Welcome to the bed. We'll go ahead and give you
the story. This is all going to happen super
fast. Welcome to the emergency room. Welcome
back to the deep dive. Today we are wading into
waters that I think a lot of nursing students,
and honestly plenty of seasoned educators, find
pretty intimidating. We are tackling pediatric
hematology and oncology. It's a unit that, you
know, it usually comes with a heavy emotional
tax, but also just... a massive cognitive load
because the physiology is so specific. It is
a massive topic. It really is. It's one of those
units where the textbook feels like it weighs
50 pounds and then the emotional weight of the
content is even heavier. Right. But we aren't
here to memorize every single cytogenetic subtype
of leukemia. We are here to figure out what actually
matters when you're standing at the bedside or
sitting in that exam room. Exactly. We need to
strip away the noise and just find the signal.
And looking at our source stack for today, we
have got some serious material to work with.
We do. We've got a comprehensive pediatric hematology
oncology textbook chapter that goes incredibly
deep into the path of physiology. I mean, the
real nitty gritty of cellular development. Then
we have a rapid review exam prep guide, which
is, you know, essentially the high yield cheat
sheet for the boards. The Cliff Notes version.
Yeah, exactly. And then we have these very, very
dense drug monographs for methotrexate and prednisone.
Which are two of the absolute cornerstones of
treatment in this world. I mean, if you don't
understand those two drugs, you just don't understand
pediatric oncology. Everywhere. They appear in
almost every single protocol. So here is the
mission for this deep dive. We know our listeners
are out there preparing students for high stakes
exams. Or maybe you are a nurse looking to sharpen
your clinical eye. Right. We want to take these.
I don't know, thousands of pages and cross -reference
them into what we're calling a Pareto 8020 map.
I love that framework. We want to find the 20
% of the hematologic concepts that generate 80
% of the exam questions, and critically, 80 %
of the safety saves at the bedside. And we're
going to filter all of that through two specific
lenses. The first lens is safety and exam priority,
basically. What kills the patient? And what fails
the student? Exactly, what fails the student.
But the second lens is the one that really makes
pediatrics unique, and that's development. Because
you aren't just treating a small adult. That's
the cardinal rule of pets, right? Right there.
Never ever you are treating a developing human.
So you have to ask yourself, how does this disease
or this lifesaving treatment, how does it mess
with their timeline? How does it affect their
ability to walk, to learn, to hit puberty, to
just be a kid? That tension between saving the
life and preserving the childhood, that's where
the real deep dive happens. It's so important.
It's not enough to cure the cancer. if we destroy
the child's development in the process. I love
that framework. So let's zoom out before we get
into the weeds of sickle cell or leukemia. When
you look at this Master 8020 map of the source
material, is there... Like a unifying pattern.
There is. There really is. If you are taking
notes, draw a big triangle. The overarching theme
here is bone marrow failure. Almost every condition
we're going to discuss today eventually leads
back to the factory, the bone marrow, either
shutting down or just malfunctioning completely.
And that creates a specific set of symptoms.
A very specific triad of symptoms that I have
to say exam writers absolutely love to test.
This is what we call the hemionc red flag pattern.
And you have to know this triad cold the first
point of the triangle is anemia The factory just
isn't making red blood cells. So clinically,
what do you see? You see pallor. You see pallor.
They look like porcelain or wax sometimes. You
see extreme lethargy. I mean, the kid who used
to run around all day is now napping three times
a day. And physiologically, you see tachycardia.
The heart is just racing to pump what little
oxygen it has to the vital organ. OK, so that's
point one of the triangle. What's the second
point? Thrombocytopenia. So the factory isn't
making platelets. These are your plagues, right?
You see bruising from minor bumps. We call it
easy bruising. You see bleeding gums when they
brush their teeth. And those little red dots.
Patechia, yes. Those tiny, non -blanching red
dots that look like a rash but are actually broken
capillaries under the skin. A huge red flag.
And the third point of the triangle. Neutropenia.
The factory isn't making functional white blood
cells, or in the case of leukemia, it's making
billions of them. But they're useless, immature
weeds. So they're not actually fighting infection.
