Resource Center → Introduction To Spinal Cord Injury → About Pressure Sores → How a pressure sore develops
3.1. How a pressure sore develops
Pressure sores are the most common and devastating medical complication of spinal cord injury. Also referred to as skin sores, decubiti, decubitus ulcers, or bedsores, pressure ulcers are more apt to occur after SCI due to lack of movement and sensation and to changes in circulation. A pressure sore is any redness or break in the skin caused by too much pressure on your skin for too long a period of time. Sitting or lying in the same position will begin to cut off the flow of blood to that area, blocking oxygen and vital nutrients from maintaining healthy tissue. When the tissue becomes starved to too long a period of time it begin to die and a pressure sore starts to form. Normally the nerves send messages of pain or feelings of discomfort to your brain to let you know that you need to change position, but damage to your spinal cord keeps these messages from reaching your brain. A pressure sore is serious. It must NOT be ignored.
What Are The Causes?
Because your blood flows more slowly after SCI, your healing ability is reduced, and your skin cannot tolerate as much pressure as before. The decrease in circulation and lower tolerance for pressure is further aggravated by the lack of sensation after SCI. This lack of sensation means there is no longer a feedback mechanism to tell you that there is a problem – that you have been sitting too long without moving or that you have injured yourself.
Symptoms
The first symptom – your warning signal – is a reddened area of the skin. No damage has occurred if you remove the pressure and the redness fades with 15 minutes after the pressure is removed. Skin damage from pressure usually begins over bony prominences – any place on the body where the bones are close to the skin surface, such as the hip. Due to the decrease in the rate of circulation that occurs following SCI, there is also less oxygen to the skin. This contributes to a lowering of the skin's resistance. If the skin is deprived of oxygen due to pressure, the body will try to compensate by sending more blood to the area. This may result in swelling, which will put even further pressure on the blood vessels and further block circulation.
How a pressure sore develops:
- Stage I. You will notice that the skin becomes white or lighter in color. Do push-ups and keep to your turning schedule so skin is never deprived of its blood supply for a long time. Blood is not getting to the skin because of pressure.
- Stage II. Your skin will redden; it is warm and may be swollen when pressure is relieved. Stay off red area until all redness is gone. Do NOT rub red area or put anything on it. If you are dark skinned and can't see redness, feel for warmth with back of fingers. At this point, you can still stop a more serious sore from developing. Redness and warmth is caused by blood rushing to the area when pressure is relieved. If redness is not gone 30 minutes after pressure is relieved, it's a danger signal (too much pressure or pressure for too long was applied.)
- Stage III. You will notice that a blister develops over the red area. The skin may have a bluish color to it. The blister often opens. This stage occurs if pressure is not completely removed from a red area. At this point the damage is deeper than you can see. Stay off the area. Call your doctor or nurse.
- Stage IV. The center of open sore turns black or brown and/or there is drainage. Stay off area. Cover with a sterile dressing. Eat foods that are high in protein to raise albumin levels. This sore may be very deep and is probably infected. You may feel very sick. If there is much drainage your body loses protein. Protein is needed for healing. Call your doctor.
