VOL: 99, ISSUE: 13, PAGE NO: 73
Elaine Bethell, SRN, DPNS, is tissue viability clinical nurse specialist, City Hospital NHS Trust, Birmingham
There have been numerous attempts to classify the aetiology of grade 1 pressure ulcers. It is agreed that a grade 1 ulcer has an intact epidermis (Hitch, 1995; Lyder, 1991) and that ulcers with a higher grade denote more severe tissue damage (Lyder, 1991). However, this implies a progression in ulcer severity based on a misconception that pressure ulcers start at the skin and extend down towards bone (Alterescu and Alterescu, 1988). However, true deep severe pressure ulcers begin at the interface of soft tissue and bone, and extend upwards, finally becoming visible at the epidermis (Alterescu and Alterescu, 1988). Thus, by the time necrosis is observed at the epidermis, damage will have occurred in the subcutaneous and muscle layers (Barton and Barton, 1981). Therefore, grading systems based on depth, where the score relates to the state of the epidermis, illustrate a misunderstanding of aetiology (Box 1).
Temperature Lyder (1991) suggests grade 1 ulcers have skin areas that are either warm or cool to the touch. Increased local blood flow and oedema, followed by the engorgement of surrounding vessels and tissues, results in warmth and redness in the area. In contrast, the skin may feel cooler in areas of non-blanching erythema. (Parish et al, 1988).
The increase in skin colour and temperature is due to the inflammatory process responding to tissue insult and injury. This erythema is an indicator of the body’s natural response to ischaemia caused by pressure and is deemed proportional to the duration of occlusion, lasting about half to three-quarters of the time of occlusion.
The National Pressure Ulcer Advisory Panel and the European Pressure Ulcer Advisory Panel (EPUAP, 1999) have recognised that erythema and grade 1 pressure ulcers are difficult to measure in patients with darkly pigmented skin, a difficulty also highlighted by Meehan et al (1999).
- Skin area is pale pink to bright red;
- Skin area will blanch or not blanch when digital pressure is released;
- Skin area is warmer to the touch;
- Erythema or possible erythema has not resolved within two hours;
- Epidermis is intact.