Pressure ulcer prevention dressing design and biomechanical efficacy

Abstract

The objective of this educational article is to explain in non-technical terms how the engineering considerations in the design of prophylactic dressings for pressure ulcer (PU, also known as pressure injury) prevention eventually determine the associated clinical and cost-benefit outcomes. The article specifically describes a bioengineering algorithm for quantitative evaluation of the biomechanical efficacy of different prophylactic dressing designs, which is exemplified for two fundamentally different dressing technologies, one based on superabsorbent cellulose core versus the conventional silicone-foam dressing design. A set of three biomechanical indices is described and employed for the above comparative evaluation, namely, the protective efficacy index, the protective endurance and the prophylactic trade-off design parameter. It is demonstrated that the dressing with the superabsorbent cellulose core is at least as good as silicone-foams but, importantly, provides a good balance between its protective performance in its ‘new’ condition, as opposed to its ‘used’ condition, i.e., after being exposed to moisture. Most notably, we show that preventative dressings are never equal in their performances; the underlying structure and the dressing ingredients together determine the extent of the delivered tissue protection and its durability.

The biomechanical efficacy of a hydrogel‐based dressing in preventing facial medical device‐related pressure ulcers

“…For the purpose of quantitatively and systematically analysing the sustained exposure of facial soft tissues to the mechanical loads induced by the CPAP mask, we plotted the volumetric distributions of the effective (von Mises) stresses and SEDs in each anatomical site as histograms, consistent with our published computational modelling work concerning pressure ulcer/injury prevention. 25 , 26 We produced such tissue‐exposure‐to‐loading histograms for facial tissues: ( i ) without the protection provided by the dressings, as a baseline condition; ( ii ) with new, straight‐from‐the‐package dry hydrogel‐based dressings (ie, considering the ‘dry’ dressing stiffness specified above); and ( iii ) with moist, used dressings (considering the aforementioned ‘moist’ dressing stiffness). These stress exposure histograms were produced separately for skin and for the entire soft tissue thickness at each facial location, henceforth termed “pooled soft tissues”, to isolate the superficial influence of the hydrogel‐based dressings on skin from its protective effect throughout the tissue depth.…”

What makes a hydrogel‐based dressing advantageous for the prevention of medical device‐related pressure ulcers

“…3,29,30 In the context of preventing MDRPUs, our research group extensively studied the biomechanical protective effects of different dressing types, as well as an alternative approach of using a cyanoacrylate skin protectant. 9,10,[31][32][33] In particular, in the aforementioned works, we have characterised the mechanical properties and behaviours of dressing materials and structures; the coefficient of friction (COF) at the dressing-skin interface, including under the effect of skin moisture; and the thermal conductivity of dressings intended for prophylactic use. The latter thermal property, which is critically important for assessing the expected microclimate environment induced by dressings in prophylactic use, has been investigated by means of a custom-made heat-flow meter as well as by using infrared thermography (IRT).…”

Chronic wounds in the elderly: Decubitus, leg ulcers, and ulcers of rare aetiology

“…Frequent comorbidity, as incontinence in older age and the consequent combined irritative and microbial dermatitis, so called "diaper dermatitis", can be a serious risk factor, and its prevention and treatment are therefore also of paramount importance [27]. In case of an existing wound, the use of smart dressings is recommended according to the principles detailed above [28][29][30]. In some cases, particularly in the case of an especially deep decubitus, which extend to the muscles or even to the bone, the use of NPWT would be favourable to obtain excellent results.…”