Investigating the pressure-reducing effect of wound dressings

Pressure Distribution Properties in Wound Dressings Using Heel and Sacrum Indenters Under Clinically Relevant Loads

OBJECTIVE

To understand the pressure distribution characteristics of a border and silicone version of a next-generation multilayered foam dressing (A and B) compared with three commercially available dressings (C, D, and E) using a novel pressure distribution model with clinically relevant pressures.

METHODS

The testing setup included a support surface analog of K45 foam covered with polyurethane fabric, a high-resolution pressure mapping system, and a silicone layer to simulate overlying tissue. The dressing was exposed to clinically relevant loads of 30 and 80 mm Hg for 60 seconds using new sacral and heel indenters. A control was conducted using the same setup without a dressing. Statistical significance was determined using a 95% CI and t test with α = .05.

RESULTS

All dressings decreased pressure and increased contact area compared with the control ( P < 0.05). Dressings A and B had lower peak pressures than dressings C and E for both indenters. Dressings D and B had the largest contact areas and lowest pressures in the heel indenters, whereas dressing E had the smallest contact area and the highest pressures for both indenters. The results also demonstrated a strong negative correlation between the average pressure and the contact area for both indenters.

CONCLUSIONS

Using anatomically accurate indenters and clinically relevant pressures, the study demonstrated that dressings A and B significantly reduced interface pressure compared with no dressing, suggesting potential advantages for pressure redistribution in vulnerable areas. Additional clinical research in various care settings is needed to validate this study's findings.

Effect of prophylactic dressings to reduce pressure injuries: a polymer-based skin model

OBJECTIVE

This study evaluated the effect of pressure injury (PI) prophylactic dressings used for patients at high risk of PI development to reduce friction, shear force and pressure, and their combined force, in an original polymer-based skin model.

METHOD

A low-friction outer-layer hydrocolloid (LFH) dressing and a multilayered silicone foam (MSF) dressing were used. Before application, compression and friction properties were measured. Our original experimental model-the 'simulated skin-shearing test'-consisted of: a weight; a polyurethane-based skin model containing a three-axis tactile sensor; dressings; a table covered with bedsheets; and a mechanical tester, by which the interface friction force, internal shear force and pressure were measured continuously during skin model movements. An estimated combined force generated by internal shear and pressure was represented as a vector. A model with no dressing was used as a control.

RESULTS

The LFH dressing had significantly higher compression strength versus the MSF dressing. In contrast, the dynamic coefficient of friction was lower for the LFH dressing versus the MSF dressing (p<0.05). In simulated skin-shearing test results, shear forces were 0.45N and 0.42N for LFH and MSF dressings, respectively, with no significant difference. The estimated combined force was lower for the MSF dressing compared with that of the LFH dressing and control.

CONCLUSION

The shear force-reducing effect in the skin model was equivalent between the LFH and MSF dressings. However, the MSF dressing significantly reduced the force generated by a combination of internal shear force and pressure compared with the LFH dressing.

Differences in prophylactic performance across wound dressing types used to protect from device-related pressure ulcers caused by a continuous positive airway pressure mask

Prolonged use of continuous positive airway pressure masks, as often required for non-invasive ventilation, involves a risk for facial tissue breakdown due to the sustained deformations caused by tightening of the stiff mask surfaces to the head and the moist environment. The risk of developing mask-related facial injuries can be reduced through suitable cushioning materials placed at the skin-mask interfaces to spread the localised contact forces and disperse the surface and internal tissue stresses. Using an integrated experimental-computational approach, we compared the biomechanical protective performance of three popular foam-based wound dressings to that of a market-lead hydrocolloid dressing when applied to protect the facial skin under a mask. We measured the compressive stiffness properties of the four commercial dressing types in dry and moist conditions, and then fed those to an anatomically realistic finite element model of an adult male head, with an applied simulated mask. Through this process, we calculated the protective efficacy index of each dressing type, indicating the relative contribution of the specified dressing to alleviating facial soft tissue loads with respect to the no-dressing case. The foam-based dressings generally performed substantially better than the hydrocolloid, but foam dressings were also demonstrated to vary by their protective performance.

Multilayered silicone foam dressings potentially used for preventing recurrence of pressure injuries: A bench-to-clinical bedside study

AIM

This study aimed to evaluate the use of multilayered silicone foam dressings for preventing pressure injury recurrence by reducing friction, pressure, and shear force at skin sites where previous pressure injuries closed.

