The care of premature newborns constitutes
a huge percentage of the
role of a neonatologist.
We’re going to go through, in this lecture,
the major issues that show up
as a result of prematurity.
Remember, a premature infant is any
infant born under 37 weeks of age.
This is about 10% of U.S. infants
and we break them down
For instance, a child who is
born between 34 and 37 weeks,
we might define as late preterm
because these infants often
don’t have any problems.
In infants who are less than 32 weeks,
we won’t just call them preterm,
we will call them very preterm.
And in infants who are born less than 28
weeks, we might say extremely premature.
So what are the major problems
that happened to these infants?
Well, prematurity affects
multiple different organ
and I’m going to go through them
and we’re going to describe some
of the main problems that happen.
In the pulmonary system, patients may
develop respiratory distress syndrome.
They also might just have apnea
where they stop breathing
because the brain is not pretty
mature to regular their breathing.
They may also long-term
develop chronic lung disease,
perhaps as a result of some
of the therapy we provided
for their respiratory
Premature infants are more
likely to have heart disease,
for example, a patent
Premature infants are more
likely to have renal disease,
especially they can have acid-base
disturbances or electrolyte disturbances.
Or they may progress to renal failure.
Eye problems are a classic
problem in a premature infant
who has been exposed
to too much oxygen,
specifically they may get
retinopathy of prematurity.
The GI tract can be a real problem
in extremely premature infants.
They are at increased risk for
and they may develop
And lastly, the brain can
certainly be affected.
Associated with premature
birth is an increased risk
for hemorrhage inside the brain
in the peripartum period.
Patients may also get a mild sort of
damage called periventricular leukomalacia
or they may just develop seizures.
So, all of these are potential
problems in a premature infant.
Let’s start with respiratory
This is probably the single entity
that takes up the most time
on any one patient in the
neonatal intensive care unit.
So RDS or respiratory distress syndrome
is caused by a low level of surfactant
in the lung in a premature
baby or at the time of birth.
This affects 90% of premature babies.
Its severity is related to
how premature the infant is.
So, younger infants who are born earlier
are going to have more severe disease.
Let’s have a timeout and
talk about surfactant.
Surfactant is produced by
the type 2 pneumocyte.
It’s like a lubrication
for the lung.
And what this allows for is efficient
inflation in atelectatic lung.
Let’s say you’re
blowing up a balloon.
You can remember doing this.
When you started blowing
up the balloon,
it was very hard to blow up the
balloon getting it started.
As a child, you remember blowing
really hard to get it started
and then once that it had
gotten better, like this child,
it could just keep expanding.
What’s going on is LaPlace’s law.
This is a basic law of physics.
The tension on that balloon
is higher when it is smaller.
So now imagine you are an infant
and your lungs are really millions
and millions of very small balloons
and you’re taking
your first breath.
You’re trying to inhale and
inflate all these tiny balloons.
If we don’t have this lubricant present,
this infant is going to have a
horrible time inflating their lungs.
This is respiratory distress syndrome.
They can’t inflate their lungs
and when they’re breathing,
the lungs might collapse down and
be very hard to inflate again.
That natural lubricant that lets this
happen is the surfactant and it’s missing.
As a result,
we need to diagnose these infants
who are having respiratory distress
early in childhood.
These infants will have a
very classic chest x-ray,
which you can see a picture of here.
We call this a ground-glass appearance.
It’s a diffuse, sort of haziness
throughout all the lung fields.
All those millions of atelectatic alveoli
are in that X-ray clouding things up,
so this is the ground-glass appearance you
will see in respiratory distress syndrome.
We see this on x-ray, we know
it’s a premature infant,
we’re pretty sure we
know what’s going on.
These patients will usually develop respiratory
distress within four hours of birth.
If we know infants are going to be
born early and we have some time,
we could hold off
on that delivery.
We can give the mother steroids.
By giving the mother steroids,
it actually reduces the morbidity and
mortality of the infant after they're born.
This is because the steroid
enhances lung maturation
and improves surfactant expression
in the baby after birth.
We also may give this
infant some surfactant.
So what you can do is you could intubate
and you can spray artificial surfactant
down into the lungs to
help lube things up.
As we’re caring for these infants
and we’re managing their breathing
generally on the ventilator,
we want to reduce the amount
of pressure we’re providing.
That’s because long-term exposure to
pressure is causing damage to those lungs
which can result in a chronic
lung disease of infancy.
But also we don’t want
to give too much oxygen.
This is a tricky balance.
We avoid excessive oxygen because oxygen
causes damage to the eyes in infants
because of free
So these infants can develop a retinopathy
of prematurity that can result in blindness.
We want to avoid extra pressures because
of that concern of chronic lung disease.
So with these two things together,
we have to be very careful about our
management of these children’s ventilators.
Sometimes, we put them on oscillators
where the respiratory
rate is very, very high
and it’s just oscillating
the air in there.
Other times, we will usually
allow for a high CO2 level.
We call it permissive
It’s okay if this child has a little
bit of a respiratory acidosis,
I’d rather that than lung
disease or blindness.