Anesthesia Grand Rounds Anesthesia Outside the OR Radiofrequency Ablations

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Anesthesia Grand RoundsAnesthesia Outside the
ORRadiofrequency Ablations

• Daniel Power, MD CCFP(EM)
• PGY-2 Anesthesia

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So whats the big deal about Anesthesia outside
the OR?
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Comfortable
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Not So Comfortable
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Anesthesiologists are comfortable in the OR

• WHY?
• Familiar surroundings
• Lots of back-up
• Experienced and familiar help
• Standard Optimized Ideal conditions
• Toys are readily available

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Anesthesia outside the OR

• Emergency Department
• ICU
• CCU
• PACU
• OB
• Radiology
• Psychiatric Ward/Hospital
• Dental Clinic
• Endoscopy
• Office based
• Private Clinics

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CAS Guidelines for Anesthesia outside at Hospital

• Basic practice principles same as for all
  anesthetic practice
• Patient selection
• ASA I,II..maybe III
• Pre-anesthetic History, Physical /-
  Investigations
• To be done by Anesthetist or other physician
• Fasting same guidelines as with any anesthetic

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CAS Guidelines for fasting before Elective
Procedures

• 8 hours after a meal that contains meat, fried
  and/or fatty food.
• 6 Hours after a light meal
• Toast and a clear fluid
• Non-human milk or Infant formula
• 4 Hours after breast-milk
• 2 Hours after clear fluids
• Unless it was a 26er of Captain Morgan

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CAS Guidelines (Cont.)

• Patients must be provided with written
  instructions for pre- and post-anesthesia
• Anesthetic and Recovery facilities must conform
  to CSA standards
• Standards of Care and monitoring are the same as
  in all anesthetizing locations

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ASA Guidelines

• Reliable source of Oxygenwith back-up
• Piped O2 encouraged, 1 full bottle
• Checked before cases begin
• Reliable suction
• Anesthetic gas Scavenger
• Equipment
• Self inflating bag capable of FiO2 90
• Adequate Drugs, Monitoring Equipment
• Standard Anesthesia machine (if inhalational
  used)

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ASA Guidelines Cont.

• Adequate and safe electrical supply including
  emergency power
• Adequate Lighting
• Patient and monitors
• Battery powered light source other than
  laryngoscope
• Sufficient Space to allow easy access to patient,
  monitors, machine

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ASA Guidelines Cont

• Crash Cart immediately available
• Two-way communication
• Adequate staff to support the anesthesiologist
• Must meet building code requirements
• Enough staff for patient transport
• Appropriate post-anesthesia care
• All anesthetics be given by or under supervision
  of an Anesthesiologist - - - in an ideal world

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Anesthetic Techniques

• Sedation
• Conscious Procedural Local with Sedation
• Monitored Anesthetic Care
• Sedation/Local with GA stand-by
• Regional
• General Anesthesia

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Planes of Sedation
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Peak effect of Drugs (IV)

• Propofol arm to brain
• Ketamine arm to brain
• Fentanyl 1-3 minutes
• Midazolam 2-4 minutes
• Allow adequate time for effects when titrating

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Planes of SedationASA Guidelines
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Choice of Anesthetic Drugs

• Technique at discretion of attending
• ASA Guidelines for ER sedation
• Level of Evidence supporting safe use of
• Ketamine in children Level A
• Propofol Level B
• Midazolam/Fentanyl Level B
• Etomidate Level C

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ASA RecommendationsSedation

• All practitioners should be trained in rescue
  from deeper levels of sedation
• Proficient in Airway management and ACLS
• Deep sedation should only be given by those
  considered trained to give a GA
• Only Physicians, Dentists, Podiatrists should
  administer moderate sedation.

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Anesthesia for Radiology

• Diagnostic Radiology
• CT
• MRI
• Invasive procedures eg Angio
• Interventional
• Angiographic procedures
• Radiofrequency ablative Procedures
• CT , MR, U/S guided interventions

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Angiography Suite
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Radiofrequency Ablation

• What is not cured by the knife may be cured by
  fire
• Hippocrates

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Radiofrequency Ablation

• Electric generator delivers high frequency AC
  current (460 000 Hz) through needle electrode
• Current passes to grounding pads (e.g.
  electrocautery)
• Thermal destruction by molecular agitation
• Tissue temperatures gt50C
• Required energy varies depending on the volume of
  the target

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RFA Cont.

