Complications of prematurity Flashcards
Definition of prematurity
less than 37 weeks of completed gestation
Definition of extremely preterm
<28 weeks
Definition of very preterm
28 to 32 weeks
Definition of moderate to late preterm
32-37 weeks
What is the neonatal period?
first 28 days of life
Low birth weight cut off
<2.5kg
Very low birth weight cut off
<1.5kg
Extremely low birth weight cut off
<1kg
Levels of care for premature babies
intensive care
high dependency
special care
transitional care
Risk factors for preterm birth
previous premature birth
pregnancy with twins, triplets or other multiples
IVF
problems with uterus, cervix or placenta
smoking cigarettes, drinking alcohol or using illicit drugs
poor nutrition
some infections eg. group B strep
some chronic conditions eg. BP and diabetes
being underweight or overweight before pregnancy
multiple miscarriages or abortions
no or late antenatal care
under 17 or over 35
Features of babies born <28 weeks
all require respiratory support (most need period of ventilation)
eyelids fused <24 weeks
thin, red skin
difficult fluid management
high risk of hypotension, infection
unable to suck, need TPN
risk of IVH
central access
long admission
500-1000g
Features of babies born 28-32 weeks
many still need respiratory support - non-invasive
may be able to feed via OG/NG tube
still at risk of complications such as NEC, infection
usually 900-1800g
Roughly when does the suck, swallow and breathe coordination kick in?
~34 weeks
Features of babies born 33-36 weeks
most able to feed if no respiratory distress
may require oxygen
better able to control temperature
weigh 1500-2200g
Why do babies develop hypothermia easily?
surface area:volume ratio
fat stores
energy demand
losses: conduction, convection, radiation + evaporation
What does BAPM stand for?
british association of perinatal medicine
Why are babies (particularly prem or sick babies) at increased risk of hypoglycaemia?
high demands
poor intake
poor reserves
lack of alternative fuels
What causes respiratory distress syndrome in preterm babies?
surfactant deficiency + structural immaturity
What does surfactant do?
helps keep alveoli open
When is surfactant produced?
bursts during pregnancy
last as ~32 weeks
Pathophysiology of respiratory distress syndrome
alveolar collapse
reduced compliance
increased dead space
inflammation
What cells produce surfactant?
type 2 alveolar cells
Characteristic clinical course of respiratory distress syndrome in preterm babies
immediate onset from birth
increased distress
low oxygen
high carbon dioxide
fatigue –> apnoea, respiratory failure, death
Characterstic xray changes of respiratory distress syndrome in babies
ground glass
air bronchograms
under-aerated
Respiratory distress syndrome in preterm babies treatment
exogenous surfactant (replacement therapy)
Other than respiratory distress syndrome, what other resp condition can preterm babies develop?
pulmonary interstitial emphysema
What causes pulmonary interstitial emphysema?
complication of mechanical ventilation
too much pressure/hyperinflation damages alveoli + allows air leakage
alveoli hyperinflate –> rupture
air escapes into interstitium
What does respiratory distress syndrome become if it is a chronic condition?
bronchopulmonary dysplasia (BPD)
When can palivizumab be useful?
in preterm babies in their first winter
RSV monoclonal antibody
helps protect them from ending up back on ventilator from RSV
What scan can be done to look for IVH in babies?
coronal section cranial ultrasound
looking for bleeding around ventricles
looks bright
What is IVH?
intraventricular haemorrhage
What is NEC?
necrotising enterocolitis
How is IVH graded?
1 = bleeding limited to small area of ventricles
2 = bleeding in ventricles but not enough to cause expansion
3 = blood presses on brain tissue, ventricle enlargement
4 = bleeding in tissues around ventricles (parenchymal)
IVH sequelae
post-haemorrhagic ventricular dilatation
porencephalic cyst
What is periventricular leukomalacia?
underperfusion of watershed regions surrounding ventricles
ischaemic insults
caused by lack of oxygen or blood flow to brain
What is retinopathy of prematurity?
Abnormal blood vessel growth in the retina, Bleeding, Scarring, Retinal detachment, and Vision loss
Most common cause of retinopathy of prematurity?
oxygen use
Retinopathy of prematurity treatment
monitoring
laser treatment
cryotherapy
