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Pinkey and the Brain (with Pinkey Shah) · Style Points

0:11
anesthesia enthusiasts and welcome to Style Points.
0:13
Today on the podcast, I'm sitting down with my
0:16
friend Pinky Shaw to talk about neuroanesthesia.
0:19
Before that, I'll hand it over to my co -host
0:21
Nate Moore to introduce this month's RSI. Thanks,
0:26
John. I'm very excited to be speaking with Dr.
0:29
David Karnbaugh today. As it turns out, David
0:31
has a lot in common with astronaut Neil Armstrong.
0:34
David also worked at NASA before he started college,
0:36
and just like Neil, David joined the University
0:38
of Cincinnati after completing his space career.
0:41
David will be teaching us about neuromuscular
0:44
blocking agents today. Welcome, David. Thanks,
0:47
Nate. Today I'll be giving a quick overview of
0:49
neuromuscular blocking agents, which are more
0:51
commonly known as paralytics. Neuromuscular blocking
0:54
agents are drugs that prevent skeletal muscle
0:56
contraction by preventing the transmission of
0:58
acetylcholine at the neuromuscular junction.
1:01
In anesthesia, we mainly use them for three reasons.
1:04
One, facilitating endotracheal intubation. Two,
1:07
providing muscle relaxation during surgery. And
1:10
three, optimizing mechanical ventilation. To
1:13
better understand how these drugs work, let's
1:16
start by first reviewing the neuromuscular junction
1:18
and its transmission. So the neuromuscular junction
1:21
is comprised of a presynaptic motor neuron, which
1:24
releases acetylcholine, a postsynaptic neuron,
1:26
which has nicotinic acetylcholine receptors,
1:29
and the neuromuscular junction, or synapse, where
1:31
these neurotransmitters travel in order to exert
1:33
their effects. The binding of acetylcholine to
1:36
these postsynaptic receptors causes various ion
1:39
channels to open, most notably sodium, potassium,
1:41
and calcium, resulting in depolarization of the
1:44
neuron and subsequent muscle fiber, which causes
1:47
contraction. Neuromuscular blocking agents interrupt
1:50
this process through various mechanisms falling
1:52
into two main categories, depolarizing agents
1:55
and nondepolarizing agents. First, starting with
1:58
depolarizing neuromuscular blockers, the only
2:02
depolarizing neuromuscular blocking agent used
2:04
clinically today is succinylcholine. Succinylcholine
2:07
works by mimicking acetylcholine and binding
2:09
to the nicotinic receptor, causing persistent
2:12
depolarization of the motor end plate. Because
2:15
the receptor remains occupied, the muscle cannot
2:17
repolarize, which results in transient fasciculations
2:20
followed by residual paralysis. The way I like
2:23
to think about it is essentially an overfiring
2:25
of the muscle. One of the main advantages of
2:28
succinylcholine is its rapid onset and short
2:30
duration. It typically works within 30 to 60
2:33
seconds and lasts about 5 to 10 minutes, which
2:36
makes it particularly useful for rapid sequence
2:38
induction, or to help facilitate intubation in
2:41
cases where residual neuromuscular blockade isn't
2:43
desired. It's also important to note, however,
2:46
that succinylcholine has several important side
2:48
effects and contraindications. Due to its mechanism,
2:52
it can cause hyperkalemia, particularly in patients
2:55
with conditions that upregulate acetylcholine
2:57
receptors, such as burn injuries, spinal cord
3:00
injury, stroke, or prolonged immobilization.
3:03
It may also trigger malignant hyperthermia in
3:06
susceptible patients as well, making it a direct
3:09
contraindication in patients with a history of
3:11
MH. Other potential effects include bradycardia,
3:15
increased intraocular pressure, and postoperative
3:17
myalgias. Non -depolarizing neuromuscular blockers
3:21
work differently. Instead of activating the receptor,
3:24
they act as competitive antagonists at the nicotinic
3:27
acetylcholine receptor. The way I visualize this
3:30
is similar to those plastic covers you place
3:32
on wall outlets to prevent kids from accidentally
3:35
shocking themselves. In other words, they block
3:37
acetylcholine from binding, preventing depolarization,
3:40
and therefore preventing muscle contraction.
3:43
Commonly used non -depolarizing neuromuscular
3:45
blocking agents include rocuronium, vecuronium,
3:49
and my personal favorite, cisatricurium. Rocuronium
3:52
is one of the most widely used agents today because
3:55
it has a rapid onset and can be used as an alternative
3:57
to succinylcholine for rapid sequence induction
4:00
when given at higher doses. Vecuronium has an
4:03
intermediate duration and minimal cardiovascular
4:05
effects. Cisatricurium is particularly interesting
4:09
pharmacologically because it undergoes Hoffman
4:12
elimination, which is a temperature and pH dependent
4:14
process that allows it to be metabolized independently
4:17
of liver or kidney function. For that reason,
4:20
it's often favored in critically ill patients
4:22
in the ICU who may have impaired function in
4:24
these organs and require significantly prolonged
4:27
use of paralytics to help with vent compliance.
