Larva therapy in wound management

Debridement

PURPOSE

To provide practitioners with an overview of debridement and its role in wound healing.

TARGET AUDIENCE

This continuing education activity is intended for physicians and nurses who assess and treat wounds.

OBJECTIVES

After reading the article and taking the test, the reader should be able to: 1. Discuss the physiologic process of wound healing and the rationale for debridement. 2. Describe evidence-based indications for and methods of debridement.

Clinical Approach to Wounds: D??bridement and Wound Bed Preparation Including the Use of Dressings and Wound-Healing Adjuvants

This is a clinical review of current techniques in wound bed preparation found to be effective in assisting the wound-healing process. The process begins with the identification of a correct diagnosis of the wound's etiology and continues with optimizing the patient's medical condition, including blood flow to the wound site. Débridement as the basis of most wound-healing strategies is then emphasized. Various débridement techniques, including surgery, topical agents, and biosurgery, are thoroughly discussed and illustrated. Wound dressings, including the use of negative pressure wound therapy, are then reviewed. To properly determine the timing of advance therapeutic intervention, the wound-healing progress needs to be monitored carefully with weekly measurements. A reduction in wound area of 10 to 15 percent per week represents normal healing and does not mandate a change in the current wound-healing strategy. However, if this level of wound area reduction is not met consistently on a weekly basis, then alternative healing interventions should be considered. There is a growing body of evidence that can provide guidance on the appropriate use of such adjuvants in the problem wound. Several adjuvants are discussed, including growth factor, bioengineered tissues, and hyperbaric medicine.

The antimicrobial activity of maggots: in-vivo results

In the literature maggot therapy is discussed as a promising and potent form of debridement therapy. The number of maggots needed to debride a wound is estimated at 10 per cm2, and more in case of a higher percentage of necrosis or slough. In the authors' hospital, from March 1999 to May 2002, 16 patients were successfully treated with maggot therapy. The average maggot treatment time was 27 days, with an average of seven maggot changes. Most patients were treated for osteomyelitis, with trauma being the leading aetiological factor. In accordance with in-vitro findings, maggot therapy was found to be more effective in gram-positive infected wounds. Gram-negative bacteria are cultured more often after maggot treatment than before it (p=0.001). The opposite effect was found for gram-positive infected wounds (non-significant p=0.07). In vivo maggots seem to be less effective against gram-negative infected wounds. The authors believe that a higher number of maggots is needed not only for a larger wound or a wound with a higher percentage covered with slough, but also for a wound infected with gram-negative bacteria.

[Wound debridement and treatment of ulcus cruris. Conservative and operative therapeutic procedures]

Effective debridement of necrotic tissue and wet wound conditions are essential for wound healing. This can be achieved surgically or with conservative measures. Non-surgical options are the use of enzymatic preparations and the application of maggots. This biosurgical approach is enjoying a renaissance. The underlying pathophysiology of chronic venous leg ulcers can only be addressed by compression therapy and vein surgery.

Larval therapy--an effective method of ulcer debridement

Since ancient times, larval therapy has been reputed to help wound healing. Its use has recently been rediscovered and it is now enjoying increasing interest in clinical practice, as well as in research. We have investigated the effects of larval therapy on wounds in an open study of 74 patients with necrotic or sloughy chronic ulcers of different aetiologies. We found larval therapy to effectively debride 86% of the necrotic ulcers, and a single application was clinically beneficial in two-thirds of the patients. Failure to debride was mostly attributable to larval death. No ulcer type was shown to be more suited to larval therapy than others; however, there was an excellent response in all 29 patients with diabetes. Larval therapy was also noted to reduce odour in 58% of the 31 foul-smelling ulcers of mixed aetiology. No serious side-effects were observed. One-quarter of the study group experienced less pain during treatment, while 41% felt no difference in pain, and, although 34% noted an increase in pain, most of these patients wanted to continue the treatment because of subjective and objective visual improvement in wound debridement. In conclusion, we found larval therapy to be effective for debriding ulcers, easy to use and well accepted by the patients.