Update on Pressure Ulcer Management and Deep Tissue Injury

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 We also searched clinical trials registries to identify ongoing and unpublished studies.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.

Autologous platelet-rich plasma for treating chronic wounds

BACKGROUND

Autologous platelet-rich plasma (PRP) is a treatment that contains fibrin and high concentrations of growth factors with the potential to improve the healing of chronic wounds. This is the first update of a review first published in 2012.

OBJECTIVES

To determine whether autologous PRP promotes the healing of chronic wounds.

SEARCH METHODS

In June 2015, for this first update, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library): Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE; and EBSCO CINAHL. We also searched for ongoing and unpublished clinical trials in the WHO International Clinical Trials Registry Platform (ICTRP) (searched January 2015). We did not impose any restrictions with respect to language, date of publication, or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared autologous PRP with placebo or alternative treatments for any type of chronic wound in adults. We did not apply any date or language restrictions.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology, including two reviewers independently selecting studies for inclusion, extracting data, and assessing risk of bias.

MAIN RESULTS

The search identified one new RCT, making a total of 10 included RCTs (442 participants, 42% women). The median number of participants per RCT was 29 (range 10 to 117). Four RCTs recruited people with a range of chronic wounds; three RCTs recruited people with venous leg ulcers, and three RCTs considered foot ulcers in people with diabetes. The median length of treatment was 12 weeks (range 8 to 40 weeks).It is unclear whether autologous PRP improves the healing of chronic wounds generally compared with standard treatment (with or without placebo) (risk ratio (RR) 1.19, 95% confidence interval (CI) 0.95 to 1.50; I(2) = 27%, low quality evidence, 8 RCTs, 391 participants). Autologous PRP may increase the healing of foot ulcers in people with diabetes compared with standard care (with or without placebo) (RR 1.22, 95% CI 1.01 to 1.49; I(2) = 0%, low quality evidence, 2 RCTs, 189 participants). It is unclear if autologous PRP affects the healing of venous leg ulcers (RR 1.02, 95% CI 0.81 to 1.27; I(2) = 0% ). It is unclear if there is a difference in the risk of adverse events in people treated with PRP or standard care (RR 1.05, 95% CI 0.29 to 3.88; I(2) = 0%, low quality evidence from 3 trials, 102 participants).

AUTHORS' CONCLUSIONS

PRP may improve the healing of foot ulcers associated with diabetes, but this conclusion is based on low quality evidence from two small RCTs. It is unclear whether PRP influences the healing of other chronic wounds. The overall quality of evidence of autologous PRP for treating chronic wounds is low. There are very few RCTs evaluating PRP, they are underpowered to detect treatment effects, if they exist, and are generally at high or unclear risk of bias. Well designed and adequately powered clinical trials are needed.

TAT-Mediated Acidic Fibroblast Growth Factor Delivery to the Dermis Improves Wound Healing of Deep Skin Tissue in Rat

BACKGROUND

The definition of deep tissue injury was derived from multiple clinical cases as "A purple or maroon localized area of discolored intact skin or blood-filled blister due to damage of underlying soft tissue from pressure and/or shear". Acidic fibroblast growth factor (aFGF) significantly improves wound healing under diabetic conditions. However, to date, the therapeutic application of aFGF has been limited, due to its low delivery efficiency and short half-life.

METHODOLOGY/PRINCIPAL FINDINGS

Using an animal model of magnet-induced pressure ulcers, transactivator of transcription protein (TAT)-aFGF was evaluated for transdermal delivery and wound healing. Immunohistochemistry and Western blotting were also performed to determine the expression of transforming growth factor (TGF)-β1, α-smooth muscle actin (α-SMA), CD68, proliferating cell nuclear antigen (PCNA) and TGF-β-receptor II (TGF- βRII) in cultured human dermal fibroblasts. We found that that mice treated with TAT-aFGF had higher accumulation of aFGF in both dermis and subcutaneous tissues compared with mice treated with aFGF alone. In the remodeling phase, TAT-aFGF treatment decreased the expression of α-SMA to normal levels, thereby facilitating normal wound healing processes and abrogating hypertrophic scarring. In human dermal fibroblasts, TAT-aFGF reversed the suppressive effect of TNF-α on α-SMA expression and restored TGF-βRII and TGF-β1 expression.

CONCLUSIONS/SIGNIFICANCE

Our results demonstrate that TAT-aFGF has a favorable therapeutic effect on the healing of subcutaneous deep tissue injury.