4:31
Intraoperatively, we monitor neuromuscular blockade
4:33
using peripheral nerve simulators, most commonly
4:36
with train of four monitoring. This involves
4:38
delivering four electrical pulses to a peripheral
4:41
nerve and observing the muscle for a response
4:43
which we call a twitch. As neuromuscular blockade
4:47
increases, the responses progressively fade,
4:49
which helps guide dosing and recovery. Proper
4:52
monitoring is critical because residual neuromuscular
4:55
blockade after surgery can lead to many complications
4:58
including airway obstruction, hypoventilation,
5:01
and aspiration. At the end of surgery, we often
5:04
reverse non -depolarizing blockade to restore
5:06
muscle function and help facilitate wake -up
5:09
and extubation. Traditionally, this has been
5:11
done with acetylcholinesterase inhibitors such
5:13
as neostigmine, which increase acetylcholine
5:16
levels at the neuromuscular junction. These drugs
5:18
are usually administered with an anticholinergic
5:21
like glycopyrrolate to counteract any unwanted
5:23
muscarinic side effects. More recently, Sugamidex
5:27
has become an important reversal agent for aminosteroid
5:30
neuromuscular blockers like rocuronium and vecuronium,
5:33
and works through a completely different mechanism.
5:35
It actually encapsulates the neuromuscular blocking
5:38
molecule, similar to how Febreze captures odors,
5:41
to effectively remove it from circulation and
5:44
rapidly reverse paralysis, allowing for very
5:47
fast and reliable recovery, even from deep levels
5:50
of blockade. So to summarize, neuromuscular blocking
5:53
agents are essential tools in anesthesia that
5:56
enable safe intubation, optimal surgical conditions,
5:59
and controlled ventilation. They work by interfering
6:02
with neuromuscular transmission and are divided
6:04
into depolarizing agents like succinylcholine
6:07
and non -depolarizing agents such as rocuronium,
6:10
becuronium, and cisatricurium. Because these
6:14
drugs cause paralysis without affecting consciousness
6:16
or pain perception, careful dosing, monitoring,
6:19
and reversal are critical to ensure patient safety.
6:22
Thanks for listening, and I hope this quick overview
6:25
helps clarify the pharmacology and clinical use
6:28
of neuromuscular blocking agents. Because when
6:40
did anesthesiology first get on your radar? And
6:43
then what was it about anesthesiology that clicked
6:46
for you? Kind of just like did a combined answer
6:49
for those questions. Yeah, sure. Well, a lot
6:52
of times I will ask something and then my guest
6:56
will go on for a while. Okay. And I don't, I
6:59
really don't stick to this. Oh, okay. I ask a
7:02
lot of just follow -up questions based on what
7:05
you say. Okay. So. Yeah. Pinky, thank you so
7:11
much for joining us. Well, thank you for having
7:13
me. It's a pleasure to be here. We have been
7:15
trying to set this up for a while now. Yeah,
7:19
we have. We have. I'm glad we could finally get
7:21
it together. Yeah. I appreciated you coming down
7:25
at Grand Rounds the other day and pinging me
7:28
about it because with our schedules, it gets
7:32
a little crazy and I'm glad that we were able
7:34
to find this time. Yeah. And I'm actually glad
7:36
you said something to me too, because, you know,
7:38
neuro is something that I've been getting into
7:40
for a couple of years now. And actually the ASA
7:43
monitor back in February did, you know, a whole
7:46
little insert about neuro anesthesia in a few
7:48
cases. So I think the timing now is very appropriate
7:51
to talk about it. I think that that's great.
7:53
Yeah. And I'm a big fan of our subject matter
7:56
as well as you. probably remember I'm somebody
7:58
who's also done a lot of neuroanesthesia. So
8:01
this is a near and dear topic to me. Yeah. Awesome.
8:04
Well, I'm excited to chat about it. Well, before
8:07
we dive into that, let's talk about you a little
8:09
bit. And I want to ask you the dinner question
8:11
that I ask everybody. I'm really curious to hear
8:13
your answer. If you could have dinner with anyone
8:16
in the world, past, present or fiction, who would
8:19
it be and why? Yeah, this was a really fun question
8:21
to answer. So I have a thing with. Spies. And
8:27
I'm really into British spies and international
8:30
espionage. So I would love to have dinner with
8:34
James Bond. which james bond are we talking sean
8:39
connery or pierce brosnan you know sean connery
8:42
definitely or roger moore was my second favorite
8:45
yes yeah yeah but you know just the character
8:49
in general is someone that he they're you know
8:54
a man of mystery so you never really know what's
8:57
going on in their heads but they're also so smooth
9:00
and so suave so i think a dinner with j James
9:05
Bond would be perfect. We'd have our vodka martinis,
9:10
shaken, not stirred. Excellent. And we'd probably
9:13
have a very nice dinner. I would be really interested
9:17
to talk about all of his world travels. Because
9:22
James Bond has been to like Monte Carlo, to Tokyo,
9:25
to India, to Madagascar. Okay. Two questions
9:31
to follow up. Number one, what do you think?
9:34
uh jacob would say to your answer about he would
9:37
love it so for uh mother's day a couple years
9:41
ago he got me the entire box set of all of the
9:46
james bond movies and we watched them all yes
9:51
every single one yes we did we did we did and
9:56
uh you know he's very he's a lot more into kind
10:00
of the spy genre than i am and and reads a lot
10:03
of books of that nature um but okay that's great
10:10
my second question are you secretly a spy I would
10:15
have to kill you if I told you. Okay, fair enough.
10:19
We won't disclose that for the podcast audience.
10:21
You can just tell me off the air later. Okay.
10:25
I appreciate a certain willingness and dedication
10:29
to get through cheesy fiction. I think that it
10:35
speaks to a certain amount of patience that you
10:39
have to have in a way. Because I feel the same
10:42
way about some of the old... Star Trek shows.
10:46
Yes, a lot of them are supremely cheesy and ridiculous.
