RNC-NIC Thermoregulation 3 — Questions and Answers
Question 1: Which of the following metabolic consequences is most directly associated with prolonged cold stress in a preterm neonate?
- Hyperglycemia due to increased glycogen breakdown
- Hypoglycemia due to rapid depletion of glucose stores (Correct answer)
- Metabolic alkalosis from increased respiratory rate
- Hypernatremia from increased insensible water loss
Correct answer: Hypoglycemia due to rapid depletion of glucose stores
Non-shivering thermogenesis rapidly consumes glucose, depleting limited glycogen stores and leading to hypoglycemia in cold-stressed neonates.
Question 2: A nurse is preparing to transport a 30-week neonate from the NICU to radiology. Which intervention is MOST important to prevent heat loss during transport?
- Pre-warming the transport incubator before transferring the infant (Correct answer)
- Applying a hat only, as the head accounts for most heat loss
- Setting the transport incubator to the same temperature as the NICU incubator
- Wrapping the infant in a single blanket over the diaper
Correct answer: Pre-warming the transport incubator before transferring the infant
Pre-warming the transport incubator creates a warm microenvironment before the infant is placed inside, preventing conductive and convective heat loss during transfer.
Question 3: When assessing a neonate for hyperthermia, which finding would MOST help distinguish environmental hyperthermia from infectious fever?
- Heart rate above 160 bpm
- Skin that is warm and flushed with no signs of distress (Correct answer)
- Elevated C-reactive protein level
- Axillary temperature greater than 38°C
Correct answer: Skin that is warm and flushed with no signs of distress
Environmental hyperthermia typically presents with warm, flushed skin and a comfortable-appearing infant, whereas infectious fever is usually accompanied by signs of illness and distress.
Question 4: A preterm infant is receiving care under an open radiant warmer. The nurse identifies that radiant heat loss is occurring from the infant to the cool incubator walls nearby. What type of heat loss is described?
- Conduction
- Convection
- Radiation (Correct answer)
- Evaporation
Correct answer: Radiation
Radiation is the transfer of heat from a warm body to cooler surfaces in the environment without direct contact, such as from the infant to cool walls or windows.
Question 5: The neutral thermal environment (NTE) for a neonate is best defined as:
- The temperature at which the infant's core temperature is 37.0°C
- The environmental temperature range at which oxygen consumption is minimal for normal core temperature maintenance (Correct answer)
- The incubator temperature that prevents all four mechanisms of heat loss
- The room temperature at which a term neonate does not require a hat or blanket
Correct answer: The environmental temperature range at which oxygen consumption is minimal for normal core temperature maintenance
The NTE is the environmental temperature range at which metabolic rate and oxygen consumption are lowest while the infant maintains a normal core temperature.
Question 6: A 26-week infant has skin integrity concerns. Which temperature monitoring method is contraindicated?
- Continuous axillary thermistor probe
- Rectal thermometer for intermittent monitoring (Correct answer)
- Servo-control abdominal skin probe
- Continuous axillary temperature via incubator skin probe
Correct answer: Rectal thermometer for intermittent monitoring
Rectal temperature measurement is contraindicated in extremely preterm infants due to risk of rectal perforation and vagal stimulation.
Question 7: Which of the following correctly describes the anatomical feature that makes preterm neonates more susceptible to heat loss compared to term neonates?
- Greater body surface area to body weight ratio (Correct answer)
- Thicker subcutaneous fat layer in the extremities
- More brown adipose tissue relative to body size
- Higher ratio of body weight to body length
Correct answer: Greater body surface area to body weight ratio
Preterm neonates have a larger surface area relative to body mass, resulting in greater heat exchange with the environment and increased susceptibility to heat loss.
RNC-NIC Thermoregulation 3
Which of the following metabolic consequences is most directly associated with prolonged cold stress in a preterm neonate?