Thermoregulation

Question 1

What are the 4 main routes of heat loss?

Answer 1

• Radiation -> loss of heat to colder objects not in direct contact
• Conduction -> when cold objects come into contact with skin
• Convection -> the flow of heat from the skin to cooler surrounding air circulating around the body
• Evaporation -> when liquid converts to vapour

Question 2

Why do neonates lose heat?

Answer 2

• less subcutaneous fat than adults
• large SA: volume ratio (3x per kg than adults)
• lose heat 4 x rate of adults
• they cannot shiver or move away from droughts
• no sphincter or bladder control
• the heat regulating centre (hypothalamus) in the medulla oblongata I attempting to adapt to a cooler extrauterine environment

Question 3

How do neonates generate heat?

Answer 3

• non-shivering thermogenesis
  
  • -> they utilise brown fat and increase their metabolic rate by increasing glucose and oxygen consumption
  • -> this is called aerobic glycolysis
• anaerobic glycolysis is when the same process occurs with a decrease/absence of oxygen
  
  • -> however, it requires 20x more energy to generate the same amount of heat
  • -> babies that undergo anaerobic glycolysis can become hypoxic

Question 4

What is the role of the midwife in preventing heat loss?

Answer 4

• delivery room approx 25 degrees to that the neonate is born into a thermo neutral environment
• ensure no open windows or draughts
• ensure plentiful warm dry towels ready for delivery
• woolly hat ready
• resuscitaire heater on
• immediate skin to skin encouraged
• thermometer ready
• clothes for discharge or transfer to ward

Question 5

What is the role of the midwife in preventing overheating?

Answer 5

• room temp of 18-20 degrees
• neonates sweat glands are blocked by vernix, cannot lose excess heat
• no hats in the hours after 24 hours
• advise to not overwrap or swaddle
• advise single layer sheets in cots, not fleece, cotton or wool
• adapt advice on time of year and temp outside
• prevent SIDS