Soundbytes Cases

Tubal Ectopic Abdominal Ectopic

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- Hello, my name is Phil Perera,
and I am the Emergency Ultrasound Coordinator
at the New York Presbyterian Hospital in New York City,
and welcome to Soundbytes.
In today's module we're going to focus in specifically
on the use of bedside ultrasound
for the paracentesis procedure.
Now, the use of bedside ultrasound for paracentesis
can actually lower your complication rate
and allow you to know who is a better candidate
for the actual procedure.
So, step number one, when you're deciding
if a paracentesis procedure is necessary,
is to determine if the patient actually has ascites
and if there's significant areas of fluid pockets
that are amendable to a drainage procedure.
The second step is to best mark the location
for the needle placement, using bedside ultrasound.
And the two techniques that have been used in the past
are the midline linea alba,
or the lateral gutter techniques.
And using bedside ultrasound can allow you to decide,
between the two, where is the best location
for the needle placement.
This illustration shows the preferred positions
for the paracentesis procedure.
The key concept here is, to avoid the epigastric vessels
during the puncture attempt,
note the location of the epigastric vessels,
just lateral to midline on the abdominal wall.
So we wanna use that 3 MHz probe,
and we can place the probe,
as shown in positions one and two,
in the traditional lateral gutter approaches
for the paracentesis procedure.
This would be above the anterior superior iliac crests.
And we can look for fluid within the lateral gutters
and plan for a puncture attempt
in either of these positions.
We can also place the probe in probe position three
as shown in the midline linea alba position.
We'd wanna place the probe below the umbilicus
in the midline, in a relatively avascular
midline linea alba position.
Now, we can also use the 10 MHz higher frequency probe
to get a better look at the abdominal wall
in relation to the bowel and the ascites fluid
prior to our puncture attempt.
In fact, this will give us a more detailed look
into the abdominal cavity, to better plan our approach
for the paracentesis procedure.
Here's the location of the probe to the lateral position
for the paracentesis procedure.
Note the placement of the high-frequency linear array probe
above the anterior superior iliac crests
along the lateral gutters of the patient.
Notice here, the location of the epigastric vessels
in relation to the lateral gutters,
and we want to avoid those epigastrics
during any puncture attempt.
Notice also the location of the bladder,
and we want to make sure that we decompress the bladder
prior to any puncture attempt for a paracentesis.
But we can see here that the probe
is safely lateral to most of these structures,
thus the paracentesis can be safely performed
from this position on the abdominal wall.
This video clip shows a small amount of ascites
as taken with a 3 MHz probe, and we can see here
a small amount of ascites is denoted
by that dark or anechoic fluid collection,
and we can see the intestine with anchoring mesentery
swaying back and forth within the ascites
as the patient breathes.
And this is known as gut sliding,
and it makes the intestine look almost like palm trees
swaying back and forth within the breeze.
So, from this location, it might be unsafe
to perform a paracentesis, as it could be difficult
to get a needle in between the areas of intestine
without puncturing through an area
of intestine or mesentery.
This video shows a moderate amount of ascites,
again taken with a 3 MHz probe.
And we note the intestine with anchoring mesentery
sliding back and forth as the patient breathes,
and we see a large collection of ascites,
that dark or anechoic fluid collection,
anterior to the intestine.
So this might be a good location to perform a paracentesis
as we could place the needle safely into that ascites
without going through into the intestine
or anchoring mesentery.
This video clip emphasizes the point
that using a higher-frequency 10 MHz probe
on the abdominal wall
gives a more detailed exam of the evaluation
of the ascites in relation to the intestine.
And we see the abdominal wall anteriorly,
and we can see the bowel floating within the ascites.
Here we can actually mark down and measure
the safety zone from in which a needle could safely go
through the abdominal wall, into the ascites,
without hitting bowel.
Note here, the safety zone is approximately two centimeters,
as marked out with the centimeter dots
towards the right of the image.
Another benefit of using the higher-frequency probe
prior to a paracentesis procedure
is to investigate the depth of the abdominal wall,
as a thick abdominal wall can frustrate attempts
at a paracentesis procedure.
Here we see the depth of the abdominal wall,
which measures 2.5 centimeters anteriorly,
and we can see the line,
which is the peritoneal lining there,
just deep to the abdominal wall.
Note the presence here of ascites,
the dark fluid collection,
just deep to the peritoneal lining
and we can see the gut sliding,
or bowel moving back and forth, deep within the ascites.
Note the two-centimeter safety zone
for placement of the needle into the ascites fluid,
but note here we'd need to use a longer needle,
a needle longer than 2.5 centimeters,
just to get through the abdominal wall
to get fluid from the abdominal cavity.
In this video clip, we've moved the probe slightly lateral
from the last position in the same patient.
Again, we note the deep abdominal wall,
at 2.5 centimeters, denoting that a longer needle
will be needed to get the ascites fluid.
But here we see a large collection of ascites,
and note here the absence of gut sliding,
denoting a larger pocket of ascites
and a more favorable position
for the paracentesis procedure.
So this is actually the position
in which we perform the paracentesis,
using a longer lumbar puncture needle
and we're safely able to get a paracentesis done
and get the ascites fluid out for evaluation in the lab.
In this video clip, we'll reemphasize the surface anatomy
for the lateral abdominal position for paracentesis.
Note we're coming with a cap needle
underneath the 10 MHz probe, at the lateral puncture point.
This would be the preferred position
for the lateral approach for paracentesis,
as shown by the black star.
Now, some of the surface anatomy that we can palpate
includes the iliac crest, and note here
we're about four to five centimeters
above the iliac crest there.
We also want to avoid
those all-important epigastric vessels,
which we can see medial to the puncture point
from the lateral paracentesis approach.
Using ultrasound guidance, we can map out
the best position on the abdominal wall
for the paracentesis approach,
and go either right or left-side
depending on the maximal pocket of ascites present.
We also want to ascertain the relative locations
of the liver and spleen, so as to avoid
iatrogenic injury to a solid organ.
And as we emphasized earlier in the video clips,
you want to look for that intestine
with anchoring mesentery,
so as to avoid intestinal puncture during the procedure.
While the lateral gutter approach to paracentesis
is commonly emphasized during medical training,
the midline linea alba position
can be a great location for a paracentesis procedure.
Note here the probe is placed along the midline linea alba
with a marker dot towards the patient's head.
And we see it placed along the midline,
just inferior to the umbilicus.
Here we'll further investigate
the midline linea alba position
for the paracentesis procedure.
Note the high-frequency probe,
placed along the midline linea alba,
and we're coming with a cap needle
at a 45-degree angle underneath the probe
looking for the ring down artifact
onto a suitable pocket of ascites.
Here's a different view point
from the same midline linea alba position.
Again, we're placing that probe along the midline.
And this would be about the appropriate position
for the paracentesis procedure.
And here we just place the needle right there,
directly inferior to the umbilicus.
And I'll indicate that with a black star.
Note here, we'd be coming through
the relatively avascular midline linea alba.
But recall that it's very, very important
from this position to not puncture
through the bladder, and we can see
the relative location of the bladder
in relation to the puncture point.
So we must have the patient void
or place a Foley catheter, prior to attempting
a paracentesis from the midline linea alba position.
Here's a video clip from the midline linea alba,
taken with a 3 MHz probe.
I have the probe oriented towards the patient's head
so the superior aspect is towards the left
and inferior's towards the right.
Note here, we see the bowels superiorly,
moving up and down within the ascites fluid,
which we see in the middle of the image here,
and note the bladder, relatively large,
towards the inferior aspect of the image here.
Now, we can see that this would be a pocket
amendable to paracentesis, but recall again,
to increase the safety of the procedure
from the midline linea alba approach,
we'd want to drain the bladder prior to a puncture attempt.
Here's a video clip taken from the same patient
after having him completely void.
And note now, we have the decompressed bladder,
making the ascites pocket much larger
and more amenable to a paracentesis puncture
from that midline linea alba technique.
And we can see here now, the pocket of ascites
as denoted by the dark or anechoic fluid collection,
between the bowel superior
and the decompressed bladder inferiorly.
In this video clip, we can see
how using the higher-frequency 10 MHz probe
can allow real-time guidance of the needle
down into the ascites pocket,
and we see the detection of the needle
coming in from left to right through the abdominal wall,
with the tip of the needle safely parked
within the ascites fluid.
Notice here that the bowel is distant
to the tip of the needle,
thereby we can minimize any puncture
through the bowel during the paracentesis procedure.
We need to put a sterile sheet over the probe
during this procedure.
So, in conclusion, thanks for tuning in
for ultrasound guidance of paracentesis.
Ultrasound guidance for this procedure
can potentially make the paracentesis procedure
a safer one for our patients, and using a combination
of both the three and 10 MHz probes
can fully evaluate the ascites prior to a procedure.
We can use either one of two techniques.
Either the static technique, we position the patient
and then mark off the puncture spot with ultrasound
prior to a procedure,
or we can actually use a dynamic technique
where we place the probe in a sterile sheet
and watch the needle in real-time
go through the abdominal wall into the ascites fluid.
Either of these techniques
can potentially decrease your complication rate,
so I hope in the future you'll consider
ultrasound guidance for paracentesis
during your next paracentesis procedure.

