Static and Dynamic Support Systems-Pressure Differences on the Body

Summary

A study has been carried out, with five subjects, to assess the relative magnitude of the pressures which develop between the skin and the support media in eight areas of the body with the patient in a lying, semi-recumbent and sitting position. Two types of support systems have been used: a dynamic system—the Low Air Loss Bed System (LALBS)—and a static system, an Ellison type King’s Fund (KF) bed. A separation indicator pad system was developed and used. It should be noted that with this method, accurate location and maintenance of the pads over bony prominences may be difficult. Additionally the pressure recorded is dependent on the material used in the construction of the pad and the area of the pad. Thus, comparison with other published results using normally the same technique cannot be made. Within such limitations the findings of this study show that there is a more even distribution of pressures with their magnitude generally less for the LALBS than for the KF type 4 in. thick foam mattress on a ribbed metal base. To prevent the development of pressure sores, two hourly changing of position on the KF type bed is required. On the LALBS attention must be paid to the position of the heel and elbow relative to the apex of the air sac. To change the position of a patient on a KF bed requires at least two nurses, with the expenditure of considerable physical effort. With the LALBS, the position of the patient can be adjusted by the patient or one nurse with relatively little effort.