Not at all. So the patient presents with fever,
or specifically in leukemia, deep bone pain.
Because the marrow is so packed with these bad
cells, it's literally expanding inside the bone
shaft. Wow. So if a student sees a test question
description of a child who is pale, bruised,
and complains of leg pain, that is not growing
pains. That is a five alarm fire. That is the
bone marrow failure triad just screaming at you.
You need to be thinking malignancy or plastic
anemia immediately. Okay. You cannot dismiss
those three symptoms when they appear together.
So within this map we also identified three.
can't miss safety items. These are the things
that are, you know, instant failures if you miss
them on an exam or catastrophic outcomes in real
life. Yes. Walk us through the top one. Sepsis
in sickle cell disease. We will unpack the why
a little later, but the headline is this. Fever
in a sickle cell patient is a medical emergency.
An emergency. not just something to watch. It
is not a give them Tylenol and wait situation.
Their spleen, which is our main filter for bacteria,
it functionally dies very early in the disease.
So they can go from a fever of 101 to dead from
sepsis in a matter of hours. That's terrifying,
but such a crucial distinction. It changes the
triage priority completely. Completely. What's
the second one? Head trauma and hemophilia. If
a hemophiliac child bumps their head, you treat
first, scan second. Say that again, treat first,
scan second. You administer the clotting factor
immediately. Do not wait for the CT scan queue.
By the time you see the bleed on the image, the
brain damage might already be done. Time is tissue.
Got it. And the third can't miss item ties back
to that neutropenia piece we mentioned in the
triad. It does. It's the calculation of the ANC,
the absolute neutrophil count. If that number
is low, usually under 1 ,000 or even 500, depending
on the protocol, the rules of engagement change
completely. And the big rule is no rectal temperatures.
No rectal temperatures. Why is that such a hard
and fast rule? I know it sounds like a basic
nursing school thing, but what's the mechanism?
It's because the rectal mucosa is so fragile.
If you insert a thermometer and cause a micro
tear, even one you can't see, you have just introduced
gut bacteria directly into the bloodstream of
a child who has zero immune system to fight it.
Wow. It's a direct line deception. It's a direct
line. It's the same reason we say no fresh flowers.
fungal spores like Aspergillus. And if they spike
a fever, you start broad -spectrum antibiotics
immediately. You don't pass -go. You don't wait
for cultures. You act. That sets the stage perfectly.
We have our safety landscape. Now let's move
into the specific disease process lecture. We
synthesize the sources into four main conditions.
Iron deficiency anemia, sickle cell, hemophilia,
and leukemia. Right. Let's start with the most
common one globally. Iron deficiency anemia or
idea. Often referred to as the milk anemia. Which
sounds so deceptively harmless. It does, but
it's a massive developmental thief. Let's strip
it down to the plain language patho. Think of
iron as the brick. Okay. You need bricks to build
a house. In this case, the house is hemoglobin,
which is the truck that carries oxygen. Right.
If you have no bricks, you build fewer trucks.
And the trucks you do build are small. We call
that microcetic and pale. We call that hypochromic.
So you have this fleet of tiny empty trucks trying
to supply oxygen to a whole growing body. Precisely.
And the body compensates by running the engines
harder. That's why you get tachycardia. The heart
is beating faster to cycle those few trucks around
as many times as possible. But eventually, you
know, the engine just can't keep up. Now, the
milk baby presentation is something that often
trips people up on exams and in the clinic, because
we usually associate malnutrition with being
you know, skinny or wasted. Right. But the classic
milk baby is a toddler, usually between 12 and
24 months, who is chubby. They look well -fed,
maybe even overweight. But they're pale. But
they're pale, almost waxy. And they are so, so
lethargic. So what's the mechanism there? Why
are they chubby if they're actually malnourished?
They are filling up on cow's milk. Some of these
kids drink 30, 40 ounces a day. And cow's milk
is high in calories, hence the weight game. But
it has... effectively zero iron. So it's empty
calories, in a way. Totally. It displaces solid
foods that contain iron. And even worse, in young
codlers, the cow's milk protein can irritate
the lining of the gut, causing microscopic bleeding,
so they aren't consuming iron, and they are losing
blood in their stool. It's a double whammy of
deficiency. It is. A complete double whammer.
