9/17/2012
WHAT A GAS!
Daksesh B. Patel, D.O.
OBJECTIVES
CO2
1. What is the role of using CO2 in endoscopy?
2. What is the efficacy of using CO2 in endoscopy?
3. What is the safety of using CO2 in endoscopy?
Argon
1. What is the role of using Argon in endoscopy?
2. What is the efficacy of using Argon in endoscopy?
3. What is the safety of using Argon in endoscopy?
Air Insufflation in Endoscopy
• Has remained the standard in most centers
around the world
• Used for optimal visualization
• Readily available
• Cannot be completely suctioned
• Residual air must be passed or expelled
• Air distention is the major cause of
abdominal pain and discomfort
• Has been associated with rare but serious
complications such as combustion and
embolism
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Versus…
Carbon Dioxide Insufflation
during Endoscopy
What is Carbon Dioxide (CO2)?
CO2 Facts
• Used in industry, it has a wide
range of uses, e.g. carbonated
drinks, foods, fire extinguishers,
welding, etc.
• Solid carbon dioxide - “Dry Ice”
Note: Do not store dry ice in a container that is
completely airtight. As the ice changes to CO2
(carbon dioxide) gas, it will cause an airtight
container to expand and possibly explode.
Carbon Dioxide (CO2) Facts
• Exists in the earth’s atmosphere as
a trace gas
• Colorless and nonflammable
• Odorless at low concentrations –
(Sharp, acidic odor noted at high
concentrations)
• If inhaled, it is an irritant and
asphyxiant – (High concentrations
can cause drowsiness, dizziness,
headache, visual and/or hearing
dysfunction, and unconsciousness)
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Carbon Dioxide (CO2) Facts
• Normal metabolic end product of
human cellular respiration
• Normally present in body tissues
from breakdown of sugars, fats,
and amino acids.
• Highly soluble in blood and
tissues
• Carried by blood from the body
tissues to the lungs
• Rapidly cleared from the body by
respiration
CO2 Procedure Advantages
As compared to ambient room air*
•
Diffuses rapidly across the intestinal
mucosa into the venous circulation
•
Absorbed 150 times faster than nitrogen
in room air
•
Excretion is by pulmonary circulation via
respiration
•
Less abdominal distention and discomfort
during and after procedure
•
Allows the physician to quickly rule out
insufflation pain post procedure
*See references
CO2 is absorbed 150 times faster
than nitrogen in room air...
As shown in a study on minimizing post-colonoscopy abdominal pain:
Residual Gas at 1 hr (Air)
Patients with Air Insufflation:
35
30
25
20
15
10
5
0
1 hour after colonoscopy, a majority of patients
insufflated with room air had significant residual gas
Trace
Minimal
Whole
Colon
Colon
Colon Filled Distended Distended
(not
> 6cm
> 10cm
distended)
Residual Gas at 1 hr (CO2)
35
30
25
20
15
Patients with CO2 Insufflation
94% of patients insufflated with carbon dioxide had
only a trace to minimal residual gas
10
5
0
Trace
Minimal
Whole
Colon
Colon
Colon Filled Distended Distended
(not
> 6cm
> 10cm
distended)
Reference: Sumanac, K, et al. Minimizing post-colonoscopy abdominal
pain by using CO2 insufflation: a prospective, randomized, double blind,
controlled trial evaluating a new commercially available CO2 delivery
system. Gastrointestinal Endoscopy 2002: 56: 190-194
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Post ERCP X-rays
Carbon Dioxide Insufflation versus Air Insufflation
CO2 insufflation
Air Insufflation
“CO2 insufflation for more comfortable ERCP: a randomized, controlled, double-blind trial”.
Bretthauer, M. Endoscopy 2007; 39:58-64
CO2 Procedure Advantages
As compared to ambient room air*
•
Improved intubation depth with
enteroscopy
•
Ability to follow endoscopy
procedures with x-ray, i.e., barium
enema, CT colonography
•
Possibility of intraoperative
laparoscopy during endoscopy
•
Does not support combustion during
procedures using Electrosurgery
*See references
Bowel Explosions
• Patients should be fully prepped any time
electrosurgery is used
• Incomplete preps, or enema-only preps for
Flexible Sigmoidoscopy, increases the risk for
bowel explosions due to the presence of
combustible gases
• Three things are needed for a bowel
explosion to occur:
– Presence of combustible gases Hydrogen and/or Methane gas
– Presence of Oxygen
– Spark created by application of
monopolar electrosurgery (Snare
Polypectomy, Hot Biopsy, APC, etc.)
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Fire Prevention
Bowel Explosions
1952 – October 2006
Ladas S, et al. Colonic gas explosion during therapeutic colonoscopy with electrocautery.
World Journal of Gastroenterology 2007; 13(40):5295-5298.
