Correct Answer: A

Rationale: In a 10-year-old with newly diagnosed osteomyelitis, the most important information for the nurse to obtain is the recent history of infection recurrences. This is crucial because osteomyelitis is an infection of the bone, and assessing for any recent recurrence of infections can help in determining the possible source of the osteomyelitis and guide the treatment plan accordingly.

Correct Answer: C

Rationale: When a client expresses concerns about family dynamics, it is important to explore their feelings and reactions to the situation. By asking about the client's response to his mother's anger, the nurse can gain insight into the client's emotions, thoughts, and coping mechanisms. Understanding these aspects is crucial in providing appropriate support and guidance.

Correct Answer: D

Rationale: Flaring of the nares is a clinical sign of acute respiratory distress in infants. It indicates an increased effort to breathe and is a crucial finding that requires immediate attention, as it signifies the child is having difficulty breathing and may be in respiratory distress.

Correct Answer: D

Rationale: A significant drop in heart rate and blood pressure should be reported immediately as it may indicate worsening of the congenital heart defect. The blood pressure of 70/40 is dangerously low and requires immediate attention to prevent further complications.

Correct Answer: A

Rationale: An increase in urine output is a reliable indicator of improving dehydration in a child. It signifies that the kidneys are functioning better, helping to restore fluid balance in the body. Monitoring urine output is crucial in assessing hydration status and response to treatment.