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)