MANAGING PRESSURE ULCERS WITH NEGATIVE PRESSURE WOUND THERAPY: EXAMINATION OF A CONSENSUS PANEL GUIDELINE

Dr Mona M. Baharestani

This paper and all algorithmic figures are adapted from Gupta S, Baharestani M, Baronski S, et al. Guidelines for managing pressure ulcers with negative pressure wound therapy. Advances in Skin and Wound Care. 2004; 17 (2–Suppl): 2–16.

Figure 1: Management of a Patient with Pressure Ulcers using V.A.C.® Therapy

Introduction
Given the plethora of active and passive local modalities available for the treatment of full-thickness pressure ulcers, it is not surprising that clinicians are often overwhelmed and unsure of which products are most clinically efficacious and cost-effective. Negative pressure wound therapy as delivered by Vacuum Assisted Closure (V.A.C.®) has consistently demonstrated both clinical efficacy and cost-effectiveness.2

Figure 2: Management of a Patient with Pressure Ulcers using V.A.C.® Therapy

For example, in a retrospective study by Philbeck et al.3 an average closure rate of 0.23 cm2 in Stage III and IV pressure ulcers (n = 566) was reported, compared to 0.090 cm2 among those having received conventional wound care. Pressure ulcers managed with NPWT were found to be 38% less costly to treat than those receiving conventional care.3

Figure 3: Stage IV Pressure Ulcer

Even more impressive are results from a 2002 prospective Japanese study in which a daily closure rate of 1.0 cm2/day was reported among infected Stage IV pressure ulcers treated with NPWT.4 Pressure ulcers and other chronic wounds treated with NPWT revealed a statistically significant decrease in depth of 66% versus 20% in those treated with normal saline wet to moist dressings (p < .0001) in a study by Joseph et al.5 Histo-logically, 81% of ulcers treated with wet to moist dressings revealed inflammation and fibrosis, whereas NPWT treated ulcers (n = 645) exhibited granulation tissue as the chief characteristic.5 Despite multiple documented clinical benefits, faster wound closure rates and cost-savings, clinicians in various practice settings remain ambiguous re-garding use of NPWT in the treatment of pressure ulcers, although comfortable with V.A.C.® use in acute wounds.

Figure 4: Surgical Candidate

Guideline Development
Acknowledging clinicians’ uncertainty in pressure ulcer treatment of when to initiate NPWT, on whom, using which settings, which foam and what pressure and for how long, a consensus panel was assembled with the mission of addressing these questions through guideline development. This interdisciplinary panel comprised of three nurses and five physicians with expertise in wound management and use of NPWT critically reviewed all literature published on NPWT use in pressure ulcer treatment, as well as current best practices for pressure ulcer management. The pressure ulcer staging system utilized by this panel was that of the National Pressure Ulcer Advisory Panel (NPUAP).6

Figure 5: Patient & wound characteristics are favourable for V.A.C.

According to the Agency for Health Care Policy and Research (AHCPR)7 now known as the Agency for Health Care Research and Quality (AHCRQ), guidelines are reflective of the current knowledge on effective and appropriate care. Furthermore, guidelines are aimed at assisting practitioners and patients in making decisions regarding specific conditions.7
Based on panel consensus and review of the literature, the fundamental algorithmic components of managing a patient with pressure ulcers using NPWT, as delivered by V.A.C.® therapy, are outlined in Figures 1 and 2. Use of NPWT in the surgical candidate is described in Figure 4. Figure 5 provides a treatment algorithm for NPWT in non-surgical candidates, while Figure 6 outlines patient and wound characteristics that are not favourable for V.A.C.®

Figure 6: Patient & wound characteristics are not favourable for V.A.C.

In the development of a treatment algorithm for the management of patients with pressure ulcers using V.A.C.® therapy, the following key questions were answered by the panel1:

1. What are the indications for NPWT in patients with pressure ulcers?

• Full-thickness pressure ulcers (Stage III & IV) (Figure 3)
• An ulcer size large enough to allow foam contact with the base and for safe extraction
• Poor or inadequate granulation tissue
• Presence of undermine or tunnelling

2. What wound characteristics do not favour use of NPWT?

• Inadequately debrided, fibrotic or desiccated wound beds
• An ulcer size too small to allow for foam contact with base and for safe foam extraction
• Inadequate haemostasis
• Inadequate perfusion to support healing

3. What patient characteristics do not favour use of NPWT?

• Inadequate patient adherence with pressure off-loading and other components of the treatment protocol
• Inadequate financial or caregiver resources
• Untreated malnutrition
• Intolerance of pain resulting from V.A.C.® therapy despite alterations made in technique
• Allergy to adhesive drape materials
• Inability to maintain an airtight seal
• Bleeding disorders impacting ability to achieve haemostasis
• Malignancy within the wound bed is cited by the manufacturer KCI, Inc. as a contraindication to the use of V.A.C.®8
  
  But, it was the consensus of the panel that NPWT can be used in palliative care when the management of pain and exudate control are treatment goals.

