[The effect of soft care mattresses on subcutaneous tissue pressure and pO2 over the os sacrum].

In this study the influence of soft-care systems on subcutaneous tissue pressure and pO2 has been examined. In 14 volunteers 3 probes were implanted over the os sacrum for measurement during the 20-minute periods. Then the probands were asked to lie on a standard mattress, on 8 static beds of various kind and on 3 dynamic soft-care systems. The clinical mattress pressure values amounted to 25.5 mm Hg (+/- 5.2; n = 14). The gell-cushion showed increased values (26.9 +/- 9.5 mm Hg; n = 5). Compared to the standard mattress the other systems showed reductions in pressure from 32.7% to 83.1%. The lowest pressure was recorded with an air-supported mattress (8.3 +/- 2.3 mm Hg; n = 5). The pO2 initial values before lying down varied greatly from individual to individual (26.9-71.3 mm Hg). In the course of the 20-minute periods the pO2 value sometimes remained constant, sometimes increased and at other times it decreased. Under extreme conditions (with 8 probands asked to lie on the floor) a correlation (r = -0.787) between pressure and pO2 was observed (pressure values between 20.6 and 192.9 mm Hg). The results indicate the use of modern soft-care systems depending on the individual risk of pressure sores.