Download Cardiorespiratory Changes After Birth

Cardiorespiratory Changes
After Birth
Dr. Harold Helbock
Generic Heart
The Cardiac Tube
The Adult Heart
Cardiac Outflow Anomalies
Abnormal conditions compatible with fetal life
are often
Incompatible, or incapacitating to some degree,
with postnatal life, including the adult.
Chief among the hazards induced by cardiac
anomalies is the distribution of inadequately
oxygenated blood to the body.
Examples of Cardiac
Anomalies
•
•
•
•
Tetralogy of Fallot
Stenosis of
pulmonary artery
Displacement of
aortic opening to the
right.
Intraventricular
opening
Hypertrophy of right
ventricle.
Examples of Cardiac
Anomalies
Patent Ductus Arteriosus
• Blood regurgitates
from the aorta to the
pulmonary artery and
is taken back to the
lungs.
Heart Rate in Labor
Characteristics of the Adult
Pulmonary Respiratory System
Functions of the Lungs
• Gas Exchange
Oxygen absorption
Carbon Dioxide removal
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Immunologic Defense
Metabolic Function
Endocrine Function
Peptide Activators
Pulmonary capillary
Transition Period from Prenatal
To Postnatal Life
• The newborn must switch rapidly from
intrauterine mechanisms to adult
physiology.
• This process is referred to as transition
and involves changes in both pulmonary
and circulatory physiology.
closed
expand
Normal
Transition
of Circulation
from Pre- to
Post- natal
closed
open
Differences in oxygenation
system of the fetus to the
newborn
Bronchi/airways
uterine artery
Air sacks/alveoli
placental sinusoids
Pulmonary vein
umbilical vein
Oxygenated blood to the heart
Pulmonary artery
umbilical artery
Venous blood to gas exchange organ
Diaphragm
maternal myocardium
Move the gas to be exchanged
Events Happening at Birth
• First breath
30-100 mm Hg vs. 5-10 mm Hg for
normal breathing
• Closure of ductus arteriosus
Functional and later anatomic
closure
Initially systemic and pulmonary
pressures are equal
• Removal of fluid from the lungs
Chloride
Protein molecules
Major steps described
in next slide
Removal of Lung Fluid at Birth
1.
2.
3.
4.
5.
6.
7.
Fetus = Cl- pumps move fluid into potential air space.
Very little protein in potential air space liquid.
Result = osmotic pressure draws liquid from the
alveolar space to the interstitium = circulation.
Newborn = Cl- pumping stops and Na+ pump moves
fluid out of alveoli.
Air pressure in the alveoli drives liquid out and into
interstitium.
Expansion of the lung stretches open the pulmonary
vessels and thereby reducing pulmonary vessel
pressure and hydrostatic pressure.
Net result = liquid leaves air spaces and exits the
interstitial space via the lymph and microcirculation.
The Apgar Score
Assessment of transition
Score
0
1
2
Heart rate
Absent
Less than 100/min
More than 100/min
Respiratory effort
Absent
Slow, irregular
Good, crying
Muscle tone
Limp
Some flexion of
extremities
Active motion
Reflex irritability
Absent
Grimace
Grimace and cough or
sneeze
Color
Blue, pale
Body pink/extremities
blue (acrocyanosis)
Completely pink
The
First
Hours of
Life
The First Week of Life
• The infant is given vitamin K.
– Eye drops are instilled to prevent blindness from
bacterial infection.
– Hepatitis B (a major cause of hepatic cancer)
immunization.
• Feedings
– Infant slowly increased volume of milk taken at each
feeding until intake is about 1 fluid oz. per hour, on
average.
– Parents get a little more sleep, but not much!!  
The First Week of Life
• Jaundice is a common problem on days 2-4 and
longer if blood group incompatibilities exist.
– Principle: post birth adaptation must take place in
multiple systems, not just lungs and heart
• A good baby is a sick baby!
• BW ~ IQ and 1/CV disease risk, mom’s diet