Newborn Adaptations Lecture 3

Explain how a newborn initiates breathing through: chemical factors, mechanical factors, thermal factors, and sensory factors.

Chemical: The infant is hypoxic during birth from contractions and squeezing. This stimulates the chemoreceptors in the carotid artery and aorta to get ready to breathe.

Mechanical: Intrathoracic pressure changes. Lungs are squished in birth. When the baby comes out, it is not squished and the lungs expand. This prompts the flow of air.

Thermal: new temp stimulates newborn

Sensory: New touch, sounds and smells awaken the baby.

What does surfactant in the baby’s lungs do.

it lowers the surface tension of the alveoli ensuring they stay open and don’t stick.

What are 4 signs of respiratory distress?

Nasal flaring

Retractions

Grunting

Acrocyanosis

What is the normal HR of a newborn?

110-160 BPM

What happens to cardiovascular system when cord is clamped? (1)

3 shunts in the heart close and heart pumps blood to the lungs for oxygen.

Explain convection, evaporation, ratiation and conduction of a newborn.

Convection: heat loss into the air.

Evaporation: heat loss through evaporating fluids

Radiation: heat loss to something cold nearby

Conduction: heat loss directly to a cold object.

Risk factors for newborn hypothermia:

low fat

high surface area

limited ability to shiver

What role does brown adipose tissue play in thermoregulation

Newborns burn this readily available fat for heat instead of shivering to generate heat.

How to prevent newborn hypothermia: (4)

dry the baby

skin to skin

swaddling

monitoring temp closely (first 20 minutes of life)

Infants are born with excess fluid which they lose 3-5 days after birth. What percent of their weight do they lose?

5-7%

Within what time frame should an infant void after birth?

24 hours. Most void by 30 hours.

What does not voiding for the first 48 hours of life indicate?

renal impairment

How many diapers should an infant produce the first 1-2 days of life and how many thereafter.

1-2 days: 2-6 diapers

thereafter: 6-8.

What are uric acid crystals and how long are they normal for?

normal crystals in diaper for first week. After a week, it is a sign of dehydration.

What is the stomach capacity for a newborn after birth and after day 3?

after birth: 15-30 mL

day 3: 90 mL

Classic symptom of pyloric stenosis

Projectile vomiting, caused by narrow pyloris

What is meconium?

Watery, green/black baby poop within first 48 hours of life.

Are babies born with a lot of iron or not enough?

They are born with a lot and have stores until 6 months of age.

What is the normal glucose for directly after birth and slightly later? What is concerning?

Directly after: 30-90

Later 50-60. 45 is concerning and hypoglycemic

How many full term and preterm babies have jaundice? How long does it take to appear and when dies it peak?

Full term: 60%

Preterm 80%

Peak: 3-5 days and longer for preterm

what is jaundice and what makes its presence pathologic instead of physiologic(normal)

Jaundice is excess bilirubin making the skin and eyes yellow. It is pathologic if it occurs before 24 hours of life or levels increase by more than 6 mg/dl in first 24 hours or if the levels exceed 15 mg/dl at any point.

Why is vitamin K not synthesized by the newborn and why is it important?

A newborn’s intestinal bacteria take 7 days to form. This bacteria is needed to synthesize vitamin K which is important for blood coagulation.

What are babies born with to prevent virus and bacterial infections? Not just vernix caseosa.

IgG (immunoglobulin G)

What are other names for slate grey nevus?

Mongolian spot, cerulean spot.

What is acrocyanosis?

Blue hands or feet

How long should vernix caseosa stay on? What are its benefits?

At least 6 hours after birth. It protects skin from amniotic fluid in sack. It is antimicrobial. Reduces erythema and improves skin hydration.

What is bone ossification?

Cartilage turns into bone

Name 5 newborn reflexes and explain them:

Babinski: Plantar flaring

Grasping

Rooting: head turns to suck

Moro: stunned

Tonic neck: turn head and limbs on that side extend while limbs on other side flex.

How many hours do newborns sleep per day? How long should each period be?

16-18 hours

Periods should be 2.5 to 4 hours at a time.

What are the 3 types of baby sleep?

quiet sleep: deep, little movement

active sleep: similar to REM with movement

Transitional sleep: moves back and forth from other stages.

How many months does it take a circadian rhythm to develop?

2-3 months

Give a small piece of information on a newborns 5 senses: vision, hearing, smell, taste, and touch.

Vision: 8-12 inches is best sight. Prefers white and black due to contrast. Prefers mother.

Hearing: Ensure testing is done by 1 month. If not, it may lead to developmental delay.

Smell: prefer sweet & mom’s smell

Taste: prefer sweet

Touch: differs for each baby