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. So if you're gearing up
for your pediatric rotation or maybe that big
PEDS exam is just looming, this one is absolutely
for you. we are going straight into, I would
argue, the most foundational and dynamic period
of a person's life. Oh, for sure. The infant.
We're talking from about two days old all the
way up to one year. And it really is biology
just in hyperdrive. I mean, the amount of change
that happens in that first year is unlike anything
else. It's staggering. Our goal today isn't just
to, you know, list off facts from a textbook.
We want to synthesize them. Really need to get
past memorization and into the why. The clinical
reasoning. Exactly. Why is the timing of that
pincer grasp a direct safety issue? Why do we
even have to use an adjusted age for preemies?
It's all about connecting the physiology to what
you do at the bedside. Right, connecting those
dots. And we've pulled everything together, the
vitals, growth, safety, the full immunization
schedule, to really give you that high -yield
80 -20 view of what you absolutely have to know.
And that context is key. Everything, and I mean
every system, neuro, respiratory, cardiovascular,
it's all starting out profoundly immature. The
whole year is this race toward functionality.
If you keep that in mind, every assessment you
make is going to be so much sharper. So let's
jump right in where every single PEDS visit starts.
The numbers. The numbers game. High -yield growth
and vital signs. Okay, so when you're looking
at an infant's chart, that rate of growth, it's
something you have to know cold. Let's start
with weight. Average birth weight is what, about
seven and a half pounds? Yeah, around 3 ,400
grams, 7 .5 pounds, but there are two rules about
weight you just can't compromise on. The first
one happens right away. Infants will lose up
to 10 % of their birth weight in those first
few days. And that's normal, right? That's not
a panic moment. Totally normal. It's mostly fluid
shifts, figuring out, feeding, all that, but...
and this is the non -negotiable part, they must
regain that weight by day 10 to 14. So if they
haven't? If they haven't, that's an immediate
red flag. You're thinking about feeding problems,
hydration, maybe an underlying illness. That
needs a full workup right away. And what's the
second big rule? The one that's on like every
exam? This is the one. They double their birth
weight by five to six months. Double it. And
they triple it by one year. Wow, I mean think
about that if you're looking at a 12 month old
who hasn't tripled their birth weight your brain
should immediately be thinking Failure to thrive
something is wrong. Yeah, that rule is pure high
yield pets. Okay, so that's weight What about
length average at birth is about 20 inches or
50 centimeters, right? And the length increase
is also really dramatic But not quite as explosive
as the weight by the end of that first year their
length has increased by about 50 percent So a
20 -inch baby becomes a 30 -inch toddler. Basically,
yeah. And just like with weight, you're tracking
that curve. Any sudden drop off from their percentile
is a sign that something might be up, like an
endocrine issue. Now, for the one that really
tells the story of that first year, head circumference.
Why is this measurement so critical in infancy?
It's all about the brain. I mean, the brain is
growing at this absolutely exponential rate.
An average head circumference at birth is around
33 to 35 centimeters. OK. In the first year,
it grows by about 10 centimeters total. But here
is the key detail. It is heavily front loaded.
The fastest growth is in the first six months.
We're talking almost a centimeter a month. So
if you see that measurement suddenly fall off
the curve at, say, four months. You're worried.
You're thinking about things like microcephaly,
maybe poor brain growth. And on the flip side,
if you see a sudden spike... Chondrocephalus.
Right. Increased intracranial pressure. That's
why you measure head circumference at every single
well child visit until they're two. It's a vital
sign for the brain. This leads us perfectly into
a topic that exam writers just love. Oh yeah.
The fontanels. The soft spots. You have to know
their closing times. They exist for a reason.
To let the head mold during birth. And, more
importantly, to allow for that rapid brain growth
we just talked about. So they're two main ones.
Right. The posterior fontanelle, that's the smaller
one in the back, it closes up really early, usually
by two months of age. OK, so that one's gone
pretty quick. Gone quick. But the anterior fontanelle,
the big diamond -shaped one on top, that one
stays open for much, much longer. To accommodate
all that brain growth. Exactly. It typically
closes sometime between 12 and 18 months. So
if you're assessing a 10 -month -old, you should
absolutely feel a soft, open anterior fontanelle.
