Correct Answer: C

Rationale: Hirschsprung disease should be suspected in a newborn with abdominal distention, vomiting, and failure to pass meconium. This condition arises from a congenital absence of nerve cells in a portion of the colon, leading to severe constipation and intestinal obstruction. Pyloric stenosis typically presents with non-bilious projectile vomiting in the first few weeks of life. Intussusception classically manifests with sudden onset of colicky abdominal pain and currant jelly stools. Celiac disease may present with chronic diarrhea, failure to thrive, and abdominal distention but is less likely in this scenario.

Correct Answer: A

Rationale: Dry mucous membranes are a common sign of moderate dehydration in children, indicating a loss of bodily fluids. When a child is moderately dehydrated, the mucous membranes in the mouth and nose may appear dry. This condition can occur due to various factors such as vomiting, diarrhea, or inadequate fluid intake. Normal capillary refill (choice B) is not typically associated with dehydration; it is a measure of circulatory status. Hyperactive bowel sounds (choice C) can be present in conditions like gastroenteritis but are not specific to dehydration. Edema (choice D) is the retention of fluid in the body and is not a typical sign of dehydration.

Correct Answer: D

Rationale: Mid-upper arm circumference is a good indicator of muscle mass and fat stores, reflecting a child's nutritional status. It is particularly useful in assessing malnutrition, as it is less affected by fluid retention or dehydration compared to other anthropometric measurements. Weight can fluctuate due to factors like hydration status, making it less reliable as a sole indicator of nutritional status. Height reflects growth but may not directly indicate current nutritional status. Head circumference is more related to brain growth and development rather than overall nutritional status.

Correct Answer: A

Rationale: The primary treatment goal for a child with juvenile idiopathic arthritis is pain management. Juvenile idiopathic arthritis is a chronic condition with no known cure, making pain management crucial to improve the quality of life for these children. While reducing joint deformity and physical therapy are important aspects of managing the condition, the primary focus is on alleviating pain and improving function.

Correct Answer: C

Rationale: The correct answer is C: Give epinephrine. Administering epinephrine is the first and most critical step in treating anaphylaxis. Epinephrine rapidly reverses the symptoms of anaphylaxis, including airway swelling, hypotension, and shock. Delaying administration can lead to severe complications or death, making it essential in emergency treatment. Choice A, administering oxygen, might be necessary but should not delay the administration of epinephrine. Starting an IV line (Choice B) is important for further treatment but not the initial step. Monitoring vital signs (Choice D) is essential but comes after administering epinephrine to stabilize the child.