Airway Management

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
• Posterior cricoarytenoid
• Tensor
• 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 TVCs
• Recurrent laryngeal n.
• Right subclavian
• Left Aortic arch (board question)
• Motor to all other muscles, Sensory to TVCs and
  trachea

5
Airway Anatomy

• Innervation of oropharynx
• Glossopharyngeal n. innervates tongue base and
  oropharynx

6
Airway Anatomy

• Membranes
• Thyrohyoid
• Cricothryoid
• Cartilages
• Hyoid
• Thyroid
• Cricoid

7
(No Transcript)
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
• Both inter-incisor gap and anterior subluxation
• lt3.5cm 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 (lt3FBs or 6cm), pharyngeal and
  laryngeal axis off

12
Airway Evaluation

• Oropharyngeal visualization
• Mallampati Score
• Sitting position, protrude tongue, dont say AHH

13
Airway Evaluation

• Difficulty ventilating
• Age gt55
• Beard
• History of snoring
• Lack of teeth
• BMI gt26

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

www.aic.cuhk.edu.hk
17
Mask Ventilation

• Upward traction of remaining fingers upward
• Fingers on bony mandible
• Fifth digit at angle displacing mandible
  anteriorly

www.aic.cuhk.edu.hk
18
Mask Ventilation

• Oral airway
• Two-handed technique

www.aic.cuhk.edu.hk
www.haworth21.karoo.net
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

www.brandianestesia.it/Images/LMA-ins.jpg
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

www.int-med.uiowa.edu/Research/TLIRP/Bronchos
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 cant 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 cant 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 patients 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 cant 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
• www.metrohealthanesthesia.com

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