Brightcove ID

5508114740001

https://youtube.com/watch?v=bWxv_a9CkBs

Case: Intrauterine Pregnancy - Part 2

Read more about Case: Intrauterine Pregnancy - Part 2

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This video discusses how to use ultrasound to determine the gestational age of a normal pregnancy, determine a fetal heart rate, and identify markers for an abnormal pregnancy and fetal demise.

Clinical Specialties

Media Library Type

Media Library Tag

Ampullary

Ovarian

Pseudogestational Sac

Subtitles

- [Voiceover] Hello, my name is Phil Perera
and I am the emergency ultrasound coordinator
at the New York Presbyterian Hospital in New York City.
Welcome to Soundbytes Cases.
In this module entitled Emergency OB/GYN Ultrasound:
Part 2 of Intrauterine Pregnancy,
we're going to focus on the further assessment
of normal pregnancy.
We'll look at two further things that
are important to assess in your pregnancies.
First of all, learning how to date the gestational age
of the pregnancy, as well as learning
how to determine the fetal heart rate.
Then we'll wrap up the module by examining further findings
in abnormal pregnancies and learning how to differentiate
these findings from a normal intrauterine pregnancy.
The first concept that we'll focus on
is dating fetal gestational age.
In the first trimester, we're going to use an assessment
of the crown rump length.
Interestingly, dating in the first trimester
is actually probably the most accurate during all
phases of pregnancy, as there's a difference in
the growth curve as the fetus develops.
In the second trimester, we'll measure
the skull biparietal diameter.
And the third trimester, the dating is composed
of the biophysical profile, focusing on the femur length,
as well as other biophysical measurements.
This is an image of a first trimester pregnancy,
and we're going to evaluate the gestational age by
measuring the crown rump length.
Here we see the fetal pole stretched across
the gestational sac and we see the crown located
over towards the right and the rump towards the left.
If we put the calipers down from the crown across
to the rump we get a measurement of 1.46cm.
By selecting Crown Rump Length in the software package
on the ultrasound machine, we'll get an assessment
of gestational age which we can see here towards
the bottom left, seven weeks and six days.
As first trimester dating is considered one of the most
accurate during the entire pregnancy, it's nice to print
this image out and give to your patient to take for
their followup visit with their OB/GYN.
In the second trimester, dating of gestational age
focuses on skull circumference or measurement of
the biparietal diameter.
We want to measure the skull at about the level
of the thalamus in an axial orientation with the face down.
As we can see here, replacing the calipers from
the outer skull table proximally to the inner skull
table distally, and we have a measurement of 3.26cm
correlating to a 16 week one day gestational age.
In addition to measuring the gestational age of the fetus,
another very important concept is to get a measurement
of the fetal heart rate.
Normal fetal heart rates will range from 120-160
beats per minute, but lower rates down to 90 beats
per minute can be seen in early pregnancy in
the early parts of the first trimester.
M-Mode is the best method for determining fetal heart rate.
Power Doppler and Contrast gives more ultrasonic energy
to the developing heart, thus M-Mode is the preferred
way of measuring the fetal heart rate at this time.
Here, we're going to use M-Mode to determine
the fetal heart rate.
Notice we have the fetus zoomed up towards the top
of the image and replacing the M-Mode caliper directly
over the fetal heart.
Towards the bottom we see the M-Mode Motion strip
and notice the little waves showing the motion
of the fetal heart.
In this particular ultrasound machine, we need to
measure between each peak, and we see here that
we get a heart rate determination towards the bottom,
158 beats per minute.
This is something we can print out and place on the chart
to show that at the time we saw the baby there was
an actual heart beat.
While fortunately most pregnancies have a successful
outcome, unfortunately there are going to be some
abnormal pregnancies that we'll see in the emergency
department, consistent with fetal demise.
Some of the measurements we'll use to determine
abnormal pregnancy with fetal demise is a very large
gestational sac greater than 10 millimeters if
no yolk sac is seen.
Once the gestational sac is greater than 18 millimeters,
we should see a fetal pole or else this is an abnormal
pregnancy.
And many times the gestational sac in an abnormal
pregnancy will have an irregular shape with a scallop
type appearance to it.
Here's video from an abnormal pregnancy.
The first thing we notice is a very large
gestational sac without a yolk sac or discernable
fetal pole with heart beat.
We also see the presence of subchorionic hemorrhage
to the superior aspect of the gestational sac.
That's that area of dark or anechoic fluid
surrounding the gestational sac.
This is seen commonly with abnormal pregnancies
or spontaneous miscarriage.
Here, we'll put the calipers down to measure the diameter
of the gestational sac.
Note that it's very large at 2.8 centimeters by
1.6 centimeters, much larger than the one centimeter
mark that we said defined an abnormal pregnancy
if there was no yolk sac or 18 millimeters if no
fetal pole was seen.
Other indicators of an abnormal pregnancy with fetal
demise is a gestation greater than seven weeks,
which is abnormal if no fetal heart beat is seen.
And if the fetal pole is greater than five millimeters
in dimension this is abnormal if no fetal
heartbeat is seen.
This was an unfortunate case in which we see
a large a fetal pole, greater than five millimeters
without a heart beat.
This is indicative of embryonic demise and we also
see a large circular amnion within the gestational sac.
While I do think it's important we're able to pick up
the findings of the abnormal pregnancy, I'm always
going to get a confirmatory ultrasound and/or OB/GYN
consultation before giving the patient the news that
there is a fetal demise.
I'd like to conclude this module with another form
of abnormal pregnancy, which is a molar pregnancy,
which is a form of Gestational Trophoblastic Disease.
Gestational Trophoblastic Disease ranges from
a spectrum from a Benign Hydatidiform Mole to
Invasive Choriocarcinoma, a form of metastatic disease.
The majority of these are derived from paternal
chromosomes; there is no maternal chromosomes in the embryo.
The ultrasound appearance will be a cyst-like bunch
of grapes with a snowstorm-type appearance,
and classically the serum Beta-HCG will be very elevated.
Here's video from a patient who presented with
a Molar Pregnancy.
Her presenting symptoms were uncontrolled hypertension
during the pregnancy, as well as vaginal bleeding, and pain.
What we see here is the presence of a molar pregnancy
within the fundal region of the uterus.
Notice it has a cyst-like type of appearance.
Very different from the normal appearance
of a intrauterine pregnancy.
As we scan back and forth, it almost looks like
a bunch of grapes within the fundus of the uterus.
So a diagnosis of a molar pregnancy and my next move
was to get an OB/GYN consultation stat.
So thanks for tuning in to Part 2 of Emergency OB/GYN
Ultrasound, focusing on intrauterine pregnancy.
Hopefully you now have a better understanding on
how to further assess a normal pregnancy by determining
gestational age and fetal heart rate.
I hope also I've been able to give you some of
the ultrasound findings that you may see in an
abnormal pregnancy to know when you need to get
an OB/GYN consultation in the ED.
I hope to see you back as we move on to Ectopic Pregnancy,
and two modules in which we'll discuss the various
findings of ectopic pregnancies that we may see
in the emergency department.
I'll see you back as Soundbytes continues.