And if it's closed early. That's a problem called
craniosynostosis. The skull is fusing too soon,
and it can restrict brain growth. That's a neurosurgery
consult. So when you're feeling that fontanelle,
you want it to be soft and flat. But what if
it's sunken or bulging? Great question. A sunken
fontanelle screams dehydration. A bulging, tense
fontanelle suggests increased intracranial pressure.
But you have to assess it when the baby is calm
and upright. Because crying can make it bulge
temporarily. Right. crying can throw you off,
so a calm sitting baby with a bulging fontanelle
is a major concern. Okay, let's talk about putting
it all together on the growth charts and this
concept of adjusted age. The key with growth
charts is the trend. It's not about a single
number. A kid who is consistently on the 10th
percentile is probably just a smaller, healthy
kid. The red flag is the change. Exactly. The
red flag is the kid who was on the 75th percentile
and over two visits has dropped to the 15th.
That kind of drop demands a full investigation.
And for our preemies, we have to adjust their
developmental clock, right? You have to. This
is a just stage. For any baby born before 36
weeks, you have to assess their milestones based
on their due date, not their birth date. How
do you calculate that? It's pretty simple. You
take their chronological age, how old they are
in months, and subtract the number of months
they were premature. So a six month old who was
born two months early. You assess them as a four
month old. You got it. It prevents us from mislabeling
a healthy preemie as delayed and gives parents
realistic expectations. OK, that's physical size.
Let's shift to how the body actually functions.
We said all their systems are immature. How does
that show up in their vitals? It means they have
very little reserve. Their metabolism is sky
high, their systems are inefficient, and they
compensate for everything by going fast. Rate
over strength. That's why their heart rate and
respiratory rate are so high. Let's start with
pulse rate. For a newborn, it's high, like 110
to 160 beats per minute. For an infant up to
a year, it settles a tiny bit, but it's still
fast, maybe 90 to 160. And a low heart rate is
the real danger. Oh, absolutely. In PIDS, bradycardia,
a heart rate under 90 for an infant is a huge
emergency. It often happens right before respiratory
arrest. High is usually OK. Low is a crisis.
What about respirations? This is where students
get nervous thinking about the adult rate of
12 to 20. Right. A newborn breathes 30 to 60
times a minute. It slows to maybe 25 to 30 for
an older infant. But the key thing to assess
isn't just the number. It's how they're breathing.
What do you mean? They are obligate abdominal
breathers. They use their diaphragm because their
chest muscles are weak. You'll see their belly
go up and down. And their breathing pattern is
often irregular. Little bursts of fast breathing,
then a pause. That's normal. So what's the difference
between that normal irregular breathing and actual
respiratory distress? It's all about the work
of breathing. Are you seeing nasal flaring where
they're widening their nostrils to get more air
in? Are you seeing retractions where the skin
is sucking in between or under the ribs? Are
you hearing grunting? Those are the signs of
distress. Those are the signs that they are failing.
Their tiny airways can get clogged so easily,
so any increased work of breathing is an emergency.
And this all ties back to those other immature
systems, right? Like their renal and hematopoietic
systems. It does. Their kidneys are terrible
at concentrating urine, so they get dehydrated
or fluid overloaded really easily. And hematologically,
their fetal hemoglobin is being replaced, and
their mom's iron stores run out around six months.
Which is why we see physiologic And why iron
-fortified cereals and foods are so important
once they start solids? Everything is just getting
started. This is a perfect setup for blood pressure,
because this is where PEDS is a totally different
world from adults. It really is. An infant's
blood pressure is the lowest it will ever be
in their life. Average systolic is maybe 85,
but here's the thing you cannot forget. Okay.
Infants are masters of compensation. If they're
going into shock, they will squeeze their peripheral
blood vessels and crank up their heart rate to
maintain that blood pressure until the very last
second. So if you see the blood pressure drop,
you're already behind. A drop in BP is a late
and catastrophic sign of shock in a child. By
the time their BP falls, their body's compensation
has already failed. So you have to catch the
early signs. The early signs. Tachycardia, poor
perfusion -like cool skin, and a cap refill over
three seconds, and a change in mental status.
Don't wait for the BP to drop. Got it. Okay,
rounding out this section. Temperature and pain.
