So, if we have a child who we’re
worried about dehydration,
we’re going to generally
give a bolus of fluid.
But additionally, we want to typically
calculate a child who’s not drinking
what their maintenance is.
Maintenance is how much fluid
an average human needs
to continue to survive
generally per hour.
And we’re going to add
on top of maintenance
any ongoing insensible losses
that this child may need.
To calculate maintenance, I
want you to use the 4-2-1 rule.
It’s a little bit easier
than the 150-25 rule,
which is calculating
Let’s focus on 4-2-1 from
a practical standpoint.
for the first 10 kilograms of a patient,
their maintenance is 4 cc
per kilogram per hour.
For their next 10 kilograms, you’re
going to add 2 cc per kilogram.
And for every kilogram of weight after
that, we’re going to add 1 cc per kilo,
This is confusing to a lot of people,
so I’m going to go through a few example
calculations just to make it really clear.
Here is a 4-kilogram child.
They have less than 10 kilograms.
So, every single kilogram they’re going
to get is going to get 4 per kilogram.
So, 4 x 4 is 16.
This child needs 16 cc per
hour of maintenance fluids.
Here’s a child who
weighs 16 kilograms.
For the first 10 kilograms,
they need 4 cc per hour.
For the next 6
kilograms, they need 2.
So, that’s 12;
40 plus 2 is 52.
So their total requirements
are 52 cc per hour.
One more example to make
it perfectly clear,
if we have a 37-kilogram child, we do 4 for
each of the first 10 kilos, that’s 40.
We do 2 for each of the first 10 kilos, that’s 20.
And we do 1 for each of the
subsequent 17 kilos, that’s 17.
Add 40 + 20 + 17 and we get 77 ccs
per hour of maintenance fluids.
The 4-2-1 rule.
However, IV fluids can have complications.
We can misestimate the
amount of sodium required
or the situation that a child has.
So it was a general rule of thumb we
want to try to use the gut first.
The first thing we’ll try is we’ll
simply ask the child to drink.
No matter how dehydrated a child is,
if a child is capable of drinking,
they’re probably going to be up to
drink themselves back into health.
So, we’ll get them
something to drink.
We often will choose something
like oral rehydration fluid.
For example, Pedialyte, which is
marketed in the United States,
or World Health Organization
Any of these things are fine.
These have some salt in them.
Remember, Gatorade doesn’t have
salt in it, it’s just sugar.
People sometimes think that it does
because of a good advertising campaign,
but it doesn’t.
We really want to use oral rehydration
fluid, especially in the younger infants.
Milk and fatty drinks are
sometimes what a child wants,
but especially in a child who’s
vomiting, we like to avoid fatty things
because they have a slower
stomach transit time,
and that child may be more likely to vomit
than if they are drinking the Pedialyte.
Additionally, and especially
with vomiting children,
we will often add ondansetron empirically,
especially in gastroenteritis
because it has been shown to improve the
odds of success of an oral challenge,
and therefore, prevent
Don’t give up on the oral route
yet if the child won’t drink.
Especially in younger kids,
we can do syringe feeding.
Here’s what we do.
We calculate what maintenance
is using the 4-2-1 rule.
Add a little extra if the patient
has ongoing losses like diarrhea.
And then we ask the
parent or the provider to
divide this amount of hourly
into 10 to 20-minute intervals.
So if the child needs 60
milliliters in an hour,
they can get 10 to 20 milliliters
every 10 to 20 minutes,
and they’ll end up
being the same amount.
Now, we place that
into an oral syringe
and literally squirt it physically into
the child’s mouth every 10 to 20 minutes.
Within a few times, the child will be used
to doing this, and will complain no longer,
and oftentimes, this attempt, if you have
the time to teach a concerned parent,
will prevent IV
administration of fluids.
Lastly, we can also give
the patient an NG tube.
The NG tube is placed into the stomach and
is effective even in a vomiting child.
For a bolus through the NG, we’re going
to give 50 to 100 cc per kilogram
of Pedialyte over three to four
hours by a pump continuously.
This seems like a lot of fluid.
If you’re worried especially in the
larger kids, I’ll bump it down to 50.
Then, calculate maintenance and run the
childhood maintenance through the NG tube.
This can be more effective than IV fluids
if the child is willing
to keep an NG in place.
Typically, it’s your two or three-rule
that will be ripping out the IG
and it may not be worth a bother
and you’ll have to go with the IV.
So we have all else fails,
we’ll consider an IV.
Clysis is not used in most center but is
out there, so I wanted to mention it.
It’s actually an IV that’s placed into the
skin often after injection of hyaluronidase,
which allows for the
skin to absorb fluids.
You can run maintenance
fluids directly into skin.
We learned about this
in veterinary medicine
and it actually works in kids and adults
too, it’s just not commonly employed.
When it is employed, we typically
use the exact center of the back
so the child can’t get
to their clysis tube.
When you decide to give IV fluids,
what are you going to use?
This is a moving
area in pediatrics.
Previously, students were taught that
we might use quarter normal saline
in very small children because
they don’t need that much sodium.
This is actively changing in pediatrics,
and it has to do with making mistakes and
what error are people likely to make.
It does not change because people
feel that children need more sodium.
Allow me to explain.
