Paediatrics: Neonatology Flashcards
What cells produce surfactant?
Type II pneumocytes (alveolar cells)
What is the action of lung surfactant?
- Reduces the surface tension of the fluid in the lungs => keep alveoli inflated + maximise alveolar SA
- Promotes equal expansion of all alveoli (because this out as alveolus expands)
what is the impact of surfactant on lung compliance? explain this
Increases lung compliance (reduces force needed to expand alveoli)
At how many weeks gestation does surfactant start to be produced?
starts being produced between 24-34 weeks gestation
After birth: what helps expand previously collapsed alveoli? (first breath)
stress of labour => Ad + cortisol release => stimulate resp effort
explain how the first breath leads to foramen ovale. what does this eventually become?
Alveoli expand => reduced pulmonary resistance => LA>RA pressure => squash atrial septum => foramen ovale (functional closure) => fossa ovalis (structural closure)
Describe how early neonatal cardio-respiratory changes lead to ligamentum arteriosus formation
increased blood oxygenation => decreased relative prostaglandins => ductus arteriosus closure => ligamentum arteriosus
When does the ductus arteriosus stop functioning
within 1-3 days of birth
(due to relative decrease in prostaglandins)
Describe how early neonatal cardio-respiratory changes lead to ligamentum venosum formation
umbilical cord clamping => no umbilical vein blood flow => ductus venosus closure => ligamentum venosum
Explain what can cause common hypoxia in neonates
during labour, contractions mean placenta is unable to carry out normal gaseous exchange => hypoxia
What do you do immediately after the baby has been born? (7)
- Skin to skin
- Delayed cord clamping
- Dry the baby
- warm the baby with hat and blankets
- Vitamin K
- Label baby
- Measure weight and length
What can extended hypoxia in neonates lead to? plus the in between bits
extended hypoxia => anaerobic respiration + bradycardia => decreased consciousness + decreased resp effort => hypoxic-ischaemic encephalopathy
What score is an indicator of progress over the fist few minutes of life
APGAR
what does APGAR stand for? is high or low bad?
Appearance
Pulse
Grimace
Activity
Respiration
(lower => bad)
Why is delayed cord clamping good?
allows for placental transfusion
- Fetal blood from placenta => fetal circulation
What examination can estimate gestational age when it is unknown/unclear?
Dubowitz/ballard examination
Describe the categories for:
- Extreme preterm
- Very preterm
- Moderate to late preterm
- Term
<28 weeks (extreme preterm)
28-32 weeks (very preterm)
32-37 weeks (moderate to late preterm)
37-42 (term)
If fetus is going to preterm, how can you try to delay birth? (not in labour yet)
- prophylactic vaginal progesterone (progesterone helps to reduce contractions)
- prophylactic cervical cerclage
When labour is suspected in a preterm fetus, what can you do?
- Tocolysis (nifedipine - CCB, progesterone (maintenance)
- Maternal corticosteroids
- IV Mg Sulphate
- delayed cord clamping
what can be given antenatally to aid lung development in a preterm fetus?
corticosteroids - dexamethasone
Why might IV Mg Sulphate be given antenatally?
in a suspected preterm fetus
- Protect fetal brain (neuroprotective)
What can be used in neonatal prematurity for treatment of apnoea ? in how many weeks of life is this used
caffeine
(<34 weeks CGA)
What Resp complications might a preterm neonate have? (3)
- RDS
- Surfactant deficient lung disease (insufficient surfactant => increased alveolar surface tension => lung collapse => poor gas exchange => hypoxia)
- CLD
What cardiovascular complications might a preterm neonate have? (2)
- Hypotension
- PDA
What neuro complications might a preterm neonate have? (3)
- Intraventricular haemorrhage
- Developmental delay
- CP
What GI complications might a preterm neonate have? (1)
NEC
What eye complications might a preterm neonate have? what do you have to do to manage?
retinopathy of prematurity
- avoid excessive oxygen exposure
how many weeks gestation is retinal blood vessel dev completed? stimulated by what?
finished by 37-40 weeks gestation stimulated by hypoxia
What might you not what a neonates oxy sats at 100%
risk of retinopathy of prematurity
- High oxy sats => abnormal retinal dev =>scarring + retinal detachment + blindness
What vitamin is given to babies at birth? how is it given?
babies are usually born with a deficiency in vit K (important in normal blood clotting)
- usually given IM
benefits of skin-to-skin contact? (4)
- Warms baby
- Improve mother + baby interaction
- Calms baby
- Improves breast feeding
Normal care after birth: what is done once out of the delivery room?
- Initiate breast or bottle feeding a soon as baby is alert enough
- NIPE (<72 hrs)
- Blood spot test
When blood spot test done? what does it test for? how long for results?
days 5
- screens for 9 congenital conditions
- results take 6-8 weeks
what reflexes should a baby have?
