Anesthesia for Robotic Surgery… - North Carolina Association of ...

jadesoreAI and Robotics

Nov 13, 2013 (3 years and 9 months ago)

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Anesthesia for Robotic Surgery…you can run but you
can’t hide

(it’s coming your way)


Julie Ann Lowery, CRNA, MS


Upon conclusion of the lecture, the learner/participant will be able to:


1.

Have a basic understanding of robotic principles and mechanisms

2.

Identify some of the surgical advantages of
using the robot with laparoscopic

procedures

3.

Describe
some of
the anesthetic considerations for the patient havin
g a robotic
assisted laparoscopic

surgical procedure



Robotic surgery has transformed laparoscopic

surgical procedures. More and more centers
across the United States are investing in robotic devices. While the initial cost may be
substantial, the end results and improved outcomes to the patient
are
worth

the investment.
Robotic devices offer the su
rgeon unprecedented control and precision of the surgical
instruments employed during minimally invasive procedures. This results in less
postoperative pain for the patient, shorter hospital stays, quicker recovery times, better
cosmetic

effects,
and phys
iologic function.
Generally speaking, one may initially think of a
robotic device in a sci
-
fi or futuristic reference, being autonomous and replacing the human
surgeon. This could not be farther from the truth. Robotics, while a sign of the times and
th
e future, require human intervention to operate. They help surgeons


not replace them.



a historical perspective


Robots were initially designed by the National Aeronautics and Space Administration
(NASA) for use in space travel. These robotic devices w
ere employed in performing manual
tasks aboard a spacecraft or out in space where a human could not go or
,
at least,
movement
would
be limited. Known as “slave devices”, these were controlled from a remote master
control on Ear
th or from another spacecraf
t and were used extensively aboard the Space
Shuttle missions between 1983 and 1997. From that technology emerged “virtual reality”
which allowed the interaction with three
-
dimensional virtual screens. Robotic engineering
and virtual reality were then co
upled together to develop a dexterous telemanipulator for the
anastomoses of nerves and vessels in hand surgery.






The U.S. Department of Defense recognized the applications that robotics and
virtual reality could provide in treating wartime casualties
on the battlefield. Through the
application of virtual reality, a wounded soldier could “be brought” to a surgeon. This
became known
as “telepresence.” Via this concept, a surgeon located on board an aircraft
carrier could perform surgical
intervention
s on a wounded soldier who remained in a remote
location near the battlefield. As a result, the Department of Defense went on to fund much
research utilizing telemanipulation combined with telepresence for use in mobile surgical
units.

In order

to incorpo
rate this technology to its full potential, engineers realized that
the distance between the patient and the surgeon had limitations. To ensure the best
accuracy and dexterity of the robotic device, the transmission delay or lag time between the
surgeon’s

maneuvers and the robot’s
reception of the commands
and implementation
required specific design.

Delays exceeding 200 milliseconds would compromise the surgical
accuracy and precision. Subsequently, the utilization of high
-
bandwidth fiberoptic
undergrou
nd cable over long distances was found to be the best solution at that time,
allowing for a latency time of 155 milliseconds.

The first video
-
laparoscopic cholecystectomy was performed in 1987

in France.
In
1988,
the innovation of laparoscopic surgery w
as introduced to the Society of American
Gastrointestinal Endoscopic Surgeons. From that point on, the implementation of
laparoscopy

exploded! The advantages were soon realized: less invasive with better patient
outcomes. On the flipside, this was virtu
ally a new surgical realm to master. Surgeons lost
their three
-
dimensional vision and impaired touch sensation. Additionally, a surgeon had to
learn how to manipulate long instruments within the patient’s body that were not directly
being viewed. While
advancements were made in regards to the logistics and the surgical
instruments of laparoscopy, a better technique was on the horizon. Hence, the incentive for
robotic development.

