The nurse is caring for an infant with suspected pyloric stenosis. Which clinical manifestation would indicate pyloric stenosis?

Correct Answer: C

Rationale: Visible peristalsis and weight loss are classic clinical manifestations of pyloric stenosis. The obstruction at the pyloric sphincter causes visible peristalsis as the stomach tries to push food through the narrowed opening, leading to the appearance of waves across the abdomen. Weight loss occurs due to poor feeding and frequent vomiting associated with pyloric stenosis. Choices A, B, and D are incorrect. Abdominal rigidity and pain on palpation, rounded abdomen and hypoactive bowel sounds, as well as distention of the lower abdomen and constipation are not typically seen in pyloric stenosis.

Correct Answer: C

Rationale: When palpating the abdomen of an infant with hypertrophic pyloric stenosis (HPS), the nurse would expect to feel an olive-sized mass in the right upper quadrant. This finding is characteristic of HPS due to the hypertrophied pylorus muscle. Choices A, B, and D are incorrect. A distended colon is not typically associated with HPS. Marked tenderness around the umbilicus is not a specific finding of HPS. Rhythmic peristaltic waves in the lower abdomen are not expected in HPS, as the condition primarily affects the pylorus region of the stomach.

Correct Answer: A

Rationale: The correct answer is A: 'Mental retardation occurs if PKU is untreated.' Phenylketonuria (PKU) is a metabolic disorder that results in the inability to metabolize phenylalanine properly. Without proper dietary management, high levels of phenylalanine can lead to severe mental retardation and other neurological problems. Therefore, educating parents about the importance of early and consistent treatment to prevent mental retardation is crucial. Choice B is incorrect because testing for PKU is typically done shortly after birth, not immediately. Choice C is incorrect because treatment for PKU primarily involves strict dietary management to control phenylalanine intake, not lifelong medications. Choice D is incorrect because PKU is inherited in an autosomal recessive pattern, not as an autosomal dominant gene.

Correct Answer: D

Rationale: The correct answer is D: Preventing cardiac overload. Infants are highly vulnerable to fluid overload, making it essential to carefully monitor IV flow rates to prevent complications such as cardiac overload. Rapid administration of IV fluids can lead to an excessive increase in circulating volume, potentially causing cardiac strain or heart failure in infants. Choices A, B, and C are incorrect. Monitoring the IV flow rate is not primarily aimed at limiting output, replacing lost fluids, or avoiding IV infiltration in this scenario. The key concern is to prevent the risk of cardiac overload due to the infant's susceptibility to fluid imbalances.

Correct Answer: B

Rationale: The correct answer is B: Covering the sac with saline-soaked nonadhesive gauze. This intervention is essential in caring for an infant with myelomeningocele as it helps prevent infection and maintains a moist environment around the sac before surgical repair. Positioning the infant supine with a pillow under the buttocks (Choice A) may be suitable for comfort but is not directly related to managing the myelomeningocele. Wrapping the infant snugly in a blanket (Choice C) and applying a diaper (Choice D) are not recommended as they can increase the risk of infection and damage to the sac.