10:49
But there's something behind all that. There's
10:52
a reason why people like it. So in a way, I feel
10:55
like I connect with what you're saying about
10:57
that. Yeah, I agree. And you know, there is there
10:59
is something comforting about it about, you know,
11:02
seeing watching something that you're familiar
11:05
with, that you like. And James Bond can teach
11:08
us some things for our job, like, you know, staying
11:13
calm under pressure or being able to think on
11:16
your toes or, you know, fight or flight reactions.
11:20
Except we are trying to not kill people. Exactly.
11:25
Okay. So Pinky, you grew up in Boston. Tell me
11:30
about growing up in Boston. It was a very unique
11:33
and transformative experience. So my time in
11:37
Boston obviously is divided. You know, I spent
11:39
25 years there. So I was. born and raised in
11:43
the suburbs of Boston. So I was there up until
11:46
high school in my little bubble there. And then
11:49
I went to Boston University for college, which
11:52
is an urban campus, a little bit on the outskirts
11:57
of Boston, but still very much part of the city.
12:00
And living by myself in Boston, meeting new people,
12:06
it really helped me. find my independence and
12:10
Boston is such a unique city and I love it to
12:14
death it's it's beautiful people there are very
12:17
passionate they are passionate about their culture
12:22
the history of Boston they're passionate about
12:24
sports about the Celtics yes yes definitely about
12:29
the Celtics Patriots Red Sox I will forever be
12:32
a New England sports fan even though I live here
12:35
now Oh, you could not convince me otherwise.
12:38
But I got to meet so many people from all corners
12:44
of the world just going to college in Boston.
12:48
You know, I met people from Asia, from my roommates
12:54
and floor mates were from New York, New Jersey,
12:57
Hawaii. To throw that in there. So I felt like
13:01
I was very lucky to grow up there because there
13:06
is just this, when you have a bunch of schools
13:11
in Boston, you know, I went to Boston University,
13:14
there's Northeastern, there's Harvard, there's
13:15
MIT. You're kind of in this atmosphere where
13:20
there's just a lot of. concentrated intellectual
13:25
energy. And it just felt really special to be
13:29
a part of that during my college years. That's
13:33
really cool. So what pointed you towards medicine
13:36
through all that? So I guess medicine, going
13:42
a little bit backwards, my parents definitely
13:44
had a big impact on me going to medicine. And
13:48
they were the ones that kind of nudged me into
13:50
it. I was not really aware of other things that
13:56
were out there. And so at an early age, and I
14:00
want to say this was probably like junior high,
14:02
they volunteered me to be an actual candy striper
14:07
at a hospital, at a local hospital. So like I
14:10
actually had like the red and white get up as
14:13
a candy striper. I would ask, does it still fit
14:17
you? Probably not. I kept doing these volunteer
14:28
things throughout high school and college. I
14:34
was pre -med in Boston at Boston University,
14:37
which was very challenging because in high school,
14:42
I did well in the sciences. I was a big fish
14:45
in a small pond. And then in college. The tables
14:49
turned, I was a small fish in a big pond, and
14:52
it just got really overwhelming to be pre -med
14:55
there. I changed my mind a lot. I changed my
14:59
majors a lot. I looked into going into laboratory
15:03
sciences. I worked in an organic chemistry lab.
15:08
for a year. And then I looked into going into
15:11
public health. I did some international trips.
15:15
I know you had Dr. Alcibate on here talking about
15:17
all of her global stuff. So I did some similar
15:20
trips to the Dominican Republic and Haiti where,
15:23
you know, we would set up temporary clinics,
15:25
treat patients in those rural areas. I actually
15:29
did this really cool trip where we Hiked up a
15:32
mountain and actually laid down piping to bring
15:34
down fresh water to village. So dabbled in that
15:40
for a little bit. And then I absolutely loved
15:43
teaching and education. So I applied for Teach
15:46
for America. I didn't get it. You know, and everything
15:52
kind of just came full circle. I took some time
15:56
off after college to kind of really reevaluate.
16:01
what I wanted to do with my life. And I know
16:03
my parents really were pushing me into going
16:07
into medicine. And there were aspects that I
16:09
really loved about medicine, about making an
16:12
impact on individuals during their most vulnerable
16:16
moments. I was lucky enough to get a job at the
16:20
Boston Children's Pediatric Emergency Department.
16:23
I was a clinical assistant there. So I was a
16:25
nursing assistant. And working there, working
16:29
amongst physicians, nurse practitioners, nurses.
16:33
I really felt at home there. I felt like these
16:37
were my people. This is the setting that I want
16:39
to be in for my career. So your parents were
16:44
right? My parents were right. Yeah. That's really
16:47
one of the toughest things. I know. So I took
16:50
the MCAT and then I applied to medical school
16:53
and I haven't looked back since. So fortunately
16:57
for us. here at our department you decided to
17:01
do anesthesia and you decided to do it here at
17:04
uc i remember uh you all the way back from the
17:07
beginning of residency yeah yes so tell me what
17:11
what pointed you towards anesthesia what pointed
17:14
you towards uc yeah so i originally thought i
17:19
wanted to do emergency medicine working in a
17:21
pcr before medical school so during medical school
17:25
i was all The first two years of medical school,
17:28
I was all for emergency medicine. Early third
17:31
year, I did an anesthesia elective because I
17:34
was told to do that to practice IVs and do intubations.
17:39
And my first day there, the attending that I
17:43
was with had me intubate a patient. And with
17:47
some help, I was able to get it. And the adrenaline
17:51
rush I got from just doing an intubation was...
