Correct Answer: B

Rationale: The correct answer is B: Tissue oxygen needs. Polycythemia occurs as the body's response to chronic hypoxia by increasing RBC production to enhance oxygen delivery. In tetralogy of Fallot, a congenital heart defect, the heart's structure causes reduced oxygen levels in the blood. This chronic hypoxia stimulates the bone marrow to produce more red blood cells, leading to an elevated RBC count. Choice A is incorrect as low blood pressure is not directly related to polycythemia in this context. Choice C, diminished iron level, is not the cause of polycythemia in tetralogy of Fallot. Choice D, hypertrophic cardiac muscle, is not the primary cause of the elevated RBC count in this case.

Correct Answer: B

Rationale: Correct! When a child is being discharged after treatment for dehydration, it is important to educate caregivers about monitoring for signs of dehydration to prevent reoccurrence. Dehydration is the primary concern in this scenario, as the child's fluid levels need to be closely monitored. Choices A, C, and D are incorrect because while infection, hypovolemia, and malnutrition are also important considerations in pediatric care, the immediate focus after treating dehydration should be on preventing its recurrence by monitoring for signs of dehydration.

Correct Answer: A

Rationale: Epicanthal folds are a common physical feature seen in individuals with Down syndrome. These are folds of skin that cover the inner corners of the eyes. Webbed neck (Choice B) is associated with Turner syndrome, not Down syndrome. Enlarged head (Choice C) is not a typical physical characteristic of Down syndrome. Polydactyly (Choice D) is the presence of extra fingers or toes, which is not specifically related to Down syndrome.

Correct Answer: B

Rationale: In a pediatric patient presenting with altered mental status, high fever, and a generalized rash, seizures are a significant concern. Febrile seizures can occur in children with high fevers and may lead to further complications. It is crucial to monitor for seizures and be prepared to manage them promptly. Vomiting, combativeness, and respiratory distress are also important considerations in pediatric patients; however, given the clinical presentation described, seizures take priority as they are a common complication in this scenario.

Correct Answer: C

Rationale: The priority nursing action after corrective surgery for hypertrophic pyloric stenosis (HPS) is to assess the IV site for infiltration. This is crucial as it ensures proper fluid administration and prevents complications such as phlebitis or infiltration-related tissue damage. Applying restraints (Choice A) would not be appropriate in this situation as it is not related to the immediate post-operative care of an infant with an IV infusion. Administering a mild sedative (Choice B) is not indicated as the primary concern post-surgery is monitoring the IV site and the infant's response to the surgery. Attaching the nasogastric tube to wall suction (Choice D) is not the priority at this time, as assessing the IV site takes precedence to prevent potential complications.