Central Line
Episode Number: 121
Episode Title: New Findings
re Postpartum Hemorrhage and Pediatric Airway Management
Recorded: February 2024
(SOUNDBITE OF MUSIC)
VOICE OVER:
Welcome to ASA’s Central
Line, the official podcast series of the American Society of Anesthesiologists,
edited by Dr. Adam Striker.
DR. ADAM STRIKER:
Welcome back to Central
Line. I'm Dr. Adam Striker, your host and editor. And today we're going to
learn about a few items highlighted in the 48 issue of SEE, or Summaries of
Emerging Evidence. We do this every once in a while to highlight some of the
important studies or items that are included in SEE, and hopefully make it
interesting for our listeners. And today we have Dr. Alyssa Brzezinski, who is
one of the SEE editors, and she's here to educate us on some fascinating recent
studies. Thanks for joining us, Doctor Brzezinski.
DR. ALYSSA BRZENSKI:
Thank you so much for
having me today.
DR. STRIKER:
Well, Dr. Brzinski, before we jump into the studies and a couple of
the items you want to highlight with the SEE issue, if you don't mind, tell our
listeners a little bit about yourself and your work with SEE and how you
arrived in this position.
DR. BRZENSKI:
Sure. Um, I am a
pediatric anesthesiologist. I work in the University of California at San Diego
and at Rady Children's Hospital. I came back to this program many years ago,
mostly with an interest in resident education. And as part of that resident
education, I really enjoyed keeping up on the literature and working with the
residents to pass on the new literature. I had a colleague who was writing for
SEE at the time, and he had let me know how much he enjoyed it, and so I
joined, um, as a question writer. And after a number of years, then I was asked
to join the editorial board, which is my role now. Um, it's a great process.
Uh, it definitely keeps me up with all the literature, and I can use all that
literature to talk with my residents that I work with on a on a daily basis.
DR. STRIKER:
Excellent. Well, we
always try to highlight a little bit of what the SEE
is currently highlighting themselves. It's such a great program and um,
hopefully a lot of our listeners are taking advantage of what it has to offer.
Let's dive in and talk a
little bit about a couple of the studies, um, that you want to highlight on
today's show. One of the studies involves a prophylactic methylergonovine and
laboring women who are obviously at higher risk for postpartum hemorrhage and
require an intrapartum C-section. I believe it's comparing the use of that with
straight oxytocin. But before I get too far afield, why don't you go ahead and
highlight what the study is about and some of the important facets of it?
DR. BRZENSKI:
Sure. So for our
anesthesia colleagues in the obstetric space, postpartum hemorrhage is a major
cause of morbidity and mortality, both in the United States and worldwide. And
in fact, um, postpartum hemorrhage rates have been increasing. They are significant
for us because they contribute to about 11% of maternal deaths in the United
States, many of which are preventable. On top of this, we know that the number
one cause of postpartum hemorrhage is uterine atony. And many of our patients
that are undergoing a C-section after having labored for a period of time are
at significant risk for that uterine atony. So there's always a search for any
methods that might help us reduce that risk of postpartum hemorrhage from
uterine atony. And to date, the standard of care has been utilizing oxytocin
following delivery of the newborn. However, even with that oxytocin, especially
on patients who are already receiving oxytocin for labor augmentation, it may
not be successful and thus, um, a finding a method that could negate or prevent
that uterine atony would be beneficial for our OB colleagues.
DR. STRIKER:
Let's just talk a little
bit about how the study was conducted. Any insights into the methodology?
DR. BRZENSKI:
Sure. There was, um,
about 160 women at a single center. And they had all been laboring and a
decision was made to proceed with the cesarean section. So in this study, women
who had a known history of any type of hypertension were excluded from the
study, given that methergine can exacerbate the hypertension. Additionally, any
patients that had any known placental anomalies were excluded. And so then the
women were randomized to receive either the standard of care, which as I
mentioned, would be an oxytocin infusion following delivery of the baby, or
they were in the trial group, which in addition to the oxytocin, they would
receive .2mg of intramuscular methergine, regardless of what the uterine tone
was. The placebo group also got an injection, but it was only an IM injection
of normal saline, so the actual anesthesiologist was delivering something in IM
form regardless. After this happened, then uterine tone was assessed every four
minutes, and additional uterotonics were administered at the discretion of the
obstetric team and obstetric anesthesiologist. They were allowed to utilize
whatever next uterotonics they felt was necessary, and typically would follow
standard ACOG guidelines. The study's primary outcome was to determine if there
was any change in the administration of additional uterotonics in the group
that received this prophylactic IM methergine dose.