17:56
like no other feeling and i couldn't describe
17:58
it but i absolutely loved it and i wanted to
18:00
keep doing it over and over and over again i
18:04
loved being on the other side of the drapes watching
18:08
the anesthesiologist work the vent drop drugs
18:13
be able to know their pharmacology frontwards
18:17
or backwards be able to think on their toes and
18:21
what also kind of attracted me towards anesthesia
18:24
is that I actually I saw a lot of female anesthesiologists.
18:28
So I thought, hey, you know, if this is this
18:30
is a very female friendly field, I think this
18:34
might be for me. One of my senior medical students,
18:39
when they were kind of coaching us during our
18:46
rotation said, find what gets you out of bed
18:50
in the morning. And I'm actually not a morning
18:53
person. Fair, yeah. But on my anesthesia residency
18:56
or my rotation, I was. I was excited to get out
19:01
of bed. There were days where my attending would
19:05
tell me to stay home, study, and I wouldn't listen
19:10
to him. I would come in and find stuff to do.
19:12
So that's where it just clicked for me is where
19:16
I wanted to do the work. I was excited to do
19:20
it. And I left the day happy and excited to do
19:25
it again. So I had the privilege to see you go
19:30
all through residency and go from knowing not
19:35
a little, or I should say, from knowing not a
19:40
lot at the beginning of your residency to passing
19:43
your boards and eventually becoming the neuroanesthesia
19:49
person. Yeah. uh that was pretty awesome for
19:53
me to get to watch what pointed you towards neuroanesthesia
19:57
yeah i've always had this peripheral interest
20:00
in the neurosciences ever since high school i
20:03
took ap biology and i loved talking about the
20:09
brain in the mind and just kind of the enigma
20:13
that it is so that really followed me throughout
20:19
my college medical school journey. And when I
20:24
got to residency, I met Dr. Cassandra Bailey,
20:27
who is no longer here, but she is an anesthesiologist
20:31
and she's also an intensivist. And she worked
20:34
in our neurocurricular care unit. And she, we
20:40
did a case together my intern year that I ended
20:43
up. presenting with her as a mentor at the Society
20:47
for Neuroanesthesia and Critical Care Conference.
20:50
And when I was at that conference, I just learned
20:53
about this whole world that blends two things
20:57
that I really like, which is neuroscience and
21:00
anesthesia. And I really loved it. I loved what
21:06
I was seeing at the conference, the research
21:07
that a lot of providers are doing across the
21:12
world, because there's really no anesthesia really
21:15
has a large international presence. So I thought,
21:19
you know, there is so much more to this world
21:22
than I ever thought there was. And I decided
21:25
that it was going to be something that I think
21:28
I wanted to make part of my practice when I thought
21:32
about my career and what I was going to do after
21:35
residency. I have nothing but great things to
21:41
say about Cassie Bailey, too. Yeah, I miss her
21:43
a lot. Yeah, she's wonderful, and she was a fantastic
21:46
associate program director that taught me a lot
21:50
of the stuff that I know in that world, too.
21:52
So she was great. Yeah. Let's talk a little bit
21:58
about being a parent in all this, too, because
22:02
you were like me. You had a kid during residency.
22:07
You have one on the way. I do. I do. So tell
22:11
me about your kids, how old they are and how
22:13
that has sort of shaped your world. Yeah. So
22:17
my oldest daughter is Sahana. So she is five
22:22
and a half. I had her at the end of CA one year
22:25
in residency. And this was actually March 2020.
22:29
So the whole world was on lockdown. Sorry, I
22:34
got her birthday wrong. It's May 2020. But the
22:38
world locked down in March 2020. I had her in
22:41
May 2020. And that just added a layer of... And
22:48
I'm not going to sugarcoat it. It was hard. It
22:50
was hard being pregnant as a resident because
22:52
I really didn't know what to expect. You know,
22:56
the nausea the first trimester, the sleeplessness,
23:00
the fatigue, and just... really having a hard
23:04
time moving around as my pregnancy progressed.
23:06
It did make residency, working every day, challenging.
23:13
But little did I know that was actually the easy
23:16
part. After I had Sahana, you know, I had six
23:22
weeks off, which is what I was allowed to take
23:26
without having to extend the duration of my residency.
23:29
And then I came back the beginning of CA2 year
23:33
and just kind of hit the ground running. And
23:36
it was really hard to juggle trying to be present
23:41
at home as a mom and present at work. as a resident
23:47
and uh those two things both demand so much yes
23:51
yeah um and so i and ultimately you know i thought
23:58
i i really wanted to be present for my daughter
24:01
so i really started to do the bare minimum as
24:05
a resident and one of the attendings pulled me
24:09
aside and said i know you have a lot going on
24:12
but you are really behind and that really lit
24:16
a fire uh under me because I didn't want to be
24:20
behind I you know I wanted to be a great doctor
24:22
I had these career goals and aspirations um but
24:27
I really wanted to be a great mom and so what
24:30
we ended up doing is you know as a family you
24:33
know me my daughter and my husband we decided
24:36
we cannot be doing this ourselves so we really
24:40
had to recruit help um My mom came and lived
24:44
with us for about two and a half months until
24:46
we could get our daughter into daycare, which
24:48
was, you know, I love my mom, but having her
24:52
live with us for that long was a little tough,
24:57
but ultimately ended up being very helpful because
25:01
having her offload some of the work really helped
25:07
me dedicate some time to studying and getting
25:10
caught up as a resident. There's a lot of mom
25:13
guilt behind that when you're away from your
25:16
kid and you're trying to do your own thing. But
25:22
looking back on that now, I mean, my daughter
25:25
loves me. She doesn't know any of that. You know,
25:28
I remember all of that. But, you know, she is
25:31
a little bit of a daddy's girl. But, you know,
25:34
she at one point would tell people that she wants
25:37
to be a doctor when she grows up, just like her
25:39
mom. She wants to be a dentist now, which I'm
25:42
not going to hold against her. I think that's
25:44
still a good career choice. But, you know, it
25:46
it makes me realize that I the guilt was there.