Brightcove ID

5750480594001

https://youtube.com/watch?v=4clxpcVLOS0

Case: Intrauterine Pregnancy - Part 1

Read more about Case: Intrauterine Pregnancy - Part 1

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This video discusses the use of transvaginal and transabdominal ultrasound for detecting intrauterine pregnancies.

Clinical Specialties

Media Library Type

Media Library Tag

Tubal Ectopic Abdominal Ectopic

Ampullary

Ovarian

Pseudogestational Sac

Subtitles

- Hello, my name is Phil Perera,
and I'm the emergency ultrasound coordinator
at the New York Presbyterian Hospital in New York City.
And welcome to SoundBytes Cases.
In this module entitled Emergency OB/GYN Ultrasound: Part I,
we're going to focus entirely on the
ultrasound findings of intrauterine pregnancy.
Now patients with early pregnancy and vaginal bleeding
with or without abdominal pain
are frequently seen in the emergency department.
Luckily for us, emergency OB/GYN ultrasound
has evolved to be one of the most helpful
applications of sonography
in a busy emergency medicine practice.
So this module will be focused
primarily on the detection of intrauterine pregnancy
and we'll examine the ultrasound findings that define
a normal pregnancy for an emergency physician sonographer.
Before launching into the sonographic findings
of a normal intrauterine pregnancy,
let's take a moment to quickly review
the OB/GYN anatomy important for this application.
We see the uterus to the left and adnexa to the right.
Notice the areas of the uterus.
We see the lower cervix,
the intermediate body,
and the fundal region towards the top of the uterus.
Now, the fundal region is where we define
an intrauterine pregnancy to be located.
We see the area where the fallopian tube
enters into the uterus,
which is the interstitial region in a normal uterus
and the cornual region in a bicornuate uterus.
And this is where some variants of ectopics can implant.
Notice the areas of the fallopian tube to the right,
which we'll concentrate more on
with regard to ectopic pregnancy.
And we see the broad ligament there encasing
the fallopian tube and the ovary as seen to the right.
When taking care of a patient
who has vaginal bleeding in pregnancy,
there's four main classifications of diagnoses.
The first is a Threatened Abortion,
which is defined as the presence
of an intrauterine pregnancy with bleeding.
The second main classification
encompasses several different terms.
The terms that are commonly used are,
Incomplete Abortion,
Missed Abortion,
Blighted Ovum,
and Fetal Demise.
Basically, all of these mean the presence
of fetal membranes or parts,
without expected fetal growth or cardiac activity.
The third main classification is a Completed Abortion,
in which there is no further presence
of fetal membranes or parts,
and on examination, usually the cervical os will be closed.
The fourth main classification is the most dangerous,
is Ectopic Pregnancy.
Here's a table showing the structures in pregnancy
and about the time that they're seen on transvaginal
versus transabdominal sonography.
As we look in the Embryonic Structure column to the left,
we see the first structure that appears
is a gestational sac, seen on transvaginal sonography
at about 4.5 to 5 weeks,
and about a week later on transabdominal sonography.
The yolk sac is seen at about 5 to 5.5 weeks
on transvaginal sonography
and a week later on transabdominal sonography.
I have this circled in red,
as this is really the way we diagnose
an intrauterine pregnancy.
Then note the fetal pole is seen at about 5.5 to 6 weeks
on transvaginal sonography
and a week later on transabdominal sonography.
The last main finding, which is a fetal heart beat,
is seen at about six weeks on transvaginal sonography
and about at seven weeks on transabdominal sonography.
Another important concept for OB/GYN sonography,
is the correlation of the serum beta HCG
to the findings of a normal pregnancy.
As we see here for transvaginal sonography,
the discriminatory zone at which we will see
findings of an intrauterine pregnancy
are about 1,500 to 2,000 mIU.
For transabdominal sonography,
the discriminatory zone is about 6,500 mIU.
Now, this rule does not apply to ectopic pregnancies,
which secrete beta HCG at atypical levels
and are commonly seen with betas all over the map.
They can be seen with betas lower than 1,000
and as high as 30,000.
The first finding that will occur
during an intrauterine pregnancy
is going to be a gestational sac.
As we see here in the ultrasound picture to the right,
it's a small, round circle that's dark
or hypoechoic in relation to the rest of the uterus.
We actually see a gestational sac below that
that came out of a patient.
Notice that it has a translucent, membrane-type appearance.
Unfortunately, gestational sac
is not diagnostic of an intrauterine pregnancy,
as a pseudogestational sac of ectopic pregnancy
can be seen from hormonal stimulation.
As a general rule of emergency ultrasound,
is that visualization of a gestational sac
is not adequate to call an intrauterine pregnancy.
Here's two video clips showing the gestational sac.
Long Axis to the left,
and Short Axis to the right.
We see here a very small diameter gestational sac
in both of these orientations.
Unfortunately, this can be seen with a
