Current Concepts In Wound Debridement

Appropriate debridement sets the stage for the conversion of chronic wounds into acute wounds, and eventual healing. With this in mind, these authors discuss essential patient considerations and offer a salient overview of debridement options ranging from sharp debridement to the emergence of ultrasonic debridement.

   Wound debridement is the first step to facilitating successful and swift wound closure in the care of acute and chronic wounds. Wound care physicians also use the phrase “wound bed preparation” to describe the process of preparing the wound for the use of skin graft and other topical wound therapy, or for healing by secondary intention.

   Common sense supports the removal of foreign substances such as dirt from acute traumatic wounds in order to minimize the risk of infection and facilitate wound closure. By the same token, it is important to remove any non-viable tissue, such as dry eschar, necrotic skin and desiccated tendon, in order to remove the physical barriers of reepithelialization over the skin defect. The buildup of callused skin around the wound, often seen in the plantar foot with diabetic neuropathic foot ulcers, also must undergo sharp debridement as the callused skin may inhibit the wound contraction.

   In heavily contaminated, infected or chronic wounds with biofilm and bacteria colonization, the debridement of infected tissues may help control infection and bioburden. Since tendons and fascias, abundant in the foot and ankle region, have relatively poor blood supply, physicians may have to sacrifice these structures and debride them aggressively to eliminate the infection in deeper wounds. In addition, one should consider exposed bone to be infected unless proven otherwise. A positive “probe to bone” test indicates an 85 percent chance of osteomyelitis.1

   Another theory behind debridement contends that the process transforms a chronic wound into an acute wound. As the wound continues to stay open, the tissue surrounding the wound may get stuck in the state of chronic inflammation and cease to heal. This is referred to as a “stunned wound,” which may require the intentional trauma from sharp debridement and/or mechanical stimulation by ultrasound to initiate the healing process.2

Key Comorbidities You Should Know Before Performing Surgical Debridement

   Prior to any medical treatment, proper patient assessment is paramount. When considering wound debridement options, the physician must consider the etiology of the wound in question along with the patient’s past medical/wound history and comorbidities. Certain patient populations will require extra caution and special considerations when it comes to the possible use of surgical debridement.

   Peripheral arterial disease (PAD) and ischemic limbs. Peripheral arterial disease is often underdiagnosed. As the physical exam and pulse palpation are not adequate for the diagnosis of ischemia and PAD, objective Doppler tests are recommended for vascular assessment. Patients who are 50 years or older are at high risk for PAD, especially if they have a history of smoking, diabetes or known atherothrombotic disease (carotid, coronary or renal artery disease).3 The vascular assessment of microcirculatory skin perfusion is essential prior to sharp debridement as careless sharp debridement of the ischemic limb will result in enlargement and further necrosis of the wound.
   In our clinic, we use a laser Doppler-based skin perfusion pressure monitor (Sensilase, Vasamed) to rule out or diagnose ischemia using both pulse volume recordings (PVR) and skin perfusion pressure (SPP) tests. A peri-wound skin SPP value of 30 mmHg or below is diagnostic of severe PAD, also known as critical limb ischemia (CLI). This calls for immediate referral to vascular specialists such as vascular surgeons, interventional cardiologists and interventional radiologists. An SPP value above 40 mmHg is considered adequate for normal wound healing and indicative of good wound healing potential.

   Multiple sources have validated these cutoff values for SPP.4-6 One can also use transcutaneous oximetry (TCOM or TcPO2) monitors for the prediction of wound healing probability, although the cutoff values are less well defined and the results are less accurate in comparison to SPP.7

   An ankle-brachial index (ABI) can assess macroperfusion when values of 0.9 or below indicate PAD. However, diabetes, old age and end-stage renal diseases are known to cause calcifications of leg arteries and falsely elevate ABI values. For this reason, ABI should not be the sole criteria of PAD screening, except for younger patients with no history of diabetes or dialysis.3

   Autoimmune conditions and pyoderma gangrenosum. Some skin ulcerations are associated with autoimmune and inflammatory conditions, such as scleroderma and rheumatoid arthritis. In particular, wounds on patients with pyoderma gangrenosum tend to enlarge with sharp debridement. This will incite an inflammatory reaction, a phenomenon called pathergy. One should avoid sharp debridement altogether for pyoderma gangrenosum.