25:52
But at the end of the day, everything worked
25:56
out. And from that point over, from that point
26:00
on, I really shouldn't feel that guilt anymore
26:04
because my I we still need to take time to ourselves.
26:10
to work on ourselves and be our best selves so
26:13
that when we are with our kids, they see us at
26:17
our best and they see us at our happiest because
26:20
they pick up on that. They pick up on your moods,
26:23
your frustrations. Sometimes my daughter will
26:28
sense if I'm sad or angry, and I really don't
26:32
want her to see all that. But part of what has
26:37
made us made our home life kind of a very positive
26:41
environment is that we have outsourced a lot
26:46
of help through babysitters, neighbors, family,
26:52
daycare, so we can have that time to ourselves.
26:58
And I talk about us as, you know, myself and
27:01
my husband have the time to ourselves to, to
27:04
be the best versions of ourselves so we can be
27:07
there for our kids and in a positive light. I
27:12
agree with you being a parent, especially of
27:15
a lot of kids and also, uh, being a doctor, that's
27:21
a really tough balance to strike, especially
27:22
for moms, I think. Yeah. So let's talk a little
27:27
bit about neuroanesthesia and some of the differences
27:30
between neuroanesthesia and just a regular OR
27:35
case. First off, what are your goals for a patient
27:39
undergoing anesthesia for a neuro case? So my
27:44
goals for a patient is protecting their brain
27:48
and spine. So whether or not they're undergoing
27:52
an intracranial procedure or a spine procedure,
27:56
we influence their physiology with the slightest
28:05
decision. So whether it's their blood pressure,
28:10
their carbon dioxide level, anesthesia depth,
28:14
ventilation, They are at our mercy, and so our
28:21
decisions can really influence how their perfusion
28:26
to their brain and spine end up during the surgery.
28:32
So I think a lot of those things are intuitive
28:35
for somebody who hasn't done anesthesia, with
28:38
the possible exception of CO2. What does that
28:43
have to do with neuroanesthesia? CO2 can cause
28:50
vasodilation. So if CO2 rises, your cerebral
28:54
blood flow increases. And so a patient that's
28:58
going in an intracranial procedure, if they have
29:01
high ICP already, it'll make their intracranial
29:04
pressures worse. But either way, so elevated
29:08
CO2s can increase your intracranial pressure.
29:14
On the other hand, if CO2 is low, it can cause
29:18
vasoconstriction, so cerebral vasoconstriction,
29:21
and that can lead to cerebral ischemia. So it
29:25
is really important to find a balance, and typically
29:28
your goal for a neuroanesthesia case is to have
29:34
probably normacapnia is what I would aim for.
29:37
So in the mid -30s is a perfect balance for that.
29:44
Okay, so you're prepping for a brain tumor case.
29:49
What kind of things are you going to set up for
29:52
your case that might be different from just a
29:56
normal OR case? Yeah, so when a patient is coming
30:02
in for an intracranial procedure, so you definitely
30:06
want to have things ready to... have smooth induction,
30:12
and a smooth emergence. So when I'm prepping
30:21
for a case where I want to avoid things like
30:25
massive spikes in blood pressure and heart rate,
30:30
I think of times during the anesthetic period
30:37
where that can occur. induction and direct laryngoscopy
30:41
is one of those. So I'm more prone to use a video
30:48
laryngoscope for that reason, just to kind of
30:50
minimize the stimulation if we have one available.
30:53
But slow, careful titration of meds, medications
31:00
that would combat. massive sympathetic surges.
31:05
So having downers available to prevent rapid
31:10
increases in heart rate and blood pressure, things
31:13
to help really keep emergent or induction nice
31:17
and smooth are things I definitely want to have
31:20
available. For these cases, I do like to consider
31:25
having second IVs. a second IV set, especially
31:29
if they're going to be doing some neuromonitoring.
31:31
So if they're going to be monitoring SSCPs or
31:34
MEPs, I like to have a dedicated line for my
31:39
propofol infusion, my opioid infusion, and then
31:42
I have another line ready for bolusing if I need
31:46
to. Now, I understand everything that you just
31:49
said, but not all of our listeners might know
31:52
about SSCPs, MEPs, and neuromonitoring. Tell
31:55
me about that. Yeah. So SSEPs, so somatosensory
32:01
evoked potentials, they assess the integrity
32:07
of the sensory pathways of the spinal cords.
32:11
So basically you stimulate a peripheral nerve
32:15
and you measure how the signal travels to the
32:19
brain. That is really important for a neurosurgeon
32:24
to know. as you know it would it would tailor
32:28
their surgical technique for us on the anesthesia
32:32
side somatosensory evoked potentials are affected
32:36
by things like your anesthetic level being too
32:40
deep severe hypotension big swings in co2 so
32:46
monitoring those variables will definitely affect
32:53
the integrity of your sensory pathways. MEPs
32:57
are your motor valve potentials. So those monitor
33:02
your motor pathway function. So those are descending
33:06
pathways. And those you check by stimulating
33:11
the motor cortex and you record responses in
33:16
muscles. So if you see your your nerve monitoring
33:21
tech or your evokes tech putting little acupuncture
33:24
type pins in various muscles in the hands and
33:28
and feet and sometimes around the face those
33:32
are what they are using to monitor the muscle
33:35
response now motor evoke potentials also affect
33:40
your anesthesia technique because they are very
33:43
sensitive to medications like volatiles. They're
33:48
sensitive to neuromuscular blockade. And then
33:51
they're also sensitive to physiological things
33:54
like changes in blood pressure, so hypotension,
33:56
and changes to cerebral perfusion. So when someone's
34:01
going to have their motor evoked potential is
34:05
monitored, a lot of times people will switch
34:09
to what's called a total intravenous anesthetic.