Here, I have a patient who’s
receiving hypotonic fluid
and a patient who’s
receiving normotonic fluid.
There is a risk in
If I give all my patients hypotonic
fluid like quarter normal saline
for those very small
children under 10 kilograms,
which would be appropriate from how much
sodium do I need every day standpoint.
The problem is I may miss a case of hyponatremia
especially in a patient with SIADH.
So, I worry about unrecognized SIADH
and just routinely giving
quarter normal saline
because that will further
drive down their sodium level
and put them a risk for seizure.
If I were to give everyone in
the hospital normotonic fluid,
there would not be that risk as much of
too much fluid in the setting of SIADH.
But instead, you might
say, “Wait, wait, wait,
you’re giving too much sodium in a
patient who has renal failure.”
The thing is that you are much
more likely, in pediatrics,
to have a patient who
has unrecognized SIADH
than you are to have a patient with
unrecognized end-organ renal failure.
So, a patient with renal failure
is going to be edematous,
be sick, be peeing blood, you’ll know
that this child has renal failure.
But unrecognized SIADH is downright common.
We see unrecognized SIADH
routinely in meningitis,
pneumonia, gastroenteritis, bronchiolitis.
Anywhere, there’s a cell
that can make SIADH
like the lungs, the meninges, the
intestines, we can have unrecognized SIADH.
So because that risk of
error is more common,
most centers are moving now to
using more normotonic fluid.
We can use the D5 half as a way to
make a guess right in
between, mitigate both risks.
But typically, we’ll either use
normal saline or half normal saline.
There is a concern in
excessive normal saline use
of worsening acidosis because
of all the chloride.
So that’s something to think about in
an acidotic patient as well though.
There is benefit because in
the hypotonic fluid case,
you’re giving less sodium in the event of
unrecognized renal failure,
which is very rare.
But there’s a huge benefit
in normotonic fluids
because you’re less likely to
cause hyponatremic and SIADH.
I feel like that’s a pretty clear
point but one that should be made.
So we’ve resuscitated the dehydrated child.
We gave normal saline boluses, 20 per
kilo, until that child has recovered.
And now, we’re selecting
a maintenance IV fluid.
We can’t use the oral tract the
child is refusing to drink
and he’s going to rip
out his NG tube.
What do we choose?
Well, first off, you’ll notice
we do D5 normal saline.
Again, not hypotonic fluid because we’re
worried about that unrecognized SIADH.
The dextrose, I’ll get to in a second,
but first, I want to talk a
little bit about potassium.
We’ll typically add 20 milliequivalents
per liter of potassium
into the IV fluids if the child is NPO
and the child does not
have renal insufficiency.
Some practitioners prefer
to wait for the child
to urinate once before
That’s really an incredibly rare thing to
have unrecognized renal insufficiency,
but you might think about it
in the critical care setting.
We always add that dextrose, that D5, which
is 5% dextrose to pediatric patients
because again, they have lower
stores of glycogen in their livers
and they’re at grave
risk for hypoglycemia.
You’d be crazy not to add dextrose
especially in a child with gastroenteritis.
For severe dehydration, we’re going
to start by giving the bolus,
and that bolus again is 20 milligrams per
kilo as an IV bolus over 20 minutes.
And you keep repeating those boluses
until the child has stable vital signs.
When I say keep repeating, we’re
talking about maybe three times.
If you’re entering your fourth bolus,
that child probably is not going
to respond to further hydration,
and you really need an
agent like dopamine.
And excessive overhydration and
overbolusing may cause a pulmonary edema.
So you want to be
careful with that.
For severe hypoglycemia, if a
child has a very low glucose,
we will typically give 5 cc per
kilo of D10 via a peripheral IV.
That will emergently raise the
sugar so they don’t seize,
and then we’ll go back to the start and
provide them with maintenance fluid.
So, how do you know
if it’s working?
Well, the best way is simply
to follow the urine output.
And we have to be careful to weigh every
single diaper that comes out of that child.
Optimal normal output in any patient of any
age is more than 1 cc per kilo per hour.
So, if I have a 10-kilo child and
I’ve been watching them for 12 hours,
I expect 120 milliliters of water or urine
coming out of them in terms
of diaper management.
The problem is if they have diarrhea, you
may be also weighing insensible losses
and you may be missing the fact that this
child is in fact getting dehydrated.
So we can’t purely rely on urine output,
we have to rely on other things as well
like the patient’s physical exam and
looking for signs of dehydration.
So, what are the signs of
dehydration that we look for?
Well, we’re going to continue to
follow that normal skin turgor,
which is the worst and
last thing to change.
We’ll continue to look for normal
mental status, which is a late finding.
We will watch for mucous
membranes becoming dry.
That is an early finding, and
in fact perhaps, the first.
And last is the normal heart rate, which
we will keep an eye on, but remember,
these children in the
hospital setting are
afraid, may be in pain,
may not like their IV,
and all of these things can
artificially raise their heart rate.
It’s not necessarily true
that they have dehydration.
Watching their heart rate
over time is important
especially at those times when they’re
cuddled in their parent’s arms,
so you can really start
to see a difference.
That’s everything I have
for you today about
dehydration and IV management
of fluids in children.
Thanks for your attention.