Mechanical Negative Pressure Wound Therapy: Real-World Effectiveness in Challenging Patient Presentations

Laura Swoboda, DNP, APNP, FNP-BC, FNP-C, CWOCN-AP

Disclosures

Wounds. 2021;33(12):E85-E89. 

In This Article

Abstract and Introduction

Abstract

Introduction: When used for wound management, negative pressure wound therapy (NPWT) delivers subatmospheric pressure at the wound site, exerting multiple beneficial effects, including microstrain, macrostrain, edema management, granulation tissue formation, drainage management, and wound stabilization. Comparative effectiveness research has demonstrated similar wound healing and adverse event outcomes between traditional NPWT (tNPWT) and mechanical NPWT (mNPWT). Therefore, considerations for patient selection for mNPWT vs tNPWT are in alignment with current recommendations, including therapeutic goals, wound-related factors, patient satisfaction, quality of life, care setting, economic-related factors, and product design.

Case Reports: The 3 complex patient cases in the present report describe the routine use of mNPWT between December 18, 2020, and June 7, 2021, at a community hospital-based outpatient wound center within an academic health system, including 2 dehisced surgical incisions and 1 complicated venous leg ulcer. All patients received local standard of care, including surgical debridement, soap and water cleansing of the wound and extremity, hypochlorous acid 5-minute soak prior to dressing application, non-sting skin barrier periwound protection, smoking cessation and nutrition counseling, and chronic disease management. Case selections for mNPWT included: the need for frequent activity at work, minimal wound depth, lack of undermining, exudate, wound size, wound location allowing for the wound to fit comfortably beneath the mNPWT dressing, need for graft stabilization, protection of the site from repeated trauma, need for granulation tissue formation, and periwound inflammation.

Conclusions: Mechanical NPWT is a convenient therapeutic option that appears to deliver healing outcomes comparable to those of tNPWT but with improved wound-related quality of life. These cases reveal the real-world effectiveness of mNPWT in challenging patient presentations and wounds that have stalled. The cases outline common endpoints for using advanced therapy in addition to wound closure, such as granulation tissue formation and quality of life.

Introduction

When used for wound management, negative pressure wound therapy (NPWT) delivers subatmospheric pressure at the wound site, exerting multiple beneficial effects. The field of mechanobiology, an emerging combination of physics, engineering, and biology, has shown that mechanical or physical forces (eg, negative pressure as seen in V.A.C. Therapy; 3M Health Care) can induce microstrain. The associated cellular deformation that occurs contributes to biological responses, including cellular division and keratinocyte migration.[1] For example, fibroblasts are important cells in the healing process; they synthesize and remodel collagen, tumor necrosis factor alpha, matrix metalloproteinases, and growth factors. Fibroblasts are also known to respond to mechanical cues such as tension, compression, and shear.[2] The microstrain exerted during NPWT is thought to contribute to the expedited healing observed. Macrostrain also occurs during the delivery of properly applied NPWT, whereby the dressing supports the wound edges and aids in wound contraction. An additional mechanism of action of NPWT is the assistance it provides with drainage management by removing and containing drainage away from the wound bed. Wound drainage can contain high levels of inflammatory cytokines and bacteria that potentiate the inflammatory cycle, contributing to stagnation and delayed wound healing. Another benefit associated with the use of NPWT is the improved perfusion that results from the removal of subcutaneous and interstitial edema. Compared with standard wound dressings, NPWT is associated with improved granulation tissue, decreased time to healing, and reduced overall cost of treatment.[3]

Mechanical NPWT (mNPWT) delivers positive wound outcomes using similar mechanisms of action.[4,5] Unlike traditional NPWT (tNPWT), however, mNPWT is disposable, lightweight, ultraportable, and quiet, and it does not require electrical power to provide subatmospheric pressure at the wound site.

The 3 complex patient cases reported herein describe the routine use of mNPWT (SNAP Therapy System; 3M Health Care) between December 18, 2020, and June 7, 2021, at a community hospital-based outpatient wound center within an academic health system. All patients received local standard of care, including bedside surgical debridement, soap and water cleansing of the wound and extremity, hypochlorous acid 5-minute soak prior to dressing application, nonsting skin barrier periwound protection, smoking cessation and nutrition counseling, and chronic disease management. For each case, -125 mm Hg negative pressure level canisters were used. No dressing interface was used between the foam and the wound.

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