Therapeutic ultrasound for pressure ulcers

Ultrasound-based Techniques as Alternative Treatments for Chronic Wounds: A Comprehensive Review of Clinical Applications

Ultrasound (US) waves have been recently developed for the treatment of different chronic wounds with promising therapeutic outcomes. However, the clinical efficacy of these techniques is still not fully understood and standard guidelines on dose ranges and possible side effects should be determined. This paper aims to comprehensively review the recent advances in US techniques for chronic wound treatment, their therapeutic efficacies, and clinical considerations and challenges. The databases of PubMed (1985-2017), EMBASE (1985-2017), Web of Sciences (1985-2017), Cochrane central library (1990-2017), and Google Scholar (1980-2017) were searched using the set terms. The obtained results were screened for the title and abstract by two authors and the relevant papers were reviewed for further details. Preclinical and clinical studies have shown strong evidence on the therapeutic efficiency of US in chronic wounds. The main limitation on developing clinical standard protocols of US for treatment of wounds is the lack of definite dose-response for each wound. However, spatial average temporal average is the main parameter for defining US dosage in wound treatment. The range of 0.5 to 3 W/cm² is a range of dose exerting significant therapeutic outcomes and minimum adverse effects. Low-frequency US waves can accelerate the healing speed of open wounds as well as deep-tissue injuries. In addition, US waves show promising therapeutic efficacy for chronic wounds. To develop clinical US protocol for each wound type, further in vitro and in vivo preclinical and clinical trials are needed to reach an exact dose-response for each wound type.

Therapeutic ultrasound for venous leg ulcers

BACKGROUND

Venous leg ulcers are a type of chronic, recurring, complex wound that is more common in people aged over 65 years. Venous ulcers pose a significant burden to patients and healthcare systems. While compression therapy (such as bandages or stockings) is an effective first-line treatment, ultrasound may have a role to play in healing venous ulcers.

OBJECTIVES

To determine whether venous leg ulcers treated with ultrasound heal more quickly than those not treated with ultrasound.

SEARCH METHODS

We searched the Cochrane Wounds Specialised Register (searched 19 September 2016); the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library 2016, Issue 8); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations, MEDLINE Daily and Epub Ahead of Print) (1946 to 19 September 2016); Ovid Embase (1974 to 19 September 2016); and EBSCO CINAHL Plus (1937 to 19 September 2016). We also searched three clinical trials registries and the references of included studies and relevant systematic reviews. There were no restrictions based on language, date of publication or study setting.

SELECTION CRITERIA

Randomised controlled trials (RCTs) that compared ultrasound with no ultrasound. Eligible non-ultrasound comparator treatments included usual care, sham ultrasound and alternative leg ulcer treatments.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the search results and selected eligible studies. Details from included studies were summarised using a data extraction sheet, and double-checked. We attempted to contact trial authors for missing data.

MAIN RESULTS

Eleven trials are included in this update; 10 of these we judged to be at an unclear or high risk of bias. The trials were clinically heterogeneous with differences in duration of follow-up, and ultrasound regimens. Nine trials evaluated high frequency ultrasound; seven studies provided data for ulcers healed and two provided data on change in ulcer size only. Two trials evaluated low frequency ultrasound and both reported ulcers healed data.It is uncertain whether high frequency ultrasound affects the proportion of ulcers healed compared with no ultrasound at any of the time points evaluated: at seven to eight weeks (RR 1.21, 95% CI 0.86 to 1.71; 6 trials, 678 participants; low quality evidence - downgraded once for risk of bias and once for imprecision); at 12 weeks (RR 1.26, 95% CI 0.92 to 1.73; 3 trials, 489 participants; moderate quality evidence - downgraded once for imprecision); and at 12 months (RR 0.93, 95% CI 0.73 to 1.18; 1 trial, 337 participants; low quality evidence - downgraded once for unclear risk of bias and once for imprecision).One trial (92 participants) reported that a greater percentage reduction in ulcer area was achieved at four weeks with high-frequency ultrasound, while another (73 participants) reported no clear difference in change in ulcer size at seven weeks. We downgraded the level of this evidence to very low, mainly for risk of bias (typically lack of blinded outcome assessment and attrition) and imprecision.Data from one trial (337 participants) suggest that high frequency ultrasound may increase the risk of non-serious adverse events (RR 1.29, 95% CI 1.02 to 1.64; moderate quality evidence - downgraded once for imprecision) and serious adverse events (RR 1.21, 95% CI 0.78 to 1.89; moderate quality evidence downgraded once for imprecision).It is uncertain whether low frequency ultrasound affects venous ulcer healing at eight and 12 weeks (RR 3.91, 95% CI 0.47 to 32.85; 2 trials, 61 participants; very low quality evidence (downgraded for risk of bias and imprecision)).High-frequency ultrasound probably makes little or no difference to quality of life (moderate quality evidence, downgraded for imprecision). The outcomes of adverse effects, quality of life and cost were not reported for low-frequency ultrasound treatment.

