Perinatal adaptions Flashcards
What is the function of the placenta?
Fetal homeostasis Gas change Nutrient and IgG transports Waste product removal Maintains acid base balance Produces hormones
What three shunts can be found within foetal circulation?
Foramen ovale
Ductus arteriosus
Ductus Venosus
What is the function of the foramen oval?
Allows oxygenated blood from the IVC to pass through the right atria into the lef.
What is the ductus arteriosus?
A shunt allowing blood from the pulmonary arteries to pass into the arch of the aorta
What is the ductus venosus?
A direct shunt between the umbilical vein and the IVC
What happens to the ductus venosus?
Becomes the ligamentum terres when it closes
What happens to the ductus arteriosus?
Closes and becomes the ligamentum arteriosus
What happens to the foramen ovale and why does this happen?
Closes as systemic pressure becomes higher than pulmonary.
What circulatory changes occur when the first breath occurs?
Pulmonary vascular resistance drops while systemic rises
Oxygen tension increases and PDE4 levels drop
What is PDE4 ?
The prostaglandin responsible for maintaining a patent ductus arteriosus
What can be administered to close the ductus arteriosus?
Indomethican or ibuprofen (NSAIDS)
What does the foetus do to prepare for birth?
Synthesis of surfactant and reduce the production of lung fluid.
Production of brown and subcutaneous fat
Swallos amniotic fluid
Where is brown fat located?
In between the scapulae and surrounding internal organs
What during labour occurs to the baby?
Increased maternal and foetal catelchoamines and cortisol
Vaginal delivery squeezes the lungs
What is PPHN?
Persistant Pulmonary Hypertension of the Newborn
What happens as a result of PPHN?
Foramen ovale and ductus arteriosus remain patent, as a result the pO2 of the systemic blood is low.
What clinical sign for PPHN can be discovered using an oxygen saturation monitor?
The right hand will have a higher O2 sat than the left arm or leg.
What is the treatment for PPHN?
Nitric oxide Ventilation Oxygen Sedation Inotropes ECLS
What is ECLS
Extracorpeal Membrane oxygenation
What does NO do in PPN?
Acts on the bronchial smooth muscles causing relaxation and reducing the pulmonary vascular resistance.
Why do babies struggle to self thermoregulate?
They are unable to shiver Have a large SA:VOL ratio Loose heat through Cond Conv Radia Evap Very little subcutaneous fat Little to no hair
How do babies regulate their body temperature?
Brown fat stores undergo lipolysis which produces heat, however this is ineffective during the first day
What is the dangers associated with hypothermia?
It predisposes to many other issues
What is the ideal body temperature for a baby?
36.5 degress
What steps should be taken to keep a baby warm?
Hat, dry, skin to skin, blanket , warm mattress , incubator
Why are babies at risk of hypoglycaemia ?
They have been use to a constant infusion of glucose via the placenta now they are on bolus loads via milk.
How are babies able to regulate glucose?
Very little glucose within the milk, low insulin levels an higher glucagon levels.
Metabolic liver glycogen stores and use ketones for the brain.
What are the three common causes of hypoglycaemia in a baby?
Increased energy demand- Infection or hypothermia
Low glycogen stores - Small or preterm
Inappropriate insulin levels - gestational or maternal diabetes
What hormones leas to milk ejection?
Oxytocin
What hormone leads to increased milk production?
Prolactin
Where does haematopoeisis move to once born?
From the liver to the bone marrow
