A 3-month-old baby girl admitted to pediatric intensive care unit with severe head injury (evident by CT scan), the history given by parents was trivial and not informative. You suspected child abuse. Of the following, the MOST helpful study to support your suspicion is

Correct Answer: D

Rationale: Radionuclide bone scans are highly sensitive for detecting occult fractures, which are common in cases of non-accidental trauma. Infantograms and X-rays may miss subtle fractures.

Correct Answer: D

Rationale: Observation is appropriate if transient synovitis is suspected without signs of infection.

Correct Answer: C

Rationale: Severe coarctation of the aorta leads to left ventricular overload and heart failure in neonates. It presents with weak femoral pulses, differential blood pressure, and signs of poor perfusion.

Correct Answer: B

Rationale: Irritability is an early sign of shock due to hypoperfusion before hypotension or organ failure develops.

Correct Answer: A

Rationale: During acidosis, potassium shifts out of cells, increasing serum levels. Correction reverses this shift, leading to a drop in serum potassium, which may cause hypokalemia.