Which pediatric disorder is associated with a 'boot-shaped' heart on a chest x-ray?

Correct Answer: A

Rationale: The correct answer is A: Tetralogy of Fallot. Tetralogy of Fallot is often associated with a 'boot-shaped' heart appearance on a chest x-ray due to the characteristic heart anatomy in this condition. This appearance is caused by the combination of pulmonary stenosis, overriding aorta, ventricular septal defect, and right ventricular hypertrophy. Choice B, Transposition of the great arteries, is incorrect because it presents with a 'egg-on-a-string' appearance on x-ray due to the abnormal position of the aorta and pulmonary artery. Choice C, Coarctation of the aorta, typically presents with rib notching on x-ray. Choice D, Ventricular septal defect, does not produce the 'boot-shaped' heart appearance seen in Tetralogy of Fallot.

Correct Answer: A

Rationale: Administering oxygen is crucial during a sickle cell crisis in a child as it helps to prevent further sickling of cells. Oxygen therapy can improve oxygen saturation levels, reducing the risk of tissue damage and complications. Applying cold compresses (choice B) is not recommended as it can potentially worsen vaso-occlusive crisis by causing vasoconstriction. Restricting fluids (choice C) is not appropriate as hydration is essential to prevent dehydration and maintain adequate blood flow. Encouraging bed rest (choice D) may be necessary but administering oxygen takes precedence in managing a sickle cell crisis.

Correct Answer: C

Rationale: The correct answer is C: Influenza. The influenza vaccine is produced using egg-based technology, so individuals with a severe egg allergy are at risk of an allergic reaction if vaccinated with the influenza vaccine. This is due to the potential presence of egg proteins in the vaccine. Choices A, B, and D are not contraindicated in children with severe egg allergy. The MMR and Varicella vaccines do not pose a risk for children with egg allergies, and the Hepatitis B vaccine is also safe for these individuals.

Correct Answer: C

Rationale: Absent breath sounds on the affected side are a primary symptom of congenital diaphragmatic hernia. Cyanosis, bradycardia, and tachypnea may also be present but are not the primary symptom. Cyanosis is a bluish discoloration of the skin due to poor oxygenation, bradycardia is a slower than normal heart rate, and tachypnea is rapid breathing.

Correct Answer: B

Rationale: The correct answer is B: Projectile vomiting. Pyloric stenosis in infants typically presents with projectile vomiting, which is forceful and projective in nature. This occurs due to the obstruction at the pylorus, leading to the stomach being unable to empty properly. Choices A, C, and D are incorrect. Bilious vomiting is more commonly associated with intestinal obstruction, blood in stools can occur in conditions such as necrotizing enterocolitis or allergic colitis, and failure to thrive is a nonspecific finding that can be seen in various pediatric conditions.