Final answer:
The early manifestation of a fat embolism following a comminuted fracture of the femur is Dyspnea. This indicates the patient may be experiencing difficulty breathing due to fat globules obstructing pulmonary blood vessels.
Step-by-step explanation:
The question pertains to a nurse assessing a client with a comminuted fracture of the femur and identifying early manifestations of a fat embolism. A fat embolism is a serious complication that can occur after a bone fracture, where fat globules are released into the bloodstream and can obstruct blood vessels. Among the options provided, the early manifestation of a fat embolism is Dyspnea (A).
Dyspnea or difficulty breathing can occur due to the emboli obstructing pulmonary vessels. Fever (B) and petechiae on the chest (C) can occur as well, but they are typically later signs. The presence of fat globules in the urine (D) is not a typical early sign of fat embolism syndrome (FES).