Efficacy of Collagenase or Papain-Urea

     Reference: Ramundo J, Gray M. Enzymatic wound debridement. J Wound Ostomy Continence Nurs. 2008;35(3):273–280.

     Rationale: Debriding necrotic tissue is an important step in wound care. Indications and efficacy are not clearly established for the major methods used. Scant evidence guides the selection of safe, effective, debriding modalities for chronic wounds.

     Objective: Identify and review evidence relating to use of collagenase or papain-urea enzymatic debridement formulations for necrotic tissue removal (NTR) and healing efficacy on leg ulcers, pressure ulcers, or burns.

     Methods: MEDLINE, CINAHL, Cochrane databases, and Google Scholar were searched from January 1960 through February 2008 for prospective and retrospective controlled clinical trials comparing either collagenase or papain-urea formulations with other debridement modalities on leg ulcers, pressure ulcers, or burns. Studies were included if NTR and/or healing outcomes were reported. Case studies, case series, and pre-clinical studies were excluded.

     Results: Five randomized controlled studies (RCTs), all using gauze dressings impregnated with petrolatum-based ointment containing bacterially-derived collagenase, showed over a 2- to 4-week period that collagenase removed necrotic tissue faster than placebo ointment or gum, but did not improve healing rates for patients with pressure ulcers (n = 14), leg ulcers (n = 30), pressure or leg ulcers (n = 47), or burns (n = 77). One small study reported faster healing in burns debrided with collagenase with added topical polymyxin B sulfate compared to silver sulfadiazine with no debridement (n = 15).

     In studies comparing enzymes to other debridement modalities on chronic wounds, collagenase-impregnated gauze dressings removed necrotic tissue from venous leg ulcers faster than 0.5% trypsin/chymotrypsin, but more slowly from pressure ulcers than papain-urea, and more slowly than autolysis using a Ringers-moistened polyacrylate dressing: 20% NTR (n = 15; P > 0.05) compared to 10% NTR with collagenase (n = 27) during the first 14 days of use on venous ulcers.

     A comparison-cohort study found debridement times similar for 78 children with partial-thickness burns managed using collagenase alone compared to 41 subjects combining it with surgical excision or receiving surgical excision alone. Patients receiving only collagenase debridement experienced fewer transfusions and shorter hospital stays, but 17 of an additional 29 patients started on only collagenase debridement experienced infections.

     The only RCT on papain reported more visible NTR and granulation tissue formation during weeks 2, 3, or 4 of debridement on pressure ulcers using papain combined with urea in a hydrophilic ointment vehicle compared to collagenase in petrolatum ointment in long-term care. There was no significant difference in healing rates (n = 26).

     Authors’ Conclusions: Enzymatic agents may be used as the primary technique for debriding certain cases, especially if surgical or conservative sharp wound debridement is not feasible.

Debriding Surgical Wounds

     Reference: Dryburgh N, Smith F, Donaldson J, Mitchell M. Debridement for surgical wounds. Cochrane Database Syst Rev. 2008;(3):CD006214.

     Rationale: Infected surgical wounds are often debrided in hopes of expediting wound healing.