cardiorespiratory changes after birth dr. harold helbock
Post on 21-Dec-2015
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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.
Patent Ductus Arteriosus
• Blood regurgitates from the aorta to the pulmonary artery and is taken back to the lungs.
Examples of Cardiac Anomalies
Functions of the Lungs
• Gas Exchange
Oxygen absorption
Carbon Dioxide removal
• Immunologic Defense• Metabolic Function• Endocrine Function• Peptide Activators
Pulmonary capillary
• 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.
Transition Period from Prenatal To Postnatal Life
Differences in oxygenation system of the fetus to the
newbornBronchi/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 breath30-100 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
Removal of Lung Fluid at Birth1. Fetus = Cl- pumps move fluid into potential air space.
2. Very little protein in potential air space liquid.
3. Result = osmotic pressure draws liquid from the alveolar space to the interstitium = circulation.
4. Newborn = Cl- pumping stops and Na+ pump moves fluid out of alveoli.
5. Air pressure in the alveoli drives liquid out and into interstitium.
6. Expansion of the lung stretches open the pulmonary vessels and thereby reducing pulmonary vessel pressure and hydrostatic pressure.
7. Net result = liquid leaves air spaces and exits the interstitial space via the lymph and microcirculation.
The Apgar ScoreAssessment of transition
Score 0 1 2Heart rate
Respiratory effort
Muscle tone
Reflex irritability
Color
Absent
Absent
Limp
Absent
Blue, pale
Less than 100/min
Slow, irregular
Some flexion of extremities
Grimace
Body pink/extremities blue (acrocyanosis)
More than 100/min
Good, crying
Active motion
Grimace and cough or sneeze
Completely pink
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!!