Special Airway Devices and Techniques for the Difficult or Failed Airway

1. Special Airway Devices and Techniques for the Difficult or Failed Airway Pat Melanson,MD

2. 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

3. ETT Placement Methods • Direct vision • laryngoscope • Bronchoscope • Indirect indicator • transillumination with light wand • listening for air ( BNTI) • Blind tactile digital intubation • Blindly without indicator

4. 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

5. 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

6. 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)

7. 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

8. 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

9. 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

10. 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)

11. 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

12. 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)

13. Emergency Surgical Access : Cricothyrotomy

14. 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

15. 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

16. 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

17. Digital Intubation • tactile technique • operator uses fingers to blindly direct ETT • not an easy technique • requires large hands

18. 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

19. 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

20. 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

21. 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

22. 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)

23. 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

24. Confirmation of ETT Placement: Esophageal Detection Devices • False positive results • massive gastric insufflation • incompetent lower esophageal sphincter (pregnancy, hiatal hernia)