The ultimate goal was to develop a master
-
slave manipulator device whic
h would
mimic the natural movements of a surgeon’s hand and wrist. Early designs contained 4
degrees of freedom and by 1992, an instrument was developed that allowed for 6 degrees of
movement. In 1999, Intuitive Surgical acquired the rights for the exist
ing technology,
utilizing this to develop robotic instruments with 6 degrees of freedom which have evolved
to what is being widely used today.



the da Vinci Robotic Surgical System


Briefly, we’ll just highlight one of the mo
st modern surgical
robotic syst
ems
approved by the FDA


the da Vinci. This is a telemanipulator robot which means that it is
under constant control of the surgeon operator who sits in a remote console.

It is
comprised of 3 components: a console, an optical three
-
dimensional vision to
wer, and a
surgical cart. The surgical cart

(the robotic component)
consists of 3 arms that are
manipulated by the surgeon via “real time” computer assisted control. One arm holds the
endoscopic camera and the other 2 hold surgical manipulators and instr
uments.

The latter
employ
s

6 degrees of freedom plus grasp, equilibrating it to the articulation of the surgeon’s
hand and wrist.
This is a very heavy piece of equipment and extreme care must be taken
with moving it. After the patient is positioned for
the surgical procedure, the cart must be
rolled into the surgical area and is then locked into position. It is imperative that the
patient’s position is not changed after the robotic side arm is “docked” to avoid injury to
patient.
The console allows for

a three
-
dimensional image of the surgical field. The
endoscope transmits two separate optical and digital images to the console’s visual monitor.
The surgeon is visualizing two separate monitors, each eye seeing through an independent
camera channel whi
ch creates a three
-
dimensional image of the surgical field.

Within the
console, there are 2 levers


“the masters”, which attach to the surgeon
’s
index fingers and
thumbs. There are

also 3 foot pedals which allow

the surgeon to disengage the robotic
moti
ons, adjust the endoscopic camera, and control the cauterization.
Lastly, the optical
tower consists of computer equipment which coordinates the left and the right “eyes” of the
surgeon providing stereotactic vision. The computer also translates the move
ment of the
surgeon’s hands into a digital format that corresponds to the robot’s articulations.






Surgical applications


Robotic technology has been successfully implemented in many surgical procedures,
including gastrointestinal laparoscopic surgery
, cardiac surgery, thoracic surgery,
neurosurgery, urologic surgery,

orthopedic procedures,
and gynecologic procedures.

I am
the most familiar with robotic assisted urologic and gynecologic procedures so that is what I
am going to specifically highlight.

If robotics
is

being utilized in other types of surgical
procedures listed above where you practice, I highly encourage you to learn about the
anesthetic implications and volunteer to provide these patients anesthesia!


Urologic surgery


At the University

of North Carolina at Chapel Hill,
the
urology surgeons are
excellent with the da Vinci.
Some of t
he primary urologic surgical procedures that
employ

the
da Vinci robot
are
:
nephrectomy,
pyeloplasty,
cystectomy with ileal conduit,
and radical
prost
ate
ctom
y
.

The latter is probably the most frequent procedure which utilizes the da
Vinci robot.


Prostate cancer is the leading form of cancer in males. It is the second highest cause
of death in males in the US, killing more than 40,000 men annually. Early
detection carries
the best prognosis and allows patients to have more treatment options, including surgical
removal of the prostate. In a nutshell, the goals surrounding a radical prostatectomy are:



Remove the prostate and cancer



Preserve urinary functi
on



Preserve erectile function

(via a nerve
-
sparing procedure or approach)



Analyze the prostate after surgery to assess
the
risk of recurrence of cancer

As outlined above, performing a robotic assisted laparoscopic radical prostatectomy
offers the surgeon A
ND the patient many advantages. The da Vinci system allows the
surgeon to have enhanced magnification, a 3
-
dimensional view of the operative field, and
preserve the nerves responsible for erections. The patient benefits greatly as well:



Decreased blood

loss



Shortened length of hospital stay



Decreased postoperative pain



Less scarring



Shorter urinary catheter time



Faster return to regular activities



Anticipation of improved potency and continence




Gynecologic surgery

R
obotic

assist
is also being widely
used in gynecologic procedures fo
r various underlying
disorders: fibroids, pelvic masses, abnormal bleeding, endometriosis, pelvic floor disorders,
and precancerous/cancerous disease processes. Depending upon the problem, treatment
options may not necessa
rily include surgery.
On the flipside, hysterectomy is the most
common surgical procedure performed in women and roughly numbers about 650,000 cases
annually in the US. The primary reason is that it is the definitive solution for many types of
common gyn
ecologic conditions. I
f surgery is indicated, minimally invasive surgical (MIS)
procedures

have numerous advantages which are quite similar to those outlined earlier:



Minimal blood loss



Preservation of fertility for fibroid removal/myomectomy



R
eduction in

hospital stay



Less postoperative pain



Absence of a midline abdominal incision



Quicker recovery time



Anesthetic considerations


Several of the anesthetic implications specific to robotic procedures mimic those for
any laparoscopic surgery. However, there

are some considerations unique to these
procedures that anesthesia providers need to appreciate and understand. Some of these are
surgeon preferences but nonetheless, have good rationale beh
ind them as they lead to
optimal surgical conditions and in the
long run, better outcomes for the patient. So, let’s
highlight a few of the main considerations…


Anesthetic technique and agents…


No mystery or surprises here. For any of the robotic procedures mentioned above
specific to urology and gynecology (my exp
erience), the
se
patients alway
s

receive a general
anesthetic. A regional block


i.e.

epidural

catheter placement
, either for anesthesia
supplementation and/or postoperative analgesia is just not indicated or even necessary. So,
for those of us who reall
y enjoy (and prefer) doing general anesthesia, this makes us happy.


Each of us has our favorite anesthetic drugs, inhaled anesthetics, and techniques that
we like to employ.
Not a problem. As with any patient having any surgical procedure
, the

selecte
d anesthetics should be catered around the patient, the patient’s history, and their
accompanying co
-
morbidities.


I personally avoid the use of nitrous oxide with laparoscopic procedures for several
reasons. But

especially with the gynecologic procedur
es, postoperative nausea and vomiting
has a higher incidence. So, why make a potentially bad problem worse? Additionally,
high
narcotic loads are not generally required as
postoperative pain is much less a problem
.



Placement of IVs and additional in
vasive lines…


For robotic assisted laparoscopic procedures, the patient’s arms will be tucked
in/secured at the sides. Additionally, you will not be able to access the patient’s arms or
check the patency of the IV or fiddle with the noninvasive blood pre
ssure cuff once the
robot is “docked” into position. There are several reasons for the latter. Not only is the
robot a huge piece of equipment but it will be literally in the way of accessing the patient.
Also, the entire area above the patient is consi
dered sterile.


So, here is the message


place anything in the patient

(additional IVs, an arterial
line)

PRIOR to the robot being positioned and locked into place above the patient. It is a
g
reat
idea

to place a second large bore peripheral IV after i
nduction. The patient usually
will have
had a bowel prep,
probably
will be dehydrated, and the surgeons are working
in
close proximity to
large

blood
vessels
. In the event
you need to give volume and/or blood
products
quickly, you can do so without troub
le

if a second large IV is in place
.
And use a
fluid warmer with the second IV set up.
An anesthesia colleague once told me that he never
had to dc an IV STAT.
Makes sense…the second IV can always be removed easily when
the patient reaches the PACU.
On
ce again, you will not be able to crawl up under the
drapes and start a second IV very easily in an emergent situation.


Just a word about an arterial line...placing one or not placing one should be
determined by the patient and the patient’s presenting
history. As with other clinical
scenarios and patients, often times we place an arterial line for “our convenience.”
Because
the patient’s arms are tucked, having an arterial line for
the
sampling
of
ABG’s
, a
hemoglobin level,
or even
a blood sugar
ca
n be invaluable.

If the patient does not warrant
an arterial line postoperatively, it is easy enough for the PACU nurse to remove it then.