AUTHORS' CONCLUSIONS

It is uncertain whether therapeutic ultrasound (either high or low frequency) improves the healing of venous leg ulcers. We rated most of the evidence as low or very low quality due to risk of bias and imprecision.

Wound bed preparation: TIME for an update

While the overwhelming majority of wounds heal rapidly, a significant proportion fail to progress through the wound-healing process. These resultant chronic wounds cause considerable morbidity and are costly to treat. Wound bed preparation, summarised by the TIME (Tissue, Inflammation/infection, Moisture imbalance, Epithelial edge advancement) concept, is a systematic approach for assessing chronic wounds. Each of these components needs to be addressed and optimised to improve the chances of successful wound closure. We present an up-to-date literature review of the most important recent aspects of wound bed preparation. While there are many novel therapies that are available to the treating clinician, often, there are limited data on which to assess their clinical value, and a lack of appreciation for adequate wound bed preparation needed before expensive therapy is used to heal a wound.

Topical phenytoin for treating pressure ulcers

BACKGROUND

Pressure ulcers are common in clinical practice and pose a significant health problem worldwide. Apart from causing suffering to patients, they also result in longer hospital stays and increase the cost of health care. A variety of methods are used for treating pressure ulcers, including pressure relief, patient repositioning, biophysical strategies, nutritional supplementation, debridement, topical negative pressure, and local treatments including dressings, ointments and creams such as bacitracin, silver sulphadiazine, neomycin, and phenytoin. Phenytoin is a drug more commonly used in the treatment of epilepsy, but may play an important role in accelerating ulcer healing.

OBJECTIVES

To assess the effects of topical phenytoin on the rate of healing of pressure ulcers of any grade, in any care setting.

SEARCH METHODS

In September 2016, we searched the following electronic databases to identify relevant randomized clinical trials: the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library); Ovid MEDLINE; Ovid Embase; and EBSCO CINAHL Plus. We handsearched conference proceedings from the European Pressure Ulcer Advisory Panel, European Wound Management Association and the Tissue Viability Society for all available years. We searched the references of the retrieved trials to identify further relevant trials. We also searched clinical trials registries to identify ongoing and unpublished studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included all randomized controlled trials (RCTs) addressing the effects (both benefits and harms) of topical phenytoin on the healing of pressure ulcers of any grade compared with placebo or alternative treatments or no therapy, irrespective of blinding, language, and publication status.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, extracted information on participants, interventions, methods and results and assessed risk of bias using Cochrane methodological procedures. For dichotomous variables, we calculated the risk ratio (RR) with 95% confidence interval (CI). For continuous variables, we calculated the mean difference with 95% CI. We rated the quality of the evidence by using Grading of Recommendations, Assessment, Development and Evaluation approach (GRADE).