DR. STRIKER:
And what did the
researchers learn?
BRZENSKI:
They actually found that
the group that received IM methergine, in addition to standard of care had less
administration of additional uterotonics. They also looked at secondary
outcomes, including the rate of postpartum hemorrhage, which in a C-section
would be anything over one liter of blood loss, the rate of blood transfusions,
as well as what the quantitative blood loss was. In those groups, the outcomes
were improved in the group that had received the IM Methergine. Um, so overall,
the percentage of women who received uterotonics achieved both primary and
secondary outcomes more frequently. When they looked at the numbers needed to
treat, it was about three patients needed to be treated to achieve this
benefit, so a relatively low number needed to treat. And overall they had no
additional or found no difference in the rates of hypertension between the two
groups. So despite the prophylactic administration of Im
methergine, there was no patients that had additional hypertension in that
group.
DR. STRIKER:
So based on that, should
labor and delivery units adopt the strategy?
DR. BRZENSKI:
It's interesting. Based
on the study, it would suggest that there's a significant advantage to
potentially utilizing the prophylactic dosing of IM methergine. I don't think
it's quite yet adopted across labor and delivery units. In speaking with our
own labor and delivery unit, they actually have not adopted it despite this
study coming out. But this is one additional piece of literature that would
support early, if not prophylactic, administration of IM methergine.
DR. STRIKER:
Well, in talk a little
bit about the SEE program in general, and the studies highlighted or the
emerging evidence highlighted, is anesthesiologists, um, do we look at it as
just in general pieces to add to the entire picture, or are we supposed to
weight the evidence more than other platforms? Or how do you, as heavily
involved in this program, how do you advise anesthesiologists to look at the
studies in general?
DR. BRZENSKI:
I think it's an
opportunity to consider the new and emerging literature that's out there.
However, I would always encourage us to view the literature, uh, along with our
colleagues that we're working with. So with something that's so
multidisciplinary as obstetric anesthesia, it is great for us to bring our own
literature to our obstetric colleagues and to discuss and create policies. But
it's hard to do that in isolation. So I think the teamwork approach has
significant advantages.
DR. STRIKER:
Well it's perfect
because I think it'll be a good segue into discussing the next study, which is
a little different. And we'll delve into that here in just a minute. But before
we do, let's go ahead and take a short patient safety break. Please stay with
me.
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DR. JEFF GREEN:
Hi, this is Dr. Jeff
Green with the ASA patient safety editorial board. Communication gaps during
patient handoffs in the perioperative setting increase the risk of patient
harm. While electronic tools can improve communication and patient safety
during handoffs, low tech strategies can go a long way toward ensuring
continuity of care and accurate information exchange. These include
standardized checklists and templates, as well as patient safety communication
techniques such as read back, repeat back, and other closed loop approaches.
Formalized structured templates ensure that key information is communicated to
all personnel involved in care transitions, such as for OR to PACU or OR to ICU transfers for shift changes in the OR, a less
formal and more portable three by five note card with key safety information
can be handed to the clinician assuming care of the patient. With both
approaches, face to face communication between providers is essential for a
safe handoff. There is no one size fits all strategy to safe handoffs, but
adopting a standardized process may improve patient outcomes.
VOICE OVER:
For more patient safety
content, visit asahq.org/patientsafety.
DR. STRIKER:
Well, we're back. And
the study I had alluded to right before the break involves a pediatric airways.
Let's go ahead and learn a little bit about this study. Dr. Brzinski
talked to us a little bit about what this study involves, maybe cover what it
was trying to study and also the nuances with the methodology and how that
might ultimately, you know, affect the conclusions.