- Moro
- Suckling
- Rooting
- Grasping
- Stepping
What is caput saccedaneum?
birth injury
- fluid (oedema) collecting in scalp outside periosteum
Where can fluid in caput go to?
fluid collecting outside the periosteum so is able to cross suture line
Caput saccedaneum management?
does not require treatment + will usually resolve within a few days
What is cephalohaematoma? where can blood go?
birth injury
- collection of blood between skull + periosteum => the lump does not cross suture lines of scalp
Cephalohaematoma managment?
usually does not require intervention but risk of anaemia and jaundice due to blood clot + breakdown
What is erbs palsy? which nerves?
result of damage to C5/C6 nerves in brachial plexus during birth
symptoms of an erbs palsy?
weakness of shoulder abduction + external rotation, arm flexion, finger extension
erbs palsy management?
function to arm usually returns in a few moths
- if not the requires surgical input
What physiology causes hypoxic ischaemic encephalopathy ? can lead to what?
HIE occurs in neonates as a results of hypoxia during birth
- can lead to permanent damage of the brain => cerebral palsy
what can cause HIE?
- maternal shock
- Intrapartum haemorrhage
- Prolapsed cord
Management of HIE?
- supportive care
- therapeutic hypothermia
what is the time frame of early onset neonatal sepsis (EONS)
sepsis occuring with the first 72 hrs of life
Common organisms of EONS? most common
- Group B Strep (GBS) [most common]
- e.coli
- listeria
- s.aureus
why is GBS the most common cause of EONS?
common bacteria found in vagina => infection by direct contact
Mum is found to have GBS in vagina, what is done?
prophylactic Abx used during labour
EONS RF?
- maternal vaginal GBS colonisation
- GBS sepsis in prev baby
- Maternal sepsis
- Prematurity
- Early ROM
- Prolonged ROM
EONS clinical features?
- Fever, decreased tone + activity, poor feeding, resp distress or apnoea, vomiting, tachy/bradycardia, hypoxia, seizures
EONS red flags?
- Confirmed or suspected maternal sepsis
- signs of shock
- seizures
- Resp distress starting more than 4 hrs after birth
- need for mechanical ventilation in a term baby
- suspected or confirmed infection in co-twin
EONS managment? which Abx?
- Start Abx within 1 hr: IV benzylpenecillin + gentamycin
- Blood cultures, baseline FBC + CRP, lactate
- Consider LP if meningitis suspected
- Monitor urine output
EONS differential?
surfactant deficient lung disease, meconium aspiration, haemolytic disease of the new-born
what is the mortality of EONS due to GBS infection in term babies?
2-3%
what is jaundice? generally
abnormally high levels of bilirubin in the blood
where is bilirubin conjugated?
in the liver
where can conjugated bilirubin go to? (3)
- excreted in the urine
- released in the bile and excreted in stool
- released in bile and reabsorbed in small intestine back into blood
How does phototherapy work to reduce jaundice?
converts unconjugated bilirubin to isomers of bilirubin that can then be excreted in urine and stool
(bypasses the liver function)
Why is physiological jaundice common?
- high conc of RBC in fetus + neonates + liver function less developed
- fetal RBC breakdown more rapidly than normal RBC and normally excreted by placenta
RF for pathological jaundice?
- Premature
- SGA
- Prev sibling requiring phototherapy
- exclusive breast feeding
(- jaundice <24 hrs)
is breast feeding or bottle feeding a RF for pathological jaundice ?
breast feeding only is a RF for pathological jaundice
What 2 categories can pathological jaundice be split into? give examples
- increased production: haemolytic disease of newborn, ABo incompatibility, haemorrhage, sepsis + DIC, G6PD deficiency
- decreased clearance of bilirubin: prematurity, breast milk jaundice
baby presents with jaundice in <24 hrs of life. what differential do you need to consider?
sepsis! need to consider
what is haemolytic disease of newborn? caused by?
caused by incompatibility of RBC surface rhesus antigen between mother and fetus (after prev pregnancy with sensitisation)
what is the management of neonatal jaundice?
- Measure and plot serum bilirubin (SBR) levels on treatment threshold chart (specific for GA of abby at birth)
- if above threshold level for phototherapy: commence
- increase no. of phototherapy lights as SBR approaches transfusion line
When do you stop phototherapy in jaundiced neonate
continue till >50 um below threshold line
What is the main concerning complication of neonatal jaundice? explain
kernicterus: brain damage caused by excessive bilirubin levels
- bilirubin crosses BBB => damage to CNS =>. CP, LD + deafness
Which structure/s in the brain does excessive bilirubin affect?
basal ganglia
What is necrotising entercollitis?
serious + sometimes fatal GI infection of typically formula fed preterm infants => bowel perforation => peritonitis + shock
What is the cause of NEC
unclear, not really understood
may be infective - E.Coli ?