pseudogestational sac of ectopic pregnancy.
So a small gestational sac, like this,
is in no way diagnostic of an intrauterine pregnancy
for the emergency physician sonographer.
Remember that the gestational sac is seen
at about 4.5 to 5 weeks on transvaginal sonography,
and about a week later on transabdominal sonography.
Here are the findings that we define
as indicative of an intrauterine pregnancy
for an emergency physician sonographer,
and that is the presence of a gestational sac
with a yolk sac inside.
As we see in the picture to the right,
the yolk sac has a circular-type appearance
that we call the Positive Cheerio Sign.
Let's just remember, gestational sac plus yolk sac
is indicative of intrauterine pregnancy.
However, bonus points are given
if you see a fetal pole with a heart beat
for confirmation of intrauterine pregnancy.
Here's a video clip showing a definitive
intrauterine pregnancy.
What we see here is a larger gestational sac
and as we look inside the gestational sac,
we see the positive yolk sac or Cheerio Sign.
Notice the circular yolk sac is seen
towards the inferior aspect of this gestational sac.
This would be diagnostic of an intrauterine pregnancy,
effectively ruling out an ectopic pregnancy
in the vast majority of patients.
Remember that the yolk sac is seen
at about 5 to 5.5 weeks on transvaginal sonography,
and about a week later on transabdominal sonography.
Here we see a pregnancy that is a bit further advanced.
Note we have a larger gestational sac,
that darker or hypoechoic area,
within the fundal region of the uterus,
and as we look inside the gestational sac,
we see the positive yolk sac or the Cheerio,
and looking just to the left of the yolk sac,
we see a tiny little fetal pole there.
Interestingly enough, as we zoomed up on that fetal pole,
we could make out the flicker of a heart beat.
So, a definitive intrauterine pregnancy.
Recall that the fetal pole is seen
at about 5.5 to 6 weeks on transvaginal sonography,
and about a week later on transabdominal sonography.
Here's a transvaginal short axis view
of a seven week intrautertine pregnancy.
We see the gestational sac here.
Notice that the gestational sac
is located in the center of the uterus
as seen here in short axis,
and there's a good amount of myometrial mantle
surrounding the gestational sac,
signifying a fundal location.
We see the positive Cheerio sign, or yolk sac,
to the upper right aspect of the gestational sac,
and right below, we see the fetal pole stretched out.
Notice the positive cardiac activity
as we scan back and forth through the fetal pole.
Here's another intrauterine pregnancy at about seven weeks,
again in the transvaginal short axis view.
We note the good amount of uterus
surrounding the gestational sac,
signifying the fundal location.
We see here the yolk sac or Cheerio sign,
and the fetal pole is stretched out below the yolk sac.
Notice the positive cardiac activity
within the fetal pole.
Now we see another very important finding here
on this ultrasound,
which is the amniotic membrane,
billowing out from around the fetal pole.
Eventually the amniotic membrane
will plaster down on the margins of the gestational sac
to form the amniotic cavity,
in which further growth of the fetus will occur.
Here's an interesting video clip
showing a twin pregnancy.
What we see here are two gestational sacs
signifying dichorionic twins,
and within each of the gestational sacs
we can see little fetal poles
with a flicker of heart beats.
Recall that fetal heart activity
is seen at about six weeks on transvaginal sonography
and about seven weeks on transabdominal sonography.
Here's an early second trimester pregnancy.
What we see here is the next Oscar De La Hoya.
Note the mean right hook on the baby here.
The important finding here is that
this is an intrauterine pregnancy
as we can define a good mantle of uterus
surrounding the pregnancy.
That's very important as there are some ectopics
that can grow to an advanced stage,
but they're discerned by a lack of uterus
around the pregnancy.
Here's another second trimester baby
and as I work in Northern Manhattan,
I refer to this baby as the Merengue baby.
Note the baby moving around fluidly within the amniotic sac.
A sure sign that this kid will grow up to be a slick dancer.
In conclusion, I'm glad I could share with you
this SoundBytes module
going over Emergency OB/GYN Ultrasound: Part I
of intrauterine pregnancy.
Emergency OB/GYN ultrasound is definitely
one of the most helpful sonographic applications
in a busy emergency medicine practice
and hopefully by going through the module
you now have an understanding
of the ultrasound findings diagnostic of a normal pregnancy.
I hope to see you back as we return
in OB/GYN Ultrasound Pregnancy Part 2,
focusing on further assessment of normal pregnancy
as well as looking further into
the ultrasound findings of an abnormal pregnancy.

Brightcove ID

5508114751001

https://youtube.com/watch?v=gv4q8ZB25JM

Case: Ectopic Pregnancy - Part 1

Read more about Case: Ectopic Pregnancy - Part 1

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This video details how bedside transvaginal ultrasound can help emergency medicine professionals evaluate OB/GYN anatomy to diagnose possible ectopic pregnancies.

