Chemical debridement of pressure ulcers: A prospective, randomized, comparative trial of collagenase and papain/urea formulations

The primary objective of this study was to evaluate the efficacy of two che mical debridement formulations: 1) a formulation containing a specific prot ease (collagenase) alone; and 2) a Formulation containing both enzymatic an d nonenzymatic agents (papain/urea). Patients with pressure ulcers requirin g debridement underwent a two-week screening period to stabilize the wound and provide supportive therapies. After the screening period, only patients whose wounds were stable or improving were enrolled into the study. Twenty -one patients received treatment with either collagenase or papain/urea. Wo unds were treated once daily until complete debridement or four weeks. Effi cacy assessments included: the type and amount of necrotic tissue; time to granulation; wound size; rate of closure; bacterial burden and overall woun d improvement. Safety assessments included: wound infection; localized irri tation; pain; and wound deterioration. Papain/urea debriding ointment was s ignificantly more effective than collagenase in reducing the amount of nonv iable tissue (68.3% vs. 22.3% at two weeks, 86.5% vs. 37.3% at three weeks, p<0.05 and 95.4% vs. 35.8% at four weeks, p<0.01). The mean time to 50 per cent granulation for the papain/urea group was 6.8 days compared to at leas t 28 days For the collagenase group. The mean overall wound response to pap ain/urea was 4.1 times better than for collagenase (p<0.01). There were no significant differences in bacterial burden or rate of wound closure betwee n the two treatment groups. Both agents were slightly better at dissolving black eschar than fibrin slough. There were no unanticipated adverse events associated with either product.