Biophysical skin properties of grade 1 pressure ulcers and unaffected skin in spinal cord injured and able-bodied persons in the unloaded sacral region

Abstract

Aim of the study: To examine biophysical skin properties in the sacral region in spinal cord injury (SCI) patients suffering from a grade 1 pressure ulcer (PU) defined as non-blanchable erythema (SCI/PU), SCI patients in the post-acute phase (SCI/PA) and able-bodied participants (CON). Also, for SCI/PU patients, both the affected skin and healthy skin close to the PU were examined.

Study design: An experimental controlled study with a convenience sample.

Setting: A Swiss acute care and rehabilitation clinic specializing in SCIs.

Materials and methods: We determined hydration, redness, elasticity and perfusion of the unloaded skin in the sacral region of 6 SCI/PU patients (affected and healthy skin), 20 SCI/PA patients and 10 able-bodied controls. These measures were made by two trained examiners after the patients were lying in the supine position.

Results: The affected skin of SCI/PU patients showed elevated redness: median 595.5 arbitrary units (AU) (quartiles 440.4; 631.6) and perfusion: 263.0 AU (104.1; 659.4), both significantly increased compared to the healthy skin in SCI/PA patients and CON (p < 0.001). Similarly, healthy skin of SCI/PA patients showed elevated redness (p = 0.016) and perfusion (p < 0.001) compared to CON. On the other hand, differences in redness and perfusion between the affected and unaffected skin in SCI/PU patients were not significant. The results for skin hydration and skin elasticity were similar in all groups.

Conclusions: Skin perfusion and redness were significantly increased in grade 1 PUs and for healthy skin in both SCI/PA patients and CON participants; thus, these are important in understanding the pathophysiology of PUs and skin in SCI.

Keywords: Skin elasticity; Skin hydration; Skin perfusion; Skin physiology; Skin redness.