Neonates Flashcards
What is meconium aspiration syndrome
Where baby inhales meconium into the lungs
This blocks the airways and starts an inflammatory process
Gives lungs a streaky appearance on X-ray
What are the 3 shunts in the foetal circulation
Ductus venosus
Foramen ovale
Ductus arteriosus
All must shut after birth
How does the foetus prepare itself for birth in the 3rd trimester
Surfactant production
Accumulation of glycogen – liver, muscle, heart
Accumulation of brown fat –for warmth
Accumulation of subcutaneous fat
Swallowing amniotic fluid - helps lungs grow and expand
How does labour help prepare the baby’s lungs for life
Synthesis of lung fluid stops
Vaginal delivery – squeezes lungs to get rid of some fluid
The first cry is very important for the baby to absorb the extra fluid into their lymphatic
What colour is a baby when it is first born
All babies will be blue or pale when born
Gradually turns pink as the circulation transitions from foetal to ‘adult’ – baby is now oxygenating their own blood as they have started breathing
Is delayed cord clamping recommended
Yes
Advocate delayed cord clamping in all babies (especially in prem babies) – this allows for final transfer of blood and immunoglobulins
Describe how foetal circulation transitions to adult after birth
Pulmonary vascular resistance drops - fluid leaves lungs when breathing starts
Systemic vascular resistance rises - cord clamped
Oxygen tension rises
Circulating prostaglandins drop - this helps close the foetal shunts
Duct constricts
Foramen ovale closes
When do the foetal shunts close
Most close physiologically in 24hrs but some can be take a few days to shut completely – some babies will have a murmur on day 1 which will go away
Anatomical closure occurs within 7-10 days
What happens to the 3 foetal shunts after birth
Foramen ovale closes
Some may persist as PFO
Ductus arteriosus should become the ligamentum arteriosus
May persist
Ductus venosus becomes the ligamentum teres
What are the complications if there is a failure of cardiorespiratory adaptation
Asphyxia – hypoxia / acidosis Prematurity Sepsis Hypoxia – meconium aspiration Cold stress
How does persistent pulmonary hypertension of the newborn present
Blue baby
Big difference between pre and post ductal sats
Sick babies
Describe persistent pulmonary hypertension of the newborn
The lung vascular resistance doesn’t fall enough and the shunts remain open
Will have patent foramen ovale and ductus arteriosus
Therefore blood cannot be effectively oxygenated
How do you manage persistent pulmonary hypertension of the newborn
Ventilation
Oxygen
Nitric oxide - given through ventilator to dilate pulmonary vasculature
Sedation - prevents baby fighting the ventilator and causing a mismatch
Inotropes
ECLS - very invasive and high risk
What is transient tachypnoea in newborns
Relatively common condition caused by excess fluid remaining in the lungs for longer than expected
Seen in large babies born by section (don’t have the squeeze to remove some of the fluid)
Diagnosis of exclusion - need to be sure its not an infection
Usually gets better on their own – will clear fluid eventually
Why are babies at high risk of heat loss
Large surface area
Lose a lot from their head as it is so big in proportion
Wet when born
They cannot shiver yet
Don’t have a lot of fat stores to use up and breaking this down isn’t effective in first 12 hours
How can you prevent hypothermia in a new-born
Keep them dry Put a hat on them Skin to skin Blanket / clothes Wraps or bags for prems Heated Mattress Incubator
How does a new-born manage their glucose levels
They lose their supply of glucose from mum
In the first few days they usually don’t get much milk
Insulin levels drop physiologically to cope with the expected ‘starvation’ stage in first few days
There is mobilisation of hepatic glycogen
Can also use ketones for brain fuel
Which babies are most at risk of hypoglycaemia
If they are unwell - sepsis
Hypothermic - use up energy stores to keep warm
Small or premature babies
Maternal diabetes baby will have high insulin
Some medications
Why is colostrum so beneficial
Colostrum contains lots of IgA, cellular immunity, growth factors
Great for the baby
Is it normal for a baby to lose weight after birth
Yes - lose some fluid before they start growing