Clinical Specialties

Media Library Type

Media Library Tag

Pseudogestational Sac

Tubal Ectopic Abdominal Ectopic

Subtitles

- Hello, my name is Phil Perrera,
and I'm the emergency ultrasound coordinator
at the New York Presbyterian Hospital in New York City,
and welcome to SoundBytes Cases.
Today's module is going to focus on ectopic pregnancy.
Ectopic pregnancies constitute
about 2% of all total pregnancies,
although they're commonly seen in the emergency department.
Ectopic pregnancy is more commonly seen in women
with a history of tubal ligation
who are using interuterine devices for contraception
or have a history of sexually transmitted diseases,
such as pelvic inflammatory disease
with scarring of the tubes.
Ectopic pregnancy is also commonly seen in women
using fertility agents,
which accounts for the increasing rate of ectopic pregnancy
over all.
As a golden rule, we must consider ectopic pregnancy
in all women with abdominal pain
and/or vaginal bleeding and a positive pregnancy test,
until ruled out by sonography.
Let's begin by reviewing the OB/GYN anatomy
that we'll need to know to perform bedside ultrasound
of the uterus and the adnexa.
We'll begin by locating the lower cervical region
of the uterus.
The portion above that, the body, and the fundal region
of the uterus above the body,
which is where we define an inter-uterine pregnancy
to be located.
Notice the intersticial region of the uterus,
that region of the uterus that abuts the fallopian tube.
In a cornual uterus this is known as cornual region.
Here we also see the portions of the fallopian tube,
the proximal isthmal region,
the distal infindibulum,
and notice the ampullary region
which comprises the majority of the fallopian tube.
We also see here, the broad ligament which encases
the fallopian tube and ovary in the lateral region
of the adnexa.
Remember that the ovary is relatively mobile
within the broad ligament.
Now let's review a transvaginal long axis scan
from a women who presented with a positive pregnancy test,
who had lower abdominal pain and vaginal bleeding.
Notice the fundus, as shown here to the left,
the cervix to the right.
We see here the presence of a thickened white
endometrial stripe in the midline of the uterus.
Notice the pelvic cul de sac that potential space
posterior to the uterus.
Notice here the absence of an inter-uterine pregnancy.
Now, confirm the absence of an IUP by scanning
in the transvaginal short axis plane.
Here we have the probe marker
oriented towards the patient's right,
and we're cutting the uterus in cross section.
Notice again the thickened endometrial stripe
in the midline of the uterus,
and the pelvic cul de sac posteriorly.
Again, we see the absence of an IUP,
and also note the absence of free fluid,
dark anechoic fluid collections
within the pelvic cul de sac.
So, given these findings we're now concerned
about the presence of an ectopic pregnancy.
So, lets begin our discussion of ectopic pregnancies
by reviewing the locations that we commonly see
ectopic pregnancies to be found.
We see here a normal uterus to the left,
and a bicornuate uterus to the right.
We remember that a fundal location is the definition
of an inter-uterine pregnancy as shown smack in the middle
of the normal uterus to the left.
However, we can have variants of ectopic pregnancies
within the uterus as shown in the interstitial location
in the normal uterus to the left,
and in the cornual region in the bicornuate uterus
to the right.
We can also have implantations low
within the cervical region of the uterus,
as shown in the normal uterus to the left.
Now, most ectopic pregnancies will be located
within the fallopian tube and of those
the majority will be found in the ampullary region
as that comprises the majority of the fallopian tube.
But we can have implantations more proximal,
within the isthmal region
or distal within the infindibular region.
Now, tough ectopics to diagnose are those that implant
within the ovary,
within the abdominal cavity,
or within the peritoneal lining.
These can be very, very hard to diagnose
and commonly grow to an advanced stage before diagnosis.
So, returning to our case, given the presence of a positive
pregnancy test and the absence of an IUP
on bedside ultrasound, we were very concerned about
ectopic pregnancy and decided to scan out
to the left adnexa.
Here, notice we're scanning out to the left adnexa,
and we have a positive finding.
What we see here is a thickened fallopian tube,
comprising what is known as the bagel sign.
Notice within the thickened fallopian tube,
we have another positive finding.
That is the presence of a fetal pole.
So, in this patient we were able to diagnose
an ampullary ectopic pregnancy and our next move
was to call OB/GYN stat for a consultation.
So, in conclusion, ectopic pregnancies constitute
the greatest cause, overall, of maternal mortality.
We must consider an ectopic pregnancy in all women
with a positive pregnancy test
where an inter-uterine pregnancy is not visualized
within the fundal part of the uterus.
Most ectopic pregnancies are going to be located
in the fallopian tube,
and we may actually visualize the ectopic
with ultrasound evaluation of the adnexa
as shown in this module.
So, we'll return with ectopic pregnancy part two
which goes over the varied manifestations
of ectopics.

Brightcove ID

5750491404001

https://youtube.com/watch?v=iui0HF95XAw

Case: Central Venous Access - Part 2

Read more about Case: Central Venous Access - Part 2

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This video (part 2 of 2) details how to use bedside ultrasound imaging to map the anatomy and orientation of the internal jugular vein, as well as determine puncture point, needle depth, and needle trajectory during central venous cannulation.

