A nurse is caring for a 6-month-old infant who has a prescription for clear liquids by mouth after a repair of an intussusception. Which of the following fluids should the nurse select for the infant?

The correct answer is: b.

Choice A: Heart rate 130/min

A heart rate of 130 beats per minute (bpm) is considered high for a 3-year-old child. Normal heart rates for children aged 1-3 years typically range from 80 to 120 bpm. While dehydration can cause tachycardia (increased heart rate), a heart rate of 130 bpm does not necessarily indicate effective rehydration.

Choice B: Urine specific gravity 1.015

Urine specific gravity of 1.015 is within the normal range (1.005–1.030) for a hydrated child. Dehydration increases urine concentration (>1.020), but a normalized value like 1.015 shows that ORT has restored fluid balance. UpToDate and NIH studies (e.g., Binder et al., 2014) highlight urine specific gravity as a precise measure of hydration status, making it the strongest indicator of ORT effectiveness.

Choice C: Respiratory rate 24/min

The normal respiratory rate for a 3-year-old child is between 20 and 30 breaths per minute. A respiratory rate of 24 breaths per minute is within this normal range. While a normal respiratory rate can indicate improved hydration status, it is not the most specific indicator of effective rehydration therapy.

Choice D: Capillary refill less than 3 seconds

Capillary refill time of less than 3 seconds suggests adequate perfusion, as normal is under 2 seconds. Dehydration may prolong this time, but “less than 3 seconds” could include slightly delayed values (e.g., 2.5 seconds). UpToDate and NIH studies (e.g., Doan et al., 2010) note it as useful but less specific than urine specific gravity for confirming ORT effectiveness.

Choice A reason: Nephritic syndrome is a kidney disorder that causes inflammation and damage to the glomeruli, the filtering units of the kidneys. It can cause hematuria (blood in the urine), proteinuria (protein in the urine), hypertension (high blood pressure), and edema (swelling). However, it does not cause a palpable abdominal mass, which is a characteristic sign of Wilms tumor.

Choice B reason: Wilms tumor is a malignant tumor of the kidney that occurs mainly in children under 5 years of age. It can cause a large, firm, and painless abdominal mass, hematuria, abdominal pain, fever, and hypertension. It is the most common renal tumor in children and requires prompt diagnosis and treatment.

Choice C reason: Pyloric stenosis is a condition that causes narrowing of the pylorus, the outlet of the stomach. It can cause projectile vomiting, dehydration, weight loss, and a palpable olive-shaped mass in the upper abdomen. However, it does not cause hematuria or a large abdominal mass.

Choice D reason: Intussusception is a condition that occurs when a part of the intestine slides into another part, causing a blockage. It can cause abdominal pain, vomiting, bloody stools, and a sausage-shaped mass in the abdomen. However, it does not cause hematuria or a large abdominal mass.