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Special Airway Devices and Techniques for the
Difficult or Failed Airway
Pat Melanson,MD
Difficult Airway Kit: ASA Recommendations
• Multiple blades and ETTs
• ETT guides (stylets, bougé, light wand)
• Emergency nonsurgical ventilation ( LMA, Combitube, TTJV )
• Emergency surgical airway access ( Cricothyrotomy kit, cricotomes )
• ETT placement verification
• Fiberoptic and retrograde intubation
ETT Placement Methods
• Direct vision – laryngoscope
– Bronchoscope
• Indirect indicator– transillumination with light wand
– listening for air ( BNTI)
– Blind tactile digital intubation
• Blindly without indicator
ETT Guides : Gum Elastic Bougie (ETT Introducer)
• Long, thin, flexible guide– 60 cm long, 15 Fr, distal 3 cm has 40 degree bend
– small diameter allows easier passage through cords than ETT
• Useful with Grade III views (epiglottis only)– direct tip underneath epiglottis and “walk up’ dorsum of
epiglottis to anteriorly to cords
– feel for “clicks” of tracheal cartilages or resistance at carina
– advance ETT over bougie into trachea
• Useful when neck movement contraindicated
ETT Guides :
Light Wand• uses transillumination of neck soft
tissues to guide tube
• technique is easier to teach, skill easier to maintain than conventional laryngoscopy
• produces less airway trauma
• less physiologic disturbance
ETT Guides :
Light Wand• Indications
– Impossible Laryngoscopy with adequate Bag-Mask-Ventilation
• TMJ ankylosis
• limited C-spine mobility
• facial trauma
• Contraindications– Upper airway masses or lesions (blind
technique)
Light Wand : Technique• Load and lubricate ETT on wand
• Bend ETT just proximal to balloon cuff to near right angle
• Place head and neck in neutral position
• Grasp and lift upward the lower alveolar ridge and mentum with non-dominant hand
• Advance light wand in midline
• Lift jaw to aid passage under epiglottis
• Position light wand for maximum well circumscribed glow at anterior neck just below laryngeal prominence
• Retract rigid stylet and advance ETT
Emergency Non-surgical Ventilation: Laryngeal Mask Airway
• Designed to be placed in the supraglottic area, seal the larynx, and direct gas into trachea
• Oval inflatable cuff seals larynx• Easy to use• Does not provide definitive management
– does not prevent aspiration
– temporizing measure after failed intubation
Laryngeal Mask Airway : Technique
• Lubricate both sides• Open airway with head tilt, sniffing position• Insert LMA with laryngeal surface down• Press device onto hard palate• Advance using index finger
– Use curve to advance over base of tongue– pushed as far as possible into hypopharynx– Stop when resistance felt(upper esophag. sphincter)
• Inflate collar and start bag ventilation
LMA and the Difficult Airway
• Consider use early in a can’t intubate, can’t ventilate situation while also getting prepared for a surgical airway or TTJV
• A temporizing measure but can be used as a conduit for endotracheal intubation– the “Intubating Laryngeal Mask”
• The LMA is a supraglottic device – Not suitable if the airway difficulty is due to laryngeal
problems i.e., (laryngospasm) or local pharyngeal abnormalities ( abscess, hematoma, edema)
Emergency Non-surgical Ventilation : Combitube
• Dual-lumen, dual-cuffed rescue airway device– The two lumens allow ventilation whether placed in
trachea or esophagus
– If in trachea position, functions like an ETT
– If in esophageal position, the two balloons seal hypopharynx proximally and esophagus distally and perforations in esophageal lumen between the cuffs allow for ventilation
– Placed blindly
Emergency Non-surgical Ventilation: Transtracheal Jet Ventilation
• Puncture cricothyroid membrane with large-bore (12 or 14 Gauge) kink-resistant catheter connected to 3-way stopcock or to a suction catheter with control vent
• 50 psi wall oxygen source• High pressure tubing• Ventilate for 2 seconds (or until chest rise)• Release valve for 4 to 5 seconds (exhalation)
Emergency Surgical Access : Cricothyrotomy
Emergency Surgical Access: Cricotomes
• Commercially available kits
• Seldinger technique– Cricothyroid membrane punctured with
needle– Guidewire advanced into trachea through
needle– Cannula loaded on dilator is advanced over
guidewire into trachea
Fiberoptic Intubation
• Indications– Predicted Difficult Airway with adequate
oxygenation/ventilation(time required)• Distorted upper airway anatomy or
• C-spine injury
• Contraindications– Excessive blood and secretions
– Inadequate oxygenation
Bullard Laryngoscope
• Indirect fiberoptic laryngoscope with anatomically shaped blade
• Not necessary to align oral-pharyngeal-laryngeal axis– Useful for C-spine immobility
• Does not require significant mouth opening
Digital Intubation
• tactile technique
• operator uses fingers to blindly direct ETT
• not an easy technique
• requires large hands
Retrograde Intubation
• Indications– C-spine motion to be avoided and difficulty
anticipated with conventional techniques– Failed intubation with adequate bag/mask
ventilation and time is not limited
• Contraindications– infected skin over puncture site– infectious or neoplastic laryngeal lesions
Confirmation of ETT Placement:
Clinical Evaluation
• Observation of ETT pacing through cords• Clear, equal breath sounds bilaterally• Absence of breath sounds over epigastrium• Symmetrical rising of chest• Condensation or “fogging” of ETT• Chest X-ray• ALL SUBJECT TO FAILURE• Pulse oximetry is LATE indicator
Confirmation of ETT Placement
• Placement of ETT in the esophagus is an accepted complication of intubation
• However, failure to recognize and correct esophageal intubation immediately IS NOT ACCEPTABLE
• Either ETCO2 detection or an aspiration technique should be used on every emergency intubation
Confirmation of ETT Placement:
End-tidal CO2 Detection
• Colorimetric– Small, disposable– Useful in pre-hospital care– Changes from purple to yellow if CO2– 100 % specific if bright yellow– Indeterminate ( brown ) can indicate
esophagus with carbonated beverage, or low output state
Confirmation of ETT Placement:
End-tidal CO2 Detection• Quantitative End-Tidal CO2 Detection
– indicates successful tube placement– early indicator of inadvertent extubation– adequacy of ventilation ( CO2 level )– prognosis in cardiac arrest– monitoring/ therapy guide in arrest
• ETCO2 detectors can be falsely negative during cardiac arrest (inadequate perfusion for CO2 delivery to lungs)
Confirmation of ETT Placement: Esophageal Detection
Devices
• Bulb or Syringe Aspiration Devices– Aspiration of a large volume of air rapidly
through an ETT to determine whether the tube is in the esophagus or trachea
– Esophagus is soft and will collapse if negative pressure applied
– Less than free and immediate ( < 2 sec) aspiration of air should be considered to be esophageal until proven otherwise
– Useful in cardiac arrests
Confirmation of ETT Placement: Esophageal Detection
Devices
• False positive results– massive gastric insufflation
– incompetent lower esophageal sphincter (pregnancy, hiatal hernia)