1. Transition, Circulation & Respiratory Changes

what is the neonatal period?

the first 28 days of life

• first 60 mins = golden hour

which four functions must the newborn establish after birth? *

• pulmonary gas exchange

• systemic perfusion

• glucose regulation

• thermoregulation

why can a problem with one newborn transition affect the others? *

respiratory distress, hypothermia, hypoglycemia, and circulatory problems can worsen one another

how does vascular resistance change after birth?

first breaths decrease pulmonary resistance, and cord clamping increases systemic resistance

what is the foramen ovale?

an opening between the atria

• allows fetal blood to bypass the lungs

what causes the foramen ovale to close?

increased left atrial pressure after the newborn begins breathing

what is the ductus arteriosus?

a connection between the pulmonary artery and aorta that bypasses the fetal lungs

what is the ductus venosus?

a shunt carrying blood from the umbilical vein toward the inferior vena cava, bypassing the liver

how many vessels should the umbilical cord contain? *

2 arteries and 1 vein

• an abnormal vessel count can indicate associated anomalies

when does the foramen ovale close? *

within minutes after birth

when does the ductus arteriosus close? *

10–15 hours after birth

which medication promotes closure of a patent ductus arteriosus? *

indomethacin

• inhibits prostaglandins

when does the ductus venosus close? *

• functional closure within minutes after birth

• structural closure in 3–7 days

where is preductal oxygen saturation measured? *

right hand

where is postductal oxygen saturation measured? *

left hand, either foot

how long is cord clamping delayed in a vigorous newborn? *

30–60 seconds after birth

what are the benefits of delayed cord clamping? *

• increased blood volume and hemoglobin

• improved iron stores

• helps transition to life outside womb

why are newborns at higher risk for jaundice?

newborn RBCs live 80–100 days, so faster breakdown produces more bilirubin

why may a newborn delivered by cesarean retain more lung fluid?

the newborn misses the thoracic squeeze that helps expel fluid during vaginal birth

what does surfactant do? *

reduces alveolar surface tension and prevents atelectasis

when does fetal surfactant production begin? *

around 26 weeks

• lungs reach maturity around 35 weeks

normal respiratory rate for a newborn *

30–60 breaths/min

• respirations are irregular, so count for one full minute at rest

what is periodic breathing in a newborn?

brief pauses up to 10 seconds without cyanosis or bradycardia

• normal for the first few days

what breathing pause indicates newborn apnea? *

at least 20 seconds of no breathing, or a shorter pause with cyanosis or bradycardia

• medical emergency !!!

what is acrocyanosis?

blue hands and feet, expected in newborns

what is central cyanosis?

blue face, oral mucosa, or trunk

• abnormal, indicating oxygenation issues

what findings indicate newborn respiratory distress?

• tachypnea

• retractions

• nasal flaring

• expiratory grunting

• central cyanosis