The popular term decubitus refers to the localised death of the skin and underlying soft tissue due to the reduced supply of oxygen to the tissue as a result of pressure.
Synonyms
Pressure sore, bedsores, decubital ulcer, lat. decumbere (to lie down)
Symptoms
Depending on the tissue damage, the decubitus is divided into four grades. Grade I: There is a reddening of the skin in the area of the undamaged skin surface. In addition to the redness, a warming of the skin is frequently observed.
Grade II: Superficial layers of the skin are damaged. The skin shows superficial defects at the pressure point, which manifest themselves by blistering and skin abrasion. Grade III: In stage III a deep soft tissue damage is visible.
There is clear tissue damage that extends to the muscle and bone tissue, although the bone is still intact. Grade IV: A deep tissue damage is visible, reaching down to the bone. One can divide the decubitis into 3 stages: Stage A: The wound is clean and covered with granulation tissue.
Necroses are not yet found in this stage. Stage B: The wound is greasy and covered with granulation tissue. There is no infiltration into surrounding tissue.
Necroses are not found at this stage. Stage C: The wound has a greasy coating of granulation tissue. An infiltration into surrounding tissue is present. This stage is found today in combination with general infections
Development of the pressure sore
The pressure load on the tissue is of decisive importance for the development of the decubitus ulcer. If the pressure on the tissue is below the capillary pressure of 25-35 mmHg, a closure of the venules (blood vessels leading to the heart) occurs with a resulting disturbance of the cardiovascular system. This circulatory disturbance is still to be corrected (reversible). However, if the pressure values are above 35 mmHg, not only the venules but also the aterioles (blood vessels leading away from the heart, i.e. rich in oxygen) close up and, depending on the time with which the pressure acts on the tissue, there is an undersupply and finally the corresponding tissue is destroyed.
Causes
There are a number of factors that favour the development of a pressure sore:
- Vascular diseases
- Advanced age
- Multimorbidity (presence of various serious diseases)
- Faeces and urinary incontinence
- Bedriddenness
- Cachexia (emaciation)
- Diabetes mellitus
- Protein loss in various diseases
- Lengthy surgical procedures
- Severe underlying diseases
Predilection sites = site of frequent occurrence
In over 80% of cases, a decubitus develops on the buttocks, the greater trochanter, the head of the fibula, the outer or inner ankle or the calcaneus.
Diagnosis
In addition to a thorough clinical examination, diagnostic measures include an X-ray to rule out osteomyelitis (inflammation of the bone) and wound swabs to assess the tissue damage. In the lower extremity, chronic arterial occlusive disease and polyneuropathy should also be excluded.