34:12
So they would do a an infusion of a hypnotic,
34:16
typically propofol, and some sort of opioid infusion
34:22
to take the place of a neuromuscular blockade,
34:25
so remifentanyl, sufentanyl, and fentanyl are
34:28
the most common ones. There's also EEG, so that's
34:34
kind of measuring the cortical electrical activity.
34:36
So that's primarily used to monitor anesthetic
34:41
depth. So in neurosurgical cases, EEG really
34:45
helps with detecting cerebral ischemia. It can
34:49
also monitor for burst suppression. So if your
34:52
hypnotic is way too high, you can tell that by
34:59
seeing if their EEG is burst suppressed. But
35:03
you can also titrate your anesthetic to for suppression
35:06
if you need some neuroprotection. So that's where
35:10
the EEG comes into play. I remember the first
35:13
time I did a case with motor evoked potentials
35:17
and my attending didn't really prepare me for
35:20
it. But in the middle of the case, the patient
35:24
just started tapping their foot really quickly
35:28
and in a very strange rhythm. And I had no idea
35:33
why or what was going on. It was terrifying.
35:37
So I called my attending in and he said, oh,
35:41
they're just doing neuromonitoring. It's like,
35:44
what? Yes. A lot of times the evokes tech will
35:50
stimulate that pathway. So you will see an extremity
35:56
start to jump or twitch. And it is very. right
36:02
of you to be vigilant about that and, you know,
36:04
try to troubleshoot or try to figure out what's
36:06
going on. But I think the first step, if you
36:09
see some movement or some twitching under the
36:11
drapes, is to look towards your neuromonitoring
36:14
check and say, you know, a little warning would
36:16
have been nice here. Yeah. It can be less than
36:20
ideal sometimes. And if you have a medical student,
36:22
that's usually the first thing that might freak
36:25
them out a little bit. Yes. Seeing the patient
36:27
start to tap dance a little bit. When you're
36:32
doing these cases, you can't chemically paralyze
36:37
the patients like we usually do. So can you talk
36:40
about how we change our anesthetic in these cases
36:45
to make up for that? Yeah. So without being able
36:50
to use neuromuscular blockade, you do have to
36:53
get creative. We have some potent opioids that
36:59
you can use as an infusion or bolus. So remifentanil
37:04
is a synthetic opioid. We also have sufentanil
37:07
available that we can use as infusions that are
37:10
so powerful that they will prevent movement to
37:17
surgical stimulus. So those are typically some
37:21
medications that we use. You can also supplement
37:24
with medications like Presidex to help with your
37:28
anesthetic depth as well. That's another infusion
37:31
that I like to use during my cases. Ketamine
37:36
is also another popular choice for infusion to
37:40
help with your anesthetic depth. And it also
37:42
has some role as a multimodal pain alternative
37:48
as well. There are different types of cases that
37:54
we do for neuroanesthesia, brain and spine. Can
37:58
you talk about what your approach would be that
38:02
might be different between a brain versus a spine?
38:06
Yes. So spine and brain surgeries, the anesthesia,
38:12
there are some similarities, but there are different
38:17
priorities. So if I'm in an intracranial surgery,
38:21
a lot of our anesthetic management kind of revolves
38:25
around the intracranial physiology. So like things
38:29
like cerebral perfusion pressure, which is your
38:32
MAP minus your ICP, and then your intracranial
38:35
pressure, brain relaxation. So you're really
38:39
focused on maintaining stable hemodynamics for
38:42
intracranial procedures so you can create optimal
38:45
surgical conditions. Because if you think about
38:48
the brain, you know, there's the Monroe -Kelley
38:50
doctrine where the brain is pretty much in a
38:55
closed cranial vault. So very small changes in
38:59
your anesthetic depth, your blood pressure, your
39:02
CO2 that can really have big effects on cerebral
39:08
blood flow and your intracranial pressure. So
39:11
that has a big effect on the surgeon and how
39:14
well they're able to visualize the brain. Spine
39:19
surgery, there's a little bit more of a focus
39:23
on neuromonitoring depending on where they are
39:27
in the spine and more systemic physiology. So
39:30
a lot of these cases really rely heavily on somatosensory
39:35
and motor evoked potentials like we talked about
39:37
before so the anesthetic does have to be tailored
39:41
to preserve those signals so that means you know
39:44
carefully balancing your intravenous agents if
39:47
you're doing a total intravenous anesthetic so
39:49
your hypnotics and your opioids or with your
39:53
volatiles if you choose to use some you have
39:56
to leave you know you use less than half a mac
39:59
of gas if you want to use some valetyl so really
40:03
balancing your agents and titrating them to maintain
40:08
signals is pretty important for the spine surgeries
40:12
um spine cases especially like your your larger
40:17
your big spine cases like your deformities your
40:21
multi -level fusion surgeries there's also challenges
40:25
with positioning. So these patients are prone
40:29
sometimes for a really long time, like six to
40:32
eight hours. So you're also managing things like
40:36
fluids and blood loss. And so there can be pretty
40:41
significant hemodynamic shifts during those surgeries
40:45
or, you know, need for a large volume resuscitation,
40:49
but you still have to be careful because they're
40:51
prone. So while like Your intracranial cases,
40:55
they do tend to be more about protecting the
40:57
brain and managing those dynamics of cerebral
41:02
perfusion pressure and ICP and CO2. Spine anesthesia,
41:07
there's a little bit more of a balance between
41:09
neuromonitoring, but also physiology during those
41:12
