Topical negative pressure (TNP) for partial thickness burns

A Novel Approach to Negative Pressure Wound Therapy: Use of High Suction Capillary Device to Improve Wound Healing

INTRODUCTION

Negative Pressure Wound Therapy (NPWT) is a procedure used for nonhealing wounds. In NPWT, a special sealed dressing of large cell foam (>400 µm) or gauze is connected to a pump. Most commonly, negative pressures between -10 and -125 millimeters of mercury (mm Hg) are used. The mechanism of healing is unknown but maybe attributable to removal of the exudate and bacteria, and the stimulation of tissue repair through microdeformation. Reticulated foams with micron-size open cells, Capillary Suction Devices (CSD; 100 to 5 µm) exert capillary suction between 10 and 70 mm of Hg with a multilayered foam dressing.

MATERIALS AND METHODS

Yorkshire pigs received 5 surgical excision wounds, 3 cm2, on each side of the back. The wounds were covered with a NPWT dressing (110 mm Hg negative pressure by a pump), CSD with capillary suctions of 30 mm Hg (CSD-30) and 70 mm Hg (CSD-70), and a conventional gauze dressing. The wounds were measured on day 2, and then every 4-5 days thereafter; the total fluid collected by the various dressing over time.

RESULTS

By post-wound day 20, the wounds treated with CSD-70 and NPWT were 100% closed while the wounds treated with CSD-30 and gauze were 65% and 45%, respectively. This indicated comparable wound closure efficacies for CSD-70 and NPWT. The average total fluid uptake measured in grams dry weight were similar for CSD-70 and NPWT, 36 and 38 g, respectively, while the values were 24 g for CSD-30 and 12 g for gauze. However, the maximum fluid uptake observed at day 2 indicated that CSD-70 and CSD 30, 24 and 14 g, respectively, were superior to NPWT and gauze 12 and 7 g, respectively.

CONCLUSION

This data indicate comparable wound closure efficacies for CSD-70 and NPWT. It is felt that CSD is an effective, safe, and lower cost alternative to vacuum-assisted NPWT.

The Combined Use of Negative-Pressure Wound Therapy and Dermal Substitutes for Tissue Repair and Regeneration

In clinical practice, skin defects occur frequently due to various kinds of acute and chronic diseases. The standard treatment for these wounds is autografting, which usually results in complications such as scar formation and new wounds at donor sites. The advent of dermal substitutes has provided a novel method for wound repair, and rapid angiogenesis of the dermal substitutes is crucial for the graft to take. At present, many strategies have been developed to improve the process of vascularisation, some of which have shown promising potentials, but they could be very far from clinical applications. Most recently, negative-pressure wound therapy (NPWT) has been used extensively in clinical practice for wound care and management. It has been reported that NPWT reduces the time required for vascular ingrowth into the dermal substitute and improves graft take, indicating great potentials for wound repair. This article presents a comprehensive overview of the combined use of NPWT and dermal substitutes for tissue repair and regeneration. Relative concerns and prospects are also discussed.

WITHDRAWN: Topical negative pressure for treating chronic wounds

This review has been split into three reviews each addressing a single wound type (pressure ulcers, venous leg ulcers and foot ulcers in people with diabetes). Protocols have been published. Two reviews have been published:

Negative pressure wound therapy for treating foot wounds in people with diabetes mellitus. Negative pressure wound therapy for treating pressure ulcers.

The third review, Negative pressure wound therapy for treating leg ulcers, will be published in 2015.

The original parent review ‐ Topical negative pressure for treating chronic wounds ‐ is being withdrawn.

The editorial group responsible for this previously published document have withdrawn it from publication.

Negative pressure wound therapy for partial-thickness burns

BACKGROUND

A burn wound is a complex and evolving injury, with both local and systemic consequences. Burn treatments include a variety of dressings, as well as newer strategies, such as negative pressure wound therapy (NPWT), which, by means of a suction force that drains excess fluids from the burn, tries to promote the wound healing process and minimise progression of the burn wound.

OBJECTIVES

To assess the effectiveness of NPWT for people with partial-thickness burns.

SEARCH METHODS

We searched the Cochrane Wounds Group Specialised Register (searched 04 September 2014); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 8).

