A randomized controlled clinical trial to evaluate the effects of noncontact normothermic wound therapy on chronic full-thickness pressure ulcers

Effectiveness of negative-pressure wound therapy to standard therapy in the prevention of complications after vascular surgery

Wound complications are common after vascular surgery and many may be preventable. Negative pressure wound therapy (NPWT) dressings may be able to reduce wound complications relating to closed incisions following vascular surgery and several devices are currently available along with a large body of literature. This review article will describe the use of NPWT dressings in vascular surgery. We will summarize the currently available systems, the likely mechanism of action of NWPT, the published studies to date and we will give our recommendations regarding the priorities for future research on this topic.

Advance in topical biomaterials and mechanisms for the intervention of pressure injury

Pressure injuries (PIs) are localized tissue damage resulting from prolonged compression or shear forces on the skin or underlying tissue, or both. Different stages of PIs share common features include intense oxidative stress, abnormal inflammatory response, cell death, and subdued tissue remodeling. Despite various clinical interventions, stage 1 or stage 2 PIs are hard to monitor for the changes of skin or identify from other disease, whereas stage 3 or stage 4 PIs are challenging to heal, painful, expensive to manage, and have a negative impact on quality of life. Here, we review the underlying pathogenesis and the current advances of biochemicals in PIs. We first discuss the crucial events involved in the pathogenesis of PIs and key biochemical pathways lead to wound delay. Then, we examine the recent progress of biomaterials-assisted wound prevention and healing and their prospects.

Breakthrough treatments for accelerated wound healing

Skin injuries across the body continue to disrupt everyday life for millions of patients and result in prolonged hospital stays, infection, and death. Advances in wound healing devices have improved clinical practice but have mainly focused on treating macroscale healing versus underlying microscale pathophysiology. Consensus is lacking on optimal treatment strategies using a spectrum of wound healing products, which has motivated the design of new therapies. We summarize advances in the development of novel drug, biologic products, and biomaterial therapies for wound healing for marketed therapies and those in clinical trials. We also share perspectives for successful and accelerated translation of novel integrated therapies for wound healing.

Negative-Pressure Wound Therapy: What We Know and What We Need to Know

Negative-pressure wound therapy (NPWT) promotes wound healing by applying negative pressure to the wound surface. A quarter of a century after its introduction, NPWT has been used in various clinical conditions, although molecular biological evidence is insufficient due to delay in basic research. Here, we have summarized the history of NPWT, its mechanism of action, what is currently known about it, and what is expected to be known in the future. Particularly, attention has shifted from the four main mechanisms of NPWT to the accompanying secondary effects, such as effects on various cells, bacteria, and surgical wounds. This chapter will help the reader to understand the current status and shortcomings of NPWT-related research, which could aid in the development of basic research and, eventually, clinical use with stronger scientific evidence.

Negative Pressure Wound Therapy: Mechanism of Action and Clinical Applications

Negative pressure wound therapy (NPWT) promotes healing by evenly applying negative pressure on the surface of the wound. The system consists of a sponge, a semiocclusive barrier, and a fluid collection system. Its effectiveness is explained by four main mechanisms of action, including macrodeformation of the tissues, drainage of extracellular inflammatory fluids, stabilization of the environment of the wound, and microdeformation. Rarely will complications linked to NPWT occur, but special care must be taken to prevent events such as toxic shock syndrome, fistulization, bleeding, and pain. New NPWT modalities have been recently developed to make NPWT suitable for a wider variety of wounds. These include NPWT with instillation therapy (NPWTi-d), different cleansing options, and application of NPWT on primarily closed incisions. Finally, vacuum-assisted wound closure therapy has been demonstrated to be efficient for various clinical settings, such as the management of diabetic foot ulcers, pressure ulcerations, chronic wounds, and skin grafts.