MAIN RESULTS

Three small RCTs met our inclusion criteria and included a total of 148 participants. These compared three treatments with topical phenytoin: hydrocolloid dressings, triple antibiotic ointment and simple dressings. In the three RCTs, 79% of participants had grade II ulcers, and 21% of participants had grade I ulcers; no participants had grade III or IV ulcers. Two RCTs had a high risk of bias overall and the other RCT was at unclear risk of bias due to poor reporting. Two RCTs had three intervention arms and the other had two intervention arms.Two studies compared topical phenytoin with hydrocolloid dressing (84 participants analysed). The available data suggest that hydrocolloid dressings may improve ulcer healing compared to topical phenytoin (39.3% ulcers healed for phenytoin versus 71.4% ulcers healed for hydrocolloid dressings (RR 0.55, 95% CI 0.33 to 0.92; 56 participants, 1 study; low quality evidence). We downgraded the evidence twice: once due to serious limitations (high risk of bias) and once due to the small sample size and small number of events. Two studies compared topical phenytoin with simple dressings (81 participants analysed). From the available data, we are uncertain whether topical phenytoin improves ulcer healing compared to simple dressings (39.3% ulcers healed for phenytoin versus 29.6% ulcers healed for the simple dressing (RR 1.33, 95% CI 0.63 to 2.78; 55 participants, 1 study; very low quality evidence). This evidence was downgraded once due to serious limitations (high risk of bias) and twice due to the low number of outcome events and resulting wide CI which included the possibility of both increased healing and reduced healing. We therefore considered it to be insufficient to determine the effect of topical phenytoin on ulcer healing. One study compared topical phenytoin with triple antibiotic ointment, however, none of the outcomes of interest to this review were reported. No adverse drug reactions or interactions were detected in any of the three RCTs. Minimal pain was reported in all groups in one trial that compared topical phenytoin with hydrocolloid dressings and triple antibiotic ointment.

AUTHORS' CONCLUSIONS

This review has considered the available evidence and the result shows that it is uncertain whether topical phenytoin improves ulcer healing for patients with grade I and II pressure ulcers. No adverse events were reported from three small trials and minimal pain was reported in one trial. Therefore, further rigorous, adequately powered RCTs examining the effects of topical phenytoin for treating pressure ulcers, and to report on adverse events, quality of life and costs are necessary.

Hyperbaric oxygen therapy for chronic wounds

BACKGROUND

Chronic wounds are common and present a health problem with significant effect on quality of life. Various pathologies may cause tissue breakdown, including poor blood supply resulting in inadequate oxygenation of the wound bed. Hyperbaric oxygen therapy (HBOT) has been suggested to improve oxygen supply to wounds and therefore improve their healing.

OBJECTIVES

To assess the benefits and harms of adjunctive HBOT for treating chronic ulcers of the lower limb.

SEARCH METHODS

For this second update we searched the Cochrane Wounds Group Specialised Register (searched 18 February 2015); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2015, Issue 1); Ovid MEDLINE (1946 to 17 February 2015); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, 17 February 2015); Ovid EMBASE (1974 to 17 February 2015); and EBSCO CINAHL (1982 to 17 February 2015).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the effect on chronic wound healing of therapeutic regimens which include HBOT with those that exclude HBOT (with or without sham therapy).

DATA COLLECTION AND ANALYSIS

Three review authors independently evaluated the risk of bias of the relevant trials using the Cochrane methodology and extracted the data from the included trials. We resolved any disagreement by discussion.

MAIN RESULTS

We included twelve trials (577 participants). Ten trials (531 participants) enrolled people with a diabetic foot ulcer: pooled data of five trials with 205 participants showed an increase in the rate of ulcer healing (risk ratio (RR) 2.35, 95% confidence interval (CI) 1.19 to 4.62; P = 0.01) with HBOT at six weeks but this benefit was not evident at longer-term follow-up at one year. There was no statistically significant difference in major amputation rate (pooled data of five trials with 312 participants, RR 0.36, 95% CI 0.11 to 1.18). One trial (16 participants) considered venous ulcers and reported data at six weeks (wound size reduction) and 18 weeks (wound size reduction and number of ulcers healed) and suggested a significant benefit of HBOT in terms of reduction in ulcer area only at six weeks (mean difference (MD) 33.00%, 95% CI 18.97 to 47.03, P < 0.00001). We identified one trial (30 participants) which enrolled patients with non-healing diabetic ulcers as well as venous ulcers ("mixed ulcers types") and patients were treated for 30 days. For this "mixed ulcers" there was a significant benefit of HBOT in terms of reduction in ulcer area at the end of treatment (30 days) (MD 61.88%, 95% CI 41.91 to 81.85, P < 0.00001). We did not identify any trials that considered arterial and pressure ulcers.