Then you have the other peak age group, the adolescents.
It presents differently there, doesn't it? Different
mechanism, same result. You have a teenager hitting
a massive growth spurt, so there's a high demand
for bricks to build muscle and blood volume.
Right. They have a poor diet, likely high in
junk food and low in leafy greens. And for females,
they start menstruation. So they are losing blood
monthly. And this kid presents differently. Very
differently. It's the student falling asleep
in class. the lazy teenager who is actually hypoxic
or the athlete who suddenly can't keep up with
the team. It's fatigue and poor concentration.
Let's hit the need to know data points for the
exam. What are the top expected findings you're
looking for? Tachycardia is a big one. Pallor.
But you have to know where to look. Don't just
look at the face, especially in darker skinned
children. Where do you look? You look at the
conjunctiva of the eyes and the palms of the
hands and often a systolic heart murmur. And
what causes the murmur? That's simply the physics
of thinner, less viscous blood rushing through
the valves. It's turbulent, and that turbulence
makes noise. It's not a structural heart problem.
It's a flow problem. And the labs, what are the
key indicators? Low hemoglobin, low hematocrit,
that's a given. But then low MCV, that's the
microcytic or small cell size. And low ferritin.
What's ferritin again? Ferritin is your iron
storage protein. It's the bricks in the warehouse.
That's actually the first thing to drop, even
before the hemoglobin itself starts to fall.
Now, interventions. Iron supplementation seems
simple, but the pharmacology has some really
specific traps that examiners love. Oh, they
love them. The biggest trap involves absorption.
Iron is finicky. It needs an acidic environment
to be absorbed effectively in the duodenum. So
you give it with something acidic. Exactly. The
golden rule is give it with vitamin C, orange
juice, tomato juice, or just a citrus fruit.
It boosts absorption significantly. And the inverse.
What kills the absorption? Calcium. Calcium neutralizes
the acid. So the exam trap is the parent who
says, oh, I mix the iron drops in his morning
bottle of milk so he takes it. You have to stop
that. You have to stop that immediately. They
are completely neutralizing the medication. So
no milk, no antacids within at least an hour
of taking the iron. What about the side effects?
This is where patient adherence usually fails,
because let's be honest, iron is rough on the
stomach. It is. It causes constipation, so we
need to push fluids and fiber. But the scary
one for parents is the stool color. Iron turns
the stool Atari dark green or black. If you don't
warn them, they will think it's a GI bleed and
rush to the ER. Every time. You have to normalize
that. You say your tile's poop will turn black.
That means the medicine is working. If it doesn't
turn black, they probably aren't taking it. And
what about the teeth staining? That's a real
issue. It is a real issue with liquid iron for
toddlers. It stains their teeth black so you
teach them to use a straw or a dropper placed
at the back of the throat to bypass the teeth
and then brush immediately after. It's temporary
but it looks very alarming. Let's apply that
developmental lens we talked about. Why is ID
such a big deal for a toddler? I mean, why not
just wait until they eat better? This is the
part that I think keeps me up at night. Iron
isn't just for hemoglobin. It is a necessary
co -factor for neurotransmitter synthesis in
the brain. Oh, wow. Chronic hypoxia and iron
deficiency in infancy causes long -term, sometimes
irreversible cognitive deficits. We're talking
about lower IQ scores, behavioral issues, and
learning disabilities that persist even after
you fix the anemia. So you're not just fixing
a lab value. You're not just fixing lab value.
You are protecting the entire architecture of
their developing brain. It's that serious. That
is a powerful why. One more quick nice to know
before we switch diseases. Lead poisoning. Ah,
yes. Peeking out the craving to eat non -food
items like dirt or paint chips is really common
in iron deficiency. The body is just screaming
for minerals. And if they eat old paint chips?