NEC RF?
- v low birth weight or v preterm
- Formula fed
- sepsis
- PDA
NEC presentation?
premature neonate wo becomes intolerant to feeds, starts vomiting, generally unwell, adobo distention/tenderness, absent bowel sounds, blood in stool
what would the vomit in NEC be like?
bilious or blood stained
What investigation would you do for suspected NEC?
- FBC, CRP, blood cultures (if sepsis suspected)
- abdo XR (diagnostic)
what would be seen on abdo XR of neonate with NEC?
- dilated loops of bowel
- Bowel wall oedema (thickened bowel walls)
- Gas in bowel wall or peritoneal cavity (bad sign)
what is the management of NEC?
- Bill by mouth with IV fluids + TPN + IV Abx
- AXR
- Surgical emergency
complications of NEC surgery?
- Intestinal stricture
- Short bowel syndrome
What is meconium aspiration syndrome? when?
respiratory distress in newborn infant following aspiration of meconium stained amniotic fluid (antenatally or at birth)
describe pathophysiology of MAS?
meconium aspirated => inflam response + inhibit surfactant action
- Causes partial/total airway obstruction: thick meconium => ball valve effect => pulmonary pressure => V/Q mismatch => R ro L shunt => hypoxia
MAS RF?
things that causes fetal hypoxia or fetal gasping
- >42 weeks gestation
- fetal distress
- maternal smoking
Clinical features of MAS?
- signs of RDS (high RR + HR, cyanosis, grunting, nasal flaring, recessions, hypotension)
- mecpmium stained liquor
- preterm ( I think )
what investigations would you do for MAS? what would they show? diagnostic test?
(clinical diagnosis)
CXR: increased lung vol, asymmetrical patch pulmonary opacities
management of MAS?
depends on severity of RDS
- Observation, ventilation, Abx (if infection indicated), surfactant
More than 90% of SIDS deaths occur before babies reach how many months?
6 months
What percentage of pregnant women carry Group B Streptococcus in their genital tract?
25%
What percentage of breast fed babies have jaundice at 1 month?
10%
(Higher risk than bottle fed)
A 3 day old neonate is though to have Hirschsprung’s disease. What is the gold standard for investigation?
Rectal biopsy
What septal defect is most common in those with downs syndrome?
atrioventricular septal defect
what is neonatal hypoglycaemia ? under what value ?
neonatal hypoglycaemia but a figure of < 2.6 mmol/L
(I think consider management when <1)
What could cause neonatal hypoglycaemia ?
- preterm birth (<37 weeks)
- GDM
- IUGR
- hypothermia
- neonatal sepsis
Feautres of neonatal hypoglycaemia ?
- asymptomattic
- jitteriness
- irritable
- tachypnoea
- reduced/poor feeding
- pallor
- weak cry
- Siezures
managment of asymptomatic hypoglycaemia ?
- encourage normal feeding (breast or bottle)
- monitor blood glucose
When would you treat neonatal hypoglycaemia ? (2) how would you treat ?
symptomatic or very low blood glucose (<1mmol/L)
- admit to the neonatal unit
- intravenous infusion of 10% dextrose
what is neonatal TORCH infection? what does it stand for ?
group of congenital conditions, infection of developing fetus inter or newborn
- Toxoplasma gondii
- Other agents
- Rubella
- CMV
- HSV
how are TORCH infections transmitted ? (3)
in utero (though placenta)
during labour
breast feeding
complications of TORCH infection ?
- miscarriage
- stillbirth
- IUGR
neonatal TORCH infection sx ? generally
- microcephaly
- lethargy
- cataracts
- hearing loss
- CHD
neonatal TORCH infection Dx ?
- prenatal: history, fetal abnormaliels
- pre/postnatal: PCR testing, viral cultures, antibody testing
TORCH Mx ?
Abx or antivirals
- supportive care
What is oesophageal atresia ? often associated with ?
rare condition wehre oesophagus no formed properly so not connected to stomach
- trachea-oeophgeal fistula ends to occur alongside OA: oesophagus is joined to trachea
how is oesophageal atresia diagnosed ?
- sometimes seen antenatally
- ty to pass NG tube but does not work
oesophageal atresia Mx ? complication of this ?
surgical
- post surgery: increased risk of tracheomalacia (due to floppy wind pipe)
what does atresia mean ?
a complete blockade (obstruction or lack of continuity
what is the most common location for small bowel atresia ?
jejunoileal atresia: most common type of neonatal intestinal obstruction
how is small bowel atresia Dx ? describe the findings
prenatal US
- dilated bowel
- double bubble (duodenal atresia)
small bowel atresia Px antenatally ? explain
polyhydramnios (usually baby continuous swallow amniotic fluid by can’t due to blockage)
- this => increase risk of preterm birth
small bowel atresia Mx ?
surgical repair
