Intro to neonatology Flashcards by Heo Mun Ho

Be familiar with the physiological differences of neonates and changes that occur after birth
Understand the common problems associated with being small for dates

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CVS starts developing in what week

End of 3rd week

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Foetal circulation

function of ductus venosus
function of foramen ovale
function of ductus arteriosus

DV - shunts blood from umbilical vein directly to IVC, so allowing OXYGENATED blood from placenta to bypass the liver

FO - a hole in the septum between the 2 atria shunting blood from left atrium to right atrium

DA - shunts blood from the pulp artery to the descending aorta, allowing blood to bypass lungs (so carries LOW OXYGENATED BLOOD)

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What happens to the following after birth

ductus venosus
foramen ovale
ductus arteriosus
umbilical arteries

DV - ligamentum venosum

FO - becomes fossa ovalis in RA

DA - becomes ligamentum arteriosum

Umbilical arteries - some becomes *MEDIAL umbilical ligament, some stays open as branch of internal iliac

*DON’T CONFUSE WITH MEDIAN UMBILICAL LIGAMENT = REMNANT OF EMBRYONIC URACHUS

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Normal vital signs of full term newborn

BP - 70/44

RR - 30-60

HR - 120-160
–> bradycardia <100

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How is a baby’s temp regulated

in utero
newborn

In-utero - relies on mum’s thermoregulation

Newborn - lack shivering thermogenesis so need metabolic source of heart instead = BROWN FAT (packed with mitochondria to burn energy when needed)

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Heat is lost through what 4 processes

Radiation
Convection
Evaporation
Conduction

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How is newborn breathing investigated

NIV

Blood gas
-> PaCO2 = 5-6kPa
-> PaO2 = 8-12 kPa

Invasive

capnography
flow volume loop

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Physiological jaundice appears within how many days of birth and disappears within how many

2-3

7-10 for term and up to 21 for preemies

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Why does physiological jaundice occur in babies

Babies have a high number of RBCs in their blood, which are broken down and replaced rapidly (HIGH CELL TURNOVER) so lots of bilirubin produced which is not removed from the body quick enough by the liver as it’s not fully developed yet

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High concentrations of bilirubin in blood can cause an irreversible change in the brain called what

KERNICTERUS - just refers to high bilirubin levels crossing BBB and damaging brain

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Neonatal jaundice only treated when it become *pathological (acute bilirubin encephalopathy)

What’s the treatment? (2)

*usually is just physiological

Exchange transfusion - removing their blood and giving new blood

+ phototherapy

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Why is phototherapy given to babies with pathological jaundice?

Blue light converts bilirubin to water soluble form and increases oxidation of bilirubin so decreasing blood conc. of it

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Full term baby is able to maintain fluid balance

Weight loss of up to 10% is normal in newborns

In what ways is fluid lost?

Shift from interstitial to intravascular

Diuresis - peeing it out

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It’s normal not to pass urine for the first … hours

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Why is fluid balance abnormal in premature babies?

Less fat

Increased kidney loss
-reduced Na reabsorption and reduced ability to concentrate or dilute urine

Increased insensible water loss
-e.g. sweating, breathing

Newborns get normal physiological anaemia

They’re born with Hb 15-20g/L but this falls when and to how much?

But increases in what week?

Week 10 - Hb 11

Week 20 - to Hb 12

Premature babies are very susceptible to anaemia - why?

Low erythropoiesis
Infection
Getting blood withdrawn (for tests)

Establish neonatal definitions.
Describe routine management and care of the premature baby.
Understand short and long term complications of being born prematurely.
Understand the potential outcomes of extreme premature birth

Low birth weight =
Very low birth weight =
Extremely low birth weight =

<2500g
<1500g
<1000g

How many weeks

preterm baby
extremely preterm baby

-what is considered the youngest age viable for a premature baby

<37 weeks

<28 weeks

24 weeks

Maternal causes of babies being small for gestational age

Smoking

Pre-eclampsia - decreases perfusion of placenta

Carrying twins

Foetal causes of being small for gestational age

Chromosomal syndromes, e.g. down’s, edward’s

Congenital infection, e.g. CMV

Placental causes of being small for gestational age

Placental abruption

Short term complications for baby of being small for gestational age

``` Perinatal hypoxia Hypoglycaemia Hypothermia Polycythaemic, thrombocytopenia GI PROBLEMS - NEC, poor feeding ARDS ```

Long term complications for baby of being small for gestational age

Hypertension Reduced growth Obesity IHD

Common short term complications of premature babies

RDS Ventilation management and complications, e.g. pneumothorax Biochemical disorders, e.g. acidosis Temperature control Nutrition and fluid management Infection, e.g. necrotising enteric colitis (NEC) Brain haemorrhage (IVH) Circulatory issues (e.g. PDA - persistent ductus arteriosus) Jaundice

A short term complication of premature (preterm) babies is RESPIRATORY DISTRESS SYNDROME How can this be prevented before birth? What is the treatment for the newborn?

Steroids (dexamethasone) to the mother Surfactant ASAP NIV

A mild short term complication of premature babies is apnoea/irregular breathing How is this treated? (2)

Caffeine | NIV (CPAP)

A short term complication of preterm babies is IVH (intraventricular haemorrhage) How can this be prevented before birth? What is the treatment for the newborn?

Steroids (dexamethasone) for mother Supportive care mainly -SYMPTOMATIC relief for newborn

A short term complication of preterm babies is IVH Long term complications of premature babies

Retinopathy of Prematurity (ROP) Periventricular leukomalacia (PVL) Post haemorrhagic hydrocephalus (PHH) Chronic lung disease/ Broncho Pulmonary Dysplasia (BPD) Developmental delay and cerebral palsy Poor growth

Post haemorrhage hydrocephalus (PPH) is a long term complication in premature babies It involves bleeding into the CSF which increases ICP and progressively DILATES VENTRICLES; usually follows IVH What is the treatment of the newborn?

VP shunt

Patent ductus arteriosus is a short term complication of premature babies What does it lead to?

Usually connects pulm artery to aorta so blood can bypass lungs but persistent patency can cause blood from the aorta to leak back to pulm circulation --> increasing pulm pressure --> lung oedema --> also stealing from systemic circulation --> systemic ischaemia

Complications of patent ductus arteriosus

Respiratory distress syndrome Hypoperfusion of end organs, e.g. necrotising enterocolitis (from GI ischaemia) CHF long term

Necrotising enterocolitis is a short term complication in premature babies It involves ischaemia of the bowel --> necrosis What is the treatment?

Supportive - STOPPING MILK FEEDS to let bowel rest - IV nutrition instead (not milk) - Antibiotics - if infection Surgical - gastric decompression - abdominal drain - laparatomy - to resect dead bowel

Potential outcomes of EXTREME PREMATURITY

Death Normal Physical or learning disability