Secondary Condition: Skin and Pressure Ulcers
by J. Glen House, MD
By J. Glen House, MD
Spinal Cord Injury Secondary Condition: Skin and Pressure Ulcers
A pressure ulcer is a localized area of skin damage that can quickly progress to a serious problem for an individual with a spinal cord injury. Prevention of a pressure ulcer is one of the most important issues after a spinal cord injury that requires lifelong attention. With knowledge about what causes a pressure ulcer and what to do to prevent a pressure ulcer, individuals with a spinal cord injury can live a very productive and fulfilling life without interruption. If pressure ulcers are not taken seriously and they develop, it will require a significant amount of time and money to help them heal and may significantly alter or interrupt work and life activities.
What is a pressure ulcer?
A pressure ulcer is damaged tissue (skin, muscle, blood vessels, etc.) caused by excessive pressure.
What is normal skin made of?
Skin is divided into two specific layers. The outer layer of skin is called the epidermis. The outermost layer of the epidermis is made up of dead cells that are continuously being replaced by cells underneath this layer. In fact, the skin that we look at and touch on the human body is made up of dead cells that shed about every two weeks. The inner living part of the epidermis contains melanin (pigment which colors our skin) and cells that function as the first line of defense of our immune system. The layer of skin beneath the epidermis is called the dermis. The dermis contains sweat glands, oil glands, nerve endings and blood vessels.
What changes occur in the skin after a spinal cord injury?
Many changes occur after a spinal cord injury to the skin below the neurological level of injury. Changes occur in the collagen, which is the supporting structure of the skin. There are also many chemical changes, including involvement of enzymes and amino acids. Changes occur in the normal ability of the skin to control its temperature. The normal sweating reflex is lost in individuals with spinal cord injuries at T6 and above. This limits the ability of the skin to cool itself by way of sweating; body temperature can increase quickly causing spinal cord injured patients to become overheated.
What causes pressure ulcers?
Pressure ulcers are caused by direct pressure on the skin from objects outside the body. Pressure ulcers develop over bony areas that are likely to be pressing against the outside object such as a bed or wheelchair cushion.
Shear is another factor that leads to pressure ulcers. Shearing occurs when a force is applied that leads to a parallel but opposite sliding motion. For example, when someone is in bed and the head of the bed is raised from a 30° incline to a 70° incline, the skin over the sacrum (bottom part of the spine) and coccyx (tailbone) slides upward while the bony areas are sliding down. This puts a strain or force on the skin that can damage blood vessels within this area of the skin. Damage to blood vessels can lead to damage of tissue because of the lack of oxygen and nutrients delivered.