Combination of thermographic and ultrasonographic assessments for early detection of deep tissue injury

Early detection and intervention of deep tissue injury are important to lead good outcome. Although the efficiency of ultrasonographic assessment of deep tissue injury has been reported previously, it requires a certain level of skill for accurate assessment. In this study, we present an investigation of the combination of thermographic and ultrasonographic assessments for early detection of deep tissue injury. We retrospectively reviewed 28 early-stage pressure ulcers (21 patients) presenting at the University of Tokyo Hospital between April 2009 and February 2010, surveying the associated thermographic and ultrasonographic findings. The wound temperature patterns were divided into low, even and high compared with the surrounding skin. Ultrasonographic findings were classified into unclear layer structure, hypoechoic lesion, discontinuous fascia and heterogeneous hypoechoic area. All 13 ulcers that were associated with low temperature showed good outcome; three ulcers had even temperatures and 12 ulcers showed high temperature on thermographic assessment. The two deep tissue injuries were rated high on thermographic assessment and showed heterogeneous hypoechoic area findings on ultrasonographic assessment. No non-deep tissue injury lesion was associated with these two findings simultaneously. The combination of thermographic and ultrasonographic assessments is expected to increase the accuracy of the early detection of deep tissue injuries.

Autologous platelet-rich plasma for treating chronic wounds

BACKGROUND

Autologous platelet-rich plasma (PRP) is a treatment that contains fibrin and high concentrations of growth factors and has the potential to aid wound healing.

OBJECTIVES

To determine whether autologous PRP promotes the healing of chronic wounds.

SEARCH METHODS

We searched the Cochrane Wounds Group Specialised Register (searched 15 August 2012); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 8); Ovid MEDLINE (1950 to August Week 1 2012); Ovid MEDLINE (In-Process & Other Non-Indexed Citations, August 14, 2012); Ovid EMBASE (1980 to 2012 Week 32); EBSCO CINAHL (1982 to 10 August 2012) and International Clinical Trials Registry Platform (ICTRP)(accessed 22 August 2012). No date or language restrictions were applied.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared autologous PRP with placebo or alternative treatments for any type of chronic wound in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed each study against the inclusion criteria, extracted data and assessed risk of bias for all included trials. We calculated the risk ratio (RR) or the mean difference (MD) and time to wound healing was analysed as survival data using the hazard ratio (HR). We considered heterogeneity as significant when I(2) was >75%.

MAIN RESULTS

Nine eligible RCTs were included, with a total of 325 participants of whom 44% were women. The median number of participants per RCT was 26 (range 10 to 86). Four RCTs recruited people with mixed chronic wounds (there were participants with wounds caused by more than one aetiology and participants who had wounds of several aetiologies in the same trial), three RCTs recruited people with venous leg ulcers and two RCTs considered foot ulcers in people with diabetes. The median length of treatment was 12 weeks (range eight to 40 weeks).One study was at low risk of bias, three studies were at high risk of bias with the remainder being at overall unclear risk of bias. The proportion of completely healed chronic wounds was reported in seven RCTs that compared PRP with standard treatment or placebo, with no statistically significant difference between the groups, in diabetic foot ulcers (RR 1.16; 95% CI 0.57 to 2.35), in venous leg ulcers (pooled RR 1.02; 95% CI 0.81 to 1.27; I(2)=0% ) and in mixed chronic wounds (pooled RR 1.85; 95% CI 0.76 to 4.51; I(2)=42%). The total area epithelialised at the end of the intervention was reported in three RCTs of mixed chronic wounds, there was no statistically significant difference between the groups (pooled MD -1.94 cm(2); 95% CI -4.74 to 0.86; I(2)=47%). The percentage of wound area healed was reported in two RCTs of mixed chronic wounds, and results were statistically significant in favour of the PRP group (RR 51.78%; 95% CI 32.70 to 70.86; I(2)= 0%). Wound complications like infection or necrosis were reported by three RCTs, and there was no statistically significant difference between groups (RR 1.08; 95% CI 0.31 to 3.73). Adverse effects were reported by three studies and there was no statistically significant difference between people treated with PRP and those not given PRP (pooled RR 1.07; 95% CI 0.32 to 3.58; I(2)=0%).

AUTHORS' CONCLUSIONS

There is currently no evidence to suggest that autologous PRP is of value for treating chronic wounds. However, current evidence is based on a small number of RCTs, most of which are either at high or unclear risk of bias. Well-designed and adequately powered clinical trials are needed.

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.