Temperature is pretty straightforward. It can
be a little higher normally, maybe 99 .5 Fahrenheit
or 37 .5 Celsius axillary. We use axillary for
screening. Rectal is the gold standard for a
core temp, but we only do it when absolutely
necessary, especially in young infants. And since
they can't tell you they're in pain... We have
to be detectives. We use objective scales. The
classic one for newborns and young infants is
the CRY -S scale. What does that stand for? It's
an acronym. CRY requires O2, increased vital
signs, expression, and sleeplessness. And you
see, vitals are built right into the score. If
their heart rate or BP is up more than 20%, that's
a sign of pain. It's a combination of behavior
and physiology. This is a ton of great detail.
Let's try to boil it down. Let's do it. So what
nurses are watching for in this section? You're
watching for any big drop across growth percentiles.
You're watching for a failure to regain birth
weight. And with vitals, you're watching for
any sign of increased work of breathing retractions,
flaring, grunting. And for the students, what
do exam writers love to test? Oh, they love the
fontanel closure times. Anterior is 12 to 18
months. Posterior is two months. They love the
weight rule double by six months, triple by 12.
And they will absolutely test you on knowing
that a drop in blood is a late, terrible sign
of shock. And our memory trick for this whole
age group. The infant is all about triple growth
weight triples, length up by 50%, and high H
vibes, high normal heart rate, and respiratory
rate. Okay, we have the numbers down. Now let's
get into the action. milestones how infants master
the world understanding this sequence is I mean
it's everything for safety counseling it is the
scaffolding for everything else you do and it
follows two very predictable rules this isn't
random okay what are the rules first gross motor
skills develop suffocato head -to -toe head -to
-toe they control their head then their trunk
then their legs it's like building a power from
the top down and the second rule Fine motor skills
develop proximodistal. Center out to the periphery.
Exactly. They control their shoulder and arm
before they can control their wrist and fingers.
You have to be able to swing the whole bat before
you can write your name. That makes perfect sense.
So let's walk through that roadmap. Let's hit
the big four. Two, four, six, nine, and 12 months.
Right. At two months, they're just starting to
fight gravity. They can lift their head a little
bit when they're on their tummy. The beginning
of head control. The very beginning. Then at
four months, that's the big head control milestone.
They can hold their head steady without any support.
This is huge. If a baby can't do this by four
months, that's a developmental red flag. Right.
And at six months, things really get moving.
Six months is the rolling age. They can roll
all the way over front to back and back to front.
This is when your safety antenna has to go way
up for falls. They also start sitting. But with
help, right? Yeah, they can often sit in a tripod
position using their hands out front for support.
And then nine months is the magic number for
sitting independently. Yes, independent sitting.
They can sit up unsupported and they can get
themselves into a sitting position. This is also
when they start pulling up to stand on furniture.
The beginning of cruising. The beginning of cruising,
which leads us to 12 months. This is the full
mobility age. They are pulling to stand easily,
cruising all over the place, and many are taking
their first independent steps. A 12 -month -old
is basically a pre -toddler. OK, so that's the
big body movements. Let's track the hands, the
fine motor skills. At two months, their hands
are still mostly reflexive. But by four months,
you see purpose. They're batting at toys, bringing
their hands to their mouth, exploring. At six
months. They start reaching and grabbing with
intent. Real intent. They see something they
want and they go for it. In around seven months,
they can transfer an object from one hand to
the other. That's a huge cognitive and motor
leap. Now for the two that are always on exams,
the pins are grasps. Nine months versus 12 months.
At nine months, they get the gross pincer grasp.
Think of it like a rake. They use their whole
hand and all their fingers to rake an object
toward them. It's clumsy, but effective. And
then the refinement happens. At 12 months, they
achieve the fine pincer grasp. This is that beautiful,
precise movement using the tip of the thumb and
the tip of the index finger. The cheerio grasp.
The cheerio grasp. It's essential for self -feeding,
but as we'll see, it's also a direct line to
a major safety hazard. So as nurses, we're tracking
all this. But what are the big signs of developmental
delay? When should we really be worried? The
number one absolute biggest red flag is regression.
Losing a skill they once had. That requires an
immediate full neurologic workup. What about
those primitive reflexes we all learn about?