They get lead poisoning. And lead actually displaces
iron in the hemoglobin molecule. So if you see
a kid with anemia, you should always scream for
lead and vice versa. They are absolute partners
in crime. OK, that's great. Moving on to the
heavyweight champion of pediatric hematology.
Sickle cell disease. The traffic jam disorder.
I love that visual. The patherol here is fascinating,
but it's pretty complex. Walk us through the
shape shifting. So, normal red blood cells are
these round, squishy donuts. They can slide through
tiny capillaries, single file, no problem. In
sickle cell, the child has a genetic mutation
where they produce hemoglobin S instead of the
normal hemoglobin A. And when these cells get
stressed by dehydration, cold, infection, or
low oxygen, they polymerize. And what does that
mean? It means they turn into rigid, sticky,
crescent moons. Or sickles. And square pegs don't
fit in round holes. Exactly. They hook together
and create a physical blockage in the blood vessel.
That's a vaso -occlusive crisis. The traffic
jam. The traffic jam. Blood can't get past it,
so the tissue downstream gets no oxygen. And
ischemia equals pain. Severe screaming pain.
Now, age presentation. A newborn with sickle
cell usually looks perfectly healthy. Why is
that? Fetal hemoglobin or HBF, we all have it
in the womb. HBF is a superstar. It holds oxygen
very tightly and it absolutely refuses to sickle.
So it's protective. It's totally protective for
the baby for the first three to four months of
life. But as it naturally fades and the adult
HGBS takes over, that's when the symptoms start.
And the first sign is usually dactylitis. Yes.
Hand -foot syndrome. The tiny vessels in the
fingers and toes are the first to get clogged,
so the hands and feet swell up like sausages
and are incredibly painful. If you see a six
-month -old crying with swollen hands, that is
sickle cell until proven otherwise. Let's talk
about the complications, because this is where
all the safety questions come from. We already
mentioned sepsis and asplenia. Right. So the
spleen gets clogged so many times by these sickled
cells that it infarcts and basically shrivels
up and dies. By age Most of these kids are functionally
esplenic. Which means they can't filter bacteria?
They can't filter encapsulated bacteria like
pneumococcus. That's why they're on prophylactic
penicillin every single day to act as a kind
of chemical shield. What about acute chest syndrome?
I see this term in every textbook. And it's always
highlighted. It should be. This is the leading
cause of death in adolescents and adults with
SED. It looks like pneumonia fever, cough, chest
pain, a new infiltrate on x -ray. But what's
happening is sickling in the lung vasculature.
And that creates a feedback loop. It's a vicious
cycle. The pain makes them breathe shallowly,
we call that splinting, which causes hypoxia,
which causes more sickling in the lungs, which
causes more pain. You have to intervene fast
with oxygen and fluids or it just spirals into
respiratory failure. And splenic sequestration.
This is different from the shriveled spleen,
right? Completely opposite. Usually this happens
in younger kids whose spleen is still working
a bit. The spleen suddenly acts like a giant
sponge. It just sucks a massive amount of blood
volume out of circulation. and traps it. So the
spleen gets huge. The spleen becomes huge, you
can feel it filling the belly, and the child
goes into hypovolemic shock because there is
literally no blood left in circulation. This
is an immediate life threat requiring volume
replacement and blood transfusion to push the
blood back out. Okay, let's get to the interventions.
The mnemonic is HOP. HOP to it. H is for hydration.
This is your number one tool. You need to dilute
the blood to break up the traffic jam and lower
the viscosity. We run IV fluids at 1 .5 to 2
times the maintenance rate. We want them well
watered. OK. H is hydration. O. O is for oxygen.
But there's a caveat here. Only if they are hypoxic.
Giving oxygen won't unsickle the cells if their
saturation is already 99%. But we absolutely
need to prevent hypoxia to stop new sickling
from happening. And P is for? P is for pain management.
And this is where we really need to have a serious
culture conversation regarding nursing bias.
We absolutely do. The pain of a vaso -occlusive
crisis is often compared to bone fracture pain
or a heart attack. It is ischemia. It is tissue
death. So we treat it seriously. We treat this
with opioids, morphine, deloaded, and we give
it around the clock, ATC, or via a PCA pump.
