Adapting to extra-utero life

Question 1

For the respiratory system to alter from the placenta to lugs the infant must have what ?

Answer 1

• good blood flow to lungs
• good amount of surfactant (lines the lungs meaning they don’t collapse, alveoli dont stick together) . this is sufficent at 34-36 weeks
• musculature to support strong enough respiration

Question 2

Breathing is initiated by...
2 gases
ph
stimulation
compression

Answer 2

• decreased o2 conc
• increased co2 conc
• decreased blood ph
• stimulation of the resp centre in the medulla
• compression of the chest during birth

Question 3

what % of newborns require resuscitation in the UK

Answer 3

5-10

Question 4

What is PVR.. what does it mean

Answer 4

Pulmonary Vascular Resistance … fluid in the lungs

Question 5

What is the role of ductus venous in the heart

Answer 5

allows blood to ‘skip’ liver

Question 6

Circularatory system fill in the gaps

1. pulmonary artery has — so pressure is —-
2. blood takes —– path of resistance and crosses the ——- —– which is located between the R and L —— and then it crosses the —— ——— which is from the pulmonary artery to the aorta to go to the rest of the body. Are these structures temporary?
3. only —-% of the pulmonary artery blood will flow to the —–

Answer 6

PVR, high
least, formen ovale, atrium, ductous arteriousus. Yes.
10-12%, lungs

Question 7

Where does the fetus receive the oxygen from ?

Is the umbilical vein deoxygenated or oxygenated?

Answer 7

Placenta

oxygenated

Question 8

What does a lung expansion of 8-10x do?
WHat does this do to lung blood vessels?
This causes PVR to …?
What does an increase in o2 do to ductous arteriosus

Answer 8

increase pulmonary blood flow
vasodilate
decrease
closes so the pattern of neonatal circulation can be established

Question 9

Which way does the blood flow in fetal circulation?

L to R or vice versa

Answer 9

R to L

Question 10

define Non shivering thermogenesis

Answer 10

Lipolysis of brown fat due to newborns being unable to shiver

Question 11

Name some newborn difficulties of thermoregulation

Answer 11

• they have a large SA:body mass
• thin layer of subcutaneous fat
• immature skin
• immature CNS - it cant vasoconstrict/dilate
• cant shiver or move
• limited metabolic substrates (food cant be broken down for heat production

Question 12

Dangers of a cold newborn

Answer 12

• hypothermia or hypoglycaemia
• respiratory distress
• risk of acidosis
• inhibits production of surfacants
• risk of mortality and morbidity

Question 13

Why does blood sugar drop rapidly once baby is born?

When should they begin to rise again ?

Answer 13

due to the constant glucose supply from placenta

3-4 hrs after birth

Question 14

What are 3 endocrine changes that happen to allow newborn to establish glucose homeostasis

Answer 14

adrenaline is released
insulin is decreased
glycogen is decreased

Question 15

what steps can you do to help newborn transition

Answer 15

dry immediatley after birth
assess for normal signs of breathing and resps
skin to skin
cover with towel to maintain warmth 
early feeding

Question 16

APGAR score stands for?
what is it used for
whats the ‘normal’ score

Answer 16

Appearance(colour), Pulse, Grimace(reflex), Activity(muscle tone), Respiration(and cry)

To see if there are any problems / resus is needed ?
3- =critically low
4-6 = fairly low
7+ = generally normal

Question 17

4 signs of respiratory distress and why do they happen ?

Answer 17

nasal flaring = attempt to decrease airway resistance
recession (depressions between the ribs) = compliant chest wall and non compliant lung
Grunting = glottis closes in effort to increase intrapulmonary pressure and keep alveoli open. this is response to a decreased partial pressure of pO2
tachypnea (more than 60 breaths a minute) = try to increase ventilation

Question 18

Ideal resps, temp and HR of newborn

Answer 18

30 - 60 resps
100-160bpm
36.5 to 37.5