Transcript introduction to anesthesia for endoscopic procedures

ANESTHESIA FOR
ENDOSCOPIC PROCEDURES
What goes in, must come out (or call a surgeon)
© 2016 Mark S Weiss, MD
Department of Anesthesiology and Critical Care
HUP GI
 Sick, ASA III and IV, patients undergoing endoscopic GI
procedures
• Or ASA II patients with acute GI symptoms
 “Minimally invasive,” but room must be set up for full
spectrum of emergencies/resuscitation/airway
management
• Set up the same as in any OR:
– MSMAIDS! (machine, suction (flexible sucker), medications,
airway, IV, special)
– Double check supplemental O2, emergency cardiac drugs
– Remember help may be far away
 Rapid turnover
• Never fast, just efficient
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Common Procedures
 BASIC PROCEDURES
• Esophagogastroduodenoscopy (EGD)
• Colonoscopy
• Flexible Sigmoidoscopy
 COMPLEX PROCEDURES (technically challenging, long
duration, etc.)
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Endoscopic retrograde cholangiopancreatography (ERCP)
Sphincterotomy, bile duct stone removal, biliary stents
Esophageal varices banding
Endoscopic Ultrasound (EUS)
Esophageal stent / dilation
Double balloon enteroscopy
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EGD
 Gastroscope (100 cm
length, 8-11 mm diameter)
 Exam scope may go as far
as duodenum
 Quick procedure
•
5-30min depending on diagnostic or
therapeutic maneuvers
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EGD Airway
 Shared airway with bite
block in place
 Watch for hypoventilation,
obstruction, apnea,
hypoxia
• Essential to have
surrogate for ventilation
– CAPNOGRAPH
– ECG respiratory leads
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Jaw thrust, chin lift
Nasal Trumpet with attach
to mapelson circuit (next
slide)
Mask ventilate, two hand
seal
Advanced airway (LMA,
ETT)
• succinylcholine
Rescue Procedures
•
Decrease infusion rate
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Nasal Airway Circuit
• Nasal airway with circuit adapter– Special adapters for nasal trumpets vs 7.0 ETT
adapter (fits best, less cost effective)
– Attached to Mapleson circuit with flex tubing
– Allows for some positive pressure
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EGD Stimulus
Gag/pharyngeal
reflex:
• Afferent limb Glossopharyngeal (CN
IX)
• Efferent limb- Vagus
nerve (CN X)
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EGD Sedation Tips
 Blunt gag reflex
• Start with a safe and effective upfront bolus
• Use Fentanyl as an adjunct to propofol
 Keep patient immobile while in fragile areasesophagus/stomach
• Stable maintenance propofol infusion
• Depth of sedation influenced by procedure complexity (variceal ligation
vs. routine diagnostic screen)
• Potential for multiple scope passes (wider lumen scopes for EUS)
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EGD Complications
Perforation
Bleeding
Infection
Rare (each
1:1000)
Variceal bleeding
in liver disease
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 Once at cecum the scope is removed
slowly-- average time 7 minutes, but
longer depending on number of biopsies
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Colonoscopy Stimulus
 Proceduralist technique greatly
impacts the amount of pain
stimulation
• “Looping” the scope
• Luminal distention through gas
insufflation
• External abdominal pressure to help
direct scope
• Retroflex at the sigmoid colon (end
of the procedure)
 Pain mechanism
• Visceral pain, mechanoreceptors
transmitted via rectal/pelvic spinal
afferents, cell bodies in the
lumbosacral region of the spinal cord
• Autonomic vasovagal reactions
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Looping Scope
 A perforation can occurs due to a transverse bowing of
the side of the scope creates an outward distention of the
bowel
• most perforations are NOT due to direct scope tip
pressure
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Colonoscopy Pain
 Patient conditions can alter acute pain processing
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Inflammatory Bowel disease
Irritable Bowel Syndrome
Functional abdominal pain from chronic disease
Cancer pain
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Colonoscopy Sedation Tips
 Scope insertion is not the most stimulating (unlike EGD)
 Propofol (small bolus plus infusion) provides optimal
procedural conditions in most patients
 Pain stimulus is not predictable (i/e when the scope loops),
but typically occurs in sigmoid and transverse colon
• Fentanyl may be given if the patient moves
 Propofol infusion can be discontinued while 20-30 cm of
scope remains
 Retroflexion at rectum may arouse the patient, but do NOT
give a reactionary bolus
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Colonoscopy Complications
 Bleeding (polypectomy)
 Perforations (mechanical trauma from colonoscope,
barotrauma, electrocautery during polypectomy)
 Postpolypectomy syndrome- electrocoagulation injury to
bowel wall
 ~2 per 1000 examinations, 85% during polypectomy
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ERCP
 Upper endoscopy with fluoroscopically
assisted guidance to cannulate the
biliary tract
 **Prone position
 Can be performed as deep sedation
with nasal airway
• when in doubt GA with ETT
 Radiation safety (lead apron, thyroid
shield, etc)
 Small Room and difficult to get rescue
equipment in case of emergency
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Glucagon Administration
Inhibit GI/biliary tract during a
fluoroscopic evaluation.
