A Comparison of Collagenase to Hydrogel Dressings in Wound Debridement, Maintenance Debridement and Wound Healing

Introduction: Maintenance debridement is a paradigm shift in wound healing. Collagenase has been suggested as one mechanism to achieve maintenance debridement.¹ Autolytic debridement using hydrogel, has not been directly associated in the literature as an option to achieve maintenance debridement goals. Published studies have not directly compared these agents in achieving the removal of necrotic tissue from the wound bed.^{2, 3}

Objective: Time to complete necrotic tissue debridement of collagenase* compared to hydrogel** in pressure ulcers with a secondary endpoint comparing reduction in wound size in the 42 days following debridement of necrotic tissue to evaluate efficacy of maintenance debridement.

Method: After randomization to collagenase or hydrogel after consent to avoid selection bias, subjects received daily dressing changes followed by a standard semi-occlusive dressing.  Phase I evaluated time to debridement up to Day 42. Those successfully completing Phase I entered Phase II, consisting of 42 additional days to evaluate effects of randomization on wound healing. Other investigators, blinded to randomization, evaluated weekly wound photographs using a digital planimetry software package*** for necrotic tissue debridement and wound healing parameters. Non-viable tissue was not cross-hatched in either group.

Outcome: 27 nursing home residents were enrolled over a period of one year. There were no significant differences (p > 0.05) patient characteristics between groups. Using a Student t test, Phase I patients randomized to collagenase showed faster reductions in non-viable tissue compared to hydrogel (p <0.05). 14 (2 collagenase; 12 hydrogel) did not fully debride by Day 42. One patient (hydrogel) developed cellulitis and was removed from the study. Of 13 patients entering Phase II, patients randomized to collagenase showed faster improvements in wound healing as compared to hydrogel (p <0.05).

* Santyl® Ointment, Healthpoint Ltd., Forth Worth, Texas

** SoloSite Gel, Smith & Nephew, Largo, FL *** PictZar®, BioVisual Technologies, Elmwood Park, NJ