1. What are pressure ulcers

Pressure ulcers, also called decubitus ulcers (the term “Decubitus” comes from the Latin term “ to lie down”) or bedsores, are the end results of constant skin pressure. A pressure ulcer is an injury caused by unrelieved pressure that damages the skin and the underlying tissue. Pressure ulcers are a common, life-threatening, expensive problem for patients. Decubitus ulcers have been estimated to be responsible for 60,000 deaths per year in the United States. Four percent to 14% of hospitalized patients develop pressure sores. They occur quite commonly in the intensive care unit (ICU) because of poor nursing care, but even more commonly in extended care facilities such as nursing home and are especially common in the elderly.

Unrelieved pressure on the skin squeezes tiny blood vessels, which supply the skin with nutrients and oxygen. When skin is starved of nutrients and oxygen for too long, the tissue dies and a pressure ulcer forms. In animal studies, 60 mmHg pressure applied to the skin for one hour produces histologically identifiable injuries such as venous thrombosis, muscle degeneration, and tissue necrosis. The average human being exerts 60 to 70 mmHg pressure on such body areas as the sacrum, occiput and heels while lying in bed or on the ischia while sitting in a chair. Decubitus ulcers are caused by pressure exerted on the subcutaneous tissue and skin when compressed between the weight of the body and a mattress or chair. The pressure affects capillary perfusion and interrupts the blood supply, producing ischemia and preventing the removal of cellular waste. When the pressure is unrelieved, cell necrosis may occur. Healthy people, however, regularly shift their body weight, even while asleep. Sitting in one position causes pain in areas of increased pressure, thus stimulating movement. Patients unable to sense pain or to shift their body weight, such as paralegics or bedridden individuals, develop prolonged elevated tissue pressure and, eventually, necrosis. Muscle tissue is more sensitive to ischemia than the overlying skin. That’s why the necrotic area is always wider and deeper than it appears on first inspection.

Other factors cause pressure ulcers too. If a person slide down in the bed or chair, blood vessels can stretch or bend and cause pressure ulcers. Even slight rubbing or friction on the skin may cause minor pressure ulcer.

2. Where Pressure Ulcers Form

Pressure ulcers form where bone causes the greatest force on the skin and the tissue and squeezes them again an outside surface, such as, other body parts, a mattress, or a chair. For persons who must stay in beds they easily develop increased pressure over bony prominences; the most common sites are the sacrum and coccyx (hip), the back of the head (occiput), behind the ear, the scapular spines (shoulder), the iliac crest, trochanter, anterior knees, heels, costal margins and the elbow.

4. The stages of pressure ulcers

Pressure ulcers can be classified as superficial or deep. Superficial ulcers may be subdivided into four stages that are useful in planning effective treatment.

Deep pressure ulcers develop in tissues under the skin and tend to occur in response to shearing forces. Necrosis begins beneath the skin rather than in the epidermis, as described in the development of superficial decubitus ulcers. Deep ulcers may present initially as blisters that change into eschars. The lesion itself may be well developed before any signs are visible. Typical signs of pressure ulcers include a hard mass under the skin and purplish discoloration of the skin area subjected to pressure. The amount of tissue damage is usually much more extensive than indicated by the amount of skin area involved.

Risk Assessment Scale System

The Risk Assessment Scale System is basically referred to The Waterlow Pressure Sore Prevention Treatment Policy and The Trial Pressure Sore Risk Assessment Scale of Watkinson. The system is intended to help guide treatment and preventive measures. The system is also aiming to design a risk assessment scale, which included guidelines on appropriate equipment selection, appropriate dressings selection and classification of the pressure ulcers in an attempt to improve consistency of use.