Final answer:
To improve arterial oxygenation without putting pressure on the areas of breakdown, the nurse should place the client in the prone position.
Step-by-step explanation:
The nurse is caring for a client with multiple areas of breakdown on the back and needs to choose a position that will improve arterial oxygenation without exacerbating the areas of breakdown. The prone position, which is described as a face-down orientation with upper limbs, including palms, touching sides and lower limbs touching at sides, is generally recommended for clients with back wounds to avoid pressure on the affected areas. Additionally, the prone position can improve oxygenation in some patients by redistributing blood flow and easing breathing.