METHODS

A bench-to-clinical bedside investigation was conducted. In the bench, three multilayered silicone foam dressings were assessed. The simulated skin-shearing test consisted of a weight, a polyurethane-based skin model containing a three-axis tactile sensor, dressings, a table covered with bedsheets, and a mechanical tester. The mechanical tester simultaneously measured the interface friction force and internal shear force and pressure continuously during skin model movements. No-dressing was used as a negative control. In clinical bedside assessments, a multilayered silicone foam dressing with lower friction and shear force was applied to two bedridden patients. Photographs and ultrasound images were used to assess the recurrence of pressure injury.

RESULTS

The dressings significantly reduced friction, pressure, and shear force compared with these parameters in the negative control. No significant differences in the shear forces between the dressings were observed. One clinical case did not develop a new pressure injury reaching the dermis. However, the second case developed a new pressure injury within one month after the first pressure injury closed.

CONCLUSION

Our bench-to-clinical bedside study revealed that multilayered silicone foam dressings can potentially prevent pressure injury recurrence.

Investigating the Efficacy of Hydrocolloid Dressing for Preventing Nasotracheal Tube-Related Pressure Injury in the PICU

OBJECTIVES

To investigate the efficacy of hydrocolloid dressing in reducing the occurrence rate and severity of nasotracheal tube-related pressure injury.

DESIGN

Randomized controlled trial.

SETTING

A PICU in a tertiary medical center in southern China.

PATIENTS

Pediatric patients received invasive mechanical ventilation via nasotracheal tubes.

INTERVENTIONS

The hydrocolloid dressing was cut into an optimal square size, which should cover the area from the nasal columella to the ala.

MEASUREMENTS AND MAIN RESULTS

Eligible participants were randomly allocated to the control group and the experimental group. The participants in the experimental group received hydrocolloid dressing to protect nasal skin from the beginning of nasotracheal intubation, while the participants in the control group received the current care procedure (without hydrocolloid dressing) unless pressure injuries occurred. The hydrocolloid dressing was changed daily to assess the nasal skin. The pressure injury staging system that was redefined and updated by the National Pressure Ulcer Advisory Panel in 2016 was used. The mean duration of nasotracheal intubation was 150.10 ± 117.09 hours in the experimental group and 161.75 ± 120.72 hours in the control group. Forty-five participants had nasotracheal tube-related pressure injuries in control group, whereas 26 patients had in experimental group (72.6% vs 43.3%; absolute difference, 29.3%, 95% CI, 12.5-46%; p = 0.001). The median survival times of the nasal skin integrity were 95.5 hours in the control group and 219.5 hours in the experimental group (p < 0.001).

CONCLUSIONS

Hydrocolloid dressing can not only reduce the occurrence rate of nasotracheal tube-related pressure injury in the child with long-term nasotracheal intubation but also improve the endurance of the nasal skin significantly.

Selection of Appropriate Wound Dressing for Various Wounds

There are many factors involved in wound healing, and the healing process is not static. The therapeutic effect of modern wound dressings in the clinical management of wounds is documented. However, there are few reports regarding the reasonable selection of dressings for certain types of wounds in the clinic. In this article, we retrospect the history of wound dressing development and the classification of modern wound dressings. In addition, the pros and cons of mainstream modern wound dressings for the healing of different wounds, such as diabetic foot ulcers, pressure ulcers, burns and scalds, and chronic leg ulcers, as well as the physiological mechanisms involved in wound healing are summarized. This article provides a clinical guideline for selecting suitable wound dressings according to the types of wounds.

Effectiveness of using a new polyurethane foam multi-layer dressing in the sacral area to prevent the onset of pressure ulcer in the elderly with hip fractures: A pragmatic randomised controlled trial

Hip fractures in the elderly are a serious problem for the health service due to the high rate of complications. One of these complications is pressure ulcers that, according to the literature, occur in 8.8% to 55% of patients and mainly arise in the sacral area. The present randomised controlled trial tests whether applying a new innovative multi‐layer polyurethane foam dressing (ALLEVYN LIFE™), reduces the onset of pressure ulcers in the sacral area. From March to December 2016, 359 fragility hip fracture patients were randomly divided into 2 groups: 182 in the control group and 177 in the experimental group. Pressure ulcers occurred overall in 36 patients (10%): 8 patients (4.5%) in the experimental group compared to 28 (15.4%) in the control group: P = 0.001, relative risk 0.29 (95% CI 0.14‐0.61) with NNT of 9 (95% CI 6‐21). In the experimental group the onset of pressure ulcers occurred on average on the 6th day compared to the 4th day in the control group (HR 4.4). Using polyurethane foam is effective at reducing the rate of pressure ulcers in the sacrum in elderly patients with hip fracture. The adhesiveness of this device also enables costs to be kept down.