00:01
Okay, now this is kind of cool.
00:03
We're going to look at the changes in normal
white blood cell count across the lifespan.
00:08
Now, I wouldn't exactly memorize
this if I were you.
00:11
Just kind of keep the references in mind.
00:13
Newborns are 13-38.
00:17
Now, remember, an adult was 5-10. So newborns --
I'm talking about the day of their birth --
they're a lot higher than an adult.
00:24
Now, an infant at 2 weeks, it's back down
closer to normal adult ranges of 5-20.
00:30
So on the day they're born, their white
blood cell count normal is 13-38.
00:35
So you don't want to look at a
newborn's lab values and go,
"Wah. They must have some
type of raging infection."
No. That's normal for newborns.
00:42
Now at 2 weeks, they kind of normal
out again. Adults are 5-10,
but pregnancy in the 3rd
trimester, they're 5.8,
which is pretty close to an adult, up to 13.2.
00:56
So, again, if I'm looking at a CBC result
of a woman who's pregnant
in her 3rd trimester,
I don't want to panic if I
see something at 13.
01:05
That doesn't mean they have any
type of infection going on. It's normal.
01:09
It is a lot of work to grow a human,
and that's just part of the process.
01:14
Okay. So this is an important point.
That's why we've highlighted it for you.
01:18
The numbers of leukocytes changes
with age and during pregnancy.
01:23
So make sure if you're looking at these
special populations, you keep that in mind.
01:28
Okay. Now, let's talk about lifespan.
It's kind of a serious topic, right?
So a newborn on the day of birth has
a really high white blood cell count.
01:37
It ranges from like 9,000-30,000 leukocytes.
01:40
Now that number will fall to adult
levels within 2 weeks.
01:43
Remember, we talked about that
on that previous slide.
01:46
Now for the first few weeks after birth,
they have a high percentage of neutrophils.
01:51
Now, wait a minute, we're talking
about 9,000-30,000 is leukocytes.
01:56
That's the total number of
white blood cell counts.
01:58
Now we're going to break that
down a little bit and talk about
the different types of white blood cells.
02:03
And in the first few weeks after birth, they
have a high percentage of neutrophils.
02:08
Now, later on, the lymphocytes will
predominate, but for the first few weeks,
they have a higher percentage of
neutrophils. So, newborns,
really high number of leukocytes
as compared to an adult,
but in the first few weeks after birth, they
have a high percentage of neutrophils.
02:25
Later on, that will switch to
lymphocyte predominance.
02:28
They'll have a higher percentage
of lymphocytes.
02:31
Until about 8 years of age, the lymphocytes
are more predominant than the neutrophils.
02:37
Now the elderly -- bless their hearts.
02:39
Everything is kind of wearing out, right,
their joints, their organs, their systems.
02:44
So they'll have a slight decrease
of total white blood cells,
and it's probably normal for them.
02:50
And remember, this is another
important time for you look at trends.
02:53
If you have other lab work from
other times in these patients
you can see what their white blood
cell count normally runs.
02:59
But their inflammatory system and their
immune system is kind of wearing out.
03:04
That's why they have a slight decrease
in total white blood cells.
03:08
Now, last, those pregnancy patients,
right? They have leukocytosis.
03:12
Primarily, it's because they have
an increase in neutrophils
with a slight increase in the lymphocytes.
03:17
So when a woman is pregnant,
she has elevated white cells.
03:21
There is a lot going on down there,
but, primarily an increase in neutrophils.
Remember, that's one of the 5 types,
and has a little bit of an
increase in the lymphocytes.
03:31
Okay, so, what's our takeaway from this slide?
Well, remember, we know that you
have extra high white cell count,
newborns, and pregnant women, right?
You're going to have low white
cell counts if you're elderly.
03:46
Then we broke it down and said in
the first few weeks after birth,
you have a higher percentage of neutrophils,
and later, the lymphocytes become a higher
percentage until about 8 years of age.
03:57
So when you're looking, again, at
this type of information,
just see how you can group things together.
04:02
We call that chunking information.
04:04
Your brain does much better when
you look for relationships
between the information as you're learning