Download Adjustments to Extrauterine Life

Adjustments to Extrauterine
Life
By : Mohammad Abuadas RN,
MSN
What after birth???
• The most important physiologic change
required of the neonate is the transition
from fetal or placental circulation to
independent respiration out of the uterus.
• “Fetal Asphyxia” is considered to be the
most fatal abnormal stressor after labor .
Immediate adjustments after birth
• Respiratory system:
Chemical factors in the blood (low pH , high
CO2), which stimulate the presence of
impulses that excite the respiratory center
in the medulla .
The production of the “surfactant” by the
alveoli epithelium that facilitate breathing .
The circulatory system:
The changes in the circulatory system
occurs gradually due to the pressure in
the lungs, heart and vessels.
The closure of the fetal shunts which are :
foramen ovale, ducus arteriosus, and the
ductus venosus.
Thermoregulation :
“”HEAT LOSS”” is the most critical event in
the thermoregulation process, the factors
behind that heat loss are :
1- the newborn’s large surface area
facilitates heat loss to the environment by
Convection , conduction, radiation , and
evaporation .
Thermoregulation
2- the newborn’s thin layer of subcutaneous
fat provides poor insulation for conservation of
heat.
3- the newborn’s nonshivering thermogenesis.
“” brown adipose tissue or brown fat, from
mitochondria is the main heat producer in
the newborn infant.
The hemopoietic system
• The fetal blood volume depends on the
amount of blood transferred from placenta.
• The blood of the full term infant is about 80
to 85 ml/kg of body weight.
• After birth , the blood volume averages
300 cc. added to 100 from placental
circulation.
Fluid and electrolyte balance
• At birth , the total weight of the infant is
73% fluids, as compared with 58% in the
adult.
• The infant rate of metabolism is twice
greater than that in adults, leading to
acidosis.
Gastrointestinal system
• Digestion of only monosaccharide (simple
carbohydrates ) in the early stages .
• The immature liver causes conjugation of
billirubin , causes physiologic jaundice.
• Salivary gland don’t function till 2 to 3 months
of age, when drooling become frequent.
• Infant’s stomach capacity is about 90cc.
• Infant’s intestine is longer than adult’s in
relation to their sizes.
Integumentary system
• At birth, all skin structures are present but
found immature .
• The “sebaceous glands” are very active late
in fetal life and early infancy related to the
androgens , they are present in the face, scalp,
and genitalia producing greasy “vernix
caseosa” that covers the infant at birth.
• The eccrine (sweat) glands are functiong.
• The apocrine gland remain immature till
puberty.
• The newborn colors are lighter at birth
because melanin is low at birth.