Collagenase vs Hydrogel in Maintenance Debridement
Collagenase vs Hydrogel in Maintenance Debridement
The role of maintenance debridement in wound healing has been well described, yet little is known regarding comparative methods and associated outcomes with this process when using collagenase or hydrogel.
Objective. Evaluation of maintenance debridement and wound closure with collagenase compared to hydrogel in institutionalized adults with pressure ulcers from time of necrotic tissue removal up to 84 days from enrollment.
Methods. This second phase of a rollover evaluation enrolled only subjects who successfully completed phase 1 (previously reported) from time of necrotic tissue debridement. Subjects received daily dressing changes with either hydrogel or collagenase followed by a standard semiocclusive dressing to evaluate wound-healing parameters and wound closure from initial enrollment to day 84. Investigators blinded to randomization evaluated weekly wound photographs using a digital planimetry software package for wound-healing parameters. Additionally, Pressure Ulcer Scale for Healing (PUSH)© Tool and wound bed scores (WBS) were monitored.
Results. Eleven of 13 subjects from the collagenase group entered into phase 2, with 4 of the 14 subjects from the hydrogel group. One subject from each group was eliminated within the first week of phase 2. All subjects (n = 3) in the hydrogel group reached complete epithelialization with a mean of 32.6 days. Nine of 10 subjects in the collagenase group reached completed epithelialization with a mean of 45 days. An independent samples t test showed no statistical significance between the 2 groups (P = 0.121) in days to healing. A Fisher's exact test performed on the primary endpoint of complete epithelialization also demonstrated no significant difference in outcomes between the groups (P = 0.99). Mean WBS at the onset of phase 2 was 13.7 (range 12–16), and the PUSH Tool mean score was 1.0 (range 0–3). In aggregating phase 1 and phase 2 data, a difference in the closure rates at the end of the study, 69% (collagenase) vs 21% (hydrogel), was statically significant (P = 0.0213) using a Fisher's exact test.
Conclusion. Facilitating maintenance debridement by either collagenase or hydrogel can be used to complete wound closure when used in conjunction with a validated predictive wound-healing tool that closely monitors therapy. This study showed statistical significance in favor of collagenase when evaluating closure rates from the onset of the pressure ulcer.
Wound bed preparation (WBP) is an established concept in chronic wound management. Addressing the relationship between necrotic tissue, exudate, and bacterial and cellular dysfunction leads to optimal outcomes. Execution of WBP includes eliminating necrotic tissue, bacterial burden, biofilms, edema, and exudate, while promoting the formation of granulation tissue. Debridement is one essential step in accomplishing these goals.
Concepts related to debridement have evolved with increased understanding of WBP. Initially considered the removal of visible, nonviable tissue, debridement is further elucidated into 2 distinct phases: initial debridement and maintenance debridement. Initial debridement is defined as "the removal of necrotic, damaged, and/or infected tissue." However, despite removal of visibly necrotic tissue, phenotypically altered senescent fibroblasts and keratinocytes, coupled with accumulating extracellular matrix materials and substrates that may contribute to bioburden, need ongoing removal from the wound bed. Maintenance debridement offers a continuous removal of cellular burden not visible to the naked eye and frees the wound bed from these obstacles to healing. Falanga's review of in vitro studies suggest that maintenance debridement may recruit functional cells to the chronic wound. Maintenance debridement can be achieved via mechanical, enzymatic, or autolytic means; though there is little literature that associates these concepts in vivo. Regardless, incorporating this key concept in clinical practice is paramount to optimizing wound outcomes.
The clinical setting in which maintenance debridement occurs often influences decision-making regarding treatment, as resources, patient populations, and expertise in wound management may differ. Clinicians often change from one therapeutic modality to another when the wound appears to be free from necrotic debris upon visual assessment. A less-skilled clinician often equates the absence of necrotic tissue with wound health, failing to appreciate the pathophysiological processes occurring at the cellular level.
Many skilled nursing facilities have adopted predetermined wound protocols, as standardization has been shown to improve wound healing outcomes. Many protocols provided by wound care vendors strongly encourage changing from an active debridement process, such as an enzymatic agent, to a product that provides corrective moisture balance when visible, non-viable tissue has been removed. Collagenase has not been traditionally accepted in clinical practice for use beyond the removal of necrotic tissue, though in vitro work suggests collagenase may play a role in reducing formation of biofilms and bacterial proliferation, and enhance keratinocyte proliferation and migration. While comparison of hydrogel dressings and enzymatic debriding agents on wound healing have been done using swine, there are no reports in the clinical area, or, specifically, the long-term care setting, where these agents are extensively used.
The aim of this 2-phase study was to evaluate the outcomes of both hydrogel and collagenase on initial debridement of nonviable tissue and impact on the maintenance debridement phase of wound bed preparation. The results of phase 1, examining initial debridement, have been published. This manuscript reports the time from complete debridement of visible, nonviable tissue to epithelialization from phase 2.
