
By Eric H. Espensen, DPM

      Diabetic wounds are a common occurrence in wound care centers and private practice. With the escalating rate of diabetes, more and more patients are developing wounds that require care. Wound care for diabetic wounds routinely includes debridement. The term debridement comes from the French desbrider, meaning “to unbridle,” and was probably first used as a medical term by surgeons working in war zones. The medical personnel and surgeons likely recognized that contaminated wounds had a better chance of healing if one surgically removed the damaged tissue to reveal a healthy, bleeding wound surface.       The modern definition of debridement is the removal of dead or necrotic tissue and foreign material from and around the wound with a sterile scalpel, scissors or other methods to expose healthy tissue. Surgical debridement involving extensive and aggressive removal of tissue with or without general or local anesthesia would take place in the operating room. Podiatric physicians may utilize more conservative (sharp) debridement, involving repeated minor tissue sparing debridement, at the bedside or in a procedure room.       Other methods of debridement include mechanical, biological, chemical, enzymatic or autolytic debridement. In 1962, Winter offered one of the earlier profound observations in wound care when he noted that moist wounds heal better in comparison to desiccated wounds.1 Proper debridement allows for exposure of the moist tissues and subsequently allows the practitioner to maintain a proper wound environment.

Underscoring The Importance Of Proper Debridement

      The clinician cannot properly assess or document the status of a diabetic wound until he or she has removed all necrotic, hyperkeratotic and devitalized tissue. Dead tissue acts as a medium for bacterial growth. Dead spaces within the tissue allow for abscess formation which can, in turn, allow for anaerobic bacterial growth such as Bacteroides species or Clostridium perfringens.       The presence of necrotic or foreign material provokes an inflammatory response, which adds to the systemic release of cytokines such as tumor necrosis factor and interleukins, which promote a septic response.       Necrotic tissues can retard wound contraction, the principle contribution to wound closure, when wounds are left to heal by secondary intention.       Diabetic wounds are often covered by scab, eschar or hyperkeratosis. Accordingly, it can sometimes be difficult to determine whether the tissue covering a wound is physiological or pathological. Indeed, podiatric physicians need to remove gangrenous, necrotic, ischemic and devitalized tissue by some method of debridement. Failure to debride diabetic wounds appropriately when necessary could be considered failure to render proper treatment.       It is a widely accepted premise that wound debridement is necessary for optimal wound healing. Surgical or sharp debridement has long been viewed as the “gold standard” for debridement. Unfortunately, the evidence for the effectiveness of different methods of debridement from randomized controlled trials is lacking and an evidence-based treatment algorithm has yet to be established. Oftentimes, the treating practitioner chooses the method of debridement based on his or her individual experience and level of comfort with the chosen method instead of an established treatment algorithm or other evidence-based rationale.

A Guide To Methods Of Wound Debridement

      Surgical and sharp debridement. For these types of debridement, one would use a scalpel, scissors or other instrumentation. Podiatrists may perform these debridements in many different settings. The results are immediately notable. However, these types of debridement require specific training and specialized equipment. One must control pain with some degree of anesthesia, whether it is general or local.       Mechanical debridement. This includes hydrotherapy, whirlpool or wound irrigation. Hydration of the eschar can reduce pain during debridement. Mechanical debridement can produce significant results. However, the methods are slow, time consuming and there is little evidence to support their use. Wound infection may occur if the practitioner does not observe strict cleanliness during such procedures.       Autolytic debridement. These methods include the use of hydrocolloids or hydrogels. Hydration of necrotic tissue by the use of a hydrogel or hydrocolloid essentially maintains a moist wound and allows enzymatic debridement to occur by utilizing the body’s own enzymes. Phagocytic cells and protein-digesting enzymes, also referred to as proteinases or peptidases, present in the patient’s own wound fluid and are responsible for accomplishing this process. Clinicians commonly employ this method but is very slow when compared to other methods of debridement. However, it is often noted to be painless.       Enzymatic debridement. These methods use preparations known as exogenously derived proteolytic enzymes such as streptokinase or papain-urea preparations. The main function is to trigger and promote hydrolysis and degradation of the proteinaceous devitalized tissue. There is little evidence to support their use when compared to alternative methods. Typical use requires the need to score the eschar before application, which may increase the risk of damage. It may be painful and one must be careful to avoid injurious contact to healthy surrounding tissue.       Biological debridement. This type of debridement typically refers to larval or maggot therapy. There is little acceptance of this method in the United States although it is often utilized in Europe. The larvae of Lucilia sericata (greenbottle fly) digest necrotic tissue and pathogens. This technique is rapid and selective although much of the evidence to support its use is derived from anecdotal reports. There have been transient reports of pain or discomfort.       Chemical debridement. Such methods rely upon the topical application of relatively caustic chemicals such as calcium or sodium hypochlorite solutions or other chemicals. It is not widely used as the application of chemical debridement may be painful and cause underlying tissue damage.       Any medical person providing wound care with debridement to a diabetic wound must be able to perform the debridement both properly and safely. Proper training and technical knowledge is essential. Of the commonly employed methods, all require some degree of training and skills. One must also be knowledgeable of possible complications that may occur and be able to deal with any complications properly. Knowledge of anatomy is essential and one must take care to avoid any iatrogenic damage during debridement.

