So children can also have secondary
causes of hypercoagulability.
This includes disease entities like any
sort of cancer in teens who smoke,
patients who are on oral contraceptives
can absolutely get clots;
immobility, for example,
on an airplane flight.
Patients with lupus might have
or patients with no lupus might
also have that condition
and those patients are at
increased risk for clots.
Especially, neonates may have
indwelling lines that can form a clot
around the spot of that line and that’s
something we have to keep an eye out for.
Patients with liver or kidney disease
may occasionally develop a
and certainly patients with vasculitis do
because of the endothelial wall damage.
Of course, patients with sickle
cell can and do form clots
during their childhood period.
What we should think about in patients
is that the more risk factors they
have for a hypercoagulable state,
the more likely they
are to form clots.
So a teenager who is on oral contraceptives
and that’s their only risk factor,
it’s very unlikely they
will actually form a clot.
However, if they are obese,
frequently immobile and they smoke,
now we might have a big problem.
So what’s key is that
children who form the clot
are most likely to
have multiple causes
or multiple different causes
within that Virchow’s triad
and that’s we have to think about in
terms of a child who is having a stroke
or an MI or other problems
along those lines.
How do we treat the hypercoagulable state?
Certainly, children may be placed on
low molecular weight heparin subQ.
is a shot every day
and obviously, children especially the
little one who don’t understand why,
don’t like this very much.
These are daily injections.
The other thing is different than adults.
It’s in children we do have to check an
anti-factor 10A level to verify our dosing.
So in adults, that’s not necessary,
but in children after the third dose,
we’ll get an anti-factor 10A level
to verify that the dose is correct
and we will adjust it
based on that level.
In the acute setting, we
can certainly use heparin.
Of course, that’s IV only and we
titrate it to the correct PTT desire.
It’s every 6 hours, so this is really
limited in hospitalized patients.
If we have a patient who we
want to place on oral agents
for preventing hypercoagulability
which is quite rare in children,
we will probably use warfarin.
It’s an anticoagulant
that inhibits vitamin K
and so it’s quickly reversible
in the event that we’ve
overdosed in a patient who
is having bleeding problems.
The initiation of warfarin, remember,
is associated with an
inhibition of protein C and S,
which are also
vitamin K dependent.
As a result, we will often
start warfarin in concert
with heparin or low
molecular weight heparin
and then once we have
been on for a while,
we will then turn off the heparin
and continue the warfarin.
There are newer agents
out there that are
oral anticoagulants that you’ve
heard about in adult medicine.
Drugs like dagibatran or rivaroxaban
All of these are oral agents
that have some advantages
over the warfarin which
also an oral agent.
In particular, they are less likely
to cause sentinel bleed events
and we don’t have to follow the levels
very carefully like we do with warfarin
or we’re constantly following that INR.
Alternatively, for patients
who have an acute clot,
we may decide to try to
break open these clots.
This is called
Examples are TPA or urokinase.
We do use these drugs commonly
in complicated pneumonia
but not really for clots.
So for example, in a complicated pneumonia
where we have placed a chest tube
and we want to break open
those fibrinous areas within
the complex pulmonary
we will inject the TPA or
urokinase into the chest tube
as a way of breaking up
those fibrinous bands.
But these drugs are
rarely used in children,
it’s not that we don’t care about a
child who has just had a stroke,
the problem is that strokes in children
can present so nonspecifically
and they are so incredibly rare
that it's unlikely that we’ll have figured
out that the child is having a stroke
prior to the time it will take to
actually have an affected period
when the thrombolytic
therapy can be used.
Again with thrombolytic therapy, we
worry about significant risk of bleed.
So it’s unlikely you will see this drug
used in children for an acute clot breakup.
So that’s my summary of the
hypercoagulability in children.
Thanks for your attention.