Final answer:
An elevated white blood cell count is an indication of a potential complication in a child postoperative following an open fracture repair, as it suggests an infection or inflammatory response by the body.
Step-by-step explanation:
The question involves interpreting laboratory results to identify potential complications in a school-age child who is 1 week postoperative following an open fracture repair. Elevated white blood cell count is an indication of a potential complication, specifically an infection that might occur after a surgical procedure. In the context of post-surgical recovery, especially dealing with bone and the potential for internal exposure, an increased white cell count is a common indicator of the body responding to an infection.
The other listed options, such as decreased erythrocyte sedimentation rate, low platelet count, or elevated hemoglobin level, are not direct indicators of a complication following this type of surgery. It is the leukocytosis that raises a concern. Leukocytosis, or an elevated WBC count, is typically associated with inflammation or infection, signaling the immune system's response to an offending agent.