   Treatment for patients with autoimmune conditions and pyoderma gangrenosum should be limited to non-contact ultrasound application and other non-sharp debridement methods. Usually a rheumatologist will use immunomodulatory medications to control the underlying disease.

   In addition, there have been anecdotal reports on the use of topical tacrolimus (Protopic, Astellas Pharma) and hyperbaric oxygen therapy to help facilitate the healing of pyoderma gangrenosum.8

Pertinent Pointers On Pain Management During Debridement

   Most debridement methods increase wound pain for the patient and it is important for practitioners to minimize and eliminate the procedural pain as much as possible.

   In our clinic, we apply topical viscous 2% lidocaine gel or EMLA cream (AstraZeneca) five to 15 minutes prior to debridement. One may supplement the local anesthetic with lidocaine injection, especially when it comes to initial aggressive debridement procedures. Randomized controlled trials have shown that EMLA cream controls pain effectively.9

   Another method to make the visit more tolerable is having the patient take analgesic medication such as OTC acetaminophen or prescription narcotic medication prior to wound debridement. In the case of patients with neuropathy (from diabetes, spinal cord injury, etc.), one should generally apply similar pain control measures to avoid undesirable autonomic responses such as sweating and vomiting.

   Some debridement methods are less painful. Autolytic debridement is virtually painless while enzymatic debridement or maggot therapy may cause some discomfort. Non-contact ultrasound debridement is also minimally painful and very tolerable whereas contact ultrasound may cause more pain. In comparison, “wet-to-dry” debridement and sharp debridement may be quite painful.

Essential Pearls For Performing Sharp Debridement

   Sharp debridement, also known as surgical debridement, is the workhorse for wound care physicians because it is fast, highly selective and an efficient way to remove non-viable tissues in the clinic.

   When it comes to sharp debridement, instruments vary depending on the physician’s preference. In our center, we mostly use sterile disposable #10 and #15 blades as well as 4 mm disposable curettes, which dermatologists often use. We supplement these tools with minor surgical kits containing various forceps and scissors as well as various sizes of rongeurs, tissue nippers and bone curettes.

   As wound debridement is generally considered a “dirty” procedure, we use regular, non-sterile gloves and perform the procedure in regular exam rooms with a surgical mask and goggles for protection. Immunocompromised patients and patients with deep wounds (tendon/muscle/bone level) will benefit from the sterile preparations of an operating room and standard sterile OR techniques.

   Once the patient has adequate perfusion, one should debride the wound by making multiple thin slices of tissues until the healthy bleeding base is visible. Necrotic or infected tissues generally do not bleed. This will maximize the wound healing potential and minimize the subsequent wound infection. Physicians can perform post-debridement irrigation with normal saline or with commercial wound cleansers.

   Steed et al., and Williams et al., address the wound healing effect of sharp debridement.10,11 Steed and colleagues enrolled 922 patients with diabetic foot ulcers for the safety and efficacy study of topical PDGF gel (Regranex, Systagenix Wound Management). In this multicenter trial, they incidentally found that a center that performed more frequent sharp debridement achieved proportionally higher healing rates.

   Healing rates were even more pronounced when researchers added the PDGF gel after debridement removed the barrier (non-viable tissue over the wound base) to this therapy.10 This is an interesting observation that may apply to other wound modalities such as VAC therapy (KCI), various skin substitutes and antimicrobial dressings.

   Williams and co-workers performed one-time sharp debridement for venous ulceration in 26 patients and monitored wound sizes over 12 weeks. Researchers compared the wound sizes in the sharp debridement group to the control cohort of 27 patients who received no debridement. The results showed that the debridement group had statistically smaller wound sizes at weeks four and 12 while the control group actually showed an increase in wound size. This study demonstrates that even one-time curettage of devitalized tissue can make a difference in healing up to three months later.11

   Hydrosurgery involves the use of a high-pressure water jet (Versajet, Smith & Nephew) as a method of sharp debridement when physicians need to clean a large and/or contaminated wound. This method requires a suction canister and an OR setting because irrigation solution may splash in the room. One may mitigate the cost of the special disposable unit by shortening the OR time by combining the cutting and the saline irrigation/suction with a special tip.