Publicly Reported Wound Healing Rates: The Fantasy and the Reality

Significance: We compare real-world data from the U.S. Wound Registry (USWR) with randomized controlled trials and publicly reported wound outcomes and develop criteria for honest reporting of wound outcomes, a requirement of the new Quality Payment Program (QPP). Recent Advances: Because no method has existed by which wounds could be stratified according to their likelihood of healing among real-world patients, practitioners have reported fantastically high healing rates. The USWR has developed several risk-stratified wound healing quality measures for diabetic foot ulcers (DFUs) and venous leg ulcers (VLUs) as part of its Qualified Clinical Data Registry (QCDR). This allows practitioners to report DFU and VLU healing rates in comparison to the likelihood of whether the wound would have healed. Critical Issues: Under the new QPP, practitioners must report at least one practice-relevant outcome measure, and it must be risk adjusted so that clinicians caring for the sickest patients do not appear to have worse outcomes than their peers. The Wound Healing Index is a validated risk-stratification method that can predict whether a DFU or VLU will heal, leveling the playing field for outcome reporting and removing the need to artificially inflate healing rates. Wound care practitioners can report the USWR DFU and VLU risk-stratified outcome measure to satisfy the quality reporting requirements of the QPP. Future Directions: Per the requirements of the QPP, the USWR will begin publicly reporting of risk-stratified healing rates once quality measure data have met the reporting standards of the Centers for Medicare and Medicaid Services. Some basic rules for data censoring are proposed for public reporting of healing rates, and others are needed, which should be decided by consensus among the wound care community.

Dressings and topical agents for treating pressure ulcers

BACKGROUND

Pressure ulcers, also known as bedsores, decubitus ulcers and pressure injuries, are localised areas of injury to the skin or the underlying tissue, or both. Dressings are widely used to treat pressure ulcers and promote healing, and there are many options to choose from including alginate, hydrocolloid and protease-modulating dressings. Topical agents have also been used as alternatives to dressings in order to promote healing.A clear and current overview of all the evidence is required to facilitate decision-making regarding the use of dressings or topical agents for the treatment of pressure ulcers. Such a review would ideally help people with pressure ulcers and health professionals assess the best treatment options. This review is a network meta-analysis (NMA) which assesses the probability of complete ulcer healing associated with alternative dressings and topical agents.

OBJECTIVES

To assess the effects of dressings and topical agents for healing pressure ulcers in any care setting. We aimed to examine this evidence base as a whole, determining probabilities that each treatment is the best, with full assessment of uncertainty and evidence quality.

SEARCH METHODS

In July 2016 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses, guidelines and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

Published or unpublished randomised controlled trials (RCTs) comparing the effects of at least one of the following interventions with any other intervention in the treatment of pressure ulcers (Stage 2 or above): any dressing, or any topical agent applied directly to an open pressure ulcer and left in situ. We excluded from this review dressings attached to external devices such as negative pressure wound therapies, skin grafts, growth factor treatments, platelet gels and larval therapy.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, risk of bias assessment and data extraction. We conducted network meta-analysis using frequentist mega-regression methods for the efficacy outcome, probability of complete healing. We modelled the relative effectiveness of any two treatments as a function of each treatment relative to the reference treatment (saline gauze). We assumed that treatment effects were similar within dressings classes (e.g. hydrocolloid, foam). We present estimates of effect with their 95% confidence intervals for individual treatments compared with every other, and we report ranking probabilities for each intervention (probability of being the best, second best, etc treatment). We assessed the certainty (quality) of the body of evidence using GRADE for each network comparison and for the network as whole.

MAIN RESULTS

We included 51 studies (2947 participants) in this review and carried out NMA in a network of linked interventions for the sole outcome of probability of complete healing. The network included 21 different interventions (13 dressings, 6 topical agents and 2 supplementary linking interventions) and was informed by 39 studies in 2127 participants, of whom 783 had completely healed wounds.We judged the network to be sparse: overall, there were relatively few participants, with few events, both for the number of interventions and the number of mixed treatment contrasts; most studies were small or very small. The consequence of this sparseness is high imprecision in the evidence, and this, coupled with the (mainly) high risk of bias in the studies informing the network, means that we judged the vast majority of the evidence to be of low or very low certainty. We have no confidence in the findings regarding the rank order of interventions in this review (very low-certainty evidence), but we report here a summary of results for some comparisons of interventions compared with saline gauze. We present here only the findings from evidence which we did not consider to be very low certainty, but these reported results should still be interpreted in the context of the very low certainty of the network as a whole.It is not clear whether regimens involving protease-modulating dressings increase the probability of pressure ulcer healing compared with saline gauze (risk ratio (RR) 1.65, 95% confidence interval (CI) 0.92 to 2.94) (moderate-certainty evidence: low risk of bias, downgraded for imprecision). This risk ratio of 1.65 corresponds to an absolute difference of 102 more people healed with protease modulating dressings per 1000 people treated than with saline gauze alone (95% CI 13 fewer to 302 more). It is unclear whether the following interventions increase the probability of healing compared with saline gauze (low-certainty evidence): collagenase ointment (RR 2.12, 95% CI 1.06 to 4.22); foam dressings (RR 1.52, 95% CI 1.03 to 2.26); basic wound contact dressings (RR 1.30, 95% CI 0.65 to 2.58) and polyvinylpyrrolidone plus zinc oxide (RR 1.31, 95% CI 0.37 to 4.62); the latter two interventions both had confidence intervals consistent with both a clinically important benefit and a clinically important harm, and the former two interventions each had high risk of bias as well as imprecision.