4. What wound size is most appropriate for NPWT use?

• As long as the ulcer meets the criteria outlined in question 1, then the wound size does not matter. For small pressure ulcers, clinicians must weigh the cost-benefit ratio of use of NPWT to that of other treatment modalities

5. How often should the wound be monitored?

• Monitor the ulcer with every dressing change
• In the absence of a heavy bioburden, the panel recommends that dressings be changed every 72 hours or sooner if indicated. KCI, Inc.’s recommendation is dressing changes every 12–24 hours for infected wounds and every 48 hours for noninfected wounds.8

6. What are the optimal settings for NPWT use in pressure ulcers?

• A target pressure of 125mm Hg is recommended based on the seminal research by Morykwas et al.9 Pressure settings may need to be titrated from lower pressures of 75–100mm Hg as tolerated for those who are elderly, malnourished, on anticoagulant therapy, have blood dyscrasias, or are intolerant of pain related to V.A.C.® application.
• A continuous mode setting should be utilized for the first 48 hours of treatment and continued in the following cases:
  † Presence of undermine
  † Significant discomfort with intermittent cycling
  † Anatomical sites in which maintenance of an airtight seal would be problematic
  † Heavy wound drainage

7. Which foam dressings should be used?

• Granufoam (Polyurethane foam)
  For stimulation of granulation tissue
• Versafoam (Polyvinyl alcohol foam)
  † For controlled ingrowth of granulation into the foam
  † Wounds in which the goal is increased re-epithelialization
  † Tunnelled areas
  † Patients who are unable to tolerate Granufoam secondary to pain

8. What should be done if the patient is experiencing pain?

• Decrease pressure settings
• Switch to Versafoam
• Line the ulcer base with a nonadherent meshed interface dressing
• Premoisten the foam prior to removal
• Allow the patient to assist with dressing changes where feasible
• Utilize topical anaesthetics or systemic analgesics
• Provide skin protection of peri-ulcer skin and dermal wound margins
• Reassess the frequency of dressing changes
  (refer back to question 5)

9. Does osteomyelitis affect NPWT use?

• Patients receiving appropriate systemic antibiotics for the treatment of osteomyelitis can be effectively treated with NPWT8
• Untreated osteomyelitis is a contraindication to NPWT use8

10. What are the treatment end points?

• The treatment endpoints are contingent upon whether the patient is a candidate for surgical closure. V.A.C.® treatment goals may include:
  † Preparation for surgical closure (Figure 4)
  * NPWT serves as a means to temporize the patient, allowing for nutritional maximization, antibiotic administration and stabilization of coagulopathies while further pre-operative wound bed preparation occurs. In many cases, the wound may progress with NPWT to such a point that a less complicated surgical procedure than originally planned becomes possible or surgery may not be required at all. If no progress is made with NPWT, reassessment of both the patient and wound must be performed with appropriate intervention implemented, followed by reconstructive surgery or institution of another adjunctive modality.
  † Promotion of flap healing
  † Closure by secondary healing for patients who are not surgical candidates. (Figure 5) NPWT can be utilized until there is:
  * A fully granulated wound surface
  * Decreased volume and the wound surface is essentially up to skin level at which time the clinician needs to consider the clinical efficacy and cost-effectiveness of continued NPWT versus another product
  * If within 2–4 weeks the wound fails to improve or deteriorates, the patient and wound must be reassessed and pressure ulcer best practice guidelines for pressure ulcer management should be followed (Figure 6)
  * Resolution of tunnels and undermined areas

11. What is the duration of NPWT treatment?

• NPWT can be continued for as long as the wound is exhibiting progress without an unfavourable patient response

Conclusions
With the results of more than twenty randomized controlled NPWT studies forthcoming, coupled with wound etiopathogenesis specific treatment guidelines, clinicians will have a more structured and scientifically rigorous foundation upon which to make patient specific treatment decisions.

References
1. Gupta S, Baharestani M, Baranoski S, et al. Guidelines for managing pressure ulcers with negative pressure wound therapy. Adv Skin wound Care 2004; 17 (2-Suppl): 2–16.
2. Baharestani MM. Negative pressure wound therapy: an examination of cost-effectiveness. Ostomy Wound Manage 2004; 50 (11A-Suppl): 29S–33S.
3. Philbeck TE, KT, Millsap MH, et al. The clinical and cost effectiveness of externally applied negative pressure wound therapy in the treatment of wounds in home healthcare Medicare patients. Ostomy Wound Manage 1999; 45 (11): 41–50.
4. Isago T, Nozaki M, Kikuchi Y, et al. Negative-pressure dressings in the treatment of pressure ulcers. J Derm 2003; 30: 299–305.
5. Joseph E, Hamori CA, Bergman S, et al. New therapeutic approaches in wound care: a prospective randomized trial of vacuum-assisted closure versus standard therapy of chronic nonhealing wounds. Wounds 2000; 12(3): 60–67.
6. National Pressure Ulcer Advisory Panel Monograph. Pressure ulcers in America: prevalence, incidence, and implications for the future. Adv Skin Wound Care 2001; 14: 208–215.
7. Bergstrom N, Bennett MA, Carlson CE, et al. Treat-ment of Pressure Ulcers. Clinical Practice Guidelines, No. 15. AHCPR Publication No. 95–0652. Rockville, MD: Agency for Healthcare Policy & Research; December 1994.
8. V.A.C.® Therapy Clinical Guidelines. San Antonio, TX: KCI, USA; October 2005.
9. Morykwas MJ, Argenta LC, Shelton-Brown EI, McGuirt W. Vacuum-assisted closure: a new method for wound control and treatment: animal studies and basic foundation. Ann plastic Surg 1997; 38(6): 553–561.

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