AUTHORS' CONCLUSIONS

In people with foot ulcers due to diabetes, HBOT significantly improved the ulcers healed in the short term but not the long term and the trials had various flaws in design and/or reporting that means we are not confident in the results. More trials are needed to properly evaluate HBOT in people with chronic wounds; these trials must be adequately powered and designed to minimise all kinds of bias.

Seeking effective interventions to treat complex wounds: an overview of systematic reviews

BACKGROUND

Numerous, often multi-faceted regimens are available for treating complex wounds, yet the evidence of these interventions is recondite across the literature. We aimed to identify effective interventions to treat complex wounds through an overview of systematic reviews.

METHODS

MEDLINE (OVID interface, 1946 until October 26, 2012), EMBASE (OVID interface, 1947 until October 26, 2012), and the Cochrane Database of Systematic Reviews (Issue 10 of 12, 2012) were searched on October 26, 2012. Systematic reviews that examined adults receiving care for their complex wounds were included. Two reviewers independently screened the literature, abstracted data, and assessed study quality using the Assessment of Multiple Systematic Reviews (AMSTAR) tool.

RESULTS

Overall, 99 systematic reviews were included after screening 6,200 titles and abstracts and 422 full-texts; 54 were systematic reviews with a meta-analysis (including data on over 54,000 patients) and 45 were systematic reviews without a meta-analysis. Overall, 44% of included reviews were rated as being of high quality (AMSTAR score ≥ 8). Based on data from systematic reviews including a meta-analysis with an AMSTAR score ≥ 8, promising interventions for complex wounds were identified. These included bandages or stockings (multi-layer, high compression) and wound cleansing for venous leg ulcers; four-layer bandages for mixed arterial/venous leg ulcers; biologics, ultrasound, and hydrogel dressings for diabetic leg/foot ulcers; hydrocolloid dressings, electrotherapy, air-fluidized beds, and alternate foam mattresses for pressure ulcers; and silver dressings and ultrasound for unspecified mixed complex wounds. For surgical wound infections, topical negative pressure and vacuum-assisted closure were promising interventions, but this was based on evidence from moderate to low quality systematic reviews.

CONCLUSIONS

Numerous interventions can be utilized for patients with varying types of complex wounds, yet few treatments were consistently effective across all outcomes throughout the literature. Clinicians and patients can use our results to tailor effective treatment according to type of complex wound. Network meta-analysis will be of benefit to decision-makers, as it will permit multiple treatment comparisons and ranking of the effectiveness of all interventions. Please see related article: http://dx.doi.org/10.1186/s12916-015-0326-3.

A pilot study evaluating non-contact low-frequency ultrasound and underlying molecular mechanism on diabetic foot ulcers

Non-contact low-frequency ultrasound (NCLF-US) devices have been increasingly used for the treatment of chronic non-healing wounds. The appropriate dose for NCLF-US is still in debate. The aims of this pilot study were to evaluate the relationship between dose and duration of treatment for subjects with non-healing diabetic foot ulcers (DFUs) and to explore the correlation between wound healing and change of cytokine/proteinase/growth factor profile. This was a prospective randomised clinical study designed to evaluate subjects with non-healing DFUs for 5 weeks receiving standard of care and/or NCLF-US treatment. Subjects were randomly assigned to one of the three groups: application of NCLF-US thrice per week (Group 1), NCLF-US once per week (Group 2) and the control (Group 3) that received no NCLF-US. All subjects received standard wound care plus offloading for a total of 4 weeks. Percent area reduction (PAR) of each wound compared with baseline was evaluated weekly. Profiles of cytokines/proteinase/growth factors in wound fluid and biopsied tissue were quantified to explore the correlation between wound healing and cytokines/growth factor expression. Twelve DFU patients, 2 (16·7%) type 1 and 10 (83·3%) type 2 diabetics, with an average age of 58 ± 10 years and a total of 12 foot ulcers were enrolled. Average ulcer duration was 36·44 ± 24·78 weeks and the average ABI was 0·91 ± 0·06. Group 1 showed significant wound area reduction at weeks 3, 4 and 5 compared with baseline, with the greatest PAR, 86% (P < 0·05); Groups 2 and 3 showed 25% PAR and 39% PAR, respectively, but there were no statistically significant differences between Groups 2 and 3 over time. Biochemical and histological analyses indicated a trend towards reduction of pro-inflammatory cytokines (IL-6, IL-8, IL-1β, TNF-α and GM-CSF), matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEGF) and macrophages in response to NCLF-US consistent with wound reduction, when compared with control group subjects. This proof-of-concept pilot study demonstrates that NCLF-US is effective in treating neuropathic diabetic foot ulcers through, at least in part, inhibiting pro-inflammatory cytokines in chronic wound and improving tissue regeneration. Therapeutic application of NFLU, thrice (3) per week, renders the best wound area reduction.

