Correct Answer: C

Rationale: The correct hematocrit range for a healthy 12-month-old infant is between 37% to 47%. At this age, this range reflects the normal blood volume and red blood cell (RBC) levels in infants. Choice A (19% to 32%) is too low for a healthy hematocrit level in a 12-month-old. Choice B (29% to 41%) is also below the typical range for a 12-month-old. Choice D (42% to 69%) includes an upper limit that is higher than expected for a healthy infant, making it an incorrect option.

Correct Answer: B

Rationale: Chest tubes are used to drain air and fluid from the chest cavity to prevent complications such as pneumothorax or cardiac tamponade after surgery. Choice A is incorrect as chest tubes are not used to increase tidal volumes. Choice C is incorrect as chest tubes do not maintain positive intrapleural pressure; instead, they assist in removing excess air or fluid. Choice D is incorrect as chest tubes do not regulate pressure on the pericardium and chest wall; they primarily aid in drainage.

Correct Answer: A

Rationale: The priority nursing diagnosis for a 3-day-old girl with Down syndrome, whose mother had no prenatal care, is imbalanced nutrition, less than body requirements related to the effects of hypotonia. Newborns with Down syndrome often experience feeding difficulties due to hypotonia, which can lead to inadequate nutrition intake. Option B is incorrect because at this age, the infant is not capable of having knowledge deficits related to a genetic disorder. Option C is incorrect as delayed growth and development are not the immediate priority in this scenario. Option D is incorrect as impaired physical mobility is not typically a priority concern for a newborn with Down syndrome.

Correct Answer: D

Rationale: In a 3-year-old child presenting with sudden respiratory distress without fever or recent illness, the most likely cause is a foreign body airway obstruction. Foreign body airway obstruction can lead to a sudden onset of respiratory distress as it blocks the air passage. Croup typically presents with a barking cough and stridor, often preceded by a viral illness. Epiglottitis is characterized by high fever, drooling, and a muffled voice. Lower respiratory infections usually present with symptoms such as cough, fever, and chest congestion. Therefore, in this case, the absence of recent illness or fever makes foreign body airway obstruction the most likely cause of the respiratory distress.

Correct Answer: C

Rationale: Administering antibiotics is a crucial nursing intervention after a tonsillectomy because it helps prevent infections, which are a common postoperative complication. Encouraging deep breathing exercises (Choice A) is also important for promoting lung expansion and preventing respiratory complications. Encouraging the child to eat (Choice B) may not be appropriate immediately after a tonsillectomy due to the risk of throat irritation and discomfort. Applying ice to the throat (Choice D) is generally not recommended post-tonsillectomy as it may cause vasoconstriction and hinder the healing process.