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- Hello, my name is Phil Perera
and I'm the emergency ultrasound coordinator
at the New York Presbyterian Hospital in New York City
and welcome to Soundbytes Cases.
In this Soundbytes module entitled part two
of Ultrasound Guided Central Venous Access
we'll look further onto the use of bedside ultrasound
to make a more precise puncture attempt
on the internal jugular vein
during central venous cannulation.
As we discussed in part one, we first wanna map out
the anatomy of the internal jugular vein
by orienting the probe
in both short and long axis configurations
to fully investigate the orientation of the vessel.
We want to use the dynamic technique for real time guidance
of the needle into the vein lumen
and for this we'll need to place the probe
into a sterile sheath barrier to observe sterile precautions
during the puncture attempt.
Here's the needle coming in underneath the probe
in a short axis configuration.
Notice that the sheath needle is coming in
underneath the probe at a 45-degree angle.
And notice that we're using the sheath needle
to first determine the location of the internal jugular vein
by the ring down artifact.
We would use the same approach for the cannulating needle
coming in underneath the probe at a 45-degree angle.
As we discussed prior, the probe should be oriented
in a side-to-side orientation
with the marker down towards our left
as we stand at the head of the bed
so it orients directly to the screen indicator dot
which will be oriented towards the left
of the ultrasound screen.
Here we're localizing the internal jugular vein
using the short axis configuration.
We're coming in underneath the probe with a sheath needle
at that 45-degree plane, pushing in underneath,
and notice the ring down artifact coming in
directly on top of that internal jugular vein
telling us this is the correct puncture point.
This video clip shows why a short axis orientation
is an excellent starting point for cannulation
of an internal jugular vein.
Here we see the echogenic tip of the needle coming down
and permeating the anterior wall of the vessel
and we then note the echogenic tip of the needle
squarely inside the lumen of the vessel.
And we can see how using the short axis orientation
can guide us in a side-to-side orientation
on the patient's neck in terms of lateral needle orientation
with regard to the surface down to the vessel lumen.
When using the short axis orientation
it's important to remember the affect of probe slice
on visualization of the needle tip.
Here we see the probe position one proximally
along the needle shaft
and note in the schematic view towards the left
we see the needle with the tip
squarely inside the venous lumen.
However, the ultrasound probe is positioned more proximally
along the shaft of the needle
and thus on the ultrasound view to the right
all we visualize is the needle above the vessel
even though the needle tip
is squarely right within the vessel lumen.
So we get a false determination of the tip of the needle.
In order to accurately determine
the location of the needle tip
we need to move the probe more distally
as we advance the needle into the patient's neck
along the course of the vessel.
Here we see the probe position more distally
now in plane with the needle tip
in the schematic view towards the left.
And there we can see we can get an accurate determination
of the location of the needle tip
with regard to the venous lumen.
We see the ultrasound view towards the right,
and now we'll be able to see the echogenic tip of the needle
accurately positioned within the vessel lumen.
A second pitfall that must be avoided
when cannulating the internal jugular vein
under ultrasound guidance is to make sure
that the needle tip does not angle to the side of the vein
during a cannulation attempt.
Even though we know the orientation of the vessel
with regard to the skin,
if we don't orient the cannulating needle
along the course of the vessel
it can veer to the side of the vessel
as shown in trajectory's one and two here.
Now if we know the course of the vessel
we can accurately position the needle
so that it goes along the course of the vessel
following trajectory three into the venous lumen.
The solution to avoiding this pitfall
is to know the course of the vessel
as it runs up and down the neck.
We can do this in two ways, the first of which
is to mark two points on the vessel
using the short axis configuration.
The needle would then enter at that distal mark
and aim towards the proximal mark
passing along the course of the internal jugular vein.
We can effectively do the same thing
by passing the probe in the long axis configuration
and knowing how the needle should pass
from the top of the neck down towards the chest.
Here we use a simulation model to show the correct approach
for a short axis cannulation of the internal jugular vein.
Notice here we have the probe in a side-to-side
or short axis orientation and the needle coming in
at a 45-degree angle underneath the probe.
Now remember that we must move the probe distally
to stay in plane with the needle tip
as we advance it underneath the skin
and into the internal jugular vein.
And as we do that
we notice that we've successfully cannulated
the internal jugular vein as shown by the red flow of blood.
And here we see a side orientation of the needle
with regard to the probe.
Here's an actual cannulation of an internal jugular vein.
Notice that we see the deflection
of the anterior wall of the vessel
as the needle pushes down on that wall
followed by the appearance
of the echogenic tip of the needle
within the lumen of the vessel.
So let's watch that again.
Notice the deflection or pushing down of that anterior wall
and then as the needle permeates that anterior wall
we see the appearance of the echogenic tip of the needle
within the vessel.
Here's a different patient receiving a central line,
and notice in this clip we actually can visualize
the echogenic needle coming from the surface
and going all the way down through that anterior wall
of the internal jugular vein to park directly into the lumen
of the vessel.
This video sequence shows cannulation
of the internal jugular vein using the long axis trajectory.
Notice we swivel the probe into the long axis orientation
along the course of the internal jugular vein
as it runs up and down the patient's neck.
By convention again,
the probe marker should be oriented towards distally
or towards us as we stand at the head of the bed.
Notice the cannulating needle will come in
at a 45-degree angle under the distal aspect of the probe.
Remembering that the distal aspect of the probe
or the marker will orient
towards the left of the ultrasound screen,
we can then know to look towards the left of the screen
for the cannulating needle coming down to the vessel.
Here we're performing cannulation
of the internal jugular vein on a simulation model.
Notice here the probe is oriented
along the longitudinal or long axis course
of the internal jugular vein with the marker dot distal
or towards the patient's head.
Here we see the needle coming in at a 45-degree angle
underneath the distal aspect of the probe.
This will allow us to see the entire aspect of the needle
as it travels down from the surface
all the way down to the venous lumen
and cannulates the internal jugular vein.
Here we see the long axis approach
and the needle coming in from left to right
and we know here how the long axis orientation
is excellent for seeing vertical needle depth.
Note the needle coming through the anterior wall
of the vessel and now the needle tip
squarely within the vessel lumen.
Here we can see how the long axis orientation
allows us to plan the optimal depth for the needle tip
with regard to the venous lumen
to squarely secure a cannulation attempt.
Now this is in difference to the short axis orientation
which was better for lateral needle orientation
with regard to the vessel lumen.
So using a combination of short and long axis orientations
will allow you to see both lateral
and vertical needle orientations
with regard to the vessel lumen.
Here's a video clip in the long axis configuraiton
emphasizing the fact that the long axis view
is great for determining the needle depth.
And here we see a needle coming in from left to right
and notice how we can visualize the needle tip
smack within the vessel lumen.
Here's another long axis clip of a patient
who's receiving a central venous catheter
and we see the catheter coming in from left to right.
Notice here the needle tip
deflects the anterior wall of the vessel
pushing it down so that it almost meets the posterior wall.
Thus the needle could easily pass
through both walls of the vessel.
Using the long axis technique
one can best adjust the needle tip depth
and avoid puncturing the back wall of the vessel.
Here's another great use of the long axis technique.
Again, we're confirming that the needle tip
is located within the vessel lumen
and now we can watch as the guidewire
passes through the tip of the needle
and moves down inferiorly
down the patient's internal jugular vein.
This is a great way of confirming
that the guidewire is safely parked
within the lumen of the vessel
before threading the catheter.
Let's end this module with a possible pitfall
that can be avoided by first looking with ultrasound.
Here we have a patient who's had a prior central line
and we notice a thrombosed internal jugular vein
with echogenic material on top of the carotid artery.
When we push down with the probe
the internal jugular vein failed to compress.
In this patient it would be best
to look for an alternative area for puncture
of a central line.
In conclusion, thanks for tuning in for part two
of Ultrasound Guided Central Venous Access.
Using ultrasound for dynamic real time guidance
of the needle into the internal jugular vein
can potentially decrease the mechanical complications
of the cannulation procedure
making the procedure a safer one for our patients.
We can employ a combination
of both the short and long axis views
of the internal jugular vein for optimal results
for a cannulation attempt.
So I hope you'll consider ultrasound
during your next central line placement
and I hope to see you back as Soundbytes continues.

Brightcove ID

5743138573001

https://youtube.com/watch?v=zV3hw_QbgK4

Case: Central Venous Access - Part 1

Read more about Case: Central Venous Access - Part 1

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This video (part 1 of 2) details how the use of bedside ultrasound for placing central venous catheters can reduce the number of puncture attempts, increase patient safety, and increase procedural efficiency.