Key Considerations In Deciding Whether To Debride A Diabetic Wound

      Proper assessment of a diabetic wound is essential to any treatment plan. A multisystem evaluation should include assessment of the patient’s neurologic and vascular status. One must also address infection status. Diabetic wounds often need debridement. However, there are times that necrotic tissue should remain in place over the wound. Necrotic tissue may play a role in auto-amputation or serve to delineate a line of demarcation between viable and nonviable tissue. Patients with ischemic disease will likely not heal without some degree of vascular intervention.       In a patient with a terminal illness, DPMs may spare the patient debridement to avoid further discomfort to the patient. Healing likely will not occur beneath the necrotic tissue. Therefore, one should carefully consider each individual case. In other circumstances, such as the presence of wet necrotic tissue, also commonly referred to as wet gangrene, immediate debridement is necessary.       Consider the pros and cons of the various debridement methods (see “A Comparison Of Debridement Methods For Diabetic Wounds” below). Pain is also paramount in the consideration for diabetic wound debridement. Many patients with diabetes have peripheral neuropathy, which may allow for subcutaneous level debridement sans any additional anesthesia. Take caution due to the fact that some patients with diabetes do not demonstrate uniform loss of sensation or even an elevated level of sensitivity due to hyperesthesia. One should carefully examine and probe the diabetic wound. Doing so will allow the practitioner to determine the level of anesthesia required. Consider infection status and treat such status appropriately.

Pertinent Pointers On Facilitating A Sterile Environment

      There are several factors to consider when debriding diabetic foot wounds. One is to maintain as high a level of sterility as possible. This typically applies to sharp or surgical debridement. If the surgeon is performing debridement in the operating room, a sterile field is rather easy to maintain. However, podiatrists often perform sharp debridement at the bedside or in a treatment room in an office or wound care center. In these circumstances, one should consider the procedure semi-sterile and maintain all reasonable measures to ensure some semblance of a “clean” or semi-sterile field.       With other forms of debridement, the DPM should make all attempts to maintain cleanliness and avoid infection. Mechanical debridement with the use of equipment that is typically reused demands extreme cleanliness and proper cleaning of all equipment to avoid cross-contamination between patients. Autolytic or enzymatic debridement typically only require topical application of ointments or wound dressings, and one can perform these debridements in a very clean fashion with minimal requirements of sterile materials aside from applicators, gauze, etc.

What About Ensuring Adequate Pain Relief?

      Pain relief is also a major consideration. Sharp or surgical debridement typically requires either the administration of oral pain medication or the use of localized or general anesthesia prior to initiating the procedure. One often performs large scale surgical debridement in the operating room, where the surgeon can utilize appropriate anesthesia.       Debridements performed in wound care centers or office centers often incorporate local anesthesia, which one can achieve with topical anesthetics or local field blocks. The surgeon can utilize topical anesthesia with lidocaine gel or EMLA but little evidence exists to show rates of efficacy. More often, one would use a local injection of anesthetic infiltrated into the area of debridement or in a regional nerve block.       Sometimes no anesthesia is necessary due to peripheral neuropathy in a patient with diabetes. However, do not make any assumptions or possibly neglect the use of anesthesia for a patient simply based on the patient having diabetes.