DR. BRZENSKI:
Sure. So difficult
airways are our thing in anesthesia. It is our domain to control and something
that we as anesthesiologists are frequently concerned about and plan
accordingly for. However, the approach to pediatric difficult airways may
differ from our approach to adult difficult airways. For many of my adult
colleagues, their approach to a known difficult airway would be to provide
topical anesthesia and then to go ahead and intubate the patient with minimal,
if any, sedation on board. In pediatrics, the incidence of an unrecognized
difficult airway is less common compared to our adult counterparts. However, we
also recognize that in our children, it is less likely that they are going to
be able to participate with us in the same manner that an adult might. It can
be very challenging to topicalize a pediatric airway, and to get buy in from a
pediatric patient to do that with minimal or no sedation on board.
Additionally, when there is difficulty with securing the airway, some untoward
side effects can happen in our children and they can be more problematic
compared to our adult patients. So our pediatric patients are at risk for, um,
not only hypoxemia, when an airway can't be secured, but that hypoxemia can
result in bradycardia and additional downstream sequelae that can be
problematic.
So because of the
developmental level, the willingness to accept, um, we often actually enter
into difficult airway management with a different plan for our pediatric
patients compared to our adult patients. Pediatric patients often will actually
receive a general anesthetic with spontaneous ventilation. Or there's some data
that suggests that perhaps we can do a general anesthetic and ultimately
actually use paralysis in some of our difficult, uh, airway patients. In this
study, it was recognized that there are a handful of anesthesiologists that
still utilize sedation for their pediatric difficult airways. Um, but we don't
have as much information as to which technique is better. We know that the
practice out there is probably more common for anesthesiologists to be doing a
general with spontaneous ventilation management of a difficult airway. But is
that truly better than a sedated airway management for a pediatric, um,
difficult airway?
So this study aimed to
answer that question. And they utilized a different study methodology.
Essentially, they are a registry. They have 34 different international
hospitals, which were contributing data, and all that data was collected
prospectively. With that data, they were then able to look at the differences
between patients that received their airway management with sedation versus,
uh, general anesthetic.
DR. STRIKER:
So a couple of things.
The pediatric difficult intubation registry, it's a topic we're going to
actually cover in an upcoming episode. But as far as the study specifically, I
just want to tease out a little bit. You mentioned that it was difficult to ascertain
what kind of techniques the practitioners were using, but as far as the study
goes, what specifically was the determining factor between sedation and general
anesthesia when classifying these into one of those two groups?
DR. BRZENSKI:
That information was
self-reported by each individual site. So that was at the discretion of the
individual site to note. However, it was noted that there was differences
amongst the sedation that was utilized and some of the sedation things that we
would consider to be topicalization or local anesthetic, um, we're also used in
some of the general anesthesia patients. So it was totally up to each
individual site to determine what they were utilizing and what level of, um,
sedation versus general anesthesia was on board.
DR. STRIKER:
Okay. Well, let's talk
now a little bit about the methodology on this study. There's some differences
you already mentioned, but let's just delve into a little bit of the details on
that if you don't mind.
DR. BRZENSKI:
Sure. Um, the study
itself, as I mentioned, was comparing the use of general anesthesia versus
sedation for, uh, airway management in patients with known or suspected
difficult airways, as well as airways that were difficult upon laryngoscopy. So
they specifically were examining the first attempt success rates for intubation
in children less than 18 years of age. And overall they had about 839 patients,
which were included. In order to be defined as a difficult airway, the child
either had to have a suspected difficult airway, which could be defined by what
the, uh, anesthesiologists suspected would be difficulty with direct
laryngoscopy due to impossibilities of anatomy. So they noted something like
severely limited mouth opening, which they would expect all the
anesthesiologists would rate that as something that they could not intubate the
child with, or would have significant difficulty. Additionally, the child could
have a history of documented difficulty with direct laryngoscopy within the
preceding six months, or had predictors of difficulty such as anatomical
features like severe or mandibular hypoplasia. Finally, they could also have
had difficulty with laryngoscopy that was noted previously, which was noted as
um formcelhane score of three or greater. So if a
child fell into that difficult airway, then they were eligible to participate,
and of all those patients that had those, they pulled out both the patients
that received general anesthesia versus a quote unquote, sedation for their
anesthetic. They, uh, separated them out and there was a great difference
between the group in the numbers. So there were 75 patients who were sedation
and 1764 patients who received a general anesthetic. So knowing that it may be
more difficult to match the patients because they wanted to do propensity
matching, um, along 21 different variables, they went ahead and took the group
with the sedation, and they took the patients that they anticipated would be
the hardest to match. And they allowed this algorithm or this matching process
to find a match with the general anesthetics. And they did this multiple times.
