Thermoregulation Flashcards
What are the four routes of heat loss?
Convection
Conduction
Radiation
Evaporation
What is convection?
Flow of heat from the skin to surrounding air around the body
What is conduction?
When cold objects come into contact with the skin
What is radiation?
Loss of heat to colder objects not in direct contact
What is evaporation?
When liquid converts or vapour
Why do neonates lose heat?
Large SA:Vol ratio (3x per kg than adults)
Lost heat at a rate 4x quicker then adults
Less subcutaneous fat than adults
They cannot shiver
They cannot move away from draught
No sphincter or bladder control
The heat regulating centre the hypothalamus attempts to adapt the extra uterine environment
How do neonates generate heat?
Non shivering thermogenesis
They utilise brown fat and increase their metabolic rate by increasing glucose and oxygen consumption (aerobic glycolysis)
Anaerobic glycolysis occurs with an absence of oxygen but takes 20x more energy to generate the same amount of heat.
Babies will become hypoxic.
What is the temperature rang?
Hypothermia- 35.5
Optimal core- 37
Optimal shell- 36.5
Hyperthermia- 37.6
Outline the role of the midwife in preventing heat loss
Delivery room approx 25 so the neonate is born in a neutral thermal environment (NICE) Ensure no open windows or draughts Plentiful warm and dry delivery towels Wooly hat ready Resuscitare on with heater Immediate skin to skin encouraged Thermometer ready Clothes for baby or well wrapped on transfer to ward
Outline the role of the midwife to prevent over heating
Room temp of 18-20
Neonates sweat glands blocked by vernix so cannot lose excess heat
No hats in house after 24 hours
Advise not to over wrap or swaddle especially while baby is sleeping
Single layer sheets in crib, not fleece. Should be cotton or breathable wool
Adapt advise based on time of year
Prevents SIDS
Outline role of midwife with documentation
Document temp at birth and one hour after
Document skin to skin commencement and end
Document SIDS discussed
Outline the hypoxic hypothermia cycle
Hypothermia causes increase thermogenesis and metabolism. This leads to hypoxia. Also causes hypoglycaemia which leads to a decrease in resps and blood is withdrawn for vital organs also causing hypoxia.