They have to disappear on time. The moro or startle
reflex should be gone by about four months. If
you see a strong moro reflex in a six or seven
month old, that's a problem. Why? Because that
involuntary reflex is getting in the way of voluntary
movement. It's a sign the central nervous system
isn't maturing correctly. And what about sensory
and language delays? For hearing, if they're
not turning to a sound by four months, that's
a concern. For vision, if their eyes are still
crossed most of the time past six months, that
needs an evaluation. And language. We want to
hear babbling, like da -da -da, by around eight
months. And by 12 months, we hope to hear at
least one or two single words used with meaning,
like mama or da -da. So our job is to screen
and refer, not diagnose. That's it. We use our
tools, we use our observation, and we get them
into early intervention if we spot a delay. OK,
let's wrap this section. What are nurses watching
for? You're watching for that loss of a milestone.
Inability to hold the head steady by four months
is a big one. Inability to sit alone by nine
months and the persistence of those primitive
reflexes. And what do exam writers love? The
sequence. They love it. Head control at four,
rolling at six, sitting at nine, cruising at
12. And they love to have you differentiate between
the gross pincer grasp at nine months and the
fine pincer grasp at 12. And our memory phrase
for motor development. Crawl before you walk
and gross before fine. Okay, the body is moving,
the senses are working. Let's dig into the mind
and the heart. The infant psyche, cognitive,
and psychosocial milestones. This is where we
lay the foundation for learning and personality.
For cognitive development, we have to talk about
page debt. For infants, it's the sensorimotor
stage. Learning through senses and movement.
Exactly. It starts with just pure reflexes. But
then from about one to four months, they hit
what he called primary circular reactions. Which
means? It means they're repeating actions centered
on their own body just because it feels good,
like sucking their thumb. They're discovering
themselves. What's the big shift after that?
From four to eight months, they move to secondary
circular reactions. Now the focus is on the outside
world. They shake a rattle on purpose to hear
the sound. They kick a mobile to make it move.
They realize they can have an effect on things.
Yes. I did that. It's a huge cognitive leap.
And that leads to truly purposeful action by
8 to 12 months. They start to understand symbols,
like when they see the bottle, they know they're
about to eat. And this is where that classic,
always -on -the -test concept emerges. Object
permanence. You have to know this one. You do.
It's the understanding that something still exists,
even when you can't see it. Before this, it's
literally out of sight, out of mind. This starts
to develop around eight months of age. And that's
so important for their emotional development,
too. It's directly tied to it. Which brings us
to Erickson. The psychosocial stage for the entire
first year is trust versus mistrust. So how does
an infant build trust? It's all about consistency
and reliability. When the infant cries, does
someone come? When they're hungry, are they fed?
When they're wet, are they changed? If those
needs are met reliably, They learn the world
is a safe, predictable place. They build trust.
And if not? They develop a fundamental sense
of mistrust. They learn the world is chaotic
and unreliable. As a nurse in the hospital, you
build trust by responding to their cries, providing
comfort, and keeping their parents close. And
this connects directly to those common anxieties
we see. The two big ones. First is separation
anxiety. It starts around four to eight months.
Once they have object permanence, they know you're
gone and they don't like it. And the second one?
which every nurse has experienced. Stranger anxiety
or stranger fear. This pops up around seven to
eight months and it's actually a good sign. It
means their brain has developed enough to tell
the difference between familiar people and strangers.
So when they scream at you, you shouldn't take
it personally. Not at all. The intervention is
to go slow, talk softly, let the parent hold
them, do the least invasive parts of your assessment
first, respect their fear. Let's talk about how
they learn through play. Play is their work.
And for infants, it is almost entirely solitary
play. They play alone, focused on their own sensory
world. So what are some good age -appropriate
toys? In early infancy, things that stimulate
the senses. Rattles are perfect for those secondary
circular reactions. Teething toys, soft toys.
A mirror is fantastic for self -discovery around
six months. And for the older infant. As they
get that pincer grasp, simple blocks are great.
Things they can stack and knock over cause an
effect. The key in the hospital is that play
is a nursing intervention. It's not just a distraction.
