Newborn Physiologic Adjustments (Cardiovascular System)

Question 1

What causes a functional closure of the foramen ovale?

Answer 1

Increased pulmonary blood flow from the left side of the heart increases pressure in the left atrium.

Question 2

During the first few days of life, what may crying do to the foramen ovale?

Answer 2

May temporarily reverse the flow through the foramen ovale and lead to mild cyanosis.

Question 3

What is an important role for circulating hormone prostaglandin E (PGE2)?

Answer 3

Closure of the ductus arteriosus.

Question 4

When does the closure of the ductus arteriosus occur in term infants?

Answer 4

Functionally class within the first hours after birth; permanent closure usually occurs within 3 to 4 wks.

Question 5

What happens to the ductus arteriosus after permanent closure?

Answer 5

Becomes ligaments

Question 6

Upon auscultation of the chest, ductus arteries can be detected as a…

Answer 6

Heart murmur.

Question 7

What can the ductus arteriosus open in response to?

Answer 7

Low O2 levels in association with hypoxia, asphyxia, or prematurity.

Question 8

Why do the umbilical vein and arteries constrict rapidly within the first 2 minutes after birth?

Answer 8

Exposure of the cord to the cooler extrauterine environment and to increased oxygenation as the infant begins to breathe.

Question 9

What happens to the umbilical arteries, vein and ductus venosus when the cord is clamped or severed?

Answer 9

They are functionally closed and convert to ligaments within 2 to 3 months.

Question 10

What is the normal HR range for a term newborn?

Answer 10

110 to 160 beats/min

Question 11

What is the normal HR range for a sleep term newborn?

Answer 11

85 to 100 beats/min

Question 12

What is the normal HR range for a crying term newborn?

Answer 12

Can increase to 180 beats/min or higher

Question 13

A HR that is either >160 or <100 should be?

Answer 13

Reevaluated within 30 mins to 1 hr or when the activity of the infant changes.

Question 14

When can the HR be palpated using the umbilical cord?

Answer 14

Immediately after birth

Question 15

Where is the apical impulse (point of maximal impulse [PMI]) located on a newborn?

Answer 15

At the fourth intercostal space and to the left of the midclavicular line.

Question 16

The PMI is often visible and easily palpable because of the thin chest wall; this is also known as…

Answer 16

Precordial activity

Question 17

How long should a nurse auscultate an infants heart rhythm and for how long?

Answer 17

Apical pulse rates should be determined in all infants for 1 whole min. Preferable when the infant is asleep.

Question 18

When is a abnormal HR not uncommon for an infant?

Answer 18

First few hours of life.

Question 19

Heart sounds during the neonatal period are of…

Answer 19

Higher Pitch
Shorter Duration
Greater intensity than during adult life.

Question 20

Are the 3rd and 4th heart sounds auscultated in a normal newborn?

Answer 20

No.

Question 21

When do half the murmurs of newborns disappear?

Answer 21

After 6 months.

Question 22

A murmur combined with what characteristics should be investigated?

Answer 22

Presence of a murmur and accompanying signs such as poor feeding, apnea, cyanosis, or pallor are considered abnormal.

Question 23

What is the average term newborn’s systolic BP?

Answer 23

60 to 80

Question 24

What is the average term newborn’s diastolic BP?

Answer 24

40 to 50

Question 25

What should the mean arterial pressure (MAP) be equivalent to?

Answer 25

Equivalent to the wks of gestation.

Example: 40 wks of gestation should have a MAP of at least 40.

Question 26

The drop of how many systolic mm Hg is common in the first hour of life?

Answer 26

15

Question 27

What device accomplishes the best infant BP reading and when is it best to use it?

Answer 27

Oscilometirnic device and when the infant is sleeping.

Question 28

When the systolic BP is ____ mm Hg higher in the upper extremities than in the lower, further diagnostic test may be needed.

Answer 28

10 mm Hg

Question 29

What does the blood volume range in term newborns?

Answer 29

80 to 100 mL/kg of body weight

Question 30

Why do preterm infants have a higher blood volume than term infants?

Answer 30

This occurs b/c the preterm infant has a proportionately greater plasma volume, not a greater RBC mass.

Question 31

What has an effect on the changes of the newborn’s circulatory dynamics?

Answer 31

Early or delayed clamping of the umbilical cord.

Question 32

Delayed clamping expands the blood volume from the so-called?

Answer 32

Placental transfusion of blood to the newborn.

Question 33

What are the benefits of delaying cord clamping for > or = 2 minutes after birth?

Answer 33

Reported to be beneficial in improving hematocrit and iron status and decreasing anemia; such benefits can last up to 6 months.

Question 34

Is polycythemia occurring due to delayed cord clamping harmful to infants and what might it cause?

Answer 34

Usually not harmful

Can cause increased risk of jaundice that requires phototherapy.

Question 35

Persistent tachycardia (more than 160 beats/min) can be associated with…

Answer 35

1. Anemia
2. Hypovolemia
3. Hyperthermia
4. Sepsis

Question 36

Persistent bradycardia (less than 100 beats/min) can be a sign of…

Answer 36

1. Congenital heart block

2. Hypoxemia

Question 37

What can reflect a newborns cardiovascular problems?

Answer 37

Newborn’s skin color.

Question 38

Pallor in the immediate post birth period is often symptomatic of underling problems such as…

Answer 38

Anemia or marked peripheral vasoconstriction as a result of intrapartum asphyxia or sepsis.

Question 39

What can the presence of jaundice indicate?

Answer 39

ABO or Rh factor incompatibility problems

Question 40

What are the most common type of congenital malformations?

Answer 40

Congenital heart defects

Question 41

What can provide the most information regarding the risk of congenital heart defects?

Answer 41

Prenatal Hx.

Question 42

What are associated with an increased risk of cardiac defects?

Answer 42

1. Maternal illness (such as rubella)
2. Metabolic disease (diabetes)
3. Drug ingestion