Exam 2 Study Guide
Chapter 17
Cardiovascular System Changes:
KNOW REFLEXES AND WHEN
THEY GO AWAY SPINA BIFIDA (2
DIMPLES?)
GALLANT REFLEX
SKIN TO SKIN BENEFITS
DEHYDRATED BABY= SUNCK IN
FONTANELS ACROCYANOSIS
WHEN FEET ARE MORE BLUE THAN
HANDS BABY IS COLD HEART RATE: 120-
160
SLEEPING BABY: HEART RATE COULD DROP AS LOW AS 100
SKIN TAGS ARE NORMAL BUT SHOULD PROMPT
FURTHER INVESIGATION BILIRUBIN: TRAUMA,
BLOOD COMPENTS, CONJUGATION
IGA, IGG, IGM
SKIN: FIRST LINE OF DEFENSE, TEMPERATURE,
PREVENTS DEHYDRATION BLACK WOMEN CAN
HAVE WHITE BABIES
108 KCAL DAY OPTIMAL DIET FOR NEWBORN
-The umbilical vein carries oxygenated blood from the placenta to the fetus
-The ductus venous allows for the majority of the blood to bypass the liver and merge with blood
moving through the vena cava bringing it to the heart sooner. The foramen ovale allows the blood
from the right atrium to move to the left atrium which bypasses the pulmonary circulation
(lungs).
-The ductus arterioles connects the pulmonary artery to the aorta which also skips the
pulmonary circuit (lungs) -Only a small amount of blood goes to the lungs for perfusion
purposes
-At birth the newborn circulation and placental oxygen exchange must switch to pulmonary gas
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exchange (lungs)
-The changes must include increased pulmonary blood flow, removal of the placenta, closure of
the foramen ovale (the opening between the right and left atrium) and closure of the venous
ductus and ductus arterioles
-The stresses of birth release catecholamine’s that are critical for the transition into extrauterine
life.
- The increased levels of epi and norepi stimulate increased cardiac output and contractility;
stimulate surfactant release (needed for oxygen and gas exchange) and promotion of lung fluid
clearance
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Fetal to neonatal Circulation Changes:
-Circulation changes as soon as the fetus separates from the placenta
-When the cord is clamped is when the first breath is taken and lungs begin to function
-Systemic vascular resistance increases and blood return via inferior vena
cava decreases -Decrease in pulmonary vascular resistance and increase in
pulmonary blood flow
-Foreman ovale closes with a decrease in pulmonary vascular resistance decreasing right sided
heart pressures. It closes when left atrial pressure increases and right atrium pressure decreases.
Normally functionally closes at birth and permantantly closes in several weeks.
-The ductus arterioles and venous ductus are no longer needed and turn into ligaments over time.
-With closure of the foramen ovale oxygenated blood and deoxygenated blood now become
separated
-During fetal life the ductus arterioles protected the lungs from circulatory overload by shunting
blood right to left into the descending aorta to the rest of the body
-Patency of the ductus arterioles is protected by prostaglandins E2 during fetal life
-Ductus arterioles functionally close a few hours after birth and its closure depends on
increased oxygenation resulting from aeration of the lungs after birth
-The venous ductus closes within a few days after birth because it’s shunting of blood is no longer
needed with the activation of the liver. The liver now takes over the function of the placenta
-The umbilical vessels (1 vein, 2 arteries) begin to constrict and are no longer needed, also
becoming ligaments (One aretery is associated with renal and GI abnormalities)
Heart Rate:
-During first few minutes after birth the infant’s heart rate is between 110-160 but then decreases
to an average of 120-130.
-The newborn is dependent on the heart rate for maintance of cardiac output and
blood pressure. -BP normally plateaus a week after birth
-Cardiac defects can be determined through a thorough physical assessment of the newborns
cardiovascular system. The nurse should be able to identify any abnormalities because this
could lead to early detection and treatment.
-A transient functional cardiac murmur may be heard during the neonatal period as a result of
cardiovascular changes.
-Fluctuations of heart rate and blood pressure mimic baby’s behavioral state. (If baby is agitated
the heart rate and blood pressure will be elevated)
-Tachycardia may be found as a result of fluid volume loss, cardio respiratory disease, drug
withdrawal and hyperthyroidism.
-Bradycardia is found with apnea and hypoxia
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Blood volume:
-The amount of blood the baby has depends on the amount of blood transferred to the infant from
the placenta at birth.
-Late clamping (after 3 minutes) is better than early clamping (30-40 seconds). Late clamping
improves the infants cardiopulmonary adaption, prevents iron deficient anemia without
increasing risk of hypervolemia, increases blood pressure, improves oxygen transport, and
increases red blood cell flow.
-Cord blood “nature’s first stem cell transplant”
Blood Components:
-Fetus has more red blood cells at birth. They are larger in size and have a greater affinity for
oxygen. After birth the RBC count increases and the RBC decreases in size. This is due the
RBC now living in an environment where there is much more pulmonary oxygenation.
-An infant’s hemoglobin initially declines as a result of a decrease in neonatal red
blood cell mass -Leukocytosis (increased white blood cell count) is present after
birth due to the trauma of birth.
-The newborns platelet aggregation and platelet count are the same as adults
-Blood test results of the newborn re dependent of where the blood is drawn from, capillary
blood has higher levels of hemoglobin and hematocrit compared to venous blood, placental
transfusion (early vs. late cord clamping), gestational age (increased age is associated with
increased RBC and hemoglobin)
NORMAL NEWBORN BLOOD VALUES
Hemoglobin- 16-18
Hematocrit- 46-68%
Platelets- 150,000-
350,000 RBC 4.5-7.0
(1,000,000) WBC 10-
30000
Respiratory System Adaptations:
-Lung aeration leads to the establishment of functional residual capacity allowing for gas
exchange to begin
-The first breath results in the lungs filling increasing pulmonary pressure which pushes the
diaphragm down
-While the mom is in labor she is breathing rapidly (hypercapnia), hypoxic, and acidodic, all of
these help initiate the baby to breath