Low-frequency ultrasound (20-40 kHz) as an adjunctive therapy for chronic wound healing: a systematic review of the literature and meta-analysis of eight randomized controlled trials

Ultrasound as a therapeutic agent in chronic wound healing has been studied extensively. This systematic review and meta-analysis specifically examines low-frequency (20-30 kHz) ultrasound delivered at either low or high intensity. The objective of this review was to determine whether low-frequency ultrasound used as an adjunctive therapy improves the outcomes of complete healing and reduction of size of chronic lower limb wounds. PubMed, Cochrane/CENTRAL, technical assessment, relevant wound-related journals, and clinical guidelines were searched along with contacting manufacturers and authors of relevant randomized controlled trials were completed. Searches focused on the use of low-frequency ultrasound in randomized controlled trials. Data were collected via a data collection form and was adjudicated independently via coauthors. Meta-analyses and heterogeneity checks were performed using Mantel-Haenszel and inverse variance (fixed and random effects) statistical methods on studies with similar outcomes (complete healing and percent wound area reduction) over similar time periods. Single study results were reported via the statistical methods used in the study. Eight randomized controlled trials were identified. Results demonstrated that early healing (at ≤5 months) in patients with venous stasis and diabetic foot ulcers was favorably influenced by both high- and low-intensity ultrasound delivered at a low frequency-either via contact or noncontact techniques. However, the quality of the data may be suspect, especially for low-frequency low-intensity noncontact ultrasound because of significant biases. In patients presenting with either venous stasis or diabetic foot ulcers (Wagner classification 1-3), early healing appears to be facilitated by either low-frequency low-intensity noncontact ultrasound or low-frequency high-intensity contact ultrasound.

Hyperbaric oxygen therapy for chronic wounds

BACKGROUND

Chronic wounds are common and present a health problem with significant effect on quality of life. Various pathologies may cause tissue breakdown, including poor blood supply resulting in inadequate oxygenation of the wound bed. Hyperbaric oxygen therapy (HBOT) has been suggested to improve oxygen supply to wounds and therefore improve their healing.

OBJECTIVES

To assess the benefits and harms of adjunctive HBOT for treating chronic ulcers of the lower limb.

SEARCH METHODS

For this first update we searched the Cochrane Wounds Group Specialised Register (searched 12 January 2012); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 4); Ovid MEDLINE (1950 to January Week 1 2012); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, 11 July 2012); Ovid EMBASE (1980 to 2012 Week 01); and EBSCO CINAHL (1982 to 6 January 2012).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing the effect on chronic wound healing of therapeutic regimens which include HBOT with those that exclude HBOT (with or without sham therapy).

DATA COLLECTION AND ANALYSIS

Three review authors independently evaluated the risk of bias of the relevant trials using the Cochrane methodology and extracted the data from the included trials. We resolved any disagreement by discussion.

MAIN RESULTS

We included nine trials (471 participants). Eight trials (455 participants) enrolled people with a diabetic foot ulcer: pooled data of three trials with 140 participants showed an increase in the rate of ulcer healing (risk ratio (RR) 5.20, 95% confidence interval (CI) 1.25 to 21.66; P = 0.02) with HBOT at six weeks but this benefit was not evident at longer-term follow-up at one year. There was no statistically significant difference in major amputation rate (pooled data of five trials with 312 participants, RR 0.36, 95% CI 0.11 to 1.18). One trial (16 participants) considered venous ulcers and reported data at six weeks (wound size reduction) and 18 weeks (wound size reduction and number of ulcers healed) and suggested a significant benefit of HBOT in terms of reduction in ulcer area only at six weeks (mean difference (MD) 33.00%, 95% CI 18.97 to 47.03, P < 0.00001). We did not identify any trials that considered arterial and pressure ulcers.

