Are overweight patients at less risk of a pressure ulcer?
ARTICLE WRITTEN BY SYLVIE HAMPTON
Very thin patients with little flesh over the bony prominences are obviously at risk of pressure ulcers. The tissue would be firmly pinched between the bone and the bed/chair/floor.
However, those who are overweight are at equal risk of a pressure ulcer due to the amount of weight above the bony prominence.
Capillaries are said to close off at between 16 and 32 millimetres of mercury depending on the physical condition and genetic make-up of the individual.
Pressure from a bed across a bony prominence can be as high as 40 or 50 millimetres of mercury or even higher. A chair is likely to provide 80 millimetres of mercury pressing the tissue against the bone. Therefore, anyone who has the skin pressed between the surface and the bone will not have any blood entering the tissue at that point, regardless of their size.
An example of an ischial tuberosity pressure ulcer can be seen in fig 1.
This wound was extremely large, due to the amount of overweight flesh. Had this lady been smaller in size, the pressure ulcer would still have occurred but would be far smaller in size.
Therefore, all individuals can develop a pressure ulcer despite their size or condition.