1. Airway Management Augusto Torres, MD Department of Anesthesiology
MetroHealth Medical Center

2. Outline Review of airway anatomy Airway evaluation Mask ventilation
Endotracheal intubation
The difficult airway

3. Airway Anatomy Ab-ductor Tensor Ad-ductors Posterior cricoarytenoid
Cricothyroid
Ad-ductors
All the rest

4. Airway Anatomy Innervation Vagus n. Superior laryngeal n.
External branch – motor to cricothyroid m.
Internal branch – sensory larynx above TVC’s
Recurrent laryngeal n.
Right – subclavian
Left – Aortic arch (board question)
Motor to all other muscles, Sensory to TVC’s and trachea

5. Airway Anatomy Innervation of oropharynx
Glossopharyngeal n. innervates tongue base and oropharynx

6. Airway Anatomy Membranes Cartilages Thyrohyoid Cricothryoid Hyoid
Thyroid
Cricoid

8. Airway Evaluation Take very seriously history of prior difficulty
Head and neck movement (extension)
Alignment of oral, pharyngeal, laryngeal axes
Cervical spine arthritis or trauma, burn, radiation, tumor, infection, scleroderma, short and thick neck

9. Airway Evaluation Jaw Movement Receding mandible
Both inter-incisor gap and anterior subluxation
<3.5cm inter-incisor gap concerning
Inability to sublux lower incisors beyond upper incisors
Receding mandible
Protruding Maxillary Incisors (buck teeth)

10. Airway Evaluation Obesity
Distribution, i. e. short, thick neck more concerning
Neck circumference

11. Airway Evaluation
Thyromental distance: bony point on mentum (mandible) to thyroid notch
If short (<3FB’s or 6cm), pharyngeal and laryngeal axis off

12. Airway Evaluation Oropharyngeal visualization Mallampati Score
Sitting position, protrude tongue, don’t say “AHH”

13. Airway Evaluation Difficulty ventilating Age >55 Beard
History of snoring
Lack of teeth
BMI >26

14. Preoxygenation
Replaces the nitrogen volume of the lungs (69% of FRC) with oxygen
Functional residual capacity (residual volume and expiratory reserve volume)
Preoxygenation with 100% oxygen via tight-fitting mask for 5 minutes  up to 10 min of oxygen reserve following apnea
Four vital capacity breaths over 30 seconds (time to desaturation quicker)

15. Patient Positioning Sniffing position Lower neck flexion
Upper neck extension
Important in obesity

16. Mask Ventilation
Induction of anesthesia produces upper airway relaxation and possible collapse
Downward displacement of mask with thumb and index finger

17. Mask Ventilation Upward traction of remaining fingers upward
Fingers on bony mandible
Fifth digit at angle displacing mandible anteriorly

18. Mask Ventilation Oral airway Two-handed technique www.aic.cuhk.edu.hk

19. LMA Placement Carries prominent position in ASA algorithm
May be held like a pencil
Balloon partially inflated
Directed posteriorly and upwards towards the palate
Jaw thrust and sniffing position may help placement

20. LMA Placement Verify placement by ventilating
Check for good chest rise, ETCO2, and adequate tidal volumes
Check for leak – if significant leak at around 10cm H2O problematic
May try size larger or smaller
May try to inflate/deflate cuff to obtain better seal
If difficulty passing may try inserting upside down and then flipping around

21. Endotracheal Intubation
Open the mouth with right hand
Scissor technique
Gently insert laryngoscope into right side of mouth pushing tongue to the left
Careful with insertion not to hit teeth
Advance laryngoscope further into oropharynx with applied traction 45 degrees

22. Endotracheal Intubation
Look for epiglottis
If initially not found insert laryngoscope further
If this maneuver does not work slowly pull laryngoscope back
Once epiglottis visualized, push laryngoscope into vallecula and apply traction at 45 degree angle to “push” epiglottis up and out of the way

23. Endotracheal Intubation
Look for vocal cords or arytenoid cartilages and try to optimize view
(i.e. lift head, apply more traction at 45 degree angle if necessary)
Do not move once view is optimized!
Assistant will hand you ETT
Insert ETT into far right aspect of mouth
Traction of laryngoscope slightly to left may assist
Traction of laryngoscope at 45 degrees will also help keep mouth open

24. Endotracheal Intubation
Insert ETT above and between arytenoids and through vocal cords
Try to visualize the ETT passing between the vocal cords
If this is not possible, then you must visualize the ETT passing above and between the arytenoids

25. Endotracheal Intubation
Common problems:
“I can’t see anything!”
Make sure tongue is swept to the left
You are probably too shallow or too deep. Even with difficult intubations the epiglottis can be visualized
Insert laryngoscope in further looking for epiglottis
Pull laryngoscope back if this fails

26. Endotracheal Intubation
Common problems
“I can’t see the cords!”
Epiglottis is visualized, vocal cords are not
Removing the epiglottis partly from view is necessary to visualize the vocal cords below
Push the end of the laryngoscope blade further into the vallecula and “toe up”
Lifting the patient’s head with your other hand may improve the sniffing position and bring the vocal cords into view

27. Endotracheal Intubation
Common problems
“I can see the cords. But I can’t get the tube there!”
You may not be giving yourself adequate room in the oral cavity
Push up and to the left with the laryngoscope to make sure the mouth is still fully opened and the tongue adequately swept away
Slide the ETT in the mouth all the way to the right side, perhaps even sideways

28. Difficult Intubation ASA Difficult Airway Algorithm

29. Fiberoptic Intubation
Oral or nasal routes
Topicalization is key
Aerosolized lidocaine 4%
Airway blocks
Thin bronchoscope inserted into trachea

30. Other airway options
GlideScope
Needle cricothyroidotomy

31. Conclusion
Airway management is an extremely important aspect of the practice of anesthesiology and critical care
A firm basis in airway anatomy is needed
Skills such as mask ventilation, endotracheal intubation, LMA placement are necessary
In the case of a difficult airway, a logical algorithm and airway equipment assist the physician in safely managing the situation