Correct Answer: A

Rationale: Administering a bronchodilator is the priority intervention for a child experiencing an acute asthma exacerbation. Bronchodilators help to dilate the airways, making breathing easier and relieving acute symptoms of asthma. Antihistamines are not the first-line treatment for asthma exacerbations; they are more commonly used for allergic reactions. Corticosteroids are beneficial in reducing inflammation in asthma but are usually administered after bronchodilators to provide long-term control. Oxygen therapy may be necessary in severe cases of asthma exacerbation, but bronchodilators take precedence in improving airway patency and respiratory distress.

Correct Answer: B

Rationale: The correct answer is the sweat chloride test. This test is crucial in diagnosing cystic fibrosis as it measures the amount of chloride in sweat, which is typically elevated in individuals with cystic fibrosis. A chest X-ray (Choice A) may show characteristic findings like hyperinflation or bronchiectasis, but it is not a definitive diagnostic test for cystic fibrosis. Pulmonary function tests (Choice C) may help assess lung function but are not specific for cystic fibrosis. Sputum culture (Choice D) may be used to identify specific pathogens causing respiratory infections but is not a primary diagnostic test for cystic fibrosis.

Correct Answer: B

Rationale: The correct first action before administering tube feeding to an infant is to offer a pacifier. Providing a pacifier stimulates the sucking reflex, aiding in digestion and providing comfort to the infant. Irrigating the tube with water (Choice A) is not typically the initial step and could potentially introduce unnecessary fluid into the infant's system. Slowly instilling formula (Choice C) should only be done after ensuring the tube is appropriately placed. Placing the infant in the Trendelenburg position (Choice D) is not necessary for tube feeding and could pose risks such as aspiration.

Correct Answer: D

Rationale: Cleft palate is considered a major congenital anomaly because it involves a gap or split in the roof of the mouth, which can significantly impact feeding, speech development, dental health, and overall well-being. Overlapping digits (Choice A) and polydactyly (Choice B) are examples of limb abnormalities rather than major congenital anomalies affecting vital functions. Umbilical hernia (Choice C) is a common condition where abdominal organs protrude through the belly button and is typically not considered a major congenital anomaly in the same way as cleft palate.

Correct Answer: B

Rationale: After a cardiac catheterization, the priority nursing care for a 3-year-old child is monitoring the site for bleeding. This is essential to promptly identify and address any signs of bleeding or hematoma formation, which are potential complications of the procedure. Encouraging early ambulation may be beneficial post-procedure but ensuring site integrity takes precedence. Restricting fluids until blood pressure stabilization is not a standard post-catheterization practice, as adequate hydration is crucial for recovery. Comparing the blood pressure of both lower extremities is not a priority immediate nursing action after a cardiac catheterization in a pediatric patient.