A nurse is caring for an infant who has spina bifida. Which of the following actions should the nurse take?

A. "Has your son had a sore throat recently?"

This question is relevant because acute rheumatic fever often occurs as a complication of untreated or inadequately treated streptococcal throat infection (strep throat). A recent history of sore throat could indicate a preceding streptococcal infection, which is an important predisposing factor for the development of acute rheumatic fever.

B. "Was your son born with this cardiac defect?"

This question is less relevant in the context of acute rheumatic fever. Acute rheumatic fever is not a congenital heart defect; it is an inflammatory condition that affects the heart valves following streptococcal infection. While it's important to assess the child's cardiac health, asking about congenital heart defects may not directly relate to the current condition.

C. "Are you aware that your son will have to be in isolation?"

This question is not applicable to acute rheumatic fever. Acute rheumatic fever is not a contagious condition that requires isolation. It is an autoimmune response triggered by streptococcal infection and does not pose a risk of transmission to others.

D. "Has your child had any injuries recently?"

Inquiring about recent injuries is not directly related to acute rheumatic fever. Acute rheumatic fever is an inflammatory condition primarily triggered by streptococcal infection and is not caused by physical injuries.

A. Pulmonary function test:

Pulmonary function tests (PFTs) assess lung function by measuring airflow, lung volume, and gas exchange. While PFTs can provide valuable information about respiratory function, they are not specific to cystic fibrosis and may show abnormalities consistent with various respiratory conditions. However, PFTs are often performed in individuals with cystic fibrosis to monitor lung function over time and assess response to treatment. They are not considered the most definitive test for diagnosing cystic fibrosis.

B. Sweat chloride test:

This option is correct. The sweat chloride test is considered the most definitive diagnostic test for cystic fibrosis. It measures the concentration of chloride in sweat, which is typically elevated in individuals with cystic fibrosis due to defective chloride transport in sweat glands. A sweat chloride concentration above a certain threshold (usually ≥60 mmol/L) is diagnostic of cystic fibrosis, particularly when confirmed with repeat testing.

C. Stool fat content analysis:

Stool fat content analysis evaluates fat absorption and fecal fat excretion, which may be impaired in individuals with cystic fibrosis due to pancreatic insufficiency. However, while stool fat content analysis can provide supportive evidence of malabsorption in cystic fibrosis, it is not considered the most definitive test for diagnosing the condition. Stool fat content analysis is often used in conjunction with other diagnostic tests to assess pancreatic function and nutritional status in individuals with cystic fibrosis.

D. Sputum culture:

Sputum culture involves culturing respiratory secretions to identify bacterial pathogens, which can be useful for diagnosing respiratory infections in individuals with cystic fibrosis. However, sputum culture is not specific to cystic fibrosis and may show similar findings in other respiratory conditions. While respiratory cultures are important for guiding treatment in cystic fibrosis, they are not considered the most definitive test for diagnosing the condition.