Correct Answer: A

Rationale: Administering oxygen is crucial during a sickle cell crisis in a child as it helps to prevent further sickling of cells. Oxygen therapy can improve oxygen saturation levels, reducing the risk of tissue damage and complications. Applying cold compresses (choice B) is not recommended as it can potentially worsen vaso-occlusive crisis by causing vasoconstriction. Restricting fluids (choice C) is not appropriate as hydration is essential to prevent dehydration and maintain adequate blood flow. Encouraging bed rest (choice D) may be necessary but administering oxygen takes precedence in managing a sickle cell crisis.

Correct Answer: A

Rationale: The 'sunset sign,' characterized by downward-driven eyes, is most commonly associated with hydrocephalus. This condition causes increased intracranial pressure, leading to the eyes appearing to be forced downward. Meningitis (choice B) typically presents with symptoms such as fever, headache, and a stiff neck, but not the 'sunset sign.' Cerebral palsy (choice C) is a group of disorders affecting movement and muscle coordination, not directly related to the 'sunset sign.' Encephalitis (choice D) is inflammation of the brain, which can cause symptoms like fever, headache, and confusion, but not the specific downward eye gaze seen in the 'sunset sign.'

Correct Answer: D

Rationale: Proton pump inhibitors (PPIs) like omeprazole or lansoprazole are most effective when given 30 minutes before breakfast. This timing allows the medication to inhibit the proton pumps in the stomach that produce acid, providing better symptom control throughout the day. Administering the PPI at bedtime (choice A) may not be as effective as giving it before breakfast due to the timing of peak acid production during the day. Giving it with a meal (choice B) might affect the absorption and effectiveness of the medication. Midmorning administration (choice C) is not the recommended time for optimal PPI efficacy.

Correct Answer: C

Rationale: The correct answer is C, Respiratory syncytial virus (RSV). RSV is the leading cause of bronchiolitis, a common respiratory condition in infants that results in inflammation of the small airways in the lung. It is highly contagious and can cause severe respiratory distress in young children, particularly those under 2 years old. Choice A, Adenovirus, is not the most common cause of bronchiolitis in infants. Choice B, Influenza virus, may cause respiratory infections but is not the primary cause of bronchiolitis. Choice D, Parainfluenza virus, can cause croup and other upper respiratory infections but is not the main cause of bronchiolitis in infants.

Correct Answer: B

Rationale: The correct answer is B. Meckel diverticulum often presents with intestinal bleeding, which can vary in severity. It is a congenital condition, meaning it is present from birth, not acquired during childhood (choice A). Meckel diverticulum is slightly more common in males than in females, so it does not occur more frequently in females (choice C). While some cases of Meckel diverticulum may require surgical intervention, medical interventions can also be sufficient to treat the problem, so it is not always necessary to resort to surgery (choice D).