Let’s switch a little bit
to surfactant deficiency
as this is a subset of those
patients with chronic lung disease,
but it’s an important subset.
So these are infants
who are born
with an inadequate amount of
surfactant in their lungs.
Let’s pause for a moment.
What is surfactant?
As you recall from you basic
surfactant is a soap-like molecule with
a hydrophilic end and a lipophilic end,
usually a long
series of carbons.
That hydrophilic end
likes to stick together
and the lipophilic end
likes to stick together.
So inside the lung, you will see
this stuff accumulating such that
the fatty ends are facing up and the
hydrophilic ends are against the wall.
What this allows is it allows patients to
easily inflate and expand their lungs.
A deficiency of surfactant
can result in anything
from mild to severe
as these infants are less
able to expand their lungs.
So decreased surfactant will result
in increased surface tension,
which results in atelectasis
and areas of lung collapse
as it is harder to keep
that lung inflated.
In infants with
they are usually in respiratory
distress within minutes of birth.
Breath sounds sound normal,
decreased, or they may have crackles.
A blood gas will show
a decreased PaO2,
and later an increased
respiratory acidosis, a PaCO2,
and, because of poor oxygenation
in the distal tissues,
a metabolic acidosis as well.
The differential diagnosis
for these patients is broad.
This could be something as simple as
transient tachypnea of the newborn,
which is simply an inadequate clearance
of amniotic fluid from the lungs
in a child usually who underwent a cesarean
section as opposed to vaginal birth.
However, this could be something
serious, like sepsis,
or maybe the patient has
a lack of development of
some area of the lung.
The child might have
This usually happens in infants with
distress during the birthing period
and they will reflectively defecate
and aspirate that defecation
while still inside the mother.
Alternatively, this child might
have congenital heart disease
and really is needing prostaglandins
to keep their duct open
that this really isn’t
a surfactant problem
or, alternatively, this child may have
a congenital abnormality of the lung.
So there are many
possible things going on
that might be causing this
child’s respiratory distress.
So how do we make a diagnosis
of surfactant deficiency?
There is a classic X-ray
appearance in these children,
which is called a ground
As you can see on this
X-ray on this slide,
these patients will have a
clouded, diffuse lung field,
which looks almost like you’re
looking at ground glass.
The margins of the heart are appropriate
There are no masses, there
are no other problems.
This a classic picture of
If these patients have it, we can
prevent it before it even happens.
One way to prevent anything
like this is to give a mother
who is about to deliver a
premature infant corticosteroids.
So mothers who are about to
deliver infants who are premature
will often be given a
course of steroids.
What the steroids do inside the
mother is they travel into the fetus,
into the baby,
and they promote both surfactant production
and lung maturation in the
infant before the child is born.
So children who are exposed
to steroids given to mom
have a better outcome from
a respiratory standpoint.
Premature babies, after birth, where
there is surfactant deficiency,
will often get
This is provided through
intubating the baby
and then blowing the surfactant
down into their lungs.
This artificial surfactant takes the place
of the deficiency of their own surfactant
and allows those lungs inflate.
They will often get
positive airway pressure
to help blow open those lungs
and relieve the atelectasis.