SELECTION CRITERIA

All randomised controlled trials (RCTs) and controlled clinical trials (CCTs) that evaluated the safety and effectiveness of NPWT for partial-thickness burns.

DATA COLLECTION AND ANALYSIS

Two review authors used standardised forms, and extracted the data independently. We assessed each trial for risk of bias, and resolved differences by discussion.

MAIN RESULTS

One RCT, that was an interim report, satisfied the inclusion criteria. We undertook a narrative synthesis of results, as the absence of data and poor reporting precluded us from carrying out any formal statistical analysis. The trial was at high risk of bias.

AUTHORS' CONCLUSIONS

There was not enough evidence available to permit any conclusions to be drawn regarding the use of NPWT for treatment of partial-thickness burn wounds.

Negative pressure wound therapy for partial-thickness burns

BACKGROUND

A burn wound is a complex and evolving injury, with both local and systemic consequences. Burn treatments include a variety of dressings, as well as newer strategies, such as negative pressure wound therapy (NPWT), which, by means of a suction force that drains excess fluids from the burn, tries to promote the wound healing process and minimise progression of the burn wound.

OBJECTIVES

To assess the effectiveness of NPWT for people with partial-thickness burns.

SEARCH METHODS

For this third update we searched the Cochrane Wounds Group Specialised Register (searched 18 May 2012); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 5); Ovid MEDLINE (2010 to May Week 2 2012); Ovid MEDLINE (In-Process & Other Non-Indexed Citations 17 May 2012); Ovid EMBASE (2010 to 2012 Week 19); and EBSCO CINAHL (2010 to 16 May 2012).

SELECTION CRITERIA

All randomised controlled trials (RCTs) and controlled clinical trials (CCTs) that evaluated the safety and effectiveness of NPWT for partial-thickness burns.

DATA COLLECTION AND ANALYSIS

Two review authors used standardised forms, and extracted the data independently. We assessed each trial for risk of bias, and resolved differences by discussion.

MAIN RESULTS

One RCT, that was an interim report, satisfied the inclusion criteria. We undertook a narrative synthesis of results, as the absence of data and poor reporting precluded us from carrying out any formal statistical analysis. The trial was at high risk of bias.

AUTHORS' CONCLUSIONS

There was not enough evidence available to permit any conclusions to be drawn regarding the use of NPWT for treatment of partial-thickness burn wounds.

Use of a nanocrystalline silver dressing and vacuum-assisted closure in a severely burned dog

OBJECTIVE

To describe the first veterinary use of a nanocrystalline silver dressing (NSD) and use of vacuum-assisted closure (VAC) to treat a severely burned dog.

CASE OR SERIES SUMMARY

A 1-year-old female intact American Staffordshire Terrier with 50% total body surface area burned was referred for definitive care approximately 18-24 hours post injury. The dog was treated with crystalloid fluids, hydroxyethyl starch, and antimicrobials based on culture and sensitivity results of wound cultures, fresh frozen plasma, human serum albumin, and packed red cells. Wound care initially consisted of daily debridement under anesthesia with silver sulfadiazine application and bandaging. Because of the extent and the location of the wounds and morbid state of the patient, early wound grafting was not an option. Because of its reported improvement in granulation tissue formation and decreased tissue edema, VAC was used once the majority of burned tissue was manually debrided. Because of the pain caused by VAC and traditional bandaging techniques with this extent of injury, an NSD was utilized. This strategy was chosen due to the antimicrobial properties of NSD and the reduced necessity for daily bandage changes, which was reduced to only every 3 days. This protocol reduced the need for daily sedation or anesthesia.

NEW OR UNIQUE INFORMATION PROVIDED

VAC and NSD were used successfully for the treatment of a severe burn injury in a dog. The use of NSD decreased the cost of therapy by reducing the need for daily bandage changes, thereby reducing the anesthetic and analgesic costs and allowing the patient to be managed on an outpatient basis.

