Correct Answer: B

Rationale: The correct answer is B: Wheezing. Wheezing is a key distinguishing feature of bronchiolitis in infants, typically caused by respiratory syncytial virus (RSV) infection. Bronchiolitis is characterized by inflammation and mucus buildup in the small airways of the lungs, leading to wheezing sounds during breathing. Choices A, C, and D are incorrect because dry cough, stridor, and productive cough are not typical features of bronchiolitis in infants.

Correct Answer: D

Rationale: Excessive vomiting in pyloric stenosis leads to the loss of stomach acid (hydrochloric acid), resulting in metabolic alkalosis, not hyperkalemia, hyperchloremia, or metabolic acidosis. Metabolic alkalosis is characterized by a higher pH level in the blood due to the loss of acid and a relative increase in bicarbonate. Hyperkalemia is an elevated level of potassium in the blood and is not directly related to excessive vomiting in pyloric stenosis. Hyperchloremia is an excess of chloride in the blood, which is not typically associated with this condition. Metabolic acidosis is a condition characterized by a lower pH level in the blood, caused by an excess of acid or a loss of bicarbonate, which is not the typical complication seen in pyloric stenosis with excessive vomiting.

Correct Answer: A

Rationale: Restlessness is an early sign of shock due to decreased perfusion and oxygenation to the brain. This symptom requires immediate attention to prevent the progression to more severe stages of shock. Rapid capillary refill (Choice B) is not typically an early sign of shock but rather a sign of adequate perfusion. Increased temperature (Choice C) may occur in later stages of shock due to the body's response to stress. Increased blood pressure (Choice D) is not an early sign of shock; in fact, blood pressure tends to decrease in shock as a compensatory mechanism.

Correct Answer: C

Rationale: The correct answer is C, 'Tripod.' In children with epiglottitis, the tripod position is recommended to help open the airway and ease breathing. This position involves the child sitting upright, leaning forward, and supporting themselves with their hands on their knees or another surface. This posture helps improve air entry into the lungs by maximizing the space for breathing. Choices A (Supine), B (Prone), and D (Semi-Fowler's) are incorrect. Placing a child with epiglottitis in the supine position may further obstruct the airway, while the prone position and semi-Fowler's position do not facilitate optimal air exchange in these cases.

Correct Answer: C

Rationale: Croup is the correct answer. It is characterized by a distinctive "barking" cough, typically worse at night, caused by the inflammation of the upper airway, specifically the larynx and trachea. Asthma (Choice A) typically presents with wheezing and shortness of breath rather than a barking cough. Bronchiolitis (Choice B) commonly causes wheezing and respiratory distress in infants and young children. Pneumonia (Choice D) often presents with symptoms like fever, productive cough, and chest pain, but not typically a barking cough.