Not just skin deep
Pressure ulcers can form in the deep tissue, so looking at the surface of the skin won’t necessarily tell you whether a patient is safe and despite what the name suggests, pressure isn’t the only cause.
From our experience a number of extrinsic factors increase the risk of pressure ulcers, including pressure, shear, friction and microclimate
Friction - A force that occurs when skin slides against another surface. One example of friction is when gravity causes a patient to slip down the bed. The amount of friction depends on how easily the two surfaces can move across each other, and on how much pressure is applied
Pressure - A force applied at right angles to the surface of the skin. Pressure compresses the tissue and can deform skin and soft tissues such as subcutaneous fat and muscle. Deformation is greater when pressure is applied over a bony prominence
Shear - A result of friction, pressure and movement. Changes in position are likely to cause shear, such as when the head of the bed is raised or lowered. Shear forces tend to cause deeper tissue damage that may not be visible immediately
Microclimate - The temperature and moisture levels where skin and support surface meet. Higher skin temperatures lead to sweating. The accumulation of heat and moisture has been shown to weaken skin and increase the amount of friction and shear between the skin and support surface