Comparison between two different protocols of negative pressure therapy for healing of chronic ulcers

Negative pressure wound therapy for treating pressure ulcers

BACKGROUND

Pressure ulcers, also known as bedsores, pressure sores, or pressure injuries, are localised damage to the skin and underlying soft tissue, usually caused by intense or long-term pressure, shear, or friction. Negative pressure wound therapy (NPWT) has been widely used in the treatment of pressure ulcers, but its effect needs to be further clarified. This is an update of a Cochrane Review first published in 2015.

OBJECTIVES

To evaluate the effectiveness of NPWT for treating adult with pressure ulcers in any care setting.

SEARCH METHODS

On 13 January 2022, we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase, and EBSCO CINAHL Plus. We also searched ClinicalTrials.gov and the WHO ICTRP Search Portal for ongoing and unpublished studies and scanned reference lists of relevant included studies as well as reviews, meta-analyses, and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication, or study setting.

SELECTION CRITERIA

We included published and unpublished randomised controlled trials (RCTs) comparing the effects of NPWT with alternative treatments or different types of NPWT in the treatment of adults with pressure ulcers (stage II or above).

DATA COLLECTION AND ANALYSIS

Two review authors independently conducted study selection, data extraction, risk of bias assessment using the Cochrane risk of bias tool, and the certainty of the evidence assessment using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) methodology. Any disagreement was resolved by discussion with a third review author.

MAIN RESULTS

This review included eight RCTs with a total of 327 randomised participants. Six of the eight included studies were deemed to be at a high risk of bias in one or more risk of bias domains, and evidence for all outcomes of interest was deemed to be of very low certainty. Most studies had small sample sizes (range: 12 to 96, median: 37 participants). Five studies compared NPWT with dressings, but only one study reported usable primary outcome data (complete wound healing and adverse events). This study had only 12 participants and there were very few events; only one participant was healed in the study (risk ratio (RR) 3.00, 95% confidence interval (CI) 0.15 to 61.74, very low-certainly evidence). There was no evidence of a difference in the number of participants with adverse events in the NPWT group and the dressing group, but the evidence for this outcome was also assessed as very low certainty (RR 1.25, 95% CI 0.64 to 2.44, very low-certainty evidence). Changes in ulcer size, pressure ulcer severity, cost, and pressure ulcer scale for healing (PUSH) sores were also reported, but we were unable to draw conclusions due to the low certainly of the evidence. One study compared NPWT with a series of gel treatments, but this study provided no usable data. Another study compared NPWT with 'moist wound healing',  which did not report primary outcome data. Changes in ulcer size and cost were reported in this study, but we assessed the evidence as being of very low certainty; One study compared NPWT combined with internet-plus home care with standard care, but no primary outcome data were reported. Changes in ulcer size, pain, and dressing change times were reported, but we also assessed the evidence as being of very low certainty. None of the included studies reported time to complete healing, health-related quality of life, wound infection, or wound recurrence.

AUTHORS' CONCLUSIONS

The efficacy, safety, and acceptability of NPWT in treating pressure ulcers compared to usual care are uncertain due to the lack of key data on complete wound healing, adverse events, time to complete healing, and cost-effectiveness.  Compared with usual care, using NPWT may speed up the reduction of pressure ulcer size and severity of pressure ulcer, reduce pain, and dressing change times. Still, trials were small, poorly described, had short follow-up times, and with a high risk of bias; any conclusions drawn from the current evidence should be interpreted with considerable caution. In the future, high-quality research with large sample sizes and low risk of bias is still needed to further verify the efficacy, safety, and cost-effectiveness of NPWT in the treatment of pressure ulcers. Future researchers need to recognise the importance of complete and accurate reporting of clinically important outcomes such as the complete healing rate, healing time, and adverse events.

The effects of whole-body vibration on wound healing in a mouse pressure ulcer model

BACKGROUND

Pressure ulcers are one of the most common complications of immobility resulting from pressure and shear. Whole-body vibration (WBV) has been shown to increase skin blood flow but little information is known about its effect on pressure ulcers. This study investigated the effects of WBV on wound healing in a mouse pressure ulcer model.

METHODS

Two cycles of ischemia-reperfusion were performed by external application of two magnetic plates to dorsal skin to induce stage II pressure ulcers characterized by partial-thickness skin loss with exposed dermis. A total of 32 male ICR mice were randomly and equally divided into untreated control and the WBV groups. Immediately after the completion of 2-cycle ischemia-reperfusion injury, mice in the WBV group participated in a WBV program using a vibrator (frequency 45 Hz, peak acceleration 0.4 g, vertical motion) for 30 min/day and 5 consecutive days/week. At days 7 and 14 post-ulceration, wound closure rate was assessed. Wound tissues were harvested for determination of collagen deposition in Masson's trichrome stained sections, neutrophil infiltration and capillary density in hematoxylin and eosin-stained sections, as well as TNF-α and VEGF levels using ELISA.

RESULTS

TNF-α levels and neutrophil infiltration were significantly decreased in wounds on days 7 and 14 of WBV treatment. Moreover, wound closure rate and collagen deposition were remarkably accelerated on day 14. Tissue VEGF and capillary density were unaffected by WBV at either time point.

CONCLUSIONS

These findings suggest that WBV has the potential to promote the healing process of stage II pressure ulcers, as evidenced by attenuation of wound inflammation and enhancement collagen deposition.

Role of microRNAs in Pressure Ulcer Immune Response, Pathogenesis, and Treatment

Pressure ulcers are preventable, yet highly prevalent, chronic wounds that have significant patient morbidity and high healthcare costs. Like other chronic wounds, they are characterized by impaired wound healing due to dysregulated immune processes. This review will highlight key biochemical pathways in the pathogenesis of pressure injury and how this signaling leads to impaired wound healing. This review is the first to comprehensively describe the current literature on microRNA (miRNA, miR) regulation of pressure ulcer pathophysiology.