long prone cases and really setting up a patient
41:17
for success for after. the case is over and you
41:20
supinate them and making sure they're extubatable
41:24
and have good pain control as well. Let's talk
41:29
about what I would guess would be Grey's Anatomy's
41:33
favorite type of brain surgery case, which is
41:36
something that we get to do here, which is an
41:39
awake craniotomy. Yeah. This is often shown on
41:44
the news as some musician will be playing the
41:47
guitar while they have their brain operated on
41:50
things like that i wonder if you can describe
41:53
what the process is and why we do awake craniotomy
41:58
it's like why would we do brain surgery on an
42:01
awake person and how do we do it yeah well an
42:04
awake patient is the best neuromonitor that you
42:08
could have it is the gold standard having an
42:11
awake patient to actually tell you or demonstrate
42:15
any deficits that are occurring depending on,
42:20
you know, where the surgeon is operating. So
42:25
really, really cool to be a part of an awake
42:29
craniotomy. I haven't been able to be a part
42:32
of a lot, but there really is a balance that
42:37
you need to achieve between, you know, Keeping
42:41
a patient calm while they're awake, so using
42:44
your skills as a compassionate physician to talk
42:50
to the patient and coach them through the awake
42:53
parts of the procedure, but then also giving
42:57
them that little bit of sedation that they need
43:00
during the more stimulating parts like the scalp
43:04
blocks and the actual drilling of the holes and
43:07
removal of the skull. getting them through that
43:11
part, but being able to wake them up quickly
43:15
to have that neuro exam. So if the surgeon is
43:21
working on the part of the brain that controls
43:26
your ability to count out loud to 10, for example,
43:29
the surgeon might be working in an area and the
43:32
patient is repetitively counting to 10. And all
43:36
of a sudden, instead of counting to 10, they
43:38
say one, two, and then the surgeon is like, okay,
43:43
well, I should probably not do whatever it is
43:45
I'm doing. right there you go yeah so that's
43:49
that's your uh that is your your best neuromonitor
43:53
that you have is your patient just stops stops
43:56
counting um something else you got to watch out
43:58
for during these awake craniotomies are seizures
44:01
so yeah these patients are are very prone to
44:04
seizures so being able to uh react uh to that
44:09
and being able to treat it quickly um with you
44:13
know And have the patient recover after that
44:17
to be able to continue on with the procedure
44:19
is also a delicate balancing act too. Yeah. I've
44:26
had that happen to one of my patients one time
44:28
during an awake cranny. Yeah. And the patient's
44:33
in pins and they're not in a position where I
44:35
can easily get to the airway. Yeah. And they
44:39
start seizing. And it can be a pretty dramatic
44:42
thing. Yeah. uh usually what the surgeons will
44:47
do which i think is just sort of an interesting
44:51
thing and i'm not sure why it works it's just
44:53
pouring cold water on the brain yeah it seems
44:56
cold saline yes yeah yeah you're right it's saline
44:59
yeah yeah but i the the idea that you would just
45:03
pour cold saline onto the brain and that would
45:05
somehow fix things like putting out a fire is
45:08
sort of an interesting concept to me uh but what
45:12
i did uh to try to stop the seizures i gave 20
45:15
of propofol which is a relatively small dose
45:18
but it works pretty well to control seizures
45:22
and it fortunately was able to break the seizure
45:24
in that patient and they were able to get back
45:26
to having a surgery it does yeah and that's really
45:30
scary too because you know a lot of times the
45:31
patients you know their head is away from you
45:34
and like you said they're they're in pins or
45:36
they're in some sort of uh immobilizer so um
45:42
You have to ask quickly, especially if they're
45:45
at risk for losing their airway. So 20 of propofol
45:53
is great. You can try like a small amount of
45:55
Versed too, so a benzo to help abort that seizure.
46:03
Oxygenation is definitely something that you
46:05
want to consider too and making sure they're
46:08
ventilating, oxygenating. Fine. And then other
46:13
things that, you know, you can work, you know,
46:16
once the patient is stabilized, you can still
46:19
work on trying to figure out what the underlying
46:21
cause was if there was something. So checking
46:24
for metabolic derangements, hypoglycemia, hyponatremia,
46:29
if they were alkalotic or hypocalcemic. Pretty
46:35
quick things that you can check on to see if
46:37
you can figure out if that was the cause of the
46:41
seizure. But, you know, a lot of times it could
46:47
be just the cortical stimulation that caused
46:49
it or if there was a little bit of a bleed or
46:53
ischemia happening there. But, yeah, so acting
46:58
quickly and making sure that the patient's airway
47:00
stays patent. put a bite block in or quickly
47:06
throw in an LMA or an endotracheal tube if you
47:08
have to use the last resort to make sure that
47:10
they don't lose their airway. I've only had to
47:12
do that one time during an awake cranny that
47:16
I had to convert to general while somebody was
47:18
in pens and sitting straight up. And of course,
47:22
it was the time where the LMA would not seat.
47:24
And I remember I had to hold it in the patient's
47:28
mouth. At a certain angle to be able to ventilate.
47:32
And it's still one of the most stressful experiences
47:35
that I had as an attending during my first year
47:38
of being an attending. Yeah. So let's talk about
47:43
the end of the procedure. We're waking up the
47:45
patient, assuming that this is a patient that
47:49
we put to sleep. Yes. Not one of the awake craniotomies.
