Abstract
Prevention of pressure sore is one of the vital problems in nursing care of long term lying patients. Long term pressure of skin tissue is considered to cause pressure sore and preventive need is to study changes of the patient's position. Now, it is generally reported that patient's position should be changed every 2 hours, which seems to be based not on scientific experiment or proof but on mere clinical experiences.
To cast analytical light on the possible mechanism of pressure sore, three experiments were carried out, including fundamental research using rabbit earlap.
1) Studies of pressure distribution on the surface of the human body
2) Studies on pulse-wave disappearance of skin tissue under high pressure points in human body and under pressure points in rabbit earlap.
3) Microscopic studies on skin tissue changes under pressed points in rabbit earlap.
Highest pressure points of pressure distribution on the surface of human body consist with high occurrence place of pressure sore. Pulse-wave of skin tissue in human body disappeared under the pressure 70-110 mmHg (100-150 g/cm2), and pulse-wave in rabbit earlap disappeared under the pressure 50 mmHg (70g/cm2). Microscopic preparation disclose degenerative changes in the skin tissue of rabbit earlap under 45-50 mmHg- 4 hours and 65-70 mmHg-2-4 hours, and histological recovery could not be identified even after the release of pressure for 1 hour.
