Neonatal & Newborn Flashcards
(37 cards)
What is the average birth weight?
3.5kg
What is the minimum birth weight before it is classified as low?
2.5kg
When is the neonatal period?
The first 4 weeks (28 days) after birth
The APGAR score is carried out as soon as the baby is born.
What does this consist of?
Appearance –> pink, blue extremeties, or completely pink/blue
Pulse –> >100, <100, no response
Grimace –> cries, pulls away, weak cry, no response
Activity
Respiratory effort
How does a baby’s weight change in the first 5 days?
Babies lose up to 10% their birthweight in first 5 days due to fluid depletion
What is lanugo?
Soft, fine hair covering a fetus while inside the uterus.
Give some physical characteristics seen in neonates
● Lanugo
● Umbilical cord will shrivel/fall off within 3 weeks
● Neonatal acne – resolves within 4 months, clean daily
● Milia – resolves within first few weeks
● Erythema toxicum – resolves within a week
What is milia?
Milia is a common skin condition that causes small white bumps (cysts) under the surface of your skin.
When shouold neonates first pass urine?
Within 12-24 hours
In the first few days after birth, you may see orange, pinkish, or chalky urine in a baby’s nappy.
What is this?
Precipitated uric acid crystals (not blood) - this is normal
How may a newborn’s genitalia be affected? What is this the result of?
● Maternal hormones can cause large scrotum/breasts or discharge from vagina/breasts
● Settles on its own
What is meconium?
Meconium is a newborn’s first poo, within 24-48 hours
What may no meconium indicate?
Obstruction - check anus is open
What is surface tension?
Surface tension is the attraction of the molecules in a liquid to each other, pulling them together and minimising surface area.
This is why, in zero gravity, water floats around in a ball rather than diffusing into a mist.
What are the alveoli?
Alveoli are the small sacs where gas collects and diffuses into the blood during inhalation. These are lined with fluid.
The molecules of this fluid pull together due to surface tension, in turn pulling the walls of the alveoli towards each-other, attempting to collapse the space in the alveoli.
What is surfactant?
Surfactant is a fluid produced by type II alveolar cells. It contains proteins and fats.
It sits on top of the water in the lungs. It has a hydrophilic side, that faces the water, and a hydrophobic side, that faces the air.
Purpose of surfactant?
1) Increases lung compliance:
- reduces the surface tension of the fluid in the lungs
- this keeps the alveoli inflated and maximises the surface area of the alveoli.
- this reduces the force needed to expand the alveoli and therefore the lungs during inspiration (compliance)
2) Surfactant promotes EQUAL expansion of all alveoli during inspiration.
What is surfactant produced by?
Type II alveolar cells.
When do Type II alveolar cells become mature enough to start producing surfactant?
Between 24-34 weeks gestation.
Therefore, pre-term babies have problems associated with reduced pulmonary surfactant.
What causes closure of foramen ovale at birth?
1) baby takes first breaths and expands the alveoli
2) this decreases the pulmonary vascular resistance
3) the decrease in pulmonary vascular resistance causes a fall in pressure in the right atrium
4) at this point the left atrial pressure is greater than the right atrial pressure, which squashes the atrial septum and causes functional closure of the foramen ovale
What does the foramen ovale become after birth?
Fossa ovalis
What causes the closure of the ductus arteriosus at birth?
Increased blood oxygenation causes a drop in circulating prostaglandins.
What does the ductus arteriosus become after birth?
Ligamentum arteriosum
What does the ductus venosus become after birth?
Ligamentum venosum