Around 10% is normal – don’t want more
Expect them to find a centile and stick to it – be more worried if they start dropping
How does foetal haemoglobin change after birth
Blood produced in liver in foetus which then shift to the bone marrow when they are born
Need to change Hb as O2 pressure increases massively
Adult Hb takes longer to produce so may be a drop
Describe physiological anaemia of the new-born
Baby needs to start using adult Hb instead of foetal
Adult Hb takes longer to produce but foetal Hb breaks down quickly
Therefore Hb will be slightly lowered while this changeover occurs
What causes physiological jaundice in new-borns
Breakdown of foetal haemoglobin
However the conjugating pathway is immature so there is a rise in circulating unconjugated bilirubin
Usually not harmful
When should you worry about jaundice in a newborn
Early or prolonged jaundice may be pathological
How would you treat pathological jaundice in a new born
If mild you use phototherapy = light breaks down the bilirubin
If very high levels they need exchange transfusion – change the circulating blood
What are the risk factors for problems with neonatal adaptation
Hypoxia / asphyxia during delivery Particularly small or large babies Premature babies Some maternal illnesses and medications Ill babies – sepsis, congenital anomalies
What is considered a normal birth weight
2.5-4kg
What birth weight is considered large for gestational age
Over 4kg
What birth weight is considered small for gestational age
Under 2.5kg
What happens to O2 levels during contractions
Every time there is a contraction the blood flow to the baby is reduced or even stopped – hypoxia
This is why prolonged labour is dangerous
What score is used to monitor new-born babies
APGAR score
Scores them based on HR, RR, responsiveness, tone and colour
Score 0,1 or 2 on each
Over 8 is normal
What is the risk of haemorrhagic disease of the new-born
Risk of GI bleed, epistaxis and worse case – brain haemorrhage
Why are babies given vitamin K after birth
To prevent haemorrhagic disease of the new-born – clotting problem
Which vaccines can be offered to new-borns
If mum has had Hep B then baby could get early vaccination
Offer BCG to babies at risk of TB contact - within first month
Which screening tests are offered to new-borns
New-born examination Universal hearing screening Hip screening - clinical and USS Cystic fibrosis - heel prick Haemoglobinopathies - heel prick Metabolic disease - heel prick
When are newborn screening tests carried out
Day 5
Includes the heel prick
What do you look for on the head during the new-born examination
Measure the circumference of the head
Overlapping sutures - seen if there has been moulding
Fontanelles
Ventouse/forceps marks
Head is often bruised or swollen due to delivery
What do you look for in the eyes during the new-born examination
Red reflex is one of the most important things to check
Most likely to have a cataract if absent – baby will have reduced vision for life if not caught and treated early
Conjunctival haemorrhage - common due to birth but must be documented so it’s not confused with abuse
Squints
Iris abnormality
What do you look for in the ears during the new-born examination
Position - sign of genetic syndromes
External auditory canal
Tags/pits - may be a sign of another condition
Folding
What do you look for in the mouth during the new-born examination
Shape Philtrum - is smooth it could be FAH Tongue tie Palate Neonatal teeth - removed as aspiration risk Ebsteins pearls Sucking/rooting reflex
What respiratory signs should you look for on new-born examination
Chest shape Nasal flaring Grunting Tachypnoea In-drawing Breath sounds
What cardiovascular signs should you look for on new-born examination
Colour/Saturation (SaO2) Pulses: femoral Apex Thrills/heaves Heart sounds
What abdominal signs should you look for on new-born examination
Distension Hernia Umbilicus - look for infection Bile stained vomiting Passage of meconuim Anus
What genitourinary signs should you look for on new-born examination
Normal passage of urine
Normal genitalia
Undescended testes - check scrotum
Hypospadias
At what point is a baby boy referred for undescended testes
If testes are still undescended by 6 months then it will need surgical repair
How is DDH diagnosed and treated
