Pediatric HESI 2023

Correct Answer: A

Rationale: Projectile vomiting is a classic clinical manifestation of pyloric stenosis in infants. This occurs due to the narrowing of the pyloric sphincter, leading to the forceful expulsion of gastric contents in a projectile manner. Diarrhea (choice B) is not typically associated with pyloric stenosis. Constipation (choice C) is also not a common symptom of this condition. Abdominal distension (choice D) may occur in pyloric stenosis but is not as specific or characteristic as projectile vomiting in diagnosing this condition.

Correct Answer: B

Rationale: The correct answer is B. Live vaccines like MMR should not be given to immunosuppressed infants because their weakened immune systems may not handle the vaccine safely. Choice A is incorrect as delaying the MMR vaccine until the infant reaches 2 years of age does not address the issue of immunosuppression. Choice C is incorrect because administering live vaccines to an immunosuppressed individual could lead to serious complications. Choice D is incorrect as immediate action is required to prevent potential harm to the immunosuppressed infant.

Correct Answer: A

Rationale: The correct answer is A: nondisjunction. Trisomy 21, also known as Down syndrome, is caused by nondisjunction, which is an error in cell division leading to an extra copy of chromosome 21. This additional genetic material alters the course of development and causes the characteristics associated with Down syndrome. Choices B, C, and D are incorrect. X-linked recessive inheritance refers to genetic disorders carried on the X chromosome, genomic imprinting involves gene expression based on parental origin, and autosomal dominant inheritance relates to disorders caused by a dominant gene on one of the non-sex chromosomes. In the case of trisomy 21, the cause is specifically related to the error in chromosome division, making nondisjunction the most appropriate answer.

Correct Answer: A

Rationale: The American Academy of Pediatrics recommends the intramuscular polio vaccine because it has a better safety profile compared to the oral vaccine. Choice B is incorrect because the AAP specifically recommends the intramuscular vaccine over the oral vaccine. Choice C is incorrect as cost is not the primary reason for preferring the intramuscular vaccine. Choice D is incorrect as the recommendation is based on safety rather than the immunocompromised status of the infant or family members.

Correct Answer: D

Rationale: After undergoing surgery for pectus excavatum correction with steel bar placement, the nurse should instruct the parents to avoid placing the child in a side-lying position. This position should be avoided to prevent displacement of the steel bar, which could compromise the surgical outcome. Semi-Fowler, supine, and high Fowler positions do not pose the same risk of displacing the steel bar and are generally safe and comfortable for the child in this postoperative period.