Airway Assessment 1 Flashcards
Single most important factor in safe and satisfactory anesthesia & resuscitation
Airway management
3 High Risk Themes
Communication failure: CRNA, surgeon, nurses, pt, etc. tx of care
Failure to comply w/ AANA standards: read through the list
Errors in judgment: fatigue/stress
Improvement in airway risk
implementation of systems for prevention/detection of errors, quality improvement, airway assessment tools, difficult airway algorithm, better equipment, drug safety, improvements in operating systems (time outs, etc)
People do not die from lack of intubation, they die from a lack of ventilation!!!
Examples of anesthesia complications
aspiration
obstruction
resp failure
high spinal
local anesthetic toxicity
anaphylaxis
sedative overdose
How many breaths of Positive CO2 is needed on monitor to confirm ETT placement?
6
Minor morbidity
Moderate distress w/o prolonging hospital stay
No permanent complications (PONV)
Intermediate morbidity
Serious distress prolonging hospital stay.
No permanent complications (dental injury, aspