Prematurity Flashcards
What counts as premature?
born before 36 wks
What is low birth weight?
birth weight <2.5kg
regardless of gestational age (50% are pretern)
(norm = 2.5-4.5kg)
What weights cound as very low birth weight and extremely low birth weight?
VLBW = <1.5kg regardless of age
ELBW = <1kg regardless of age
What may cause prematurity (risk factors)?
- Cervical incompetence
- intrauterine stretch
- intrauterine bleeding
- maternal medical conditions
- foetus
- trauma
- PMhx preterm birth
- SMOKING”
What can cause intrauterine stretch making it a RF for prematurity?
- multiple foetueses
- polyhydramnios
- uterine abnormality
What can cause intrauterine infection making it a RF for prematurity?
- chorioamnionitis
- bacterial vaginitis
What can cause intrauterine bleeding making it a RF for prematurity?
Abruption
APH (bleeding from or into the genital tract occuring from 24+0 weeks of pregnancy)
What can cause maternal medical conditions are a RF for prematurity?
PET or HTN
pyelonephritis
What can cause foetal conditions are a RF for prematurity?
congenital malformations
IUGR
What can trauma is a RF for prematurity?
where emergency section is indicated e.g. PROM
What general care problems can prematurity cause?
Rx?
- hypothermia from:
- large surface area:mass ratio,
- thin skin &
- little subcut fat
hypothermia leads to increased energy consumption –> hypoxia, hypoglycaemia, failure to thrive & death
- incubator/radiant heaters!
Respiratory distress syndrome
pneumothorax
apnoea, bradycardia and desaturation episodes
are all what?
problems / complications of prematurity
when a baby takes their first breath there is supposed to be a fall in pulmonary vascular resistance
if this doesnt happen what conditon does it result in?
-> pulmonary HTN!
this interrruption of normal fall in pulm vasc resistance w/1st reath is can be due to:
- meconium aspiration
- pneumonia
- RDS
- diaphragmatic hernia
- GBS infection
- pulmonary hypoplasia
You suspect pulmonary hypertension in a neonate.
What test do you (Ix) do and what would it show?
Echo
- shows R–>L shunting (cyanotic, due to high pressure) at ductus arteriosis
- IN ABSENCE of structural heart disease
What is ECMO?
- Extra-corporeal membrane oxygenation - complex procedure available in 3o units - can be used in pulmonary HTN
- Providing life support for respiratory failure (&cardiac)
- for those whose heart and lungs are unable to provide adequete life sustatining gas exchange
- obviates the need for lung gas exchange
What are very low birth weight babies particularly at risk of? [VLBW = <1.5kg regardless of age[
Apnoea / desaturation
This neonatal condition can be spontaneous or have an underlying cause including:
- infection,
- hypoxia,
- anaemia,
- electrolyte disturbance,
- hypoglycaemia,
- seizures,
- heart failure,
- aspiration due to GORD
what condition is it? & Rx?
Apnoea / desaturation
Prevention: maternal corticosteroids (23-34wks gestation)
management is that it is mostly self limiting, if not:
- Airway: Check airway
- Breathing:
- Gentle tactile stimulation
- CPAP
- Methylxanthine e.g. caffeine (used in babies <28wks to stim breathing)
- Mechanical ventilation if the above do not succeed
A CXR of a neonate shows areas of opacification and cystic chenge also hyperinflation and radiolucent areas alternanting with thin, denser lines.
What condition is this related to & its Rx?
its is bronchopulmonary dysplasia caused by pressure & volume trauma from artificial ventilation, O2 toxicity & infection.
The neonate is @ risk of developing chest infections
–> Rx: give monoclonal abtibody to RSV (commonest cause of bronchiolitis)!
What do patent ductus arteriosus and shock represent regarding newborn conditions?
PDA and shock are both cardiac problems/complications of prematurity
A neonate has raised HR, low BP, low UO & is in a coma. What is this?
What could have caused it?
SHOCK!
-
Blood loss
- placental haemorrhage, Twin-twin transfusion, intraventricular haemorrhage, lung haemorrhage
-
capillary plasma leaks
- sepsis, hypoxis, acidosis, necrotising enterocolitis,
-
fluid loss
- D&V, inappropriate diuresis
-
cardiac causes
- hypoxia, L-R shunts, valve disease, coarctation
a neonate is vomiting, has distended abdomen, blood in stools and appears septic/shock
What could be causing this and why?
Necrotising enterocolitis
younger gest. age = more likely to have this
possible causes =
- bowel infection,
- milk feeds (6x greater risk compared to breast milk),
- hypoxia-ischaemia of bowel
an AXR of a neonate shows:
distended bowel loops,
thickened bowel walls,
intramural gas & air in portal tract
what condition is this? & its complications?
necrotising enterocolitis
short term complications:
-
necrosis & bowel perforation
- will see air under diaphragm on AXR if bowel perforation
long term complicatons:
- malabsorption & strictures (25% mortality!)
How do you manage neonatal shock?
- ABCDE,
- colloid 10-20mL/kg IV as needed,
- inotropies e.g. Dopamine, dobutamine
How do you Rx necrotisin enterocolitis?
- ABC support
- Broad spectrum abx
- parenteral nutrition (as gut isnt functioning!)
- surgical correction if bowel perforates
What do the following conditions relate to?
- Jaundice
- Cholestatic obstructive jaundice
- Acute renal failure
renal/liver complications of prematurity
What do the following conditions relate to?
- Hypoglycaemia
- Electrolyte abnormalities
- Osteopenia
metabolic conditions/complications of prematurity
A premature neonate presents with visual loss what condition causes this and what is the management?
retinal detachment caused by abnormal fibrovascular proliferation of retinal vessel = retinopathy of prematurity
RF: premature, low birt weight (<2.5Kg), supplemental oxygen especially with large fluctuations in PaO2
Rx: diode laser therapy (causes less myopia (short sightedness) than cryotherapy
A baby is born at <27wks old when should they be screened for retinopathy of prematurity using indirect opthamoscopy?
if they were born at 27-32 weeks when should they be screened using indirect opthalmoscopy?
~4 weeks after both times
- so if < 27 wks do it at 20-31 wks age
- if 27-32 wks do the check at 28-35 days of life –> repeat 2 weekly depending on severity of disease
- sensorineural hearing loss
- retinopathy
are related to what?
vision and hearing impact of prematurity
- Neurodevelopmental problems - cognitive delay, seizures, education difficulties, behavioural problems, cerebral palsy
- Hydrocephalus
- intraventricular haemorrhage
- hypoxic-ischemic encephalopathy
- neonatal seizures
are related to what?
neurological complications of prematurity
- anaemia
- Impaired leucocyte function
- Septicaemia, meningitis
- Urinary tract infection
- Fungal and viral infections
are related to what?
haematology and infection complications of prematurity
+ anaemia of prematurity
How do you treat anaemia of prematurity?
Anaemia of prematurity -
iron supplementation is required for up to 6 months to correct
- Parental anxiety and distress
- Family relationship disruption
are related to what?
social complicatons of prematurity
What causes mortality in prematurity?
mortality in prematurity is mainly due to:
- infection of the resp tract (from impaired leucocyte function) or
- brain injury
unsupported blood vessels in the brain and unstable BP (can get this from birth trauma & resp distress) in can cause 1/4 premature babies to have what?
risk factors: include perinatal asphyxia, RDS & pneumothorax
intraventricular haemorrage
- bulging fontanelle
- seizures
- cerebral irritability
- asymptomatic
How do you investigate intraventricular haemorrhage in neonate?
- USS through fontanelle (sx: is bulging fontanelle)
- MRI
What does delayed cord clamping help prevent?
Intraventricular haemorrhage!
complications of IBH = lower IQ, CP, hydrocephalus Rx (LP, ventricular tap, VP shunt)
hydrocephalus is a complication of IVH. What is the Rx for hydrocephalus?
hydrocephalus Rx:
- LP,
- ventricular tap,
- VP shunt
What do you call brain injury secondary to hypoxic-ischaemic insult? and what can cause the hypoxic-ischemic insult?