AUTHORS' CONCLUSIONS

In people with foot ulcers due to diabetes, HBOT significantly improved the ulcers healed in the short term but not the long term and the trials had various flaws in design and/or reporting that means we are not confident in the results. More trials are needed to properly evaluate HBOT in people with chronic wounds; these trials must be adequately powered and designed to minimise all kinds of bias.

Therapeutic modalities--an updated review for the hand surgeon

The number of therapeutic modalities available to the hand surgeon has greatly increased over the past several decades. A field once predicated only on heat, massage, and cold therapy now uses electrical stimulators, ultrasound, biofeedback, iontophoresis, phonophoresis, mirror therapy, lasers, and a number of other modalities. With this expansion in choices, there has been a concurrent effort to better define which modalities are truly effective. In this review, we aim to characterize the commonly used modalities and provide the evidence available that supports their continued use.

Effects of non contact low-frequency ultrasound on healing of suspected deep tissue injury: a retrospective analysis

The purpose of this study was to assess the effectiveness of non contact low-frequency ultrasound on the healing of suspected deep tissue injury (SDTI). Participants were adults ranging in age from 28 to 93 years old, with multiple diagnoses including anaemia, diabetes mellitus and hypertension. Data were examined retrospectively on 85 patients (intervention group = 43 and non intervention group = 42) with 127 SDTI (intervention group = 64 and non intervention group = 63). Participants in both groups received standard of care for treating pressure ulcers. A severity score was used to assess SDTI severity before treatment and healing/progression after treatment. This scale measures surface area, wound colour/tissue assessment, and skin integrity with potential scores of 3 to 18 (higher scores indicate greater severity). A significant difference in changes in wound severity was found (t = 5·67, P < 0.000). Difference in mean change scores was 2·52 on the 3-18 severity scale. The decrease in wound severity for the intervention group was 1·45. Severity in the non intervention group increased by 1·06. This exploratory study of the effect of the non contact low-frequency ultrasound provides initial findings that support its use with SDTI.

Support surfaces for treating pressure ulcers

BACKGROUND

Pressure ulcers are treated by reducing pressure on the areas of damaged skin. Special support surfaces (including beds, mattresses and cushions) designed to redistribute pressure, are widely used as treatments. The relative effects of different support surfaces are unclear.

OBJECTIVES

To assess the effects of pressure-relieving support surfaces in the treatment of pressure ulcers.

SEARCH METHODS

We searched: The Cochrane Wounds Group Specialised Register (searched 15 July 2011); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 3); Ovid MEDLINE (2007 to July Week 1 2011); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, July 14, 2011); Ovid EMBASE (2007 to 2011 Week 27); EBSCO CINAHL (2007 to 14 July 2011). The reference sections of included studies were also searched.

SELECTION CRITERIA

We included published or unpublished randomised controlled trials (RCTs), that assessed the effects of support surfaces for treating pressure ulcers, in any patient group or setting, that reported an objective measure of wound healing.

DATA COLLECTION AND ANALYSIS

Data extraction and assessment of risk of bias were performed independently by two review authors. Trials with similar patients, comparisons and outcomes were considered for pooled analysis. Where pooling was inappropriate the results of the trials were reported narratively. Where possible, the risk ratio or mean difference was calculated for the results of individual studies.

MAIN RESULTS

We identified 18 trials of support surfaces for pressure ulcer treatment, involving 1309 participants with samples sizes that ranged from 14 to 160. Of three trials comparing air-fluidized devices with conventional therapy, two reported significant reductions in pressure ulcer size associated with air-fluidized devices. Due to lack of reported variance data we could not replicate the analyses. In relation to three of the trials that reported significant reductions in pressure ulcer size favouring low air loss devices compared with foam alternatives, we found no significant differences. A small trial found that sheepskin placed under the legs significantly reduced redness and similarly a small subgroup analysis favoured a profiling bed compared with a standard bed in terms of the healing of existing grade 1 pressure ulcers. Poor reporting, clinical heterogeneity, lack of variance data and methodological limitations in the eligible trials meant that no pooled comparisons were undertaken.

