Final answer:
Padding under bony prominences in patients helps prevent pressure ulcers. A color change from blue to purple in a liquid is typically due to a pH change. Fluid output exceeding input could be the result of capillary action.
Step-by-step explanation:
The padding should be placed under bony prominences such as the sacrum, heels, or mid thoracic curvature of older or debilitated patients for comfort and to prevent the development of pressure ulcers. These are also known as bedsore or decubitis ulcers and occur due to constant, unrelieved pressure on the skin reducing blood flow and leading to necrosis.
The color change in the liquid from blue to purple could be indicative of a pH change. This is a general phenomenon that occurs in solutions containing pH indicators, which alter color in response to changes in hydrogen ion concentration.
More fluid coming out than went in can occur due to capillary action. This is the ability of a liquid to flow in narrow spaces without the assistance of external forces like gravity. It occurs because of intermolecular forces between the liquid and surrounding solid surfaces. If the diameter of the tubes is small enough, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container act to propel the liquid.