which laboratory test would be most important for the nurse to assess when caring for a toddler suspected of having cystic fibrosis

ATI RN

Nursing Care of Children Final ATI

1. Which laboratory test would be most important for the nurse to assess when caring for a toddler suspected of having cystic fibrosis?

A. Liver enzymes
B. Serum calcium
C. Sweat chloride test
D. Urine creatinine

Correct answer: C

Rationale: The sweat chloride test is the primary diagnostic test for cystic fibrosis. Cystic fibrosis is characterized by abnormal transport of chloride and sodium across epithelial cell membranes, leading to increased chloride in sweat. This test is crucial for diagnosing cystic fibrosis in suspected cases. Liver enzymes (Choice A), serum calcium (Choice B), and urine creatinine (Choice D) are not specific tests for cystic fibrosis and would not provide the necessary information for diagnosis in this case.

2. What is the best indicator of fluid balance in a pediatric patient?

A. Blood pressure
B. Heart rate
C. Weight
D. Urine output

Correct answer: C

Rationale: Weight is the most accurate indicator of fluid balance in pediatric patients. Changes in weight reflect shifts in body fluid levels more directly compared to other parameters. Blood pressure and heart rate may be affected by various factors other than fluid balance. While urine output is important in assessing renal function, it may not provide a comprehensive picture of overall fluid balance in pediatric patients.

3. Why are neonates predisposed to problems with thermoregulation?

A. Renal function is not fully developed
B. Flexed posture favors heat loss
C. A large body surface area favors heat loss to the environment
D. A thick layer of subcutaneous fat provides excellent insulation

Correct answer: C

Rationale: Newborns have a large surface area relative to their body weight, making them more susceptible to heat loss and requiring careful thermoregulation. Choice A is incorrect because renal function is not directly related to thermoregulation. Choice B is incorrect because a flexed posture actually helps reduce heat loss by minimizing the surface area exposed to the environment. Choice D is incorrect because neonates have limited subcutaneous fat, which contributes to their susceptibility to heat loss.

4. Which congenital heart defect causes a "boot-shaped" heart on a chest x-ray?

A. Tetralogy of Fallot
B. Coarctation of the aorta
C. Transposition of the great arteries
D. Ventricular septal defect

Correct answer: A

Rationale: The correct answer is A: Tetralogy of Fallot. Tetralogy of Fallot, a congenital heart defect with four distinct abnormalities, often presents with a "boot-shaped" heart on chest x-ray due to right ventricular hypertrophy. This characteristic finding is due to the specific combination of defects in this condition. Coarctation of the aorta (choice B), Transposition of the great arteries (choice C), and Ventricular septal defect (choice D) do not typically result in a "boot-shaped" heart on a chest x-ray like Tetralogy of Fallot does.