Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Y4 Neonatology > Perinatal adaptation > Flashcards

Perinatal adaptation Flashcards

1
Q

Define what the perinatal period is

A

This is the period from 22+0 wks until 7 days after birth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the function of the placenta ?

A
  • Gas exchange - supply O2 & clearance of CO2
  • Nutrients supplied to fetus - H2O, glucose, electrolytes (iron,Ca2+), free fatty acids
  • Waste product removal
  • Acid-base balance
  • Hormone production - oestrogen, progesterone, HCG, Human chorionic somatotropin, human placental lactogen, placental growth hormone, relaxin & kisseptin
  • Transport of IgG - mainly in the 3rd trimester
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

When in utero does the fetal lungs carry out gas exchange ?

A

No, there alveoli are filled with fluid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the function of IgG transport during the 3rd trimester ?

A

To give the baby passive immunity to everything the mother is immune to (passive immunity continued with breastfeeding upto 6 months)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the fetal circulation

A
  1. 2 umbilical arteries take deoxygenated blood from the fetus to the placenta, to be reoxygenated
  2. Oxygenated blood is then transported from the placenta to the fetus via the umbilical vein
  3. Blood then enters the R side of the fetal heart
  4. Blood then passes through one of the 2 extra connections in the fetal heart (they close when born)
  5. Some blood goes through the foramen ovalae travelling from R to L atrium then to L venitrcle & subsequently the aorta & then the rest of the body (blood travelling this route is the most oxygenated
  6. Blood coming back from the fetus’ body also entres the R atrium (so essentially have oxygenated & deoxygenated blood entering the R atrium, with oxygenated blood passing through the foramen ovalae), deoxygenated blood passes through to pulmonary artery & bypasses lungs through ductus arteriosus
  7. Some blood then transported to lower half of fetal body but most deoxygenated blood leaves fetus to placenta via the umbilical arteries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What 3 shunts exist in the fetal circulation ?

A
  1. Foramen ovalae
  2. Ductus arteriousus
  3. Ductus venosus - this shunts a portion of umbilical vein blood flow directly into IVC ==> bypassing the liver
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How do the fetal lungs remain perfused ?

A

7% of the fetal circulation does actually pass into the lungs but this is to just keep them perfused (==> not all the blood actually bypasses the lungs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the main fetal changes which occur during the 3rd trimester in preparation for birth ?

A
  • Surfactant production - produced by type 1 pnuemocytes to aid fetal alveoli/lung patency
  • Accumulation of glycogen
  • Accumulation of brown fat
  • Accumulation of subcutaneous fat
  • Swallowing amniotic fluid - this helps drive fetal lung development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the importance of the accumulation of fat during the 3rd trimester ?

A
  • It is important because once delivered the baby will no longer have a continuous supply of nutrients from the placenta, so they need to use fat stores in the inital stages for energy following birth (why breastfeeding babies often loose weight first)
  • It is also important for insulation/ breakdown for heat production
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What changes occur during labour & delivery which help prepare the baby for birth ?

A
  • Increased catecholamines (adrenaline, noradrenaline, dopamine), cortisol & T3 (thyroid hormone) - all required for gluconeogenesis & thermogenesis after birth to help keep the baby fed & warm whilst breastfeeding kicks in
  • Sythesis of lung fluid stops
  • Vaginal delivery squeezes the babies lungs helping alveolar cells to switch from fluid production to reasorption (so they can inflate & arent filled with fluid)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the normal appearance of a baby in the first few seconds after birth ?

A
  • Appears blue initially then gradually goes pink
  • Starts to breath & cries
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the purpose of delayed cord clamping ?

A

To allow the cord to pulsate for a few mins - this improves iron stores, Hb & transition to life outside the uterus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the transition from fetal to normal circulation after delivery

A
  • There is decreased pulmonary vascular resistance (fluid in alveoli removed within first few breaths)
  • Systemic vascular resistance increases (this is resistance to blood flow offered by all the systemic vasculature except pulmonary vasculature)
  • O2 tension in blood rises (dilating pulmonary vessels)
  • Decreased prostaglandins
  • Ducts constrict
  • Foramen ovalae closes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What happens to each of the 3 fetal shunts following birth ?