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- Hello, my name is Phil Perera and I'm the
emergency ultrasound coordinator at the
New York Presbyterian Hospital in New York City
and welcome to SoundBytes Cases.
Today's module is going to look at the use of bedside
ultrasound for placement of central venous catheters,
specifically the internal jugular vein in the neck.
So the question is,
why use ultrasound for central venous access
and why not just use the traditional landmark technique?
Well, interestingly, multiple research studies now show
a decreased number of puncture attempts
are needed using ultrasound guidance
and there's also a lower complication rate
such as lowering the risk of pneumothorax and hematoma.
The US Agency for Health Care Research, the AHRQ,
recommends ultrasound guidance for central lines
right up there in the top 10 patient safety practices.
Ultrasound will allow precise determination
of the anatomy of the vascular structures in the neck
prior to a puncture attempt.
Here's the middle triangle of the neck
that serves as the standard approach for cannulation
of the internal jugular vein.
We see here the branches of the sternomastoid muscle,
the sternal head medially,
and the clavicular head laterally.
Here we're putting our finger into the triangle of the neck
and this indentation between the muscle heads
would be the standard approach for placement of the needle.
We see here that the clavicle forms the inferior
boundary of the middle triangle of the neck.
Within the middle triangle of the neck
run two very important vascular structures
and as per the textbook orientation of the carotid artery
to the internal jugular vein,
we see in the image here that the carotid artery
should run medial to the internal jugular vein
which lies lateral to the artery.
However, unfortunately, there's great variability
in human anatomy and many times the internal jugular vein
can overlap the carotid artery as shown in the drawing here.
Notice the variation in location
of the internal jugular vein to the carotid artery
and many times the internal jugular vein
is located on top of the carotid artery,
making it difficult to cannulate.
Thus, it's important to look with ultrasound
before cannulation attempts to avoid puncture
to the carotid artery.
Here's the high-frequency linear type array probe
that we'll be using to best map out
the internal jugular vein before puncture attempts.
Notice the probe marker there to the side of the probe.
Here are the orientations that we can place
the high-frequency probe in relation to the
internal jugular vein for vascular line placement.
Here to the left, we see the short axis configuration
with the probe perpendicular to the vessel
and notice that the vessel will appear on the ultrasound
screen as a circle, as the vessel will be cut end on.
To the right, we see the long axis configuration
and note the probe placed along
the long axis course of the vessel.
The vessel therefore on the screen will appear
as a tubular structure as shown here
in the image to the right.
Here's the high-frequency linear type array probe
placed over the middle triangle of the neck
over the internal jugular vein and carotid artery.
Now, I like to have the probe positioned
in a side-to-side orientation,
with the marker dot oriented towards my left
as I stand at the head of the bed.
The reason for that is then the orientation
of the probe marker will line up to the orientation
of the screen indicator dot,
which we see here is orientated towards the left
on the ultrasound screen.
Thus the left side of the probe
will orient directly to the left side of the screen,
and this will allow us to orient ourselves
as we place the needle underneath the patient's neck
and cannulate the vein.
Here's a typical appearance of the internal jugular vein
and carotid artery in a short axis configuration,
taken with a B mode or gray scale image.
Note lateral here towards the left and medial to the right.
Here we notice the internal jugular vein in a location
more lateral and superficial to the carotid artery,
which lies deeper and medial to the vein.
We can see the depth markers to the side
and we note the internal jugular vein
at about 1.5 centimeters depth.
Now we can apply Doppler sonography to further
differentiate the two structures
and here again we notice the internal jugular vein
lying lateral and superficial to the carotid artery.
We note the Doppler sonography steady pulsations
of the internal jugular vein that
vary with respiratory pattern
and we can also see the carotid artery
with the pulsations with each heart beat
differentiating the two structures.
We can also press down with the probe
to differentiate the two structures.
The internal jugular vein should compress completely,
while the more muscular outer walls of the carotid artery
should keep it open with compression of the probe.
Here's another video clip showing the internal jugular vein
and carotid artery in a short axis configuration.
Notice here that this internal jugular vein
is much more distended than in the last patient.
Here we see that the internal jugular vein
is located more superficially at about 0.5 centimeters
and that it overlaps the carotid artery medially.
Highlighting the fact that there's great variability
in the course of the internal jugular vein
in relation to the carotid artery,
even within the same patient,
we're running the probe from a position high within the neck
in which the internal jugular vein is seen more laterally,
to a position more inferiorly in which the internal
jugular vein comes to rest more medially
on top of the carotid artery.
Here's a different patient in which the internal jugular
vein is seen smack on top of the carotid artery.
Notice here, we'll place Doppler flow to confirm
the carotid artery shown here deeper to the
more superficial internal jugular vein.
In this patient, it would be extremely difficult
to cannulate the internal jugular vein
without puncturing the carotid artery.
Best to attempt cannulation in another area of the body.
One pearl that can be used to further distend the internal
jugular vein and make it a better target for a cannulation
attempt is to have the patient Valsalva or hum.
Notice here in the image to the left,
the patient is bearing down and notice that the
internal jugular vein becomes much bigger
as the patient pushes down.
In the image to the right, note the relatively small
caliber of the internal jugular vein.
Notice that it's almost as big here as the carotid artery,
but that it becomes much more distended
as the patient bears down.
Using the Valsalva technique can make it a much better
target for placement of the large cannulation needle.
Here's the high-frequency probe placed in a
longitudinal or long axis manner on the patient's neck.
Notice here that it's running along the course of the
internal jugular vein as it runs
up and down the patient's neck.
By convention here, I like to have the probe marker
towards the patient's head.
Therefore, I know where it lines up
on the ultrasound screen.
Notice here as a screen indicator dot is towards the left
that superior on the internal jugular vein
will be located towards the left of the screen
and inferior will be located
towards the right of the screen.
Here's a long axis view of an internal jugular vein.
I have the probe marker going more distally
or superior within the neck
so to the left is distal and to the right is proximal.
Notice the internal jugular vein that appears like
a tubular structure on the ultrasound screen
and we see the blood flowing here from left to right.
Here's a video clip, again a long axis configuration
in a different patient and here we see a much more
distended internal jugular vein that's lying on top
of the carotid artery.
Notice the swirls of blood in the internal jugular vein
showing the course of the blood flow
from high within the neck to the left,
low within the neck here to the right.
In conclusion, thanks for tuning in for part one
of Ultrasound Guided Central Venous Access.
I hope I've been able to score the point
that ultrasound is very helpful in determining
the relative anatomy of the internal jugular vein
and carotid artery prior to an invasive procedure
as a textbook anatomy of the vein to artery
is often incorrect and it's best to use a combination
of short and long axis views prior to a puncture attempt
to best define the anatomy.
So I hope to see you back in the future
as SonoAccess continues and we return
in central venous access part two.

Brightcove ID

5743132351001

https://youtube.com/watch?v=_RHRy64jQ6s

Case: Peripheral Venous Access - Part 2

Read more about Case: Peripheral Venous Access - Part 2

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Use ultrasound imaging to identify anatomy prior to intravenous catheter needle punctures, verify needle depth, and use dynamic techniques for attaining optimal needle guidance during deep vein cannulation & IV placement.