We do not give it PRN as needed. Why not PRN?
If you wait for the child to be crying in agony
before you give the next dose, you are chasing
the pain and you will never ever catch it. And
please check your bias. These children are not
drug -seeking addicts. They are seeking relief
from dying tissue. Is there a specific medication
contraindication here? An exam favorite? Meparidine
or Demerol. Never use it. It breaks down into
a metabolite called Normaparadine, which accumulates
and lowers the seizure threshold. And these kids
are already at risk for stroke. Exactly. Sickle
cell kids are already at high risk for strokes
and CNS changes. Giving them a drug that can
cause seizures is just malpractice. Do not choose
Demerol on the exam. What about temperature management?
You're managing pain, you're managing hydration.
Good question. Heat is good. It vasodilates.
Cold is bad. It vasoconstricts. Never, ever put
an ice pack on a sickle cell pain crisis. You
will tighten the vessels and make the traffic
jam a hundred times worse. Looking at the developmental
impact, this is a chronic, lifelong battle. It
has to take a toll. It does. A huge toll. Growth
retardation is common because their metabolic
rate is so high the body is working overtime
just to make blood and fight and section. They
are often smaller than their peers and hit puberty
later. And that's tough socially. It's so tough
socially for a 14 -year -old who looks 10. And
school. They miss a lot of school due to pain
crises. But the shadow that's always looming
over them is stroke. About 11 % of untreated
kids will have a stroke by age 20. Even silent
strokes can cause cognitive decline. That's why
we do transcranial Doppler screenings annually
from age 2 to 16. We are looking for high -velocity
blood flow in the brain, which implies the vessels
are narrowing. One nice -to -know therapy before
we move on? Hydroxyurea. It's a chemotherapy
agent, technically. But at lower doses, it stresses
the marrow just enough to trick it into making
fetal hemoglobin again. And we know HPF is protective.
Exactly. Remember, HPF doesn't sickle. It's the
only drug we have that actually modifies the
course of the disease. It's a game changer. Incredible.
OK, let's shift gears to number three, hemophilia.
The missing glue. So in this case, the platelets,
the initial plug, they work. Just fine. Correct.
You get a cut, platelets rush in, they form a
plug, the bleeding stops initially, but to keep
that plug there, you need the fibrin mesh, the
clot. That comes from the clotting cascade. And
in hemophilia. One of the dominers in that cascade
is missing, so the plug eventually washes away
and the bleeding restarts. Can you distinguish
hemophilia A versus B for us? Hemophilia A is
missing factor 8. I always say A, it sounds similar,
helps to remember. That's the most common, about
80 % of cases. Hemophilia B is missing factor
9. also called Christmas disease. And this is
X -linked recessive. Which means mom is the carrier
and the son gets the disease. It is overwhelmingly
a male diagnosis. When do we usually spot this?
Often at circumcision, that's a big one. Prolonged
bleeding. If not then, it's when they become
mobile. The toddler phase is so dangerous they
fall, they bump their heads. A normal kid gets
a bump. A hemophiliac gets a massive hematoma.
Or a frenulum tear in the mouth that just won't
stop bleeding because saliva breaks down clots
naturally. Let's look at the need -to -know exam
profile for hemophilia. Easy bruising, obviously.
But the hallmark is hemarthrosis bleeding into
the joint spaces. Knees, ankles, elbows. What
does that look like? The joint fills with blood.
It becomes hot, swollen, incredibly painful,
and locked in place. And over time, that iron
in the blood actually destroys the cartilage
and causes permanent deformity. And the labs.
This is a classic question. differentiating bleeding
disorders. It is. You have to know the difference
between platelets and factors. In hemophilia,
the platelet count is normal. The PT is normal.
The PTT partial thromboplastin time is prolonged.
Why the PTT? Because PTT measures the intrinsic
pathway, which is where factors eight and nine
live. So that's the one that will be abnormal.
Interventions. We talked about treat first for
head trauma. That's paramount. Vital. Factor
replacement is the priority. If a hemophiliac
falls off a swing and hits their head, you push
factor eight or I. immediately. You don't wait
for symptoms. You don't wait for the scan. You
push the factor. What about for the joint pleats?
