座位姿勢をとる高齢者の褥瘡形成の実態把握調査―褥瘡の形状と車椅子接地形状の関係から

The Relationship between Pressure Ulcer Development and Wheelchair Position in the Elderly: Comparison between Lateral and Wheelchair Position

要旨

　座位時に発生する褥瘡研究は脊髄損傷の患者に関するものが多く，発生要因や褥瘡の管理方法，および予防方法が報告されている．しかし，痩せていて顕著な骨突起があり，拘縮や変形およびしわやたるみが多い高齢者にはこれらの先行研究とは異なる原因が考えられるが，高齢者の座位における褥瘡の研究は少なく，車椅子を中心にした姿勢保持や圧管理についての報告にとどまっている．

　今回，高齢者の座位姿勢における殿部の褥瘡を予防することを目的に殿部の皮膚の状態を観察し，高齢者の座位時における特徴的な皮膚の形状とその原因を検討した．方法は，座位になる患者59名，寝たきりの患者31名，歩行する患者23名の殿部の皮膚の状態を比較して，座位特有の褥瘡の形状を抽出した．さらに，座位になる患者に対しては，座布と背布の部分が透明の塩化ビニールで作られた車椅子に，下着をはずした状態で座位になり座位での接地形状を観察し，圧迫が加わらない側臥位での褥瘡の形状と座位での接地形状の関係から原因を追求した．

　その結果，座位特有の褥瘡の形状は円，輪，馬蹄，蝶，不整があった．この形状と座位での接地形状の関係をみたところ，円と輪は圧力が関与し，馬蹄と蝶と不整はずれ力が関与していた．

　以上より，褥瘡の形状を観察することで外力の方向性を予測する指標を得ることができ，早期治癒に向けたケア方法の検討が可能になった．

Abstract

　Much research has been undertaken concerning the care and prevention of pressure ulcers in spinal cord injuries patients. There are also some studies on sitting posture and pressure management for wheelchair using elderly. However, there is little research related to sitting positions and pressure ulcers in the elderly. Many elderly people have very brittle bones, and are effected by deformation and contracture from skinny body frames.

　This research focuses on practices that can prevent of pressure ulcers in the buttocks of the elderly. Skin tissue form was obtained for inquiry into the special shapes and causes of pressure ulcers effected by sitting position. Subjects were sitting position patients (n＝59), bedridden patients (n＝31), and walking patients (n＝23).Views of their buttocks skin were compared, and the shapes of the pressure ulcers obtained. Moreover, ulcers from sitting patients were obtained using a wheelchairs are made from transparent polyvinyl chloride and without any underlining； thus enabling contact areas of the ulcers to be observed.The contact area shapes were compared with lateral and the wheelchair positions.

　Pressure ulcer wounds effected by sitting positions are shaped like a circle, a ring, a horse's hoof, butterfly and irregular shapes. The relationship between pressure ulcers and the contact area shapes was determined；circles and rings were related to pressures, while horse's hooves, butterflies and irregular shapes were related to shear forces.

　Consequently, early care of pressure ulcers can be aided from the knowledge that the direction of the external force effecting the patient's condition can be determined from the shape of the pressure ulcer.