   The appropriate CPT codes for the surgical wound debridement range from 11040 to 11044, depending on the level of tissue one removes, not the depth of the wound. For example, even if the bone is exposed and is visible after the debridement, do not bill 11044 unless the deepest tissue you removed was bone. Muscle and bone debridement are deeper tissues with a high probability of complications such as excess bleeding and infection. It is advisable to perform bone and muscle debridement in an OR setting and the CPT codes for those procedures (11043-11044) carry 10-day global periods.

Mitigating The Complications Of Sharp Debridement

   The most common complication of wound debridement is bleeding. Patients with chronic wounds tend to be older. The average age of patients in our wound care center is 70. It is very common to see a patient who is on multiple anticoagulant medications such as aspirin, warfarin (Coumadin, Bristol-Myers Squibb) and clopidgrel (Plavix, Bristol-Myers Squibb/Sanofi Pharmaceuticals).

   In order to control bleeding, direct pressure and limb elevation can be effective. However, chemical cauterization with silver nitrate and electrocautery, or direct ligation with a suture may be more definitive. It is important to visualize and anticipate the underlying anatomy, if possible, in order to avoid cutting arteries or veins.

   Procedural pain after debridement is also quite common. The pain is often proportional to the depth and the amount of debridement although there is significant individual variability. One should prescribe the pain medication proactively. Patients may apply an ice pack directly over the wound dressing temporarily if they desire more pain relief. It is important to note that wound infections may increase the amount of wound pain. Appropriate use of wound culture and antibiotics may decrease pain severity if wound infection is present.

Salient Pointers On Ultrasonic Debridement

   The most recent innovation in wound debridement is ultrasound-assisted debridement devices. For decades, researchers have studied therapeutic ultrasound, which is known to promote tissue restoration in various tissues and organs.

   In the United States, there are currently four different devices that have FDA approval for wound debridement. These devices include SonicOne (Misonix), Sonoca (Soring USA), MIST (Celleration) and Qoustic (Arobella Medical). These devices use a continuous spray of sterile saline as the coupling and cooling medium of the ultrasound energy. These modalities save time by combining ultrasound mechanical debridement, sharp debridement and continuous saline irrigation while simultaneously delivering therapeutic ultrasound to the wound bed.

   While a higher frequency ultrasound (1 to 3 MHz) is in use for various imaging and physical therapy, these ultrasound wound devices use lower frequencies between 20 kHz to 100 kHz. The therapeutic effects of ultrasound on wounds include a cavitation effect and a stimulatory effect.

   Cavitation effect. Bursting micro-bubbles assist in fibrinolytic separation of denatured protein, resulting in selective debridement and fragmentation of non-viable tissue. These cavitation events are also known to have a direct killing effect on surface bacteria such as Staphylococcus aureus and Pseudomonas.

   Stimulatory effect. “Fluid shear stress” generates nitric oxide within the endothelium for vasodilatation, resulting in resolution of vasospasm and increased blood flow. The stimulation of fibroblasts, macrophages and endothelial cells augments healing.

   A pilot study in our institution found that applying five minutes of low-frequency ultrasound to lower extremity wounds increases the periwound blood flow significantly when we measured this with a laser Doppler-based SPP monitor.12 We believe this increase in SPP values in response to ultrasound treatment will contribute to wound healing, perhaps by promoting angiogenesis in the wound bed. The latest Cochrane review suggests that ultrasound treatment may increase the healing of venous leg ulcers based on a meta-analysis of eight randomized controlled trials published prior to 2007.13

   The most recent and largest published study on low-frequency ultrasound therapy enrolled 210 patients with lower extremity wounds of mixed etiologies. Researchers compared patients receiving ultrasound therapy and standard care to patients receiving standard care alone. The results showed that a higher percentage of the ultrasound group healed in comparison to patients in the standard care group at 90 days (53 percent vs. 32 percent).14

   There are currently no CPT codes specific to ultrasound-assisted debridement therapy so one may use sharp debridement codes (11040-11044) instead. Since the MIST® therapy device is a non-contact device by design, the specific T-code, 0183T, is the appropriate code to use at this time.

