Microlaryngoscopyairway management with anesthetic techniques for CO2 laser

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Microlaryngoscopy-airway management with
anesthetic techniques for CO2 laser

• Padiatric Anesthesia 20041490-94
• Jay A. Werkhaven MD
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Outline

• Carbon dioxide (CO2) laser
• Airway fire
• Selection of the airway / ventilation technique
• Jet ventilation
• Intermittent endotracheal intubation
• Endotracheal tubes
• Carbon dioxide laser bronchoscopy

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• Carbon dioxide (CO2) laser

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• Wavelength 10600 nm, mid-infrared range of the
  spectrum
• Close to the bending frequency of water
• Strongly absorbed by tissues that have higher
  water content
• Damage tissue surfaces to a depth of 0.2mm

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Advantages of CO2 laser

• Its effects on tissues can be controlled with
  extreme precision
• Spot size as small as 250 microns
• The depth of thermal injury can be controlled
  within 50-80 microns

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Disadvantages of CO2 laser

• Produce a plume of vapour and vaporized tissue
• Viral particles might be transmitted in the
  vapour
• Smoke can obstruct the surgeons view and
  obstruct the laser beam itself
• Smoke inhalation followed by a pulmonary
  parenchymal response
• CO2 laser beam may ignite flammable materials
  causing an airway fire

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• Airway fire

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• Flammable materials
• tubes placed to secure the airway of for
  ventilation
• cottonoid pledgets placed in the airway by the
  surgeon for hemostasis
• Oxygen concentration
• Jet ventilation
• Helium as a diluent gas
• Absence of helium

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Strategies to reduce the incidence of airway fire

• Reduction of the flammability of the endotracheal
  tube
• Removal of flammable materials from the airway
• Reduction of the available oxygen content to the
  minimum required for reasonable arterial
  saturation

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Management of airway fire

• Extract remove combustible material
• Eliminate shut-off oxygen being delivered to the
  endotracheal tube
• Extinguish any present fire in the airway need
  to be extinguished by saline flush
• Evaluate evaluation of damage from the fire

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• Selection of the airway ventilation technique

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Jet ventilation Subglottic jet ventilation

• The delivery system should potentially obstruct
  portions of the surgical field
• The delivery system may be a source of
  combustible material
• Significant risk of pneumothorax

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Jet ventilation Subglottic jet ventilation

• For certain surgical procedures, subglottic jet
  ventilation is the only method available to
  provide oxygen to the patient
• Require very controlled insufflation of oxygen
  with scrupulous monitoring of exhalation

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Jet ventilation Supraglottic jet ventilation

• True Venturi type of ventilation
• Entrain outside air through the laryngoscope
• 100 oxygen delivered via a cannula within the
  lumen of the laryngoscope
• The delivered system should be in a completely
  closed position
• Short-duration jet? Suspended ventilation?

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Jet ventilation Supraglottic jet ventilation

• The risk of airway fire is essentially zero
• Jet may force papilloma fragments deeper into the
  airway
• Jet may deliver the laser plume deeper into the
  airway

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Millers anesthesia, 6th edition, chap 67
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Intermittent endotracheal intubation

• Intermittent intubation and ventilation
• No obstructions within the operative field
• May allow the surgeon only a short time to
  conduct the procedure
• May disrupt the surgical field for some
  procedures
• Potential risk of fire, although seems very small

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Continuous endotracheal tubes

• Provide ventilation for the patient
• Obstruct the surgical field
• May be required when surgery is being performed
  on the supraglottis or the hypopharynx
• Fire resistance of various material
• malleable metal tubes ? flexible metal
• tubes ? red rubber endotracheal tubes

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Laser-safe endotracheal tubes

• wrap the tube with fire-resistant material (foil)
• Silver-foil-wrapping tube, soaked with water or
  saline
• Wire-impregnated tubes
• Wire-protected silicon tubes

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CO2 laser bronchoscopy

• No risk of fire with carbon dioxide laser
  bronchoscopy
• Ventilation can be maintained during use of the
  laser
• Ventilation rates are usually faster to allow
  surgeon better visualization
• Eliminate the humidifier from the anesthetic
  circuit

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• Thanks for your attention!!