Neonatology - normal newborn Flashcards
Pressure changes after the first breath of a baby
Resistance to pulmonary blood flow decreases massively - 6times as much blood can flow through pulmonary arteries.
This leads to increased pressure in Left Atrium.
Meanwhile, pressure in right atrium falls because the placenta is excluded from the circulation: closure of the foramen ovale.
When does the ductus arteriosus close?
Normally within the first few hours or days
If there is a duct-dependent lesion, the baby will deteriorate within days
Respiratory changes from fetus to neonate
Lung liquid reabsorbed (chest compression during birth squeezes out 1/3. Release of adrenaline promotes the rest)
Surfactant release. Triggered by adrenaline and steroids.
Fall in the capillary pressure due to expansion of alveoliy and the vasodilatory effect of oxygen. respiratory movements commence
By when should the neonate open its bowels
Usually first 6 hours
Up to 24hrs
By when should the neonate urinate
First 24 hours
By when should the neonate regain its birth weight
Newborns lose around 7-10% of their weight
Should regain in ca. 2 weeks
What are the effects of Vit K deficiency in a neonate
haemorrhagic disease of the newborn
Can occur in first week of life.. or from week 1-8
Usually mild symptoms eg. bruising, haematemesis, melaena or prolonged bleeding from umbilical stump..
Some suffer INTRACRANIAL HAEMORRHAGE (50% permanently disabled or die)
What is the content of Vit K in breast milk?
Poor source of Vit K (wholly breastfed children may develop haemorrhagic disease of the newborn)
Infant formula has much higher content.
Risk factors for haemorrhagic disease of the newborn
Wholly breastfed
Mother on anti-convulsants (impair synthesis of Vit K clotting factors)
Infant with liver disease
Prophylaxis for haemorrhagic disease of the newborn (normal mothers vs mothers on anticonvulsants)
In normal, give vit K to all infants immediately after birth. Either IM injection or orally over the first 4 weeks (3 doses needed)
If on anticonvulsants, Oral prophylaxis from week 36 and baby should receive IM injection
Outline the hearing screening in the UK
Evoked optoacoustic emission (EOAE) testin - earphone is placed over the ear and a sound is emitted which evokes an echo or emission from each ear if cochlear function normal
If abnormal, test with an Automated Auditory Brainstem Response (AABR) audiometry - computer analysis of EEG to a series of clicks
Refer to paediatric audiologist if abnormal
What is the Guthrie test
Biochemical screening, on every baby.
Hypothyroidism
Haemoglobinopathies (sickle cell and thalassaemia)
Cystic fibrosis
Inherited metabolic diseases: PKU MCAD MSUD (maple syrup urine disease) IVA GA1 HCU
Screening for CF is performed by measuring the serum immunoreactive trypsin.. Raised with pancreatic duct obstruction
What is ultrasound used for antenatally
Show babies measurements. Number of babies. Abnormalities? (head and spine) Show position of baby Check for normal development.
celft lip/palate Cardiac problems Spina bifida Bowel problems Down syndrome
What is erythema toxicum
Neonatal urticaries
Usually appears 2-3 days of age
White pinpoint papules at the centre of an erythematous base
Lesions concentrated on the trunk
They come and go at different site
What are mongolian blue spots
Blue/black macular discoloration at the base of the spine and on the buttocks.. occasionally on legs and other parts
Usually in Afro-caribbean or asian infants
Fade slowly over first year. Don’t misdiagnose for a bruise