Is it rice? Yes. Rest, ice, compression, elevation.
Here, ice is your friend because the vasoconstriction
slows the bleeding into the joint. But again,
rice is secondary to factor replacement. You
have to give the glue first. Now let's talk about
pain meds. We said opioids for sickle cell. What
about for hemophilia? This is a really tricky
one and a huge safety point. No NSAIDs. No aspirin,
no ibuprofen, no naproxen. And why is that? Because
NSAIDs inhibit platelet aggregation. These kids
already have a broken clotting cascade. If you
knock out their platelets too, they have literally
zero defense. They will bleed uncontrollably.
So Tylenol acetaminophen is the king here. Correct.
Unless the hematologist specifically clears a
certain NSAID regimen for joint inflammation,
you stick to Tylenol in opioids if needed for
severe pain. The elemental impact here really
changes how they play, doesn't it? It does. Contact
sports are completely out. No football, no rugby,
no wrestling, no hockey. One hard tackle could
cause a life -threatening bleed. And that's really
hard for a boy who wants to fit in with his friends.
So what do we encourage? Non -contact sports.
Swimming is the absolute best. It builds muscle
to support the joints without any impact. Golf,
fishing, cycling with a helmet and pads, things
like that. And what about autonomy? This is one
of the great success stories of modern nursing.
We teach these kids to self -administer their
5E factor prophylactic infusions at home. By
age 8 to 12, many of these boys are mixing their
own factor and sticking their own veins. That's
incredible. It gives them control over a disease
that threatens to control them. It's really empowering.
A quick nice to know before we move on. DDAVP,
or desmopressin, it's a synthetic hormone. For
mild hemophilia A, it stimulates the body to
release stored factor from the blood vessel walls.
So it can stop a minor bleed. It can, without
a transfusion, but it does not work for hemophilia
B because they don't have a factor eight issue,
or for severe hemophilia A because they have
no stores of factor eight to squeeze out. Got
it. Okay, fourth and final disease, leukemia.
Specifically, all acute lymphoblastic leukemia.
Weeds in the garden. Break that down for us.
The bone marrow is a garden. It's meant to grow
flowers, which are your red blood cells, vegetables,
your white blood cells, and fruits, your platelets.
In leukemia, a single immature cell, a blast,
mutates. It's a weed. It replicates incredibly
fast. It doesn't do any work. It just takes up
space. And eventually, the garden is nothing
but weeds. The good plants are crowded out, and
they die. So the patient has these super high
counts of blast cells, but they're still immunocompromised.
Exactly. A child might have a WBC count of 50
,000. Normal is maybe 10K. But they're all useless
blasts. They don't fight infection. So the child
is functionally neutropenic, even with a high
white count. Who gets this? What's the typical
age? Peak onset is two to five years old. It's
really a preschool disease. And the presentation
ties right back to our initial triad. It does.
Anemia, so they're tired. Thrombocytopenia, so
they're bruising. Neutropenia, so they have a
fever. But for leukemia, you really need to watch
for bone pain and a limp. The marrow is expanding
from the pressure of the tumor burden inside
the bone. If a toddler suddenly refuses to walk,
you check a CBC. A peripheral smear will show
the blasts, but the definitive diagnosis is the
bone marrow biopsy. You need to see greater than
25 % blast cells in the marrow to confirm leukemia.
Leukemia cells are smart. They like to hide in
what we call sanctuary sites where 5e chemo can't
reach them easily. The central nervous system
is one of them because of the blood brain barrier.
So you check the spinal fluid. We check the spinal
fluid. If there are cells there, or even if there
aren't, as prophylaxis, we have to inject chemo
directly into the spine. We call that intrathecal
chemotherapy. Let's talk about a major safety
emergency during treatment. Tumor lysis syndrome.
This happens usually during induction. That's
the first phase of chemo, where we just blast
the cancer. We kill millions of cells instantly.
