Neonatal Intensive Care Nurse Exam Neonatal Thermoregulation and Fluid Balance 1 — Questions and Answers
Question 1: A preterm infant in an open radiant warmer has excessive insensible water losses primarily due to:
- Thin, immature skin with high transepidermal water loss (Correct answer)
- Increased urine output
- High metabolic rate causing sweating
- Excessive respiratory water loss only
Correct answer: Thin, immature skin with high transepidermal water loss
Preterm infants have thin, poorly keratinized skin with minimal subcutaneous fat, causing dramatically elevated transepidermal water loss.
Question 2: The thermoneutral zone for a neonate is defined as:
- The environmental temperature range in which metabolic rate is minimal and body temperature is normal (Correct answer)
- The core temperature range considered safe for neonates
- The incubator temperature for all neonates
- The temperature at which neonates begin shivering
Correct answer: The environmental temperature range in which metabolic rate is minimal and body temperature is normal
The thermoneutral zone minimizes metabolic oxygen consumption while maintaining normal body temperature through minimal thermogenesis.
Question 3: Brown adipose tissue (BAT) in neonates is used for:
- Non-shivering thermogenesis to generate heat (Correct answer)
- Energy storage only
- Immune function
- Shivering-based heat production
Correct answer: Non-shivering thermogenesis to generate heat
Neonates cannot shiver effectively; they rely on BAT metabolism (non-shivering thermogenesis) mediated by norepinephrine to generate heat.
Question 4: Which sign indicates hypothermia in a neonate?
- Peripheral vasoconstriction, lethargy, poor feeding, and acrocyanosis (Correct answer)
- Fever, tachycardia, and diaphoresis
- Hyperthermia with bulging fontanelle
- Bradypnea with flushed appearance
Correct answer: Peripheral vasoconstriction, lethargy, poor feeding, and acrocyanosis
Cold stress causes peripheral vasoconstriction to conserve heat; neonates respond with lethargy, poor feeding, and acrocyanosis.
Question 5: The normal urine output for a neonate after the first 24 hours of life is:
- 1–3 mL/kg/hour (Correct answer)
- 0.1–0.5 mL/kg/hour
- 5–8 mL/kg/hour
- 0.5 mL/kg/day
Correct answer: 1–3 mL/kg/hour
Normal neonatal urine output of 1–3 mL/kg/hour reflects adequate hydration and renal perfusion after initial physiologic oliguria.
Question 6: Which electrolyte imbalance is most common in preterm neonates in the first week of life due to immature renal tubular function?
- Hyponatremia (Correct answer)
- Hypercalcemia
- Hyperphosphatemia
- Hypermagnesemia
Correct answer: Hyponatremia
Preterm neonates lose excess sodium in urine due to immature renal tubular sodium reabsorption, causing late hyponatremia.
Neonatal Intensive Care Nurse Exam Neonatal Thermoregulation and Fluid Balance 1
A preterm infant in an open radiant warmer has excessive insensible water losses primarily due to: