1. The Difficult or Failed Airway
Pat Melanson, MD

2. The Difficult Airway
Must be able to assess or anticipate the degree of difficulty
Then select method most likely to succeed
If properly assessed and felt to be intubatable without significant difficulty
1-4 /1000 will be impossible intubations (O.R.)
1 / 280 obstetrical patients
1 /10,000 impossible to intubate or ventilate(O.R.)
1-2 % cricothyroidotomy rate in ED

3. Definitions Failed intubation Difficult intubation
inability to place an ETT
Difficult intubation
requires more than 3 attempts or 10 minutes
Difficult laryngosopy
Cormack and Lehane grade III (epiglottis only) or grade IV view (soft palate only)
Difficult mask ventilation
Failed airway
can’t intubate, can’t ventilate

4. The Difficult Airway: Necessary Skills
Clinical Airway Assessment
ability to recognize/ predict Difficult Airway
Facility with array of airway equipment
knowledge of indications and advantages
ability to choose most appropriate technique for the particular situation
manual skills
Detailed knowledge of intubation medications

5. The Difficult Airway
Not all airway management failures are avoidable or predictable
Attempt to minimize failures
Have several definite back-up plans ready for the “Failed Airway”

6. Prediction of the Difficult Airway
Historical features ( prior AW difficulty)
Anesthesia record in old chart
Medic alert bracelet
Cric or tracheotomy scar
Anatomic features

7. Prediction of the Difficult Airway
C-spine mobility
External dimensions ( rule)
Mouth opening 3 fingers (TMJ)
Mandible large enough to accommodate tongue - 3 fingers from tip of chin to hyoid
Length of neck/position of larynx - 2 fingers between top of thyroid and floor of jaw

8. Prediction of the Difficult Airway (con’t)
Teeth
large or protruding incisors obstruct vision
jagged teeth can lacerate balloon
Oral dimensions
narrow facial features and high arched palates (decreased lateral space)
Mallimpadi classification

9. Mallimpadi Classification (Tongue to Pharyngeal Size)
I - soft palate, uvula, tonsillar pillars visible
99 % have grade I laryngoscopic view
II - soft palate, uvula visible
III - soft palate, base of uvula
IV - soft palate not visible
100% grade III or grade IV views
*** this exam is seldom possible in an emergency situation

10. Predictors of Difficult Laryngoscopy
Short,thick, muscular neck
Receding mandible
Protruding maxillary incisors
“Buck teeth”
Poor TMJ mobility/ limited jaw opening
Limited head and neck movement
( including trauma )
High, arched palate

11. Difficult Airway : Laryngoscopy
Tumor, abscess or hematoma
Burns
Angioneurotic edema
Blunt or penetrating trauma
Rheumatoid arthritis, ankylosing spondylitis
Congenital syndromes
Neck surgery or radiation

12. Plan B : Response to Unanticipated Difficulty
Difficult laryngoscopy and intubation
Can’t intubate but Can ventilate
Can’t intubate and Can’t ventilate
Difficult Mask Ventilation

13. Unsuccessful Intubation : Plan B
Bag the patient
Maximize neck flex/ head ex
Move tongue out of line of site
Maximize mouth opening
ID landmarks and adjust blade
BURP maneuver
(Backwards Upwards Rightwards Pressure on Thyroid Cartilage)
Increasing lifting force
Consider Miller blade

14. Unsuccessful Intubation : Plan B
An optimal or best attempt at difficult laryngoscopy should consist of :
use of optimal sniffing position
no significant muscle tone
use of optimum external laryngeal manipulation (BURP)
one change in length of blade
one change in type of blade
a reasonably experienced laryngoscopist

15. Unsuccessful Intubation : Plan B
Remember, the first response to failure to intubate should always be to Bag-Mask-Ventilate the patient
The first response to failure of bag-mask-ventilation is always better bag-mask-ventilation

16. Algorithm for Difficulty “Bagging”
Remove FB - Magill forceps
Triple maneuver if c-spine clear
Head tilt, jaw lift, mouth opening
Nasal or oropharyngeal airways
two-person, four-hand technique
Do not abandon bagging unless it is impossible with two people and both an OP and NP airway

17. The Failed Intubation: Definition
Three failed attempts to intubate
by an experienced intubator
Inability to ventilate with BVM
Inability to oxygenate

18. The Failed Intubation
If can’t intubate but can ventilate with BVM have time to consider options
Light guided technique (Lighted stylet)
Combitube
LMA
Fiberoptic techniques
Retrograde intubation
Cricothyrotomy

19. The Failed Intubation
If can’t intubate, can’t ventilate , must act immediately
Cricothyrotomy
Percutaneous Transtracheal Jet Ventilation
Combitube
LMA
The last three are temporizing measures and not definitive airway management

20. Clinical Approach to the Difficult Airway
Is a difficult airway predicted?
“nothing should be taken away from the patient that the airway manager can’t replace”
Bag-Mask predicted to be successful?
Intubation deemed reasonably likely ?
Do I have the ability to rescue the airway if “can’t intubate, can’t ventilate”?

21. Awake Oral Intubation
Consider for anticipated can’t intubate, can’t ventilate situation
distorted upper airway anatomy
(i.e., penetrating neck trauma)
Avoids ‘burning bridges”
maintains ventilation
maintains patient’s ability to protect airway
May use to take quick look to assure that you can see enough for RSI

22. Awake Oral Intubation Prepare patient psychologically Pre-oxygenate
Topical anesthesia if time permits
Titrated sedation - avoid obtundation
Reassure patient throughout procedure

23. Difficult Airway Kit Multiple blades and ETTs
ETT guides (stylets, bougé, light wand)
Emergency nonsurgical ventilation ( LMA, Combitube, TTJV )
Emergency surgical airway access ( cricothyroidotomy kit, cricotomes )
ETT placement verification
Fiberoptic and retrograde intubation

24. Techniques for Difficult Intubation
Alternative laryngoscope blades
Awake intubation
Blind oral or nasal intubation
Fiberoptic intubation
Gum Elastic Bougé
Light wand
Retrograde intubation
Surgical airway

25. Techniques for Difficult Ventilation
Combitube
Laryngeal Mask Airway
Oral and nasopharyngeal airways
Two person mask ventilation
Transtracheal jet ventilation
Surgical airway

26. Difficult Airway Maxims
The first response to failure of Bag-Mask Ventilation is always better BVM
optimize airway position
place both OP and NP airways
two-handed, two-person technique
try lifting head off pillow to open airway
Generate as much positive pressure as possible without inflating the stomach

27. Difficult Airway Maxims
Use judicious sedation and topical airway anesthesia to have a quick look in doubtful cases
In certain situations a paralytic agent and RSI may still be the best choice

28. Difficult Airway Maxims
“It is preferable to use superior judgement -- to avoid having to use superior skill”.