Lastly, make sure the IVs run well after the arms have been tucked in and the arterial
line has an acceptable wavef
orm.


Positioning the patient…


The patient is under general anesthesia, the needed lines are in place, and now the
surgeons are ready to go! It is very important that all personnel in the operating room take
an active role in properly positioning ANY p
atient for the surgical procedure. However,
with robotic assisted procedures, there are a few nuances. Also, a surgeon may have a
particular positioning technique or strategy which is fine as long as it’s safe for the patient.
S
ince my primary experienc
e is with urology and gynecology procedures, that is what I am
going to
discuss.
For the most part, both require similar positioning of the patient.


Robot assisted laparoscopic prostatectomy



Arms padded and tucked at sides and well secured
.



We place a be
anbag high on the OR table with the U shaped tops wrapping around
the patient’s shoulders for stabilization.
B
lue foam donuts are also placed
between
the

shoulder AC joints
and bean bag
for padding.

Padded shoulder blocks are then
placed
behind the bean
bag
for extra stabilization to prevent the patient sliding in the
cephalad direction when placed into steep Trendelenburg.




Towels are placed across the patients chest and then wide adhesive tape is crossed
across the patient’s chest and shoulders in an
X formation to secure the patient to
the OR table
.



Our surgeons use a special OR table which splits the legs for surgical positioning.

This minimizes the risk of peroneal nerve injury.




Once all of that is done, a “testing” of the Trendelenburg position
is
performed
to
ascertain that the patient is secure on the OR table and does not slide down in the
cephalad direction. This is very important as the patient will be in steep
Tren
delenburg for quite some time.


Robot assisted pyeloplasty



L
ateral position


kind of a tilt, with the operative site on the body (
i.e.

left or right)
being up and the patient can remain relatively flat
.



A beanbag is used to secure the patient
.



Don’t forget the axillary roll
.



Proper padding must be present between the arms and the

legs
, especially between
bony prominences.



Ensure that the “up arm” is well secured so it does not fall

and stretch any nerves.




Make sure the male genitalia
are

not getting squished between the bean bag and
body.


Robot assisted gynecologic procedures



Ar
ms padded and tucked at sides and well secured
.



While supine, padded shoulder blocks are placed superior to the AC joints and fit
snug on the OR table
.



The patient’s legs are placed into padded leg holders

and gently bent at the knee.



Steep Trendelenburg i
s also required for this patient
.


Nerve injuries remain one of the most common adverse outcomes in surgical patients
and reported closed claims event. And while a patient may sustain a nerve injury even with
the most meticulous surgical positioning and p
recautions placed, most nerve injuries are
preventable. That means that we need to be knowledgeable about proper surgical
positioning techniques, have the proper surgical padding and positioning equipment to
utilize, and know the nerves which are at great
est risk for injury for this patient and for this
procedure.

The ulnar nerve is the most common nerve injured during surgical procedures

and
anesthesia.
One reason for its vulnerability is
its
superficial
lie
to the skin surface. It also can
easily be
trapped between the bony prominences

surrounding it.
Ulnar nerve injury is
slightly less prevalent when the arms are tucked at the side. However,
it
remains
important
to wrap gel pads or foam around the ulnar area. The hands and fingers also need to be
properly padded and secured. With
gynecological
surgery, the foot of the bed will be
lowered. Ensure the fingers are not wedged
in
-
between

the OR table and the moveable
end
of the table
foot piece. If they are, it is a great way to crunch fingers. Addi
tionally, cut off
the clamps on the IV tubing that will be next to the patient’s skin. Also, place a 4x4 between
any IV connections and/or stopcocks so that these do not place pressure or leave an
indentation in the skin.

Once the arms are secured, doubl
e check that the arms are really
secured. With draping and positioning, it becomes more difficult to detect if the arms
“slipped” and are now dangling along side of the OR table.

When the legs are placed into padded leg holders, check that the legs are
symmetrical


one should not be higher than the other. Also, excessive flexion and extension should be
avoided as this can stretch the sciatic nerve. Ideally, the leg should be in a relaxed mid
-
position and both sides of the knees padded.