Using CO2 in Endoscopy
1952
“Potential risk for explosion
in the rectum”;
Becker, GL
1974
“The safety of CO2
insufflation during
colonoscopic electrosurgical
polypectomy”;
Rogers, BH
1980’s
2012
Anecdotal reports and studies
suggested CO2 use was
associated with less pain
during and after the
procedure
To date, a multitude of clinical
studies have been written
supporting the benefits of
CO2 for insufflation in
endoscopy
Important to note - When used with therapeutic endoscopy,
CO2 does NOT support combustion
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Reported:
• Less pain and discomfort post
procedure
• Elimination of the risk of
explosion during electrosurgical
procedures
• Greater small bowel intubation
depth during enteroscopy
• Possibility of immediate
computed colonography or other
radiology procedures after GI
endoscopy
• Possibility of intraoperative
endoscopy during laparoscopy
Carbon Dioxide (CO2) Insufflation
Safety Considerations for Endoscopy
CO2 elimination from the body is by respiration
Therefore, its use requires knowledge of the following WARNINGS:
•
Sickle cell disease
•
Pulmonary Insufficiency
These are medical diseases at increased risk of metabolic imbalance
when the removal of CO2 from the blood is restricted (acidosis)
•
Consider respiratory and CO2 monitoring w/ These
Patients
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Clinical Studies Overview
NORCAPP –a randomized trial to assess the safety
and efficacy of CO2 vs. air insufflation in
colonoscopy
• 240 patients in study (156 patients used for ETCO2
measurements
• No rise in ETCO2 levels
• 93% patients completed pain survey
• 90 % of CO2 group were pain free
• 40% of air group still had discomfort 1 hr post
procedure
• Conclusion :
–CO2 safe for colonoscopy
–No rise in ETCO2
–CO2 less pain post procedure
Carbon Dioxide (CO2)
Endoscopy procedures using CO2
for insufflation* rather than air:
• Colonoscopy and/or EGD
• Flexible Sigmoidoscopy
• Intraoperative Endoscopy
• ERCP
• Endoscopic Ultrasound (EUS)
• Double-balloon Enteroscopy (DBE)
• Peroral Endoscopic Myotomy (POEM)
• Natural Orifice Transluminal Endoscopic
Surgery (NOTES)
*See references
Argon Plasma Coagulation
APC is a non-contact monopolar application
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Argon Plasma Coagulation
Advantages:
• Non-contact application
Non-contact
no sticking to tissue
• As target tissue becomes coagulated,
current automatically seeks new
conductive tissue resulting in uniform
hemostasis
• Smoke is reduced
• Thinner eschar, more flexible which
reduces the risk of a re-bleed
• Limited penetration depth
Argon Plasma Coagulation
Three items needed for
Argon Plasma Use:
• Sufficient voltage to jump
the air gap
• Proximity to tissue: 1-5
mm
• Conductive tissue – moist
surface, feeder vessels
Argon Plasma Coagulation
The extent of the thermal effect of APC on tissue depends on several factors:
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Argon Plasma Coagulation
GI Thermal Tissue Sensitivity
GI Tract Wall
Millimeters
Diameter of the
esophagus 24
mm = diameter
of a quarter
Cecal wall
thickness= 2
mm
Esophageal wall
thickness
4 mm = width of
three pennies
Argon Plasma Coagulation
Scope Technique:
• Purge at least twice before
placing the probe in the scope
• Advance the tip of the probe
until the first black line is
visible on the monitor
Probe tip
First Black Line
• Leave the probe stationary –
move the SCOPE
• APC probe must always remain
in the clinicians field of vision
• Activate only when the tissue
being treated is within the field
of view
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Argon Plasma Coagulation
Application techniques:
Static:
• The probe is focused in one
single area, thermal penetration will
increase over time
• If applied for long periods of time in
the same area, carbonization and
vaporization can occur
• For superficial treatment, short
activation times of 1 to 2 seconds are
used
Dynamic:
• The probe is moved with paintbrush-like
strokes over the target area while
observing the target tissue effect
PHYSICIAN LITERATURE USES FOR ENDOSCOPIC
ARGON PLASMA COAGULATION*
• Hemostasis
 Radiation Proctitis
 Watermelon Stomach/GAVE
 Arteriovenous Malformations
(AVM)
 Angiodysplasia
 Telangiectasias
 Mallory-Weiss Tears
 Active Ulcer Bed Bleeding
 Esophageal Varices
 Post – Polypectomy Bleeding
•Devitalization
Superficial Adenoma
Villous Adenoma(nonsurgical)
Residual Islands/Margins of
adenomatous tissue
Seed polyps, flat polyps,
and familial polyposis
Exophytic Tumors/Lesions
Esophageal Tumors
Tumor overgrowth/ingrowth
of stents
APC GI Clinical Applications
Palliative Management for Esophageal Tumors
Before
Post
APC
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APC GI Clinical Applications
APC for Watermelon Stomach - Gastric Antral Vascular Ectasia
(GAVE)
Before
During APC
Post APC
APC GI Clinical Applications
APC for Radiation Proctopathy
• Before – Patient was on regular
blood transfusions
• POST – No transfusions were
required for 6 months
Post
APC
Before
APC GI Clinical Applications
Telangiectasias
Before
During APC
Post APC
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APC GI Clinical Applications
Snare Adenoma of Cecum APC Polyp Bed Ablation
1. Adenoma of
Cecum
2. Adenoma Injected
3. Adenoma Snared
(piecemeal)
4. Ablation of Bed
with APC
RESIDUAL TISSUE ABLATION POST
POLYPECTOMY
Long term clinical study results show 50%
reduction in adenomatous polyp re-growth with
APC use of residual tissue.