Peak GI effect in 1 min, Peak
glucose effect 5-20 min
Dose 0.2 - 0.5 mg IV
Common side effects
• hypertension, hyperglycemia,
nausea/vomiting, secondary
hypoglycemia
Contraindications
• hypersensitivity,
pheochromocytoma, insulinoma
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Common Endoscopy Related Complications
Attributed to sedation
• Hypoxia, hypotension, consequences of
hypercarbia, prolonged PACU stay
• 50-85% complications attributed to
cardiopulmonary events in setting of sedation
What is our value?
• Safe administration of deep sedation during
complex procedures
• Reduction complications in low risk
procedures
• Rescue during sedation care
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Hypotension
 Sympathetic blunting of response to hypovolemia by
anesthetics
 Vasovagal reaction
 Procedural complication
 Rare:
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Decreased LV contractility (from anesthetics),
Hypercapnia/hypoxia
Increased PVR (decreased RV function)
anaphylaxis
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Procedure Specific Level Of Sedation/Anesthesia
 Review lecture 1 on Sedation levels (minimal, moderate,
deep)
 Healthy patients undergoing basic procedures can often
tolerate moderate sedation
 Complex patients / cases often require escalating
sedation including deep sedation and general anesthesia
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Anesthesia Controversy
 Is there a need for anesthesiologists caring for ASA I and II
patients undergoing colonoscopies?
• Not used routinely in Europe
 IV conscious sedation (mild-moderate sedation) using
midazolam fentanyl or MD (GI) directed deep sedation with
propofol
• Large data sets showing safe use
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Anesthesiologists: ASA I or II Colonoscopies
Pro
CON
 Faster scope in
time
 Increased costs
 Deeper level of
sedation
(increased patient
comfort)
 Greater need for airway/respiratory
intervention
 More hypotension (same outcomes)
 Faster PACU
discharge
 Division of labor
(GIs focus the on
procedure with
more successful
procedure in
some studies)
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Specific Issues Impacting Care
 Colonoscopy bowel prep
• Hypovolemia, electrolyte
abnormalities, nausea/vomiting,
patient discomfort
 High volume, rapid turnover
• Efficiency while keeping patient
safety
 Global NORA issues
• less resources, remote proximity
from anesthesia staff with
identical OR standards
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Common GI Pathologies Affecting Care
 IBD (Crohn’s,
Ulcerative Collitis)
• GI cancer
• Chronic pain,
frustration with chronic •
medical care
• Failure to thrive,
anemia
 IBS
• chemotherapy side
effects, chronic pain
Zenker's
diverticulum, bowel
obstruction, active
vomiting
• Aspiration precautions
• Psychological comorbidities
 Hepatic pathology
• Coagulopathy, low
SVR, hepatitis C,
ETOH use
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Co-Morbidity Specific Issues
 Obstructive Sleep Apnea/
 Pulmonary Hypertension, Right
Obesity
Heart Failure
• Sensitivity to anesthetics
• Avoid hypercarbia/hypoxia
leading to decreased
which increases PVR, ensure
oropharyngeal tone and upper
adequate SVR (so SVR is not
airway obstruction
< PVR)
 High dose chronic opioid
therapy
• Lower pain threshold, higher
anesthetic requirements,
greater risk for post-op
complications
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Low Left Ventricular EF
• Avoid high doses of
myocardial depressants
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Seizure disorder
• Low - moderate doses may
increase risk of severe
myoclonus or (rare) seizure
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