Abstract and Introduction
Abstract
The role of maintenance debridement in wound healing has been well described, yet little is known regarding comparative methods and associated outcomes with this process when using collagenase or hydrogel.
Objective. Evaluation of maintenance debridement and wound closure with collagenase compared to hydrogel in institutionalized adults with pressure ulcers from time of necrotic tissue removal up to 84 days from enrollment.
Methods. This second phase of a rollover evaluation enrolled only subjects who successfully completed phase 1 (previously reported) from time of necrotic tissue debridement. Subjects received daily dressing changes with either hydrogel or collagenase followed by a standard semiocclusive dressing to evaluate wound-healing parameters and wound closure from initial enrollment to day 84. Investigators blinded to randomization evaluated weekly wound photographs using a digital planimetry software package for wound-healing parameters. Additionally, Pressure Ulcer Scale for Healing (PUSH)© Tool and wound bed scores (WBS) were monitored.
Results. Eleven of 13 subjects from the collagenase group entered into phase 2, with 4 of the 14 subjects from the hydrogel group. One subject from each group was eliminated within the first week of phase 2. All subjects (n = 3) in the hydrogel group reached complete epithelialization with a mean of 32.6 days. Nine of 10 subjects in the collagenase group reached completed epithelialization with a mean of 45 days. An independent samples t test showed no statistical significance between the 2 groups (P = 0.121) in days to healing. A Fisher's exact test performed on the primary endpoint of complete epithelialization also demonstrated no significant difference in outcomes between the groups (P = 0.99). Mean WBS at the onset of phase 2 was 13.7 (range 12–16), and the PUSH Tool mean score was 1.0 (range 0–3). In aggregating phase 1 and phase 2 data, a difference in the closure rates at the end of the study, 69% (collagenase) vs 21% (hydrogel), was statically significant (P = 0.0213) using a Fisher's exact test.
Conclusion. Facilitating maintenance debridement by either collagenase or hydrogel can be used to complete wound closure when used in conjunction with a validated predictive wound-healing tool that closely monitors therapy. This study showed statistical significance in favor of collagenase when evaluating closure rates from the onset of the pressure ulcer.
Introduction
Wound bed preparation (WBP) is an established concept in chronic wound management. Addressing the relationship between necrotic tissue, exudate, and bacterial and cellular dysfunction leads to optimal outcomes. Execution of WBP includes eliminating necrotic tissue, bacterial burden, biofilms, edema, and exudate, while promoting the formation of granulation tissue. Debridement is one essential step in accomplishing these goals.
Concepts related to debridement have evolved with increased understanding of WBP. Initially considered the removal of visible, nonviable tissue, debridement is further elucidated into 2 distinct phases: initial debridement and maintenance debridement. Initial debridement is defined as "the removal of necrotic, damaged, and/or infected tissue." However, despite removal of visibly necrotic tissue, phenotypically altered senescent fibroblasts and keratinocytes, coupled with accumulating extracellular matrix materials and substrates that may contribute to bioburden, need ongoing removal from the wound bed. Maintenance debridement offers a continuous removal of cellular burden not visible to the naked eye and frees the wound bed from these obstacles to healing. Falanga's review of in vitro studies suggest that maintenance debridement may recruit functional cells to the chronic wound. Maintenance debridement can be achieved via mechanical, enzymatic, or autolytic means; though there is little literature that associates these concepts in vivo. Regardless, incorporating this key concept in clinical practice is paramount to optimizing wound outcomes.
The clinical setting in which maintenance debridement occurs often influences decision-making regarding treatment, as resources, patient populations, and expertise in wound management may differ. Clinicians often change from one therapeutic modality to another when the wound appears to be free from necrotic debris upon visual assessment. A less-skilled clinician often equates the absence of necrotic tissue with wound health, failing to appreciate the pathophysiological processes occurring at the cellular level.
Many skilled nursing facilities have adopted predetermined wound protocols, as standardization has been shown to improve wound healing outcomes. Many protocols provided by wound care vendors strongly encourage changing from an active debridement process, such as an enzymatic agent, to a product that provides corrective moisture balance when visible, non-viable tissue has been removed. Collagenase has not been traditionally accepted in clinical practice for use beyond the removal of necrotic tissue, though in vitro work suggests collagenase may play a role in reducing formation of biofilms and bacterial proliferation, and enhance keratinocyte proliferation and migration. While comparison of hydrogel dressings and enzymatic debriding agents on wound healing have been done using swine, there are no reports in the clinical area, or, specifically, the long-term care setting, where these agents are extensively used.
The aim of this 2-phase study was to evaluate the outcomes of both hydrogel and collagenase on initial debridement of nonviable tissue and impact on the maintenance debridement phase of wound bed preparation. The results of phase 1, examining initial debridement, have been published. This manuscript reports the time from complete debridement of visible, nonviable tissue to epithelialization from phase 2.
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