It promotes normal development. Great. Let's
summarize the psyche section. What are nurses
watching for? You're watching for an infant who
is just inconsolable, who doesn't respond to
comfort. That could be a sign of illness or a
failure to form trust. Also, a lack of babbling
by eight months is a language red flag. And what
do exam writers love? They love pairing the theorists.
Erickson's trust versus mistrust goes with Pejat's
sensory motor stage. And you absolutely must
know the timing of object permanence, around
eight months, and how it leads to separation
anxiety. Our memory phrase for this one. Trust
me, I'll find the object. for trust versus mistrust
and object permanence. All right. We've got a
growing, moving, thinking infant. Now we have
to protect them. Let's move into protecting the
infant immunizations and safety. This is where
our knowledge of development becomes life -saving
intervention. Let's start with the vaccine schedule.
It's so complex. But there's a pattern, right?
There is. For students, focus on the two -month,
four -month, six -month pattern. Most of the
core series happens then. Why so many shots so
early? Two reasons. First, their own immune system
is immature and needs multiple doses to build
a strong memory. Second, the antibodies they
got from mom and utero start to wear off, leaving
them vulnerable. OK, so let's run through the
high points. It starts at birth. At birth, they
get their first dose of hepatitis B. Then the
big one at two months. This is The Good Visit.
They get DTaP -P, which is diphtheria, tetanus,
and pertussis. They get rotavirus, which is an
oral vaccine. They get Hib, pneumococcal, PCV,
and polio, IPV. And their second dose of Hep
B. Wow, that's a lot. And at four months? It's
mostly a repeat. They get the second doses of
DTaP, rotavirus, hep, PCV, and IPV. It's all
about reinforcing that initial immune response.
And it's six months. Another round to continue
building immunity. DTaP, IPV, PCV, and usually
the third doses of hep B and hep. And critically,
after six months, they're now eligible for the
annual flu shot. which is so important for their
little respiratory systems. Absolutely vital.
A nurse's job is to know the schedule, educate
the parents, and monitor for reactions. OK, now
let's connect development to risk. Injury prevention.
Every single new milestone opens up a new way
for them to get hurt. We have to anticipate it.
Let's start with aspiration choking. So infants
are in that oral stage. Everything goes in the
mouth. But the risk goes through the roof once
they get that fine pincer grasp around 12 months.
Because now they can pick up the tiny things.
The coin, the button, the piece of a dog food.
The rule is, if an object can fit through a toilet
paper tube, it's a choking hazard for an infant.
Next up, falls. The risk starts the second they
can roll, around six months. The rule is simple
and absolute. Never leave an infant alone on
a high surface. Not for a second. And what about
the crib? Once they can pull to stand, that mattress
has to go to the lowest possible setting. And
we need to talk about baby walkers. The recommendation
is to not use them. Do not use them. They give
a mobile infant access to stairs and other hazards
before they have the judgment or control to handle
them. They are a major cause of serious injuries.
OK, drowning in burns. An infant can drown in
an inch of water. You need touch supervision
in the bath at all times. For burns, turn your
water heater down to 120 degrees Fahrenheit and
never ever heat a bottle in the microwave. It
creates dangerous hot spots. And poisoning? Once
they're mobile crawling, cruising everything
is a target. All cleaning supplies, all medications
need to be locked up high and out of reach. Have
the poison control numbers saved in your phone.
Let's hit the big two for exams. First, motor
vehicle safety. Non -negotiable. The car seat
must be rear -facing in the back seat for as
long as possible, at least until age two. This
protects their fragile neck and spinal cord,
and it has to be installed at a 45 -degree angle
to keep their airway open. And the other big
one, SID's prevention, the sleep environment.
This is critical teaching. The mantra is, back
to sleep. Always place the infant on their back
in a crib with a firm mattress and nothing else.
Nothing else. Nothing. No pillows, no bumper
pads, no blankets, no stuffed animals. Just the
baby in a sleep sack. A clear crib is a safe
crib. So let's summarize protection. What are
nurses watching for? You're watching for unsafe
practices, an improperly installed car seat,
a crib full of blankets, small toys left within
reach of a newly mobile infant. And what do exam
writers love to test? They love the safety triad.
Back to sleep for SIs, rear -facing for car safety,
and connecting that fine pincer grass directly
to the choking hazard. Our memory phrase for
infant safety. Everything goes in the mouth and
they never stop moving. Okay, we've covered the
body, the mind, and how to protect them. Let's
wrap up with the day -to -day guidance. Nursing
care, nutrition, sleep, and common concerns.