And each sedation case could be matched with up to 15 general anesthesia cases.
Not every sedation case received a match from the general anesthesia cases, and
there may not have been a total of 15 that were available to match um from the
general anesthesia cases, so they could be anywhere from zero matches up to 15
matches. And they also went ahead and grouped the patients by age cohort, with
the knowledge that it would be more likely that our older patients would be
able to tolerate a sedated intubation, and thus they suspected that it would be
more likely that our older patients would be represented with the sedation
cases as opposed to our younger patients.
DR. STRIKER:
Okay, so let's just
elaborate just for a second on why no general anesthesia patients were matched
to more than one sedation patient. Why is that?
DR. BRZENSKI:
The authors didn't want
to reutilize any of the general anesthesia patients, so they wanted to include
as many patients as possible, but they wanted to ensure that every sedation
patient that could be matched would be matched. And thus, since there were just
so many more general anesthesia cases, they went through the process and
matched up to 15, but did not reuse any of the general anesthesia cases for
multiple sedation patients.
DR. STRIKER:
Okay. So then, um, let's
talk about the outcomes. What were the outcomes they were looking at?
DR. BRZENSKI:
Sure. So primary outcome
was success of the first intubation attempt. They wanted to see how likely it
was with either anesthesia technique that the intubation could be done
successfully. Secondarily, they wanted to look at factors such as the number of
intubation attempts if more than one was needed, the type of airway device that
was used on the first intubation attempt, the initial anesthetic technique
versus the anesthetic technique that was required for successful intubation,
which would lead to potential conversions to another anesthetic technique. And
then finally, they wanted to look at any complications, whether they be severe
or non severe. So they defined a severe complications
as things that would be particularly problematic. Things like cardiac arrest,
severe airway trauma, an unrecognized esophageal intubation, um pneumothorax,
aspiration, even death. The non severe complications
included desaturations, minor airway trauma, esophageal intubation that was
recognized and remedied immediately. Laryngospasm, bronchospasm, um, some
bleeding or even emesis during or after the procedure.
DR. STRIKER:
Okay, well, now let's
get to what the, uh, takeaways were.
DR. BRZENSKI:
Within the study, the
rate of first attempt success for intubation didn't differ between the patients
in the two groups. So the patients that received sedation and those that
received general anesthesia had similar first attempt success rates at
intubation. Um, there are some things to acknowledge with this. Specifically, I
think I mentioned it previously, but it's was more likely that teenagers, um,
received sedation versus the younger children, which may be a factor for us. But
overall, it argues that that it is less important the technique that is chosen
for a difficult airway management, and rather that the anesthesiologist should
use the technique that they are most comfortable with, depending on the
resources that they have around, as well as the patient factors that are
present, and that will ultimately make one more successful. Additionally, I do
want to point out a large number of patients, um, a little over a quarter of
the patients who were in the sedation group ultimately required general
anesthesia for their successful intubation. So having a backup plan available,
even if you utilize one technique, should be considered, and backup plan should
be determined before embarking in your chosen anesthetic approach.
DR. STRIKER:
Well, we both practice
pediatric anesthesia. Generally, what do you take away from a study like this
as a pediatric practitioner?