A Closer Look At Other Debridement Options

   There are many debridement methods that one can use in conjunction with sharp debridement. Most of our wound patients visit our center once a week for sharp and/or ultrasound debridement. Additionally, they may receive any number of the following wound debridement methods along with a moist wound dressing to facilitate optimal wound healing.

   Autolytic debridement. With autolytic debridement, one applies an occlusive dressing in an effort to saturate the wound and promote the separation of non-viable tissues using the naturally occurring enzymes in the wound exudate. The most important step with this method is to protect periwound skin from maceration. If intact skin is constantly wet, it may be damaged and the wound may enlarge. Therefore, it is imperative to protect the periwound skin by using zinc oxide ointment or film dressing with protective skin wipes.

   When it comes to autolytic debridement, the typical dressings are hydrocolloids and one may also hydrate the wound with hydrogel. Pooling data from three randomized controlled trials, the Cochrane review suggests that autolytic debridement using hydrogel increases the healing rate of diabetic foot ulcers in comparison to gauze dressings.15 One typically changes autolytic dressings every two to three days but this depends on the amount of wound drainage.

   Wet-to-dry gauze. Often described as a dressing method, wet-to-dry gauze is more appropriately categorized as a form of mechanical debridement. With this procedure, moisten a piece of gauze with saline, pack or apply the gauze over a wound, and then subsequently remove the gauze after the gauze has dried and desiccated approximately 24 hours later. Since the superficial tissue, whether it is non-viable or viable, firmly adheres to the gauze surface, this method is non-selective debridement.

   Although wet-to-dry gauze should not be confused as a standard of care (which calls for a moist wound dressing), it may be a useful tool in the care of heavily contaminated and/or infected wounds until one can perform definitive surgical debridement.

   Enzymatic debridement. Various enzymes, such as papain-urea and trypsin, has been in use for many decades in the U.S. for debridement of non-viable tissue. The FDA recently halted the manufacturing and sales of the papain-urea agents based on reports of adverse events. Topical trypsin agents have been determined to be ineligible for reimbursement by CMS due to FDA guidance that trypsin “lacks substantial evidence of effectiveness of labeled claims of anti-infective and debriding action.”16 Collagenase (Santyl, Healthpoint) is currently the sole alternative for these enzymatic products.

   Biologic debridement. Also referred to as larval therapy, medical-grade sterilized eggs of Lucilia sericata species (Medical Maggots, Monarch Labs) are useful for biologic debridement of various wounds. One can order this FDA-approved therapy via prescription. The maggots are painless, effective and offer a safe way to perform debridement.

   One would apply these larvae with a special dressing to “cage” the worms over the wound bed and replace the dressing every two to three days until the desired debridement has occurred.17 The debridement occurs via secreted proteolytic digestive enzymes that liquefy the necrotic tissue, which, in turn, the larvae absorb and ingest.

   In addition, the maggots also secrete broad-spectrum bactericidal chemicals (ammonia, phenylacetic acid and phenylacetaldehyde), which kill Staphylococcus aureus, Streptococci and Pseudomonas species, regardless of the antibiotic resistance. For that reason, the larval therapy may be quite useful in the treatment of severely infected wounds and fungating lesions needing palliation. Larvae are also effective for extremely debilitated patients (i.e. end-of-life or multiple trauma) who may not be candidates for surgical debridement procedures.18

Key Coding Insights For Non-Surgical Debridement

   The coding of non-sharp debridement procedures, CPT 97602 (non-selective, non-excisional debridement) may be appropriate for the topical application of enzymatic agents and medical maggots.