The peroneal n
erve runs lateral to the knee
and the sapphenous nerve runs medial to the knee. If there is excessive pressure to either of
these areas, these nerves are at jeopardy for injury.


If padded shoulder blocks are used (as mentioned above), astute and frequen
t checks for
excessive pressure over the AC joint are mandated, especially when the patient is placed into
the steep Trendelenburg position. Excessive pressure on this part of the shoulder can cause
brachial plexus injury. Keep in mind that when the bloc
ks are placed superior to the
shoulder while the patient is in the supine position,
they may not feel “tight” above the
shoulder. But when the patient’s head is lowered and gravity forces the body weight
downward, the latter force will be exerted against
the shoulder blocks. Therefore, it is
prudent to check the positioning of the blocks after they are put into place and make sure
they fit very loosely around the shoulder


2 fingers can easily be wedged between the
shoulder and the block. This is somewh
at of an insurance
policy

so that when the patient
goes head down, at least the blocks were not too tight to begin with.


Positive pressure ventilation


the challenges and the solutions


All of us have administered anesthesia for patients undergoing vario
us laparoscopic
procedures and are aware of the potential pulmonary dynamic changes that occur secondary
to the CO2 insufflation.
While this holds true for robotic assisted laparoscopy, it is worth
mentioning a few words about the steep
head
-
down position

which is required.


The combination of the positioning and CO2 insufflation can make ventilating these
patients challenging. If the patient is obese, it becomes even more challenging. Utilizing
pressure ventilation can nicely circumvent this problem a
nd allow us to achieve adequate
tidal volumes. Keep in mind that you need to be watchful of the peak
aspiratory

pressures
and not allow them to become excessive. The placement of an

oral gastric tube is warranted.



IV fluids…minimize!


Because patients
have been NPO and especially if they have undergone
a
bowel

prep, we are inclined to want to give our patients a ton of IV fluids, especially at the
beginning of the case. When you are providing anesthesia for a robotic assisted
urologic or
gynecologic
pr
ocedure, forget about that concept!
The exception is for pyeloplasties.


Our surgeons request that fluids intentionally be minimized before and during the
surgical procedure. The primary reason for this i
s that excessive IV fluids potentiate the
format
ion of edema in the face and in the airway mucosa quite possible preventing
extubation of the patient. When these cases were taking longer to perform, this was a very
real encountered problem. In robotic prostatectomies, minimizing the IV fluids can also

keep excessive urine out of the pelvis which could obscure the surgeons’ view while sewing
the anastomses. At

the end of the case once the patient is flattened out, the surgeons then
approve for us to give the patient IV fluids as
needed.
In robotic pro
statectomies, our
surgeons
actually
ask us to start loading the patient with IV fluids at this time point.
Preoperatively,
I like to inform the patient and any family members that it is not unusual for
there to be visible swelling in the patient’s face an
d eyes postoperatively due to the steep
head down position. While this will normalize within the first few hours after the procedure
is complete, it may be a bit alarming to see and experience, especially if it were not discussed
ahead of time.



One co
uld possibly say that robotic assisted laparoscopic surgery is still in its
infantile stages. With that stated, there is somewhat a lack of
information in the
literature
discussing the specific anesthetic considerations

for it. Therefore, consider this i
nformation
a starting point and build upon it as you are able. From all indicators, it appears that the
robot in surgical procedures is here to stay. Good luck!






References


Nishanian E, Mets B. Anesthesia for robotic surgery. In R. Miller (ed)
Mill
er’s Anesthesia

(6
th

ed). Elsevier Churchill Livingstone. Philadelphia. 2005


Many thanks to Les Meadowcroft, clinical sales rep with Intuitive Surgical, for his help and
provision of data and slides pertaining to the da Vinci system.


Also I am very gra
teful to the advice and information from 2 of the best robotic surgeons I
have the pleasure to work with at UNC: Dr. Eric Wallen (Urology) and Dr. John Boggess
(GYN oncology).