Congenital heart defects have traditionally been divided into acyanotic or cyanotic defects. Based on the nurse's knowledge of congenital heart defects, this system in clinical practice is

Correct Answer: D

Rationale: The classification system of congenital heart defects into acyanotic or cyanotic defects is problematic because children with acyanotic heart defects may develop cyanosis, complicating the differentiation. Cyanosis can occur in some acyanotic defects due to various reasons such as right-to-left shunting or decreased pulmonary blood flow, making the classification based solely on cyanosis misleading. Choice A is incorrect because while the classification may involve hemodynamics, the main issue lies in the potential for acyanotic defects to develop cyanosis. Choice B is incorrect as the ease of identifying children with cyanotic defects does not address the main problem with the classification system. Choice C is also incorrect as the presence of cyanosis is not the only factor determining the classification's validity.

Correct Answer: C

Rationale: Visible peristalsis and weight loss are classic clinical manifestations of pyloric stenosis. Visible peristalsis refers to the wave-like movements in the abdomen caused by the stomach trying to empty into the intestines due to the obstruction at the pylorus. Weight loss is often seen due to inadequate feeding and vomiting associated with this condition. Choices A, B, and D are not typical of pyloric stenosis. Abdominal rigidity and pain on palpation are more indicative of conditions like peritonitis. A rounded abdomen and hypoactive bowel sounds are more suggestive of conditions like constipation or bowel obstruction. Distention of the lower abdomen and constipation are not specific to pyloric stenosis and may be seen in various gastrointestinal issues.

Correct Answer: A

Rationale: The correct answer is A: petechiae, infection, fatigue. In leukemia, bone marrow involvement leads to a decrease in normal blood cell production, resulting in petechiae (small red or purple spots on the skin), increased susceptibility to infections due to decreased white blood cells, and fatigue from anemia. Choices B, C, and D are incorrect because they do not directly relate to the typical signs and symptoms of leukemia with bone marrow involvement. Headache, papilledema, irritability, muscle wasting, weight loss, decreased intracranial pressure, psychosis, and confusion are not typically associated with leukemia and bone marrow involvement.

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, where the hypertrophied pyloric muscle forms a palpable mass in the abdomen. Choices A, B, and D are incorrect. A distended colon is not a typical finding in HPS, marked tenderness around the umbilicus is not specific to this condition, and rhythmic peristaltic waves in the lower abdomen are not associated with HPS.

Correct Answer: A

Rationale: The correct answer is A: 'Mental retardation occurs if PKU is untreated.' Phenylketonuria (PKU) is a metabolic disorder that, if left untreated with dietary management, can lead to severe mental retardation due to the accumulation of phenylalanine. It is crucial for parents to understand the potential consequences of untreated PKU to emphasize the importance of early and consistent treatment. Choice B is incorrect because testing for PKU is typically done through newborn screening shortly after birth, not immediately. Choice C is incorrect as treatment for PKU primarily involves strict dietary management that restricts phenylalanine intake, not lifelong medications. Choice D is incorrect as PKU is inherited in an autosomal recessive pattern, meaning that both parents must pass on a mutated gene for the disorder to manifest.