   Alternatively, one should bill the “active wound management procedure” with CPT 97597 (wound area > 20 cm2) or CPT 97598 (wound area < 20 cm2), when the wound does not require surgical debridement or the patient cannot tolerate surgical debridement. This procedure requires the provider to have direct (one-on-one) patient contact for wound assessment and instruction of ongoing care along with removal of devitalized tissue from wounds.

Dr. Suzuki is the Medical Director of 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 of Tokyo Medical and Dental University in Tokyo, Japan. One can contact the author at kazu88@gmail.com.

Dr. Cowan is a second-year medical student at the Keck School of Medicine at the University of Southern California at Los Angeles, Calif.

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References:

1. Grayson ML, Gibbons GW, Balogh K, et al. Probing to bone in infected pedal ulcers: a clinical sign of osteomyelitis in diabetic patients. JAMA 1995; 273(9):721. 2. Ennis WJ, Menesses P. Wound healing at the local level. The stunned wound. Ostomy Wound Manage. 2000; 46(1A Suppl):39S-48S. 3. Hirsch AT, et al. ACC/AHA guideline for the management of patients with peripheral arterial disease. J Am Coll Cardiol 2006; 47(6):1239-312. 4. Castronuovo J, et al. Skin perfusion pressure measurement is valuable in the diagnosis of critical limb ischemia. J Vasc Surg 1997; 26(4):629-637. 5. Yamada T, Ohta T, Ishibashi H, et al. Clinical reliability and utility of skin perfusion pressure measurement in ischemic limbs – comparison with other noninvasive diagnostic methods. J Vasc Surg 2008; 47(2):315-23. 6. Tsuji Y, Kitano I, Tsuji Y, et al. Efficacy of skin perfusion pressure measurement in the surgical treatment for critical limb ischemia. Jpn J Vasc Surg 2008; 17:1-6. 7. Schechter R, Bailey B. Paired noninvasive vascular testing modalities evaluated for clinical utility and detection of arterial disease. Poster presentation, Symposium on Advanced Wound Care/ Wound Healing Society Meeting, San Diego, 2008. 8. Davis JC, Landeen JM, Levine RA. Pyoderma gangrenosum: skin grafting after preparation with hyperbaric oxygen. Plast Reconstruct Surg 1987; 79(2):200-07. 9. Briggs M, Nelson EA. Topical agents or dressings for pain in venous leg ulcers. Cochrane Database of Systematic Reviews 2003; Issue 1. 10. Steed DL. Clinical evaluation of recombinant human Platelet-Derived Growth Factor for the treatment of lower extremity ulcers. Plast Reconstruct Surg 117 (Suppl.): 143s, 2006). 11. Williams D, Enoch S, Miller D et al. Effect of sharp debridement using curette on recalcitrant nonhealing venous leg ulcers: a concurrently controlled, prospective cohort study. Wound Repair Regen 2005; 13(2):131-7. 12. Suzuki K, Cowan LA, Aronowitz JA. Low-frequency ultrasound therapy of lower extremity wounds significantly increases the peri-wound skin perfusion pressure. Poster presentation, DFCON Diabetic Foot Global Conference, Los Angeles, 2009. 13. Al-Kurdi D, Bell-Syer SEM, Flemming K. Therapeutic ultrasound for venous leg ulcers. Cochrane Database of Systematic Reviews 2008; Issue 1. 14. Kavros SJ, Liedl DA, Boon AJ, et al. Expedited wound healing with noncontact, low-frequency ultrasound therapy in chronic wounds: a retrospective analysis. Adv Skin Wound Care 2008; 21(9):416-423. 15. Edwards J. Debridement of diabetic foot ulcers. Cochrane Database of Systematic Reviews 2002; Issue 4. 16. The Center for Drug Evaluation and Research (CDER) at the Food and Drug Administration. FDA Compliance Policy Guide. Sec 440.100. Dated September 23, 2008. 17. Sherman RA. Maggot therapy for treating diabetic foot ulcers unresponsive to conventional therapy. Diabetes Care 2003 Feb; 26(2): 446-51. 18. Horobin AJ, Shakesheff KM, Woodrow S, et al. Maggots and wound healing: an investigation of the effects of secretions from Lucilia sericata larvae. Br J Dermatol 2003; 148(5):923.