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- Hello, my name is Phil Perera
and I'm the emergency ultra sound coordinator
at the New York Presbyterian hospital in New York City
and welcome to SoundBytes Cases.
In this SoundBytes module, entitled Ultrasound Guided
Cannulation of Arm Veins Part 2,
we'll look further into the techniques needed
to use ultrasonography to guide a IV into
one of the deep arm veins.
As we discussed in part one of this module,
we first want to map out the vein using both short
and long axis views and we'll employ a dynamic technique
for optimal guidance for the catheter down to the vein.
Want to use a longer angiocath for the procedure,
preferably 1.88 inch or longer
as we need a good amount of plastic catheter in the vein
to avoid extravasation of fluids or meds
during resuscitation of the patient.
This recent published study showed that it's crucial
to select the correct target vessel when deciding
to cannulate a deep arm IV.
169 patients were enrolled in the study
and it was determined that the size of the vessel
directly correlated with the success rate
of the cannulation procedure.
A vessel with a diameter less than three millimeters
correlated to a success rate of only 56%.
While a diameter greater than 6 millimeters correlated
to success rate of 92%.
That's showing that the diameter was directly correlating
to the success rate of placement of a deep arm IV.
Also the depth of the vessel was very important
as no vessel that was deeper than 1.6 centimeters
was successful cannulated.
A very nice study by Dr. Panebianco et al.
A academic emergency medicine, 2009.
Armed with the knowledge of the last study,
here we're going to measure the diameter of a brachial vein
prior to a puncture attempt.
Notice here, we've selected a brachial vain
and we're measure the diameter at 3.7 millimeters
by 4.3 millimeters.
Thus, this would correlate with a low likelihood
of success rate during a cannulation attempt.
Notice also we're measuring the depth of the vessel
and while the depth of the vessel is six millimeters
less than the 1.6 centimeters that correlated
to no successful outcomes of peripheral IV cannulation,
the diameter of the vessel would be very difficult
to cannulate.
Now let's take a look at a better target.
This is a basilic vessel and we can see here
that the diameter is much larger than the last
brachial vein and we measure it at 6.5 millimeters
by 6.7 millimeters.
Thus, this would have a very high success rate
in terms of cannulation with a ultrasound guided IV.
We can also see that the vessel depth is relatively
superficial, again making it more amenable
to a cannulation attempt.
Once we have selected a favorable target vessel
for cannulation, we can place the probe in a short axis
of side to side orientation.
Here we're using a q-tip coming in underneath the probe
at 45 degree angle to look for the ring down artificat
for guidance for placement of the IV in a side to side
or lateral orientation on the patients arm.
We can look for a finding know as the ring down artifact
on the ultrasound screen as shown here.
Notice we have a nice plump basilic vein in the middle
of the field here and we can see a dark mark
emanating from the surface directly down.
Which is the ring down artifact caused by pressure
from the q-tip.
Thus this would be the appropriate poke point
on the side to side orientation on the patients arm
for placement of the IV.
We can also localize a vessel using the long axis technique.
Notice here we have the probe oriented
in an up and down configuration on the patients arm
and are placing the q-tip underneath the distal aspect
again at a 45 degree angle
to look for that ring down artifact onto the vessel.
To increase the accuracy of an ultrasound guided IV,
it's important to know the course of the vessel
as it runs up and down the arm.
Here we see in the picture to the left
that we're localizing the vessel at one point
on the patients arm but it's not enough
to know only one point.
We need to know the course of the vessel
as it runs up and down the arm as show in the picture
here to the right.
Notice we're marking two points on the vessel.
We have the distal poke point as noted by the blue x
towards the outer part of the patients arm
and then we're moving the probe more up the arm
more proximally to mark a second point on the vessel.
A line drawn between these marks would identify
the trajectory that the IV should follow
once it comes in at the the distal poke point
to successfully cannulate the vessel.
This longer angiocath at 1.88 inches would be more
optimal for cannulation of a deep arm vein
using ultrasound guidance.
This schematic shows the reason
that we need a longer angiocath when cannulating
a deeper arm vein.
While the vein my only be one centimeter deep to the skin.
Notice that the needle is not going directly down,
it comes in at about a 45 degree angle
to cannulate the vessel.
So we need a longer aspect of the needle just
to make it down to the target vein.
Plus we also need an ample amount of catheter
to be within the vessel lumen
to avoid extravasation of fluids or medications.
For this reason, 1.88 inch or longer is essential
for cannulation of a deep arm vein.
Now we're ready to cannulate a vessel
using ultrasound guidance.
We'll begin using the short axis or side to side orientation
of the probe with the probe maker
orientated towards the left
as we stand in front of the patient.
This will correlate with the ultrasound screen indicator
dot which is towards the left of the screen.
Generally I want to go and place the IV at a 45 degree angle
underneath the patients skin and then I'll place
the probe over the area of the IV to guide the IV
directly into the vein.
This phantom shows why using the short axis technique
can be an excellent starting point for guiding
the IV directly down to the vein under ultrasound guidance.
Here we can see a target vessel and note we see
the echogenic tip of the needle going
through the anterior wall of the vessel
and permeating into the vessel lumen.
So the short axis technique is optimal
for viewing lateral needle orientation
across the patients arm and guiding the IV directly
down into the venous lumen.
When using the short axis technique,
one must keep in mind the effect of probe slice
on visualization of the needle.
Note here, the probe is position more proximally
along the course of the needle and even though the needle
tip is securely within the vessel lumen,
we're only visualizing the needle to be above the vessel.
Notice the schematic view here towards the left
and we can see the probe is more proximal along
the course of the needle and the ultrasound view
towards the right and even thought the tip of the needle
is securely within the lumen of the vessel,
we're only visualizing the needle above the vein
and may get a false determination of where the tip
of the needle is.
Therefore, when using the short axis technique
when cannulating a deep arm vessel,
it's important to move the probe along the course
of the vessel to stay in plane with the tip
of the needle as you advance the needle under the skin
and into the vessel lumen.
Here we see we've moved the probe more distally along
the course of the vessel and now we're more
in plane with the tip of the needle.
We see the schematic view to left
and the ultrasound view towards the right
showing successful cannulation of the vessel
and the tip of the needle right within the vein lumen.
This video clip shows successful cannulation
of a brachial vein using the short axis technique.
Notice here we see the vessel and notice
we see the echogenic tip of the needle coming down
from the surface and permeating the anterior wall
of the vessel
and there we can see the echogenic tip of the needle
right within the vessel lumen.
We can also use the long axis configuration
for cannulation of a deep arm IV.
Optimally, you want to place the probe in the configuration
of the vessel as it runs up and down the patients arm.
By tradition, we want to have the probe marker oriented
distal so that the distal aspect of the probe
will line up to the left of the ultrasound screen,
as shown here.
So distal on the screen will be to the left
and proximal to the right.
The IV would then enter underneath the probe
at that 45 degree angle.
While the short axis configuration gives
a lot of information about side to side
or lateral orientation of the needle,
the long axis configuration gives a lot of information
with regard to vertical needle depth.
Here we see a needle coming from the left
and permeating into the vein lumen.
Notice here we can get an accurate determination
of the optimal depth of the needle
in relation to the venous lumen for cannulation
of the vessel.
Here's a real cannulation of a brachial vein
in a long axis configuration.
We see the vein stretching out in a long axis configuration
as a tubular structure running from left to right
along the screen and we see the needle coming
in from the left to the right moving up and down
and cannulating within the venous lumen.
So at this point, we're ready to thread the catheter.
This video clip captures a long axis cannualtion
of a deep arm vein and we can see the needle coming
in from left to right and we can see the needle tip
permeating through the vessel lumen.
Now we can see the actual threading of the plastic catheter.
So again we'll look at the needle coming in from left
to right and now we'll go ahead and freeze it
so we can see the actual plastic catheter
securely within the lumen of the vessel
and it's nice to visualize the catheter
within the vessel lumen to ensure
that there's enough catheter there to give a good amount
of medications and fluids with extravasation
of either of these liquids into the patients arm.
In conclusion, thanks for tuning in to this SoundBytes
module going over part 2 of ultrasound guided
cannulation of arm veins.
Ultrasound guidance for peripheral IV insertion
is an extremely helpful technique
and optimally you want to choose a target vessel
greater than six millimeter in diameter
and at a depth of less than 1.6 centimeters
to optimize our cannulation success.
We want also pick a longer catheter so we have
enough needle and plastic catheter to get into
these deep arm vessels.
We use a combination of short and long axis views
to dynamically guide the angiocath into the vein
and just bear with it because there is a steep learning
curve for these ultrasound guided IVs.
So you'll get it with time so don't give up
and practice practice practice.
So I hope to see you back in the future
as we SoundBytes continues.

Brightcove ID

5508134289001

https://youtube.com/watch?v=riizCYcXhRU

Case: Peripheral Venous Access - Part 1

Read more about Case: Peripheral Venous Access - Part 1

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Use ultrasound imaging to help identify deep and nonpalpable veins that can accommodate the placement of an IV catheter. Doppler color flow is used to differentiate the brachial artery from other anatomical structures.

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