Case 7 - Newborn with respiratory distress

Question 1

WHat are some major perinatal and birth complications to ask about when coming up with a differential for newborn respiratory distress?

Answer 1

maternal diabetes?
prematurity?
maternal GBS infection?
C-section or vaginal?
premature rupture of membranes > 18 hrs?
Meconium in amniotic fluid?

Question 2

What is the main risk factor for respiratory distress syndrome?

Answer 2

prematurity (born before 38 wks) because they don’t have surfactant

Question 3

What type of delivery predisposes a baby to having transient tachypnea of the newborn?

Answer 3

c-section (because baby needs the stress response from being squeezed out of the vaginal canal to really clear those secretions early on)

Question 4

Why is maternal group B strep and premature rupture of membranes important to consider for newborn respiratory distress?

Answer 4

they increase risk for neonatal sepsis, which should alwways be on your differential for neonatal respiratory distress

Question 5

What’s counted in the APGAR score?

Answer 5

Appearance (color)
Pulse
Grimace (reaction to pain)
Activity (tone)
Respiration

Question 6

You can call a baby large for gestational age if their birth weight is above what percentile?

Answer 6

90th

Question 7

What is the most common cause of large for gestational age-ness?

Answer 7

maternal diabetes

Question 8

What are potential complications for babies that are large for gestational age?

Answer 8

difficult delivery (section, forceps, vacuum)
birth injuries (fractured clavicle, brachial plexus injury, facial nerve palsy)
Hypoglycemia (if born to diabetic mom)

Question 9

You can call a baby small for gestational age if their birth weight is between what percentiles?

Answer 9

3-10th

Question 10

How are SGA and intrauterine growth restriction technically different?

Answer 10

SGA cant be diagnosed until birth, while IUGR is diagnosed in-utero.

Question 11

What are some unique problems specific to SGA babies?

Answer 11

temperature instability (hypothermia)
inadequate glycogen stores (hypoglycemia)
polycythemia and hyperviscosity

Question 12

In utero, oxygenated blood is carried from the placenta to the fetus by what vessel?

Answer 12

umbilical bein

Question 13

A portion of the oxygenated blood in the umbilical vein perfuses the liver and the rest passes through what structure to enter the IVC?

Answer 13

ductus venosus

Question 14

One-third of the vena caval blood crosses what structure to the left atrium to be pumped to the coronary, cerebral and upper body circulations?

Answer 14

PFO

Question 15

THe remaining two-thirds of blood is combined with venous blood from the upper body in what chamber of the heart?

Answer 15

right atrium through pulmonary artery

Question 16

Why does only 8-10% of the blood in utero to through the pulmonary vasculature?

Answer 16

because vasoconstriction of the pulmonary arterioles produces high pulmonary vascular resistance in utero

Question 17

The remaining 90-92% of blood is shunted from the pulmonary artery through what structure to the descending aorta?

Answer 17

patent ductus arteriosus

Question 18

What events need to happen for the newborn to successfully transition to extrauterine life in terms of oxygenation and circulation?

Answer 18

1. need to cut the cord
2. initiation of air breathing
3. reduction of pulmonary arterial resistance by vasodilation
4. closure of the PFO and PDA

Question 19

How does the amniotic fluid leave a newborn’s lungs?

Answer 19

1. squeezed out during uterine contractions

2. absorbed through pulmonary lymphatics

Question 20

If you have delayed absorption of pulmonary fluid, what develops?

Answer 20

transient tachypnea of the newborn (or persistent postnatal pulmonary edema)

Question 21

What should happen to the respiratory and heart rates in babies during the first and second hour of life?

Answer 21

first hour: HR 160-180 and RR 60-80

second hour: HR 120-160 and RR 40-60

Question 22

What are the classic signs of respiratory distress in a newborn?

Answer 22

tachypnea
retractions
grunting

Question 23

Why do infants born to diabetic moms have a risk for hypoglycemia after birth?

Answer 23

Because mom’s high sugars trigger insulin secretion in the baby and then when they’re born that insulin makes their sugars drop

Question 24

Babies born to mom’s with an A1c>12% have a __-fold increase of major malformations

Answer 24

12-fold…how convenient

Question 25

What are some reasons why breast milk is generally better than formula?

Answer 25

1. provides a lower renal solute load then formula 2. has anti-infective and anti-allergic properties, including mom's antibodies 3. fosters mother-infant bonding

Question 26

What are some of the risk factors for hip dysplasia?

Answer 26

``` breech position (30-50% of DDH cases occur in breech infants) gender (female 9:1 predominance) family history ```

Question 27

How often should a breastfed newborn typically feed?

Answer 27

every 2-4 hours, feeding 10-15 minutes per breast

Question 28

How many wet diapers should a newborn have in a day?

Answer 28

at least 6

Question 29

What vitamin should all exclusively breastfed infants be given?

Answer 29

At least 400 IU of Vitamin D a day

Question 30

What type of car seat is necessary for an infant?

Answer 30

rear-facing in the backseat

Question 31

How and where should a baby sleep to avoid suffocation?

Answer 31

on his or her back, in her own crib/basinette (no co-sleeping)

Question 32

What should be on your differential in a newborn with tachypnea?

Answer 32

``` RDS TTN pneumothorax hypoglycemia CHF (from congenital heart defect) neonatal sepsis (usually GBS) congenital diaphragmatic hernia severe coarctation of the aorta meconium aspiration maternal drug exposure hypothermia ```

Question 33

What diagnostics should you obtain in a newborn with cyanosis?

Answer 33

``` ABG CSF cultures CBC with diff CXR Echo Oxygen challenge test Pulse ox ```

Question 34

What can an oxygen challenge test give you?

Answer 34

helps differentiate between a cardiac cause and a pulmonary cause osygen will increase the PaO2 of an infant with a respiratory cndition, but will not significantly increase the PaO2 if a cardiac lesion causes the cyanosis (because it doesn't fix the shunt)

Question 35

What will a CXR look like in TTN?

Answer 35

"wet" looking lungs without consolidation and no air bronchograms

Question 36

What will a CXR look like in RDS?

Answer 36

diffuse reticulogranular appearance of lung fields (ground glass) WITH air bronchograms

Question 37

Most diaphragmatic hernias develop on which side?

Answer 37

left

Question 38

Why don't we usually give D5 to a hypoglycemic infant?

Answer 38

because the glucose water only raises the serum glucose transiently and then you get rebound hypoglycemia so just do milk feeding

Question 39

What is considered a normal glucose range for an infant?

Answer 39

over 40 mg/dL