Vacuum-assisted closure of laparostomy wounds: a critical review of the literature

Vacuum-assisted closure (VAC) reduces the burden for carers of laparostomy wounds but evidence from randomised trials is lacking. This review analyses the evidence for the VAC abdominal wound management system (KCI, San Antonio, TX) in the open abdomen. Three prospective studies provide level III evidence that VAC allows delayed primary fascial closure in the majority of these wounds up to 21 days after occurrence, but not where duration of VAC was less than 9 days or if vacuum pack techniques were used in place of VAC. Fistulae occurred in a minority of wounds complicated by multi-organ failure or sepsis and could not be attributed to VAC itself. Two retrospective analyses suggested VAC may reduce re-operation rate and length of stay in complex wounds. Whilst randomised controlled trials remain the gold standard of evidence for effectiveness of health care interventions, contemporaneous level III evidence supports the hypothesis that VAC increases the rate of primary fascial closure. Whilst enterocutaneous fistula formation is reported in the most complex of these wounds, there is no more evidence that these are consequential to as opposed to coincident with VAC use.

An overview of negative pressure wound therapy for the lower extremity

Since its introduction into the market, negative pressure wound therapy (NPWT), also known as topical negative pressure, has become an important adjuvant therapy for the treatment of many types of wounds. Surgeons and physicians of all subspecialties have adopted NPWT into their practices. NPWT has become a mainstay in the management of lower extremity soft tissue pathology, especially in patients with traumatic, diabetic, postsurgical, and peripheral vascular disease-associated wounds. This article reviews the background, currently understood mechanisms of action, applications, contraindications, reported complications, advantages, criticisms, and techniques in the lower extremity.

Topical negative pressure for treating chronic wounds

BACKGROUND

Chronic wounds mainly affect the elderly and those with multiple health problems. Despite the use of modern dressings, some of these wounds take a long time to heal, fail to heal, or recur, causing significant pain and discomfort to the person and cost to health services. Topical negative pressure (TNP) is used to promote healing of surgical wounds by using suction to drain excess fluid from wounds.

OBJECTIVES

To assess the effects of TNP on chronic wound healing.

SEARCH STRATEGY

For this second update of this review we searched the Cochrane Wounds Group Specialised Register (December 2007), The Cochrane Central Register of Controlled Trials (CENTRAL) - The Cochrane Library Issue 4, 2007, Ovid MEDLINE - 1950 to November Week 2 2007, Ovid EMBASE - 1982 to 2007 Week 50 and Ovid CINAHL - 1980 to December Week 1 2007. In addition, we contacted authors, companies, manufacturers, and distributors to identify relevant trials and information.

SELECTION CRITERIA

All randomised controlled trials which evaluated the effects of TNP on people with chronic wounds.

DATA COLLECTION AND ANALYSIS

Selection of the trials, quality assessment, data abstraction, and data synthesis were done by two authors independently. Disagreements were solved by discussion.

MAIN RESULTS

Two trials were included in the original review. A further five trials were included in this second update resulting in a total of seven trials involving 205 participants. The seven trials compared TNP with five different comparator treatments. Four trials compared TNP with gauze soaked in either 0.9% saline or Ringer's solution. The other three trials compared TNP with hydrocolloid gel plus gauze, a treatment package comprising papain-urea topical treatment, and cadexomer iodine or hydrocolloid, hydrogels, alginate and foam. These data do not show that TNP significantly increases the healing rate of chronic wounds compared with comparators. Data on secondary outcomes such as infection rate, quality of life, oedema, hospitalisation and bacterial load were not reported.

AUTHORS' CONCLUSIONS

Trials comparing TNP with alternative treatments for chronic wounds have methodological flaws and data do demonstrate a beneficial effect of TNP on wound healing however more, better quality research is needed.

A systematic review of topical negative pressure therapy for acute and chronic wounds

BACKGROUND

Topical negative pressure (TNP) therapy is becoming increasingly popular for all kinds of wounds. Its clinical and cost effectiveness is unclear.

METHODS

A search of randomized controlled trials (RCTs) on TNP in adult patients with all kinds of wounds in all settings was undertaken in Medline, Embase, Cinahl (to October 2007) and the Cochrane Library (to issue 4, 2007). Information was also sought from manufacturer of the VAC device. Selection of trials for analysis, quality assessment, data abstraction and data synthesis were conducted by two authors independently. The primary endpoint was any measure of wound healing. Secondary endpoints were infection, pain, quality of life, oedema, microcirculation, bacterial load, adverse events, duration of hospital stay and cost.

