Which of the following is an early sign of respiratory distress in an infant?

Step 1 is: Calculate the total daily fluid requirement using the Holliday-Segar formula. The child weighs 32.7 kg. For the first 10 kg: 10 kg× 100 mL/kg = 1000 mL. For the next 10 kg (from 10.1 kg to 20 kg): 10 kg× 50 mL/kg = 500 mL. For the remaining weight: 32.7 kg - 20 kg = 12.7 kg. Remaining weight fluid: 12.7 kg× 20 mL/kg = 254 mL. Total daily fluid requirement: 1000 mL + 500 mL + 254 mL = 1754 mL.

Step 2 is: Calculate the infusion rate in milliliters per hour (mL/hr). Rate = Total fluid÷Total hours. Rate = 1754 mL÷ 24 hr = 73.0833… mL/hr.

Step 3 is: Round the answer to the nearest tenth. 73.1 mL/hr. The infusion rate is 73.1 mL/hr.

Choice A rationale

Nasal flaring is a cardinal early sign of respiratory distress in infants and children, representing an involuntary attempt to decrease airway resistance. Flaring the nares widens the upper airway opening, allowing a greater volume of air to pass and maximizing gas exchange efficiency during inspiration.

Choice B rationale

Central cyanosis (bluish discoloration of the mucous membranes and torso) signifies inadequate oxygenation and is a late and ominous sign of severe hypoxemia. It indicates a substantial 5 g/dL or greater increase in deoxygenated hemoglobin, signaling decompensated respiratory failure.

Choice C rationale

Bradycardia (abnormally slow heart rate) in an infant is a late and critical sign of severe hypoxia and impending cardiorespiratory arrest. The heart slows as a compensatory response to profound oxygen deficit, indicating a failure of the body to maintain adequate oxygen delivery.

Choice D rationale

Hypotension (abnormally low blood pressure) is a very late and decompensated sign of shock, often due to severe prolonged hypoxemia and acidosis. The body's initial response to respiratory distress is typically to maintain or increase blood pressure, so a drop indicates circulatory collapse.