DR. BRZENSKI:
Yes. So I think as, uh,
pediatric anesthesiologist, I'm curious your opinion too. Uh, we all have our
techniques and our ways that we prefer to do things, and many of us are
successful with it. So it's really much less about protocols using one specific
technique for these difficult airways, but rather ensuring that you use the
technique that you are most comfortable with. So if you don't feel most
comfortable doing a spontaneous leave ventilating general anesthetic for a
difficult airway and a teenager, and you would feel more comfortable and have
more experience with, uh, utilizing sedation in that patient population. You should
utilize that technique as your go to technique rather than deviating from your
technique just because someone else tells you that it might be better.
DR. STRIKER:
Yeah, certainly. I
agree. And but I also think, with a study like this, I kind of think it
highlights just how complicated the pediatric population really is. Dividing up
the groups was paramount to teasing out some differences, but I think that
that's borne out in our practice. I think we would all agree that a difficult
airway and a teenager is so different than a neonate, and obviously they both
potentially fall into the pediatric population. To me, one of the biggest
things is just that it highlights how difficult it is to truly tease out real
evidence on how best to manage the airways. And then you couple that with the
fact that, what was it, 20 some percent? You said over a quarter of the, um,
study population actually, that were in the sedation category had to be bumped
to general and whatever that means, if we don't know the specific techniques. I
think it also, as you alluded to, highlights how we need to be flexible with
these patients, especially the younger ones, and that a sedation quote versus an
anesthetic quote may not it may not matter that kind of binary thought process
as much. It is, you know, the continuum and the constant reassessment and
alteration of of whatever is necessary to accomplish
the airway management safely.
DR. BRZENSKI:
I couldn’t agree more. You
need to know what your resources are around you, including what can help you
for a difficult airway is especially important. So I certainly would not jump
into a known, difficult neonatal airway without having potentially my ENT
colleagues around or other backup plans available for me.
DR. STRIKER:
Absolutely. You know,
some of the evidence out there shows the significant increase in potential
difficulty with neonatal airways. And so and that's again borne out even my
practice, I mean, some of the more recent airway issues I've had have been in
some neonates. And so, um, it can be pretty dicey. And having those colleagues
having the support systems around, it's so important, and especially as you
determine how you're going to go about airway management in these kids.
DR. BRZENSKI:
Definitely.
DR. STRIKER:
Okay. Well let's bring
it all back now overall with SEE again what do you in the SEE team. What would
you all like to see individuals understand about the program.
DR. BRZENSKI:
Yeah. So I think overall
SEE is a group of individuals who are really dedicated to giving back to the
anesthesia community at large. And through this process, we really attempt to
thoroughly review the current literature and bring it into a more digestible
form for all of our anesthesia community. Um, so it's probably impractical that
everyone's going to be reading each and every one of these articles, um, in
their entirety. And thus SEE can be a wonderful source of continuing medical
education, keeping up on the literature for any practice, whether you be in
academics or in private practice, etc.. Additionally, um, because we are so
passionate about it, there is a lot of review that goes into each individual
write up. Approximately eight different levels of review occur to create this
easily digestible product for everyone. And so we're really trying to do
everything we can to bring something that's beneficial back to the anesthesia
community, and we hope that it's helpful for everyone.
Finally, uh, we are
always looking for anyone who might be interested in joining. You may be
someone like myself who just hears about the product. Perhaps you haven't even
been utilizing it, but we are always looking for people who want to join us.
Initially, you start out as a writer and then, um, can jump on to the editorial
board down the line once you get involved in the process.
DR. STRIKER:
Wonderful. Well, it's an
excellent program. And, you know, by highlighting it every once in a while here
on this podcast, we're hoping that our members can take advantage of it.
Excellent work by all of you. So if you're listening and you haven't checked it
out yet, please check out the SEE program. The website address is asahq.org/see.
Asa HQ. And Dr. Brzinski, thanks so much for joining
us today. Highlighting a couple items on the current issue. And thank you for
all your hard work on the SEE program as well.
DR. BRZENSKI:
Thank you so much for
having me. I really enjoyed the time here.
DR. STRIKER:
Great. And to our
listeners, one of our upcoming episodes will be covering Pediatric Airway
Registry in detail. That'll be a few episodes from now, so please tune in again
next time and take care.
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