Neonatology Flashcards
Describe the development of CVS
Begins at end of 3rd week and beats at 4th week
Day 20 to day 50 is critical
Describe the foetal circulation
Oxygenated blood via umbilical vein - ductus venosus
Some blood via foramen ovale to LA - LV - aorta
Some blood to right RV - pulmonary artery - patent ductus arteriosus - PA - aorta
What does the ductus arteriosus carry?
Low oxygen saturated blood
Protects lungs against circulation overload
Describe the ductus venosus
Foetal blood vessel connecting the umbilical vein to the IVC
Carries mostly oxygenated blood
What are the normal vital signs of a new born?
Heart rate - 120-160 bpm
(bradycardia under 100 bpm)
Temp - 37 degrees +/- 0.5
RR - 30-60/ min - periodical breathing
BP - 1 hr is 70/44 then 3 days is 77/49 (+/- 10)
What is babies thermoregulation?
Brown fat well innervated by sympathetic neurons
Cold stress leads to lipolysis and heat production
How can new born breathing be assessed?
Non-invasive - blood gas and trans-cutaneous pCO2/O2 measurement
Invasive - capnography, tidal volume, minute ventilation and flow-volume loop
Describe physiological jaundice
Appears on day of life
Disappears within 7-10 days in term infants and up to 21 in premature infants
Breastfed babies have more risk of jaundice
Describe fluid balance in term new born
Weight loss up to 10% is normal
Loss is due to shift of interstitial fluid to intravascular and diuresis
Normal to not pass urine in the first 24hrs
Describe fluid balance in premature infants
Less fat in body composition
Increased loss through kidneys - slower GFR, reduced Na reabsorption and decreased ability to concentrate or dilute urine
Increased insensible water loss via immature skin and breathing
Describe physiological anaemia of the new born
RBC production is 10% of in uterus
Increase production of erythropoietin
Anaemia of prematurity - reduced erythropoiesis and blood letting
What are the maternal causes for small babies for dates?
Maternal smoking
Maternal pre-eclamptic toxaemia (PET)
What are foetal causes for small babies for dates?
Chromosomal ex. Edward’s syndrome
Foetal infection ex. CMV
Other - twin pregnancy
What is a placental cause for small babies for dates?
Abruption of placenta
What are common problems experienced by small babies after birth?
Perinatal hypoxia, hypoglycaemia, hypothermia, polycythaemia, thrombocytopenia, and GI problems
What are long term problems of small babies?
Hypertension, reduced growth, obesity and ischaemic heart disease
What is the treatment and prevention of respiratory distress syndrome?
Due to lack of surfactant - decreased tension leading to collapse
Prevention - antenatal steroids
Early treatment - surfactant
Early extubation, non-invasive support (N-CPAP) and minimal ventilation
Describe BPD/ Chronic long disease (CLD)
Consequence of RDS
Overstretch by volu-baro-trauma
Atelectasis, infection via ETT, O2 toxicity, inflammatory changes and tissue repair (scarring)
Treatment is patience, nutrition + growth, and steroids
What are minor respiratory problems in prematurity?
Apnoea, irregular breathing and desaturations
Treatment is double espresso (caffeine) and N-CPAP
Describe IVH - intraventricular haemorrhage
Most common limiting factor for good long term prognosis
Lack of ability to control the swings of BP - brain autoregulation needs to mature
Prevention is AN steroids
Treatment is symptomatic
What is PVL - periventricular leukomalacia?
Injury of the white matter due to multiple ischaemic episodes
Can cause major cystic
What is PHH - post-haemorrhagic hydrocephalus?
Complication of IVH
Blood products block draining system of CSF - ventricles increase - ICP increases
Causes opening of sutures
Treatment - ventriculo-peritoneal shunts
Describe PDA - patent ductus arteriosus
Pressure is more in aorta than PA - left to right shunt - additional blood to pulmonary circulation - over-perfusion of lungs and lung oedema - steal from systemic circulation - systemic ischaemia
Consequences - worsening of resp. symptoms, GI problems and retention of fluids
What is the presentation of NEC - necrotising entero-colitis?
Distended, shiny, tender and painful to palpate abdomen
Filled with air
Due to bacterial flora entering crypts overcoming mucosal barrier - produce gas
Risk of perforation
