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Background
Pressure ulcers which occur while in the sitting position remain a challenging issue, especially in elderly patients. This is partly due to the lack of an appropriate cushion, properly suited to the bony prominence, and thus resulting in the occurrence of bottoming out. To resolve these problems, we newly developed an alternating pressure air cushion which can adjust inner pressure automatically and sense and avoid its bottoming out. The purpose of this study was to evaluate the function of a newly developed dynamic wheelchair cushion. Two crossover experimental studies were conducted; study 1: Functional evaluation for tissue blood oxygenation retention during alternating pressure air among healthy volunteers, study 2: Functional evaluation for pressure redistribution among elderly patients.
Methods
Study 1 involved 19 volunteers. During 30-minute sitting on two different modes of cushion, static or alternative regulation, the tissue blood oxygenation was monitored by near-infrared spectroscopy. To assess the tissue blood oxygenation retention, reactive hyperemia was quantified. Study 2 involved 28 elderly patients who cannot keep or adjust their adequate sitting posture by themselves. During two 30-minute sitting on new and commercialized air-filled cushions, interface pressure was measured. These experiments were approved by institutional review board.
Results
The alternating mode induced significantly lower level (P=0.003) of reactive hyperemia in study 1. At the end of the 30-minutes sitting in study 2, the experimental group showed significantly lower maximum pressures (P<0.001) and larger contact areas (P<0.001).
Discussion
The alternating mode repressed the reactive hyperemia after 30-minute sitting which indicates the retention of tissue oxygenation level during sitting was effective in alternating the air-cells. Study 2 revealed the effectiveness in pressure redistribution among elderly patients compared to commercially available cushion. From these comprehensive functional analyses, it can be expected that the new dynamic cushion has effectiveness of pressure ulcer prevention for elderly who has problem in sitting.
Pressure ulcers which occur while in the sitting position remain a challenging issue, especially in elderly patients. This is partly due to the lack of an appropriate cushion, properly suited to the bony prominence, and thus resulting in the occurrence of bottoming out. To resolve these problems, we newly developed an alternating pressure air cushion which can adjust inner pressure automatically and sense and avoid its bottoming out. The purpose of this study was to evaluate the function of a newly developed dynamic wheelchair cushion. Two crossover experimental studies were conducted; study 1: Functional evaluation for tissue blood oxygenation retention during alternating pressure air among healthy volunteers, study 2: Functional evaluation for pressure redistribution among elderly patients.
Methods
Study 1 involved 19 volunteers. During 30-minute sitting on two different modes of cushion, static or alternative regulation, the tissue blood oxygenation was monitored by near-infrared spectroscopy. To assess the tissue blood oxygenation retention, reactive hyperemia was quantified. Study 2 involved 28 elderly patients who cannot keep or adjust their adequate sitting posture by themselves. During two 30-minute sitting on new and commercialized air-filled cushions, interface pressure was measured. These experiments were approved by institutional review board.
Results
The alternating mode induced significantly lower level (P=0.003) of reactive hyperemia in study 1. At the end of the 30-minutes sitting in study 2, the experimental group showed significantly lower maximum pressures (P<0.001) and larger contact areas (P<0.001).
Discussion
The alternating mode repressed the reactive hyperemia after 30-minute sitting which indicates the retention of tissue oxygenation level during sitting was effective in alternating the air-cells. Study 2 revealed the effectiveness in pressure redistribution among elderly patients compared to commercially available cushion. From these comprehensive functional analyses, it can be expected that the new dynamic cushion has effectiveness of pressure ulcer prevention for elderly who has problem in sitting.