And they burst open. They lie. And cells are
just bags of chemicals. Right. They are full
of potassium and uric acid. When they burst,
they dump all of that into the bloodstream all
at once. And that causes two huge problems. Two
huge problems. First, you get hyperkalemia. High
potassium leads to fatal cardiac arrhythmias.
Second, you get hyperuricemia. Uric acid crystals
form in the kidneys and cause acute renal failure.
So how do nurses prevent this from becoming a
catastrophe? Hydration, hydration, hydration.
We flush the kidneys like a fire hose to keep
those crystals from forming. And we give a drug
called allopurinol, which stops uric acid production
in the first place. The developmental impact
here is so visibly profound. It's heartbreaking.
You have a four year old, they lose their hair,
alopecia. They get a moon phase from the high
dose steroids. They look different. And because
of the neutropenia, they are isolated. They can't
go to preschool. They can't go to preschool.
They can't see friends. You often see regression
potty trained kids go back to diapers or they
start baby talking again. It's a totally normal
response to trauma and isolation. One safety.
Nice to know regarding vaccines. This seems critical.
Absolutely critical. No live vaccines while on
chemo. No MMR. No varicella for chickenpox. No
nasal flu mist. Their immune system cannot handle
the live virus. It can cause the actual disease.
We have to rely on herd immunity to protect these
kids. That covers the diseases. Now let's pivot
to the how the medication module. We are focusing
on two drugs that appeared in every protocol
we reviewed. methotrexate and prednisone. Let's
start with methotrexate. This is a chemo drug,
but it's also used for juvenile rheumatoid arthritis.
How does it work? It's an anti -metabolite, specifically
a folate antagonist. It's a master of disguise.
It looks chemically just like folic acid. The
cancer cell, which is hungry and dividing really
fast, grabs the methotrexate thinking it's food,
thinking it's folate to build DNA. But it's a
trap. It blocks DNA synthesis, and the cell starves
and dies. But it affects healthy, rapidly dividing
cells, too. It does. Any rapidly dividing cell.
That includes the bone marrow, which is why you
get myelo suppression, and the lining of the
GI tract, which is why you get mucositis. There's
a specific rescue associated with high -dose
methotrexate that we have to talk about. Leucovorin
rescue. Leucovorin is a form of folic acid that
actually bypasses the metabolic block from the
methotrexate. It effectively rescues the healthy
cells from the toxic effects of the drug. And
the timing is critical. The timing is everything.
In high -dose protocols, if you miss the leukovorin
dose or give it late, the patient can suffer
fatal toxicity. It's a huge med safety issue.
Well, we also have to watch the urine. Yes. Methotrexate
precipitates. It crystallizes in acidic urine.
It will destroy the kidneys. So we have to keep
the urine pH alkaline, usually greater than 7
.0. We run IV fluids with sodium bicarbonate
to alkalize the urine. And you're checking it
constantly. We literally check the pee with a
dipstick every single time they void. If it's
acidic, we don't give the drug. It's that simple.
There was a specific warning in the monograph
about neonates. Yes, this is so important. The
formulation matters. Some methotrexate vials
contain benzyl alcohol as a preservative. In
neonates, their immature livers can't process
this. It causes gasping syndrome, fatal respiratory
distress, acidosis, and death. So you always
check. Always check for preservative -free formulations
for infants and for any intrathecal use. OK.
Moving to prednisone. The corticosteroid. The
love -hate drug of pediatrics. Oh, you say that.
Because it's so effective, but the side effects
can be brutal. We use it for leukemia induction.
Lymph flasks are actually very sensitive to steroids.
It just melts them. Asthma, nephrotic syndrome,
all sorts of things. And the mechanism. It suppresses
inflammation and the immune response. It's also
lympholytic. It actually breaks down lymphocytes.
But the side effects in children are really distinct.
They are. First is growth suppression. Long -term
use can literally stunt a child height. Second
is mood changes. We call it roid rage. A normally
sweet child can become aggressive, irritable,
or severely depressed. You have to warn the parents.
You have to warn the parents. This is the drug,
not your child being naughty. Third is the cushion
-goy appearance. The moon face, the round cheeks,
the buffalo hump, the weight gain. For an adolescent
focused on body image, this is just devastating.
