Our contemporary understanding of the aetiology of pressure ulcers/pressure injuries

TLDR

The 2019 Clinical Practice Guideline on Pressure Ulcer Prevention and Treatment outlines current evidence‑based guidance and highlights that sustained soft‑tissue deformation—especially high pressure combined with shear—causes rapid cell death and tissue damage leading to pressure ulcers. This paper aims to summarise the latest understanding of pressure ulcer aetiology, focusing on the role of soft‑tissue deformation. The authors review recent evidence linking soft‑tissue deformation to pressure ulcer development, emphasizing the impact of strain, stress, and shear on cell viability.

Abstract

In 2019, the third and updated edition of the Clinical Practice Guideline (CPG) on Prevention and Treatment of Pressure Ulcers/Injuries has been published. In addition to this most up-to-date evidence-based guidance for clinicians, related topics such as pressure ulcers (PUs)/pressure injuries (PIs) aetiology, classification, and future research needs were considered by the teams of experts. To elaborate on these topics, this is the third paper of a series of the CPG articles, which summarises the latest understanding of the aetiology of PUs/PIs with a special focus on the effects of soft tissue deformation. Sustained deformations of soft tissues cause initial cell death and tissue damage that ultimately may result in the formation of PUs/PIs. High tissue deformations result in cell damage on a microscopic level within just a few minutes, although it may take hours of sustained loading for the damage to become clinically visible. Superficial skin damage seems to be primarily caused by excessive shear strain/stress exposures, deeper PUs/PIs predominantly result from high pressures in combination with shear at the surface over bony prominences, or under stiff medical devices. Therefore, primary PU/PI prevention should aim for minimising deformations by either reducing the peak strain/stress values in tissues or decreasing the exposure time.