Brooker J, Saunders B, et al. Treatment with argon plasma coagulation reduces recurrence after
piecemeal resection of large sessile colonic polyps: A randomized trial and recommendations.
Gastrointestinal Endoscopy 2002; 55:371-375.
APC GI Reported Clinical Applications
Stent Shortening (“Trimming”)
• Self-expanding metal stents may become displaced causing bleeding
or ulceration
• Although this is an off-label use, the projecting ends of the metal stent
have been shortened (“trimmed”) using APC with short activations
Note: Literature reported during ex-vivo testing, with long activations of APC trimming
Permalume (silicone) covered Wallstents, flaming of the Permalume was noted.
Chen Y, Jakribettuu, V, et al. Safety and Efficacy of Argon Plasma Coagulation Trimming of
Malpositioned and Migrated Biliary Metal Stents: A Controlled Study in the Porcine Model.
American Journal of Gastroenterology. 2006.
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Choosing The Best APC Probe
Circumferential Delivery
2.3 mm (7fr) 360º Circumferential Probe provides additional protection
from perforation. Ideal for those new to APC and thin walled anatomy
where The covered probe tip helps protect against incidental wall
contact in close, active tissue. The plasma is available at any angle
and reaches towards the conductive pathology regardless of probe
orientation. This probe is useful on all areas of the
anatomy.
Straight Fire Probe
- All Purpose Probe - 2.3 mm (7 fr.) Straight Fire. Probe is good for
general use. It can be focused when fired en face, or broadcast
tangentially. The (10 fr.) 3.2mm works well for tumor ablation in the
stomach and esophagus It requires a therapeutic scope with a
larger working channel and supports higher gas flow….
Side-Fire Probe
- 2.3 mm (7 fr.) Side Fire Probe works well in large areas requiring
hemostasis: stomach, colon, small bowel or rectum. The 45 degree
opening provides a wide wedge-shaped path of APC. It can paint surface
areas quickly with homogenous hemostasis.
Argon Plasma Coagulation
Another important factor involving thermal effect is the APC Mode
APC has evolved through specialized
modes with more controllable thermal
effect:
• Pulsed 1 APC: pulses one time per
second, used for focused coagulation
• Pulsed 2 APC: pulses 16 times per
second, used for wide spread
coagulation
• Forced APC: Constant beam, often
used for devitilization of tissue Original
APC for GI
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Argon Plasma Coagulation
Precise APC:
• The Precise mode creates a more
superficial coagulation effect using
a low-energy output, suitable for
temperature sensitive, thin-walled areas
where probe contact with the tissue is
difficult to control if not impossible
• Due to its potential to auto-regulate the
beam by increasing and decreasing
intensity with probe movement (up to 5
mm from target tissue), the thermal effect
is more homogenous.
Regula J, Wronska E, et al. Vascular lesions of the gastrointestinal tract.
Best Practice and Research Clinical Gastroenterology 2008; 22: 313-328
Clinical Safety: Argon Plasma Coagulation
• ALWAYS verbally confirm settings prior
to activation and document confirmation.
• Avoid probe contact with the tissue
• Keep 1-5 mm distance between probe
and tissue during activations
• Activation in static applications
should be short (1-2 sec)
• Output settings, mode, and application
durations should be based on clinical
indications, anatomical location and
wall thickness
Clinical Safety: Argon Plasma Coagulation
Emphysemas, Embolisms and Perforations:
• Use the lowest possible
settings and gas flow rates
• Avoid activating an APC probe
near a metal clip or metal stent
• Avoid aiming the probe
directly at large open vessels
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Electrosurgical Clinical Safety
Bowel Preps
Patients should be fully prepped any time electrosurgery is used
• Incomplete Preps or enema-only preps
increase the risk for bowel explosions
due to the presence of combustible
gases. Room Air 78% Nitrogen & 20%
O2
Three things are needed for a bowel
explosion to occur:
• Presence of combustible gases Hydrogen and/or Methane gas.
• Presence of Oxygen with
concentrations greater than 5%
• Spark created by application of
monopolar electrosurgery (Snare
Polypectomy, Hot Biopsy, APC, etc.
Clinical Safety: Bowel Preps
Nursing responsibility for preps:
• Question patients
THOROUGHLY about prep
compliance and results.
• Observe the quality of the prep.
Fecal clumping and sludge
increases risk. Localized rinsing
may not lower risk.
• Confirm with physician of
incompatibility of monopolar
current in a “dirty” bowel.
• Document the physician
confirmation.
THANK
YOU
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