A
  1. Foramen ovalae closes (persists in 10% of people = patent foramen ovalae PFO)
  2. Ductus arteriosus becomes ligamentum arteriosus or persistent ductus arteriosus
  3. Ductus venosus becomes ligamentum teres
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

List the risk factors for failure of cardiorespiratory adaptation at birth i.e. PPHN

A
  • Pre-term
  • Babies that pass meconium prior to birth
  • Babies which get cold during delivery (hypothermia)
  • Babies with infections
  • Congenital disorders that cause underdeveloped lungs or CHD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define what persistent pulmonary hypertension of the newborn is (PPHN)

A
  1. This is when the babys circulation does not change over from fetal to normal newborn circulation.
  2. Essentially the pulmonary arteries are narrowed & obstructed (shunts persist) resulting in the R ventricle having to pump harder to properly pump the blood ==> pulmonary HTN
  3. This can result in R to L intracardiac shunting of blood at the foramen ovalae & ductus arteriosus resulting in hypoxaemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the signs & symptoms of PPHN?

A
  • Asphyxia - O2 deprivation causing unconciousness or death
  • Tachypnoea, resp distress
  • Resp acidosis
  • Loud, single second heart sound or harsh systolic murmur
  • Low APGAR score
  • Cyanosis due to poor cardiac function
  • Systemic hypotension
  • Symptoms of shock
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is PPHN diagnosed ?

A
  1. Preductal & postductal O2 sats via pulse oximetry show a 5-10% gradient difference, with preductal O2 5-10% higher
  2. Echocardiography is the gold standard test to establish diagnosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the management of PPHN ?

A
  • Ventilation - O2
  • Nitric oxide (pulmonary vasodilator)
  • Ionotropes - dopamine 1st line
  • Sedation
  • ECLS (Extracorporeal membrane oxygenation) used
  • Give surfactant - if evidence of parenchhymal lung disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is transient tachyponea of the newborn (TTN)?

A
  • This is when extra fluid stays in the lungs or is cleared out too quickly.
  • This as a result makes it harder for the baby to breathe
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How long does TTN last ?

A

< 24hrs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the risk factors for TTN development ?

A
  • Preterm
  • C-section (because fluid not been squeezed out like in SVD)
  • Mother has asthma or DM
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the signs/symptoms of TTN ?

A
  • RR > 60
  • Grunting or moaning on exhalation
  • Flaring nostrils
  • Use of excessory resp muscles (skin pulling between ribs)
  • Central cyanosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How is TTN diagnosed ?

A
  • Physical exammination +/- CXR
  • O2 sats monitoring
25
Q

What does this CXR show ?

A

TTN - interstitial oedema - predominantly perihilar often seen as perihilar streakiness

26
Q

What is the management of TTN ?

A
  • Conservative - if O2 sats are low, then give O2
  • Ensure adequate nutrition
27
Q

Following starting to breath and successfully switching to normal circulation, what 3 things does the baby now need to establish ?

A
  1. Thermoregulation
  2. Ensure glucose homeostasis
  3. Feed/nutrition
28
Q

Why are babies prone to becoming cold (hypothermia)?

A
  • Because they have:
  • A large surface area to volume ratio
  • They are wet & naked
  • They cannot shiver
  • There main source of heat is non-shivering thermogenesis = heat produced by the breakdown of adipose tissue in response to catecholamines which is not efficient
  • Peripheral vasocontriction
29
Q

Why do you want to avoid hypothermia in babies ?

A

Becuase it predisposes them to other problems

30
Q

Why are SGA/preterm babies more predisposed to hypothermia ?

A
  1. Low stores of brown fat
  2. Little S/C fat
  3. Larger surface area to volume ratio
31
Q

What will SGA/pre-term babies be born into to help keep them warm immediately ?

A

A plastic bag

32
Q

What measures are taken to help keep babies warm following birth ?

A
  • Dry
  • Hat
  • Skin to skin
  • Blanket / clothes
  • Heated Mattress
  • Incubator
33
Q

Why is maintaining glucose homeostasis for newborns difficult ?

A
  • Because in the early stages following birth there is stoppage of the continual glucose supply & lack of oral intake of milk (mother takes 3-4 days before milk production starts to increase)
  • In the first 24hrs the baby only gets roughly 5-10mls of milk
34
Q

How do babies despite the difficulties, maintain glucose homeostasis in the early stages following birth ?

A
  • To maintain glucose levels, insulin decreases & glucagon increases. This results in mobilisation of glycogen stores (stored in 3rd trimester) for gluconeogensis
  • Also newborns are able to utilise ketones as brain fuel
35
Q

What are the causes of hypoglycaemia in newborns ?

A
  1. Increased energy demands due to being unwell or hypothermic
  2. Low glycogen stores due to being SGA or premature
  3. Inappropriate insulin / glucagon ratio due to maternal diabetes or hyperinsulinism
  4. Some drugs e.g. B-blockers
36
Q

How is hypoglycaemia avoided/treated in newborns ?

A
  • Feed effectively; if preterm may need additional feeding ontop of breast feeding
  • Keep warm
  • Monitor BG levels
37
Q

Is it normal for a baby during the first 2 weeks of life to gain very little or usually loose some weight ?