AUTHORS' CONCLUSIONS

A network meta-analysis (NMA) of data from 39 studies (evaluating 21 dressings and topical agents for pressure ulcers) is sparse and the evidence is of low or very low certainty (due mainly to risk of bias and imprecision). Consequently we are unable to determine which dressings or topical agents are the most likely to heal pressure ulcers, and it is generally unclear whether the treatments examined are more effective than saline gauze.More research is needed to determine whether particular dressings or topical agents improve the probability of healing of pressure ulcers. The NMA is uninformative regarding which interventions might best be included in a large trial, and it may be that research is directed towards prevention, leaving clinicians to decide which treatment to use on the basis of wound symptoms, clinical experience, patient preference and cost.

Can subphysiological cold application be utilized in excessive dermal scarring prophylaxis and treatment?: A promising hypothetical perspective

Excessive dermal scarring (EDS) is a wound healing complication, characterized by protruded erythematous and inelastic 'proliferative scar tissue' which is associated with increased and prolonged inflammation process within the wound microenvironment. As inflammation plays a key role in this process, methods to contain or attenuate excessive inflammation hold promise in treatment and prophylaxis of EDS conditions. While cold exposure is notorious as the causative agent a wide array of morbidities and fatalities, its tempered use is exploited in medicine for ablative and therapeutic applications. "Subphysiological cold" has been administered for its antiinflammatory effects which act via decreasing vascular permeability and downregulating proliferation of cells in the wound environment; this knowledge supports our hypothesis that "subphysiological cold application" can also be utilized in human EDS prophylaxis and treatment. In this study, we are reviewing the mechanisms of its both deleterious and therapeutic actions and suggesting another possible application for prevention and/or treatment of human EDS conditions.

The external microenvironment of healing skin wounds

The skin wound microenvironment can be divided into two main components that influence healing: the external wound microenvironment, which is outside the wound surface; and the internal wound microenvironment, underneath the surface, to which the cells within the wound are exposed. Treatment methods that directly alter the features of the external wound microenvironment indirectly affect the internal wound microenvironment due to the exchange between the two compartments. In this review, we focus on the effects of temperature, pressure (positive and negative), hydration, gases (oxygen and carbon dioxide), pH, and anti-microbial treatment on the wound. These factors are well described in the literature and can be modified with treatment methods available in the clinic. Understanding the roles of these factors in wound pathophysiology is of central importance in wound treatment.

Treatment of pressure ulcers: a clinical practice guideline from the American College of Physicians

DESCRIPTION

The American College of Physicians (ACP) developed this guideline to present the evidence and provide clinical recommendations based on the comparative effectiveness of treatments of pressure ulcers.

METHODS

This guideline is based on published literature on this topic that was identified by using MEDLINE, EMBASE, CINAHL, EBM Reviews, the Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, and the Health Technology Assessment database through February 2014. Searches were limited to English-language publications. The outcomes evaluated for this guideline include complete wound healing, wound size (surface area, volume, and depth) reduction, pain, prevention of sepsis, prevention of osteomyelitis, recurrence rate, and harms of treatment (including but not limited to pain, dermatologic complications, bleeding, and infection). This guideline grades the quality of evidence and strength of recommendations by using ACP's clinical practice guidelines grading system. The target audience for this guideline includes all clinicians, and the target patient population is patients with pressure ulcers.

RECOMMENDATION 1

ACP recommends that clinicians use protein or amino acid supplementation in patients with pressure ulcers to reduce wound size. (Grade: weak recommendation, low-quality evidence).

RECOMMENDATION 2

ACP recommends that clinicians use hydrocolloid or foam dressings in patients with pressure ulcers to reduce wound size. (Grade: weak recommendation, low-quality evidence).

RECOMMENDATION 3

ACP recommends that clinicians use electrical stimulation as adjunctive therapy in patients with pressure ulcers to accelerate wound healing. (Grade: weak recommendation, moderate-quality evidence).