AUTHORS' CONCLUSIONS

There is no conclusive evidence about the superiority of any support surface for the treatment of existing pressure ulcers. Methodological issues included variations in outcomes measured, sample sizes and comparison groups. Many studies had small sample sizes and often there was inadequate description of the intervention, standard care and co-interventions. Individual study results were often inadequately reported, with failure to report variance data common, thus hindering the calculation of mean differences. Some studies did not report P values when reporting on differences in outcomes. In addition, the age of some trials (some being 20 years old), means that other technologies may have superseded those investigated.Further and rigorous studies are required to address these concerns and to improve the evidence base before firm conclusions can be drawn about the most effective support surfaces to treat pressure ulcers.

Use of weekly, low dose, high frequency ultrasound for hard to heal venous leg ulcers: the VenUS III randomised controlled trial

OBJECTIVE

To assess the clinical effectiveness of weekly delivery of low dose, high frequency therapeutic ultrasound in conjunction with standard care for hard to heal venous leg ulcers.

DESIGN

Multicentre, pragmatic, two arm randomised controlled trial.

SETTING

Community and district nurse led services, community leg ulcer clinics, and hospital outpatient leg ulcer clinics in 12 urban and rural settings (11 in the United Kingdom and one in the Republic of Ireland).

PARTICIPANTS

337 patients with at least one venous leg ulcer of >6 months' duration or >5 cm(2) area and an ankle brachial pressure index of ≥ 0.8.

INTERVENTIONS

Weekly administration of low dose, high frequency ultrasound therapy (0.5 W/cm(2), 1 MHz, pulsed pattern of 1:4) for up to 12 weeks plus standard care compared with standard care alone.

MAIN OUTCOME MEASURES

Primary outcome was time to healing of the largest eligible leg ulcer. Secondary outcomes were proportion of patients healed by 12 months, percentage and absolute change in ulcer size, proportion of time participants were ulcer-free, health related quality of life, and adverse events.

RESULTS

The two groups showed no significant difference in the time to healing of the reference leg ulcer (log rank test, P=0.61). After adjustment for baseline ulcer area, baseline ulcer duration, use of compression bandaging, and study centre, there was still no evidence of a difference in time to healing (hazard ratio 0.99 (95% confidence interval 0.70 to 1.40), P=0.97). The median time to healing of the reference leg ulcer was inestimable. There was no significant difference between groups in the proportion of participants with all ulcers healed by 12 months (72/168 in ultrasound group v 78/169 in standard care group, P=0.39 for Fisher's exact test) nor in the change in ulcer size at four weeks by treatment group (model estimate 0.05 (95% CI -0.09 to 0.19)). There was no difference in time to complete healing of all ulcers (log rank test, P=0.61), with median time to healing of 328 days (95% CI 235 to inestimable) with standard care and 365 days (224 days to inestimable) with ultrasound. There was no evidence of a difference in rates of recurrence of healed ulcers (17/31 with ultrasound v 14/31 with standard care, P=0.68 for Fisher's exact test). There was no difference between the two groups in health related quality of life, both for the physical component score (model estimate 0.69 (-1.79 to 3.08)) and the mental component score (model estimate -0.93 (-3.30 to 1.44)), but there were significantly more adverse events in the ultrasound group (model estimate 0.30 (0.01 to 0.60)). There was a significant relation between time to ulcer healing and baseline ulcer area (hazard ratio 0.64 (0.55 to 0.75)) and baseline ulcer duration (hazard ratio 0.59 (0.50 to 0.71)), with larger and older ulcers taking longer to heal. In addition, those centres with high recruitment rates had the highest healing rates.

CONCLUSIONS

Low dose, high frequency ultrasound administered weekly for 12 weeks during dressing changes in addition to standard care did not increase ulcer healing rates, affect quality of life, or reduce ulcer recurrence. Trial registration ISRCTN21175670 and National Research Register N0484162339.

Therapeutic ultrasound for venous leg ulcers

BACKGROUND

Venous leg ulcers pose a significant burden for patients and healthcare systems. Ultrasound (US) may be a useful treatment for these ulcers.

OBJECTIVES

To determine whether US increases the healing of venous leg ulcers.