And the safety rule for stopping. This is a big
one. Taper. You can never stop steroids abruptly
after long -term use. The drug suppresses the
child's own adrenal glands. If you pull the drug,
the adrenals are asleep and can't make cortisol.
And the child goes into... Adrenal crisis. Which
is shock. You have to taper slowly to wake the
adrenals back up. Any tips for administration?
Because it tastes terrible. It tastes horrific.
incredibly bitter. You have to crush it and mix
it with something strong chocolate syrup, strong
jam, but mix it in a small amount, like one spoonful.
If you mix it in a whole bowl of pudding and
they only eat half, you have no idea how much
drug they actually got. Okay, we're in the home
stretch. This is section D, cross -linking and
synthesis. Let's connect these dots. Let's link
leukemia and methotrexate. We said methotrexate
attacks rapidly dividing cells. Well, the lining
of the mouth divides rapidly. This causes mucositis
-severe ulcers from the lips all the way to the
anus. And this links back to nutrition. Of course.
If a kid's mouth feels like raw meat, They won't
eat. So the nursing intervention is bland, soft
foods, no orange juice because the acid burns,
no potato chips because the sharp edges cut.
And you use things like Magic Mouthwash. We use
Magic Mouthwash, which is usually a combo of
lidocaine, malox, and defenhydramine to numb
the mouth so they can eat and get some nutrition
in. OK, let's link leukemia and prednisone. This
is the double whammy for bones. The leukemia
itself causes bone infiltration and pain. Then
you add prednisone, which causes osteoporosis
or bone weakening. So you put them together.
And you have a child with incredibly fragile
bones. So the safety point is, handle them gently.
No rough housing. They are at a very high risk
for pathological fractures. And let's synthesize
pain management across the board, because it
can be confusing. It is. So let's simplify. For
sickle cell, opioids are the standard of care.
Do not fear addiction. Treat the crisis. OK.
For hemophilia, Tylenol is safe. NSAIDs like
ibuprofen or aspirin are dangerous because of
the bleeding risk. And for leukemia. For leukemia,
you can use Tylenol for pain, but UT, you have
to be careful. A Tylenol masks fever. And in
a neutropenic kid, fever is the only warning
sign you might get of a deadly sepsis. So you
might hold it. We often hold Tylenol until we
have thoroughly assessed for infection. We need
to see that fever if it's there. That is the
kind of nuance that really separates. a novice
from an expert. It's all about knowing the why
behind the rule. So we've built the map. We've
covered the diseases, the meds, the connections.
What does this all mean for the listener standing
at the nurses station? It means that when you
review a chart, you aren't just checking boxes.
You are looking for the safety patterns. Is the
airway safe? Is the immune system working? What's
the ANC? Is the blood clotting? What are the
platelets and factors? And critically, is this
child able to be a child? That brings us to our
final thought. The resilience of the pediatric
patient versus the fragility of their physiology.
It's the great paradox of pediatrics. Kids bounce
back emotionally and physically from things that
would absolutely crush an adult, but their physiology
has so much less reserve, they crash faster.
So what's the provocative thought you want to
leave everyone with? The thought I want to leave
you with is this. We spent so much time treating
the numbers, getting the HGB up, getting the
ANC up, but the patient, the person, is trying
to grow up. Every time you intervene, whether
it's a hospital admission, a steroid course that
changes their face, or a restriction on sports,
you are altering the architecture of their childhood.
So the challenges? The challenges. How do we
keep them safe? That's our 80 -20 clinical focus.
Well, disrupting their development as little
as humanly possible. So when you review a chart,
ask, Is this safe? And then immediately ask,
how does this affect their next birthday party?
Can they go? If you can answer both of those
questions, you're doing the job right. That is
powerful. Can they go to the party? That's the
real goal. Thank you for joining us on this deep
dive into pediatric hemionc. It's a beast of
a topic, but hopefully the 80 -20 map makes a
little more navigable. Keep looking for the patterns.
Safety first, development always. See you on
the next dive.