Hypoxic-ischemic encephalopathy (HIE)
can be caused antenatal, intrapartum or postpartum e.g.
- cord prolapse
- placental abruption
- maternal hypoxia
- inadequate postnatal CPR
After placental abruption a woman gives birth to a baby who is experiencing respiratory depression, is acidotic within 24h of birth. What is this?
Rx?
hypoxic ischaemic encaphalopathy
(sx: of neonate encephalopathy - dc consciousness, seizures, difficulty maintaining and initiating respiration, depression of tone and reflexes)
Rx:
- resucitation,
- avoid hyperthermia - therapeutic hypothermia in term babies reduces death and disability,
- exclude other causes of encephalopathy, monitoring and rx of seizures.
When do neonatal seizures commonly occur?
12-48hrs after birth
they can be generalised, focal, tonic, clonic or myoclonus
What do these all represent?
- Hypoxic-ischaemic encephalopathy (antenatal or intrapartum hypoxia)
- Infection - meningitis, encephalitis
- Intracranial haemorrhage/ infarction
- Structural CNS lesions - focal cortical dysphasia, tuberous sclerosis
- Metabolic disturbance - hypoglycaemia, low Ca, high Na, low Mg
- Metabolic disorders - urea cycle disorders, amino acid metabolism
- Neonatal withdrawal from maternal drugs or substance abuse
- Kernicterus
- Idiopathic e.g. Being 5th day fits
they are all causes of neonatal seizures
How do you diagnose neonatal seizures?
:there are subtle signs, TF–> EEG can confirm seizure activity
also look for cause (part of Rx for neonatal seizures)
- Cerebral function analysis monitoring (CFAM) if available
- US or MRI head
- Toxicology screening,
- serum ammonia, urine organic acid, (urea cycle disorders)
- serum amino acids, (amino acid metabolism)
- karyotype,
- TORCH screen (neonatal infections screen)
How do you rx neonatal seizures?
ABCDE, turn on side
- Rule out reversible causes e.g. Hypoglycaemia
- Commence empirical abx
- IV access & bloods - FBC, U&E, LFTs, calcium, Mg, glucose, blood gas
- Treat cause
- STATUS (>5mins) *see notes*
- HYPOCALCAEMIA - calcium glauconite, monitor ECG
- HYPOMAGNESAEMIA - MgSO4 IV
Where should peterm babies be looked after?
whats their prognosis at >32 weeks and at 23-26wks?
Delivery should take place in a centre capable for caring for preterm babies
Adequate resuscitation once born –> NICU/SCBU
- >32 weeks have excellent prognosis
- 23-36 weeks, babies will develop many problems & will have to remain in hospital for many weeks - overall mortality is high
What feeding do neonates/preterm <1.5kg need?
<1.5kg =
- phosphate supplementation + supplemental calories,
- protein,
- vit D,
- calcium
What feeding do babies <2kg need?
<2kg:
supplemental breast milk or low-birth-weight formula
[if under <1.5kg phosphate supplementation + supplemental calories, protein, vit D, calcium }
What age preterm baby needs an oro- or nasogastric tube?
if <35weeks
if very premature (<30wks) = need parenteral feeding
What monitoring does a neonate have?
- Vitals
- Temp,
- pulse,
- BP (intra-arterial if critical)
- respirations,
- Bloods:
- blood gasses,
- U&E,
- bilirubin,
- FBC,
- General
- weight ,
- weekly Head Circumference
Regarding the ethics of intervention in extreme premature neonates.
What is considered so premature/small that it has a negligible chance of survival and with parents permission a ventilator can be switched off?
- Neonate <24wks or <500g has a negligible chance of survival
- With parents’ permission a ventilator can be switched off
- [NB: >32weeks have excellent prognosis
23-36weeks, babies will develop many problems & will have to remain in hospital for many weeks - overall mortality is high]