SEARCH STRATEGY

We searched the Cochrane Wounds Group Specialised Register (searched 24 February 2010); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 1, 2010); Ovid MEDLINE (1950 to February Week 2 2010); In-Process & Other Non-Indexed Citations (searched 24 February 2010); Ovid EMBASE 1980 to 2010 Week 07; EBSCO CINAHL 1982 to 24 February 2010.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing US with no US.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the search results and selected eligible studies. Details from included studies were summarised using a data extraction sheet, and double-checked. We tried to contact trial authors for missing data.

MAIN RESULTS

Eight trials were included; all had unclear, or high, risks of bias, with differences in duration of follow-up, and US regimens. Six trials evaluated high frequency US and five of these reported healing at 7 - 8 weeks. Significantly more patients healed with US than without it at 7 - 8 weeks (pooled RR 1.4, 95% CI 1.0 to 1.96), but later assessments at 12 weeks showed the increased risk of healing with US was no longer statistically significant (pooled RR 1.47, 95% CI 0.99 to 2.20). One poor-quality study of high-frequency US found no evidence of an effect on healing after three weeks' treatment.Two trials evaluated low frequency US and reported healing at different time points. Both trials reported no evidence of a difference in the proportion of ulcers healed with US compared with no US: both were significantly underpowered.

AUTHORS' CONCLUSIONS

The trials evaluating US for venous leg ulcers are small, poor-quality and heterogeneous. There is no reliable evidence that US hastens healing of venous ulcers. There is a small amount of weak evidence of increased healing with US, but this requires confirmation in larger, high-quality RCTs. There is no evidence of a benefit associated with low frequency US.

Therapeutic ultrasound for venous leg ulcers

BACKGROUND

Venous leg ulceration is a common problem, representing a significant burden on the patient and the healthcare system. They are caused by venous insufficiency and tend to be chronic and recurring. Management usually includes use of wound dressings plus compression stockings or bandages. It has been suggested that therapeutic ultrasound may have an adjuvant effect and promote healing however its effects are unclear.

OBJECTIVES

To determine whether therapeutic ultrasound increases the healing of venous leg ulcers.

SEARCH STRATEGY

We searched the Cochrane Wounds Group Specialised Register (August 2007), The Cochrane Central Register of Controlled Trials (CENTRAL) - The Cochrane Library Issue 3, 2007, Ovid MEDLINE - 1950 to July Week 4 2007, Ovid EMBASE - 1980 to 2007 Week 31, Ovid CINAHL - 1982 to August Week 1 2007.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing therapeutic ultrasound with placebo (sham) ultrasound, or other (standard) treatment.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the results of the searches for eligible RCTs and obtained full reports. A third author assessed the results of the update searches for eligible RCTs. Details from the eligible studies were extracted and summarised by a review author using a data extraction sheet. Attempts were made to contact trial authors to obtain missing data or for clarification.

MAIN RESULTS

A total of eight eligible trials were identified and were all of either medium or high risk of bias. Five trials compared ultrasound therapy with placebo (sham) ultrasound, three trials compared ultrasound therapy with standard treatment. Trials varied in terms of ulcer size, regimen and duration of follow up. No trials individually found a statistically significant difference in the number of ulcers healed between any of the therapies, however on pooling trials (different durations of follow up) for the outcome of risk healing, significantly more ulcers were completely healed with ultrasound (RR 1.49, 95% CI 1.07 to 2.09). Some trials also found that ultrasound increases the rate of change of wound size and/or reduces the size of existing ulcers, whilst other trials did not find this effect to be significant. When all trials reporting percentage ulcer area remaining were pooled there was a significant benefit associated with ultrasound (WMD -5.34%, 95% CI -8.38 to -2.30).

AUTHORS' CONCLUSIONS

The available evidence suggests that ultrasound may increase healing of venous leg ulcers. These conclusions are based on the results of only eight small studies of generally poor quality and therefore should be interpreted with caution.

Wound Healing in the Veterinary Rehabilitation Patient

Wound healing is a biologically complex cascade of predictable overlap-ping events and is a natural restorative response to tissue injury. The biologic process for wound healing is the same for all wounds, although the specific mechanisms may vary. This article reviews the wound heal-ing process, discussing factors that may delay normal healing progression and potential modalities and treatments to aid healing.