A

Yes - reassure mothers about this

38
Q

What is jaundice caused by ?

A

Raised bilirubin levels

39
Q

If jaundice is severe what can it result in if untreated ?

A

Kernicterus which is a permanent form of brain damage

40
Q

Why do newborns become slightly anaemic following birth and when does this reach its worst ?

A
  • Due to fetal Hb breakdown being faster than adult Hb synthesis
  • Hb nadir around 8-10 days
41
Q

List the causes of jaundice in newborns

A
  • Physiological
  • Blood group incompatability (most commonly Rh or ABO incompatability)
  • Other haemolytic disorders e.g. GGPD deficiency
  • Sepsis
  • Liver disease
  • Metabolic disorders
42
Q

When does physiological jaundice develop between and what is it due to ?

A

Between days 2-14, due to:

  1. Increased bilirubin production due to breakdown of fetal Hb
  2. Decreased bilirubin conjugation & subsequent excretion due to hepatic immaturity, causing rise in unconjugated bilirubin
43
Q

Is physiological jaundice harmful ?

A

No - unless very high levels

44
Q

Is jaundice before 24hrs post delivery abnormal ?

A

Yes - it is always abnormal!

45
Q

What are the causes of jaundice in newborns before 24hrs post delivery ?

A
  • Rhesus incompatability - main cause
  • ABO incompatability
  • Sepsis
  • Red cell anomalies e.g. GGPD
  • If there is substantial increased conjugated bilirubin (>15%) consider hepatitis as the cause
46
Q

What investigations should be done for jaundice in newborns <24hrs ?

A
  • Total & conjugated serum bilirubin levels
  • Maternal blood group & antibody titres if Rh -ve
  • Babys blood group, direct antiglobulin (coombs test) which detects antibodies against the babys RBC’s & elution test to detect Anti-A/B antibodies to babys RBC’s
  • Full blood exammination looking for evidence of haemolysis, unusually shaped RBC’s or infection
  • CRP indicator of infection
47
Q

Which test is diagnostic of rhesus haemolytic disease i.e. therefore the most important when investigating jaundice < 24hrs ?

A

Coombs test

48
Q

Define prolonged jaundice

A

This is jaundice occuring or lasting after 14days (or >21 days in preterms)

49
Q

Is prolonged jaundice always pathological ?

A

No - 10% of babys have jaundice still at 1 month

50
Q

List the causes of prolonged unconjugated hyperbilirubinaemia

A
  • Breast milk jaundice
  • Poor milk intake
  • Haemolysis
  • Infection esp UTI
  • Hypothyroidism
51
Q

List the causes of prolonged conjugated hyperbilirubinaemia (conjugated is always pathological)

A
  • Hepatitis
  • Biliary atresia (usually have pale stools & dark urine)
52
Q

What is another name given to kernicterus ?

A

Bilirubin encephalopathy

53
Q

What are the signs/symptoms of bilirubin encephalopathy ?

A
  • Lethargy
  • Poor feeding
  • Temp instability
  • Hypotonia
  • Arching of the head, neck & back
  • Spasticity
  • Seizures
54
Q

What levels of unconjugated bilirubin are considered unsafe ?

A

>340 or > 300 in preterms

55
Q

What is the treatment of jaundice and when is it initiated ?

A
  • Treat the cause
  • Ensure adequate hydration - put to breast 8-12 times per day, supplement with expressed breast milk or formula if needed, but not water. If oral intake inadequate give IV fluids
  • Phototherapy if total serum bilirubin ≥ 350
  • Exchnage transfusion if total serum bilirubin ≥ 450
  • Use IV immunoglobulin for infants with Rh or ABO incompatability which bilirubin levels rise > 8.5 micromol/L/hr or are within 30-50 for exchange transfusion depsite intensive phototherapy
56
Q

What is resp distress syndrome due to ?

A

This is due to deficiency of alveolar surfactant, and is a condition mainly confined to premature babies

57
Q

What are the signs/symptoms of resp distress syndrome ?

A
  • Tachypnoea > 60
  • Grunting
  • Nasal flaring
  • Intercostal recession
  • Cyanosis
  • CXR - diffuse granular pattern (ground glass appearance)
  • Worsens over mins to hrs. Gradual worsening to a nadir at 2-4 days then gradual improvement (this is modified by treatment)
58
Q

How is resp distress syndrome prevented ?

A

Steroids for preterm deliveries

59
Q

What is the treatment of resp distress syndrome ?

A
  • O2
  • Pulmonary surfactant
  • CPAP if breathing on own

Y4 Neonatology (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions