Final answer:
For a patient with a recent leg fracture wearing a cast, the highest priority nursing diagnosis is likely to be Acute Pain, considering the intense sensation following the injury and its implications for complications.
Step-by-step explanation:
Using a "patient preferences" framework, the nursing diagnosis with the highest priority for a patient who fractured his leg yesterday and is now wearing a cast would likely be Acute Pain. This diagnosis reflects the immediate and intense sensation likely experienced after such an injury and the application of a constrictive device like a cast. For many patients, especially the elderly, acute pain management is crucial as it can lead to complications such as immobility, which increases the risk for blood clots, pneumonia, pressure sores, and infections, all of which could be life-threatening. Moreover, effective pain management is typically a high priority for patient comfort and recovery quality.