In Conclusion

      Podiatric physicians routinely perform debridement of diabetic wounds in the lower extremity. Several methods and techniques exist that allow the wound care professional to utilize the best method for each wound. Being proficient in all methods allows the treating physician to provide the highest level of care to patients. With advances in autolytic and enzymatic debriding ointments and dressings, continuing education is important to stay abreast of the different methods and modalities available to podiatric physicians. With the ever expanding research into wound care, it will also be important to be aware of any comparison studies detailing the efficacy of the various methods for superiority.       Dr. Espensen is the Chief of Foot Surgery at Providence St. Joseph Medical Center in Burbank, Calif. He is on staff at several area hospitals, actively participates with several wound care centers in the Greater Los Angeles Area and lectures frequently concerning caring for the diabetic foot. He maintains a private practice in Burbank, Calif. and Los Angeles.       Reference       1. Winter GD. Formation of the scab and the rate of epithelialization of superficial wounds in the skin of the young domestic pig. Nature 1962:193:293-4.       Further Readings       2. Mosher BA, Cuddigan J, Thomas DR, Boudreau DM. Outcomes of 4 methods of debridement using a decision analysis methodology. Adv Wound Care. 1999 Mar;12(2):81-8       3. Lewis R, Whiting P, ter Riet G, O'Meara S, Glanville J. A rapid and systematic review of the clinical effectiveness and cost-effectiveness of debriding agents in treating surgical wounds healing by secondary intention. Health Technol Assess. 2001;5(14):1-131.       4. www.worldwidewounds.com       5. Wright J, Barry, Shi L. Accuzyme: Papain-Urea Debriding Ointment: A Historical Review. Wounds Supplement 15(4), 2003.       6. www.lifesteps.com/gm/Atoz/ency/debridement.jsp       7. www.fpnotebook.com/SUR12.htm       Editor’s note: For related articles, see “Current Concepts In Managing The Wound Microenvironment” in the September 2006 issue, “How To Manage Heel Ulcers In Patients With Diabetes” in the March 2005 issue or “Assessing The Role And Impact Of Enzymatic Debridement” in the July 2004 issue. Also check out the archives at www.podiatrytoday.com.
 

 

References:

CE Exam #150 Choose the best single answer to the following questions. 1. Surgical or sharp debridement … a) is supported by three evidence-based treatment algorithms for wound debridement in the lower extremity. b) has long been viewed as the “gold standard” for debridement. c) has had demonstrated efficacy in several randomized controlled trials involving diabetic foot wounds. d) None of the above 2. Which of the following debridement methods involves hydrotherapy, whirlpool or wound irrigation? a) Sharp debridement b) Biological debridement c) Mechanical debridement d) Enzymatic debridement 3. Which of the following statements on autolytic debridement is false? a) With this method, podiatrists commonly employ exogenously derived proteolytic enzymes such as streptokinase. b) Autolytic debridement includes the use of hydrocolloids such as papain-urea preparations. c) It is the quickest method of debridement. d) All of the above 4. When it comes to enzymatic debridement … a) the main function is to trigger and promote hydrolysis and degradation of the proteinaceous devitalized tissue. b) one typically needs to score the eschar prior to applying enzymatic debridement agents. c) it may be painful for the patient. d) All of the above 5. Biologic debridement … a) is commonly utilized in the United States to help facilitate the digestion of necrotic tissue and pathogens in diabetic foot wounds. b) typically refers to the use of larval or maggot therapy. c) offers a rapid and selective technique but much of the evidence supporting its use is derived from anecdotal reports. d) b and c 6. Necrotic tissue … a) should remain in place over most diabetic foot ulcerations. b) may play a role in auto-amputation or serve to delineate a line of demarcation between viable and nonviable tissue. c) is rarely found in infected diabetic wounds. d) None of the above 7. Which of the following statements is true about wet necrotic tissue? a) It requires immediate debridement. b) It can only be removed with chemical debridement. c) Podiatrists can spare the patient debridement in order to avoid further discomfort to the patient. d) None of the above 8. When it comes to performing debridements in wound care centers or office centers, podiatrists often … a) give the patient oral pain medication prior to the procedure. b) provide general anesthesia. c) incorporate local anesthesia via topical anesthetics or local field blocks. d) None of the above 9. Which of the following debridement methods is not utilized for exudating and necrotic wounds? a) Enzymatic debridement b) Mechanical debridement c) Sharp debridement d) Autolytic debridement 10) Which of the following debridement methods can podiatric physicians incorporate for all types of lower extremity wounds? a) Sharp debridement b) Chemical debridement c) Enzymatic debridement d) Autolytic debridement Instructions for Submitting Exams Fill out the enclosed card that appears on the following page or fax the form to the NACCME at (610) 560-0502. Within 60 days, you will be advised that you have passed or failed the exam. A score of 70 percent or above will comprise a passing grade. A certificate will be awarded to participants who successfully complete the exam. Responses will be accepted up to 12 months from the publication date.

 

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