Which of the following conditions is characterized by a 'machine-like' murmur in children?

Correct Answer: A

Rationale: The correct answer is A, Patent ductus arteriosus. This condition is characterized by a continuous 'machine-like' murmur due to abnormal blood flow between the aorta and pulmonary artery. Ventricular septal defect (choice B) is characterized by a harsh holosystolic murmur, atrial septal defect (choice C) typically presents with a fixed split S2 and a pulmonary flow murmur, and coarctation of the aorta (choice D) is associated with a systolic murmur in the back and bilateral lower extremities.

Correct Answer: B

Rationale: Hypokalemia is the correct answer because it is a common concern in children with severe diarrhea. Diarrhea can lead to significant potassium loss, resulting in hypokalemia. Hypernatremia (Choice A) is less common in diarrhea as sodium concentration is usually diluted by the fluid loss. Hypercalcemia (Choice C) is not typically associated with severe diarrhea. Hypomagnesemia (Choice D) can occur but is not as common as hypokalemia in this scenario.

Correct Answer: C

Rationale: Frequent spitting up is indeed a common symptom of gastroesophageal reflux in infants. It is caused by the backward flow of stomach contents into the esophagus, leading to infants regurgitating milk or formula shortly after feeding. Projectile vomiting (choice A) is more commonly associated with conditions like pyloric stenosis rather than gastroesophageal reflux. Bilious vomiting (choice B) often indicates an obstruction in the gastrointestinal tract. Diarrhea (choice D) is not typically a primary symptom of gastroesophageal reflux in infants.

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.

Correct Answer: D

Rationale: The correct answer is D: Prepare for surgery. Acute appendicitis is a surgical emergency that requires prompt removal of the appendix to prevent complications like rupture and peritonitis. Administering antibiotics (choice A) may be part of the treatment plan but should not delay surgical intervention. Applying heat to the abdomen (choice B) is not recommended as it can worsen the inflammation of the appendix. Encouraging oral fluids (choice C) is generally beneficial, but the priority in acute appendicitis is surgical intervention.