• With necrosis tissue becomes more resistant
• Resistance or Temperature based systems
• Treatment time varies
• Liver 12-30 mins
• Lung 10-30 mins
• Smaller tumours lt3-4 cm
• More sessions for larger
• Control vs. Cure

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RFA Cont.

• Technology is not new
• Catheter ablations 1980s
• Application to Cancer treatment is relatively new

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Radiofrequency Ablation (RFA)Clinical
Applications

• Cardiology
• Used to destroy aberrant conductive pathways
• Oncology
• Solid Organ Tumours
• Liver, Kidney,Adrenal
• Bone (palliative, pain control)
• Lung
• Soft tissue tumours
• Pre-op for hemostasis
• Chronic Pain nerve ablation
• Varicosities

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RFA of a Spinal Nerve Root
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RFA for Liver Cancer

• Hepatocellular Cancer
• Post-treatment 2 hrs

• Same patient
• 2.5 years post treatment

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RFA Advantages

• Minimally Invasive
• Outpatient Day Surgery - usually
• Treatment alternative for those who are not
  surgical candidates
• Sparing of normal organ tissue
• Radical Nephrectomy vs RFA
• Minimal post-op pain
• Rapid return to normal activity
• Less expensive (?)

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RFA Techniques

• Percutaneous
• Catheter via blood vessel
• Direct insertion by laparoscopy or open technique
• Guidance
• U/S, Fluro, MR, CT, Eyes
• Needle inserted
• Tines then inserted
• Bzzz, Bzzz, Bzzz

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RFA TechniquesAnesthetic

• Similar to Angiography
• Local infiltration with IV sedation
• Most procedures are done this way
• Monitored Anesthetic Care
• General Anesthesia

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RFA Contraindicationsall relative

• Coagulopathy
• Use of Platelet inhibiting agents
• Anticoagulants
• Location of targeted tissue
• This list may grow as experience with this
  procedure mounts

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RFA Complications

• Common
• Fever
• Localized mild to moderate discomfort
• Hemorrhage
• Abscess / infection
• Injury to adjacent tissue / organ
• With the probe bowel perf, PTX
• With the Energy Bile duct stricture, thrombosis
• Nerve Injury

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RFA at the Civic

• Plan U/S guided treatment of solid tumours
• U/S Suite
• Satisfactory
• Conditions?

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Case Report

• 82 year old female
• CT shows
• 2.6 x 2.7 cm Renal Mass
• 2.6 x 2.8 cm Adrenal Mass
• PMH
• Renal Cell Carcinoma
• Transitional Bladder Carcinoma
• Adenocarcinoma of the Breast

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Case Report Continued

• Meds
• Atorvastatin
• Good exercise tolerance
• ECG Normal
• V/S BP 150/68 HR 68
• Physical Exam Unremarkable
• Endocrine consult pre-op confirmed solid,
  nonfunctioning adrenal mass

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Case Report Cont.

• Plan GA for RFA of adrenal mass
• Standard Monitors
• Induction
• Lidocaine 40mg IV
• Fentanyl 50mcg IV
• Propofol 120mg IV
• Sux 120 mg IV
• Maintenance
• 70 Nitrous Oxide
• 0.5-1.2 Isoflurane
• NIBP set for q 3 mins

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Case Report

• Ablation of renal mass Uneventful
• During Ablation of Adrenal Mass
• Sudden increase in BP 249/140
• SVT (140-150) with multifocal PVCs

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Case Report

• Treatment
• Esmolol 100mg IV (in increments)
• BP / Rhythm normalized within 5 minutes
• Decided to continue with the RFA
• Pre-treated with Esmolol 50mg IV
• Extubated
• Uneventful PACU stay
• No long term sequellae

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Discussion

• Hypertensive crisis thought to be the result of
  catecholamine release from adjacent normal
  adrenal tissue
• Authors recommended (in addition to ASA
  guidelines)
• Invasive BP measurement for this procedure
• Available direct acting vasodilators and short
  acting Beta-blockers
• Infusion pumps

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Key Points

• A wide variety of procedures can be done safely
  with anesthesia outside the OR
• Patient Selection Important
• Pre-op evaluation like any other procedure
• Appropriate Facilities
• Get to know your equipment
• Appropriate assistance / back-up
• Unlike the OR, we are often the outsiders
• Get to know the staff
• Emergency procedures
• Be familiar with the procedure and its potential
  complications

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Thank You