Which medical devices and/or local drug should be curatively used, as of 2012, for PU patients? How can granulation and epidermidalization be promoted? Developing French guidelines for clinical practice

INTRODUCTION

Management of a patient with pressure ulcer sore(s) must associate local and general treatment.

OBJECTIVES

To determine which medical devices other than supports and which treatments may be used for pressure sore healing (granulation tissue and epithelization/epidermidalization) as of 2012.

METHODS

Systematic review of the literature querying the databases: PASCAL Biomed, PubMed, and Cochrane library from 2000 through 2010.

RESULTS

Data in the literature on granulation tissue and epithelisation/epidermidalization in pressure sore healing are poor. The level of evidence regarding the relative effectiveness of one modern dressing compared to another has remained low. However, the study data on the interest of hydrocolloid dressing compared with impregnated gases are more significant.

DISCUSSION

Studies with heterogeneous results and populations have shown low power. Meta-analyses are difficult due to the wide range of therapeutic aims. Further clinical studies with adequate methodology are needed prior to elaboration of more specific recommendations.

CONCLUSION

The use of hydrocolloid dressing may be recommended to improve granulation tissue development and epithelization/epidermidalization in pressure sore (Level B).

Mechanisms of action of microdeformational wound therapy

Microdeformational Wound Therapy (MDWT) is a class of medical devices that have revolutionized the treatment of complex wounds over the last 20 years. These devices, are a subset of Negative Pressure Wound Therapy (NPWT), in which there is a highly porous interface material placed between the wound and a semi-occlussive dressing and connected to suction. The porous interface material acts to deform the wound on a micro scale promoting cellular proliferation. These devices appear to significantly improve the speed of healing in many wounds, facilitate granulation tissue formation and reduce the complexity of subsequent reconstructive operations. The mechanisms through which such effects are obtained are beginning to be better understood through basic research and clinical trials. Further work in this field is likely to yield devices that are designed to treat specific wound types.

Methods to assess cost-effectiveness and value of further research when data are sparse: negative-pressure wound therapy for severe pressure ulcers

Health care resources are scarce, and decisions have to be made about how to allocate funds. Often, these decisions are based on sparse or imperfect evidence. One such example is negative-pressure wound therapy (NPWT), which is a widely used treatment for severe pressure ulcers; however, there is currently no robust evidence that it is effective or cost-effective. This work considers the decision to adopt NPWT given a range of alternative treatments, using a decision analytic modeling approach. Literature searches were conducted to identify existing evidence on model parameters. Given the limited evidence base, a second source of evidence, beliefs elicited from experts, was used. Judgments from experts on relevant (uncertain) quantities were obtained through a formal elicitation exercise. Additionally, data derived from a pilot trial were also used to inform the model. The 3 sources of evidence were collated, and the impact of each on cost-effectiveness was evaluated. An analysis of the value of further information indicated that a randomized controlled trial may be worthwhile in reducing decision uncertainty, where from a set of alternative designs, a 3-arm trial with longer follow-up was estimated to be the most efficient. The analyses presented demonstrate how allocation decisions about medical technologies can be explicitly informed when data are sparse and how this kind of analyses can be used to guide future research prioritization, not only indicating whether further research is worthwhile but what type of research is needed and how it should be designed.

Feasibility of virtual wound care: a pilot study

OBJECTIVE

A 9-month pilot study was initiated to evaluate the feasibility of a Web-based telemedicine program for remote wound care team consultations for patients with chronic wounds.

METHOD

Wound care nurses in Veterans Health Administration outpatient clinics evaluated 56 patients with chronic wounds over the course of 208 clinic visits. The wounds were predominantly lower-extremity ulcers (diabetic and vascular). The Veterans Affairs Computerized Patient Record System and the Internet were used to obtain consultations and transmit data (store-forward) between the nurse specialists and a multidisciplinary wound care team located at the regional tertiary care center.

RESULTS

During the course of the study, 76% of wounds treated decreased in size; mean response time for consultations was 2.61 days. Exit surveys indicated that 98.2% of patients were satisfied with care; referring providers also indicated a high degree of satisfaction with the teleconsult system.

CONCLUSIONS

This study demonstrated that a multidisciplinary wound care team using a store-forward approach can feasibly provide telemedicine consultations for patients in remote locations.

Effects of warming on healing

Systemic and local warming may accelerate wound healing and minimise postoperative wound infection, although more research is needed to confirm this. The existing evidence of the benefits of warming therapies is outlined here.