RESULTS

The search identified 15 publications on 13 RCTs. These reported on patients with chronic wounds, diabetic wounds, pressure ulcers, skin grafts and acute wounds. In chronic and diabetic wounds, TNP did not allow earlier complete wound healing. It was, however, associated with a 1-10 day reduction in the time needed to prepare the wound for secondary closure surgery. In one trial on acute wounds, 17 (95 per cent confidence interval (c.i.) 0.02 to 0.32) per cent more wounds appeared to heal with TNP; the number needed to treat was six. This was, however, at the cost of an 11 (95 per cent c.i. 0.01 to 0.21) per cent higher complication rate; the number needed to harm was nine.

CONCLUSION

There is little evidence to support the use of TNP in the treatment of wounds.

The efficacy of negative pressure wound therapy in the management of lower extremity trauma: review of clinical evidence

A large number of aids have been conceived and introduced into clinical practice (nutritional supplements, local dressings, technical innovations) aimed at facilitating and optimising wound healing in both acute and chronic wound settings. Among these advances, negative pressure wound therapy (NPWT) has been introduced during the last 30 years, and has been analysed in over 400 manuscripts of the English, Russian and German literature. Until very recently, vacuum assisted closure (VAC) (KCI, TX, USA) has been the only readily available commercial device that provides localised negative pressure to the wound and is the predominant agent used to deliver NPWT featured in this review. We conducted a comprehensive review of the existing clinical evidence of the English literature on the applications of NPWT in the acute setting of trauma and burns of the lower extremity. Overall, 16 clinical studies have been evaluated and scrutinised as to the safety and the efficacy of this adjunct therapy in the specific environment of trauma. Effectiveness was comparable to the standard dressing and wound coverage methods. The existing clinical evidence justifies its application in lower limb injuries associated with soft tissue trauma.

Topical negative pressure for treating chronic wounds

BACKGROUND

Chronic wounds mainly affect the elderly and those with multiple health problems. Despite the use of modern dressings, some of these wounds take a long time to heal, fail to heal, or recur, causing significant pain and discomfort to the person and cost to health services. Topical negative pressure is used to promote healing of surgical wounds by using suction to drain excess fluid from wounds.

OBJECTIVES

To assess the effectiveness of topical negative pressure (TNP) in treating people with chronic wounds and to identify an optimum TNP regimen.

SEARCH STRATEGY

The Cochrane Wounds Group Specialised Trials Register was searched until July 2000. Experts in the field and relevant companies were contacted to enquire about ongoing and recently completed relevant trials. In addition citations within obtained papers were scrutinised to identify additional studies.

SELECTION CRITERIA

All randomised controlled trials which evaluated the effectiveness of TNP in treating chronic wounds were considered.

DATA COLLECTION AND ANALYSIS

Eligibility for inclusion, data extraction and details of trial quality was conducted by two reviewers independently. A narrative synthesis of results was undertaken as only two small trials fulfilled the selection criteria and they used different outcome measures.

MAIN RESULTS

Two small trials with a total of 34 participants evaluated the effectiveness of TNP on chronic wound healing. Trial 1 considered patients with any type of chronic wound; Trial 2 considered patients with diabetic foot ulcers only. The trials compared TNP (as open cell foam dressing with continuous suction) for the first 48 hours with saline gauze dressings. Trial 1 reported a statistically significant reduction in wound volume at 6 weeks in favour of TNP. Trial 2 (continuous suction, followed by intermittent suction after 48 hours) reported a reduction in the number of days to healing and a reduction in wound surface area at 2 weeks in favour of TNP, - although no statistical analysis was reported.

REVIEWER'S CONCLUSIONS

The two small trials provide weak evidence suggesting that TNP may be superior to saline gauze dressings in healing chronic human wounds. However, due to the small sample sizes and methodological limitations of these trials, the findings must be interpreted with extreme caution. The effect of TNP on cost, quality of life, pain and comfort was not reported. It was not possible to determine which was the optimum TNP regimen.