The foundation of nutrition for the first year
is simple. Breast milk or iron -fortified formula.
That is their primary food. And we need to remember
to supplement with vitamin D if they're exclusively
breastfed. Yes, that's a key point. Human milk
is low in vitamin D, so they need drops starting
soon after birth. OK, so when do we introduce
solid foods? The window is between four and six
months, but it's based on developmental readiness,
not just the calendar. What are those readiness
cues? They need good head control, so they can
sit up and eat. They need to show interest in
food, and most importantly, that extrusion reflex,
the tongue -thrust reflex that pushes food out,
has to be gone. And the process of introducing
foods is very specific. Very. You introduce one
new, single ingredient food every three to four
days. That way, if they have an allergic reaction,
you know exactly what caused it. And we usually
start with iron -fortified rice cereal. Typically,
yes. Then you can move on to pureed vegetables
and fruits. And remember, until they have enough
teeth, which start coming in around six to 10
months, everything needs to be soft and mashed.
What about weaning from the bottle? You can introduce
a cup around six months. The goal is to be off
the bottle by 12 to 18 months to prevent dental
caries and never, ever put a baby into bed with
a bottle. Let's hit a few of those common concerns
that stress parents out. Sure. Spitting up is
normal. Just keep them upright for a bit after
they eat. Colic, that intense crying, is awful,
but it's temporary. It usually resolves by three
months. And teething? Teething can make them
fussy and mess with sleep. You can offer cool
teething rings or a washcloth. For pain, acetaminophen
is fine, but a key test point. No ibuprofen for
infants under six months of age. Let's talk about
sleep. What should parents expect? A newborn
sleeps like 20 hours a day. But the big change
happens around three to four months. Their sleep
starts to consolidate. They might start sleeping
a seven or eight hour stretch at night. And by
12 months. They should be sleeping eight to 12
hours at night with a couple of naps during the
day. The best nursing intervention is to encourage
a consistent, predictable bedtime routine starting
around four months. It sounds like the nurse's
role is constant anticipatory guidance. You are
always preparing the parent for what's coming
next. You assess milestones, you teach about
safety, you guide them on nutrition and sleep.
You are their trusted resource. Let's go find
a wrap -up for this section. What are nurses
watching for? You're watching for inappropriate
feeding, like propping a bottle. You're watching
for delayed introduction of solids past six months.
And you're watching for colic that doesn't resolve.
And for the exams, what's the high yield takeaway?
The timing of solids four to six months and the
rule for introducing new foods one at a time
every three to four days. And the memory phrase.
Milk first, then mash. That was an incredible
deep dive. We've really covered the A to Z of
the infant. We connected that triple growth and
high H vibes physiology to why you have to track
them so closely. And we linked the developmental
sequence directly to risk. The cephalocautal
development means head control happens, then
sitting happens, and when you add the fine pincer
grasp, you get this cascade of new safety needs.
It really is predictable. If you know that two,
four, six, nine, 12 -month timetable, you know
the milestones, you know the cognitive leaps
like object permanence, and you know the anxieties
that come with them. And it all comes back to
the maturation of the central nervous system.
Those primitive reflexes have to go away to unlock
all of this purposeful voluntary movement. us
to a final thought for you to take with you.
We said the Moro reflex should be gone by four
months. So if you're assessing a nine month old
and they still have this huge uncontrolled startle
reflex every time there's a loud noise, what
does that really imply about their ability to
master their own body? What complex skill might
that be getting in the way of? Think about what
those arms do during a morrow reflex. They fly
out. How can an infant learn to purposefully
reach for a toy or transfer an object from hand
to hand or even bring food to their mouth if
their arms are being hijacked by this involuntary
reflex? It's a sign of a major delay in cortical
maturation. It is. The primitive brain is still
in charge. And that persistence is getting in
the way of every voluntary motor skill that's
supposed to follow. Making that connection from
a simple reflex to its functional consequence
is what takes you from being a good student to
being a great pediatric nurse. Thanks for joining
us for this deep dive. Study smart, anticipate
the risk, and we'll catch you on the next one.