Clinical examination and targeted US (if high risk)
Put baby in the Pavlik harness to fix the hips – wear for 2-4 weeks
What are the primitive reflexes that should be checked for
Suck Rooting Moro - spread arms when dropped ATNR - fencing Stepping Grasp
List some common birth marks that need to be recorded on new-born examination
Haemangiomas – can be raised and get irritated but usually go away on their own
Port wine stain - vessel abnormality which wont go away
Blue spots – common but need documented as can look like bruises
What are the risk factors for neonatal death
Pre-term delivery Low birth weight Twins etc Maternal age Smoking Disadvantaged circumstances
What are the risk factors for pre-term delivery
> 2 preterm deliveries Abnormally shaped uterus Multiple pregnancy Interval of < 6 months between pregnancies IVF Smoking, drinking alcohol and using illicit drugs Poor nutrition Multiple miscarriages or abortions
What are some common problems of prematurity
Temperature control
Feeding/nutrition
Sepsis
System immaturity / dysfunction - respiratory distress, PDA etc
Why are premature babies at increased risk of nutritional compromise
Limited nutrient reserves
Gut immaturity
Immature metabolic pathways
Increased nutrient demands
What is the difference between early and late onset neonatal sepsis
early onset (EOS) is mainly due to bacteria acquired before and during delivery
Late onset (LOS) is acquired after delivery
Which organisms are usually responsible for early onset neonatal sepsis
Group B Streptococcus
Gram negatives
Which organisms are usually responsible for late onset neonatal sepsis
Coagulase negative staphylococci
Gram negatives
Staph Aureus
What causes respiratory distress syndrome in premature babies
Usually due to surfactant deficiency or structural immaturity
Occasionally due to secondary pathology
How does respiratory distress syndrome present in premature babies
Respiratory distress Tachypnoea Grunting Intercostal recessions Nasal flaring Cyanosis
Gradually gets worse
How do you manage respiratory distress syndrome in premature babies
Maternal steroid before birth
Surfactant
Ventilation - Invasive / non invasive
What are the outcomes of intraventricular haemorrhage
Neurodevelopmental delay
Death
What is considered a neonatal death
All deaths up to 28 days old
What is a normal heart rate in a term baby
100-140bpm
What is a normal respiratory rate for a term baby
40-60 breaths per minute
How may a seizure present in a neonate
They are subtle in neonates – cycling movements, lip smacking, eyes rolling, apnoea
What are some signs of breathing difficulties in neonates
Grunting
Nasal flaring
Subcostal or intercostal recession
Some can have apnoea’s when unwell
Why might you deliberately lower a neonates temperature
Gives hypothermia in a controlled way for 72hrs – protective if baby is at risk of neurological damage
What is hydrops foetalis
Congenital abnormality causes HF a few days after birth
Baby will be very oedematous and lungs will fill with fluid
How is next generation sequencing used
Can sequence the whole genome or just all known exons
Finds lots of polymorphisms
What are the symptoms of patent ductus arteriosus
Constant machine-like systolic murmur Cyanosis Low O2 sats Heavy, fast breathing Fatigue Failure to thrive and feed
When is it normal for neonates to develop jaundice
It is common 2-3 days after birth
What is kernicterus
It is a rare but serious complication of untreated jaundice in babies
Caused by excess bilirubin damaging the brain or central nervous system.
Risk of cerebral palsy
Is HIV a contraindication to breastfeeding
Yes and No
Only a risk if they have a high viral load
Is Hep C a contraindication to breastfeeding
No
What are the signs of hypoglycaemia in a neonate
Temperature is low or dropping Sleepiness Not feeding Irritability High pitched cry Apnoea Hypotonia Cyanosis Seizures
How do you manage neonatal abstinence syndrome (withdrawal)
Calm and secure environment
Lots of cuddles from mum and rocking them
Monitor them and score them every 4 hours
Oral morphine solution for those withdrawing from opioids
What is tested for in the heel prick
PKU, congenital hypothyroidism, maple syrup urine disease, cystic fibrosis, MCADD, homocystinuria, sickle cell disease and another metabolic disorder