47:53
What does a good wake up look like for one of
47:56
these cases? Yeah. So. You really want it to
48:00
be smooth. You want a hemodynamically stable
48:03
transition from anesthesia to wakefulness. So
48:08
definitely want to prioritize having a smooth
48:16
transition. One where you're not having a patient
48:21
really cough or buck on the tube, you know, depending
48:25
on what surgery you did. But, you know, what
48:28
comes to mind is intracranial surgeries because
48:29
you really want to prevent those large blood
48:33
pressure spikes after those surgeries. So making
48:39
sure that you can avoid those large blood pressure
48:42
spikes that will really affect cerebral perfusion.
48:47
bleeding cerebral edema um so trying to really
48:52
aim for like a gradual return of their sympathetic
48:56
tone rather than like experiencing a sudden surge
49:00
so uh smooth and and quick so the surgeons ideally
49:06
really want to do a neuro exam before you leave
49:09
the room so you want to have a um a wake up where
49:17
the patient isn't excessively sedated. So you
49:22
want to have your anesthetic designed so that
49:25
the patient can wake up and be able to really
49:29
follow commands before you leave the room. So
49:32
avoiding long acting, sedating medications, narcotics.
49:38
towards emergence if you used an opioid infusion
49:41
making sure you turn that off in a timely manner
49:44
depending on what you used so things that would
49:49
help them wake up without being too too groggy
49:57
or unable to follow commands And then going along
50:03
with that, you also want to make sure that they're
50:06
not in too much pain. So having some sort of
50:11
pain control, but then also having some agents
50:14
that can help prevent hypertension. So I always
50:17
like to have cardine available for waking up
50:21
these patients just to avoid the hypertension.
50:26
Ideally, I do like to... a very nice remy wake
50:32
up i don't know if you've ever had one before
50:34
um i'm not the biggest fan of remy fentanyl but
50:38
it does when you time it perfectly uh it's one
50:45
of those medications where So you have a patient
50:48
on a Remy infusion and then all you have to do
50:50
is say their name and they just wake up. They
50:52
open their eyes and it's beautiful. You just
50:54
take the tube out and they're just they're there
50:57
and you can talk to them and they will follow
51:01
commands. And and that is has been a very reliable
51:06
wake up for me. Yeah, I'm a big fan of the Remy
51:09
wake up myself. That's how I'd prefer. To wake
51:11
up in the mornings, I think. Just a blissful
51:15
opening of my eyes. Yeah. Although preferably
51:18
not with a breathing tube in, I think. I think
51:22
that that covers a tremendous amount of ground.
51:25
And my final question for you is, what are some
51:29
of your personal style points? Some of the things
51:32
that have brought you success both in and out
51:34
of the OR. Yeah. And as an aunt, as a doctor,
51:37
everything. really like I show up to work with
51:41
a positive attitude. And I really think that
51:44
just sets the tone for the day. And that could
51:49
be just anything small, just from having like
51:52
a really good talk with a nurse, getting to know
51:56
your staff in the operating room, if you don't
51:58
know them already having a good relationship
52:00
with them. It really does set the tone for the
52:04
course of the day. And you know, what, what kind
52:07
of the environment that you'll be in for the
52:10
rest of the day so the positive attitude and
52:14
communication so I you know communicate with
52:19
my trainees I communicate with my CRNAs my CAAs
52:22
surgeons as soon as I can just to make sure everyone's
52:26
on the same page before we start the day because
52:29
the last thing you want is for you know people
52:32
to to not be on the same page and for there to
52:35
be confusion. So having a really good line of
52:39
communication throughout the day has really helped
52:42
with success in the operating room. And then
52:46
I just don't let small things get to me anymore.
52:48
When I was a new attending, you know, if I...
52:52
Missed an art line or an IV, I would really like
52:55
perseverate on that. And someone told me they're
52:59
like, you know, if you if you keep doing that,
53:01
you're going to have a long career ahead of you.
53:05
So really just not letting those things get to
53:09
me, you know, if I if something like that happens
53:13
to me where I, you know, I. i can't get an art
53:16
line or something i'll you know probably just
53:18
debrief with myself for like five minutes and
53:20
then i will just move on when i was a trainee
53:25
uh one of my associate program directors uh dr
53:29
wendrix uh he was having a day where he's normally
53:33
clinically awesome but he was having a day where
53:36
he just could not get an art line in and uh he
53:41
eventually After a couple of attempts, he said,
53:45
you know what? I quit. John, come rescue me and
53:48
do this arterial line for me. And I went and
53:51
I was able to get it. But what I remembered more
53:54
than getting the A -line was him being deferential,
54:02
even though he had done a million more arterial
54:05
lines than me and asked me to rescue him. And
54:07
that made me feel a lot better about. When I
54:14
was in attending and I had those similar situations
54:17
when I couldn't get something. So I've tried
54:21
to remember that and pass that along and tell
54:23
people, now it's my turn to be rescued. Can you
54:26
come do this for me? Yes. Yeah. And I have no
54:29
problem doing that too. Anesthesia is, there
54:32
are times where it can be a very humbling field.
54:36
And I think that's okay to ask for help, especially
54:40
from someone that's junior to you. I think that's
54:44
totally fine. I agree. Well, Pinky, thank you
54:47
so much for joining us. Thank you for having
54:49
me. Thanks for listening to another episode of
54:54
Style Points. If you enjoyed the show, please
54:58
consider leaving us a rating or a written review.
55:00
It's the best way to help other people find the
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surgery. Lastly, you can always reach us at stylepointspodcast
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55:17
We're all done.