Airway Management
Augusto Torres, MD
Department of Anesthesiology
MetroHealth Medical Center
Outline
Review of airway anatomy
Airway evaluation
Mask ventilation
Endotracheal intubation
The difficult airway
Airway Anatomy
Ab-ductor
– Posterior
cricoarytenoid
Tensor
– Cricothyroid
Ad-ductors
– All the rest
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
Airway Anatomy
Innervation of
oropharynx
– Glossopharyngeal n.
innervates tongue
base and oropharynx
Airway Anatomy
Membranes
– Thyrohyoid
– Cricothryoid
Cartilages
– Hyoid
– Thyroid
– Cricoid
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
Airway Evaluation
Jaw Movement
– Both inter-incisor gap and
anterior subluxation
– 55
– Beard
– History of snoring
– Lack of teeth
– BMI >26
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)
Patient Positioning
Sniffing position
– Lower neck flexion
– Upper neck extension
– Important in obesity
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
Mask Ventilation
Upward traction of
remaining fingers
upward
Fingers on bony
mandible
Fifth digit at angle
displacing mandible
anteriorly
www.aic.cuhk.edu.hk
Mask Ventilation
Oral airway
Two-handed technique
www.aic.cuhk.edu.hk
www.haworth21.karoo.net
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
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
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
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
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
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
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
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
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
Difficult Intubation
ASA Difficult Airway Algorithm
www.metrohealthanesthesia.com
Fiberoptic Intubation
Oral or nasal routes
Topicalization is key
– Aerosolized lidocaine 4%
– Airway blocks
Thin bronchoscope inserted into trachea
Other airway options
GlideScope
Needle cricothyroidotomy
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