下列何項護理措施最能有效預防臥床病人的壓瘡產生？
Which of the following nursing actions best prevents the development of pressure ulcers in a bedridden client?
- AMaintain the head of the bed at 45 degrees保持床頭抬高45度
- BApply a thick layer of powder to the skin在皮膚上塗抹厚層粉末
- CMassage bony prominences twice a day每天按摩骨突處兩次
- DReposition the client at least every two hours✓ 正解至少每兩小時為病人重新擺位
預防壓瘡（Pressure Ulcer）的核心在於減壓與維持皮膚完整性。長期臥床病人因持續性的局部壓力導致微血管血流受阻，進而造成組織缺氧壞死。臨床上，每兩小時翻身是標準的減壓護理措施，能有效重建局部組織的灌流。護理師在評估預防策略時，必須考量物理性壓力的分佈，避免剪力（Shearing）與摩擦力造成的傷害。
The core of pressure ulcer prevention is pressure relief and maintenance of skin integrity. Continuous local pressure in bedridden clients impairs capillary blood flow, leading to tissue hypoxia and necrosis. Clinically, repositioning every two hours is the standard pressure-relief intervention and effectively restores local tissue perfusion. When evaluating preventive strategies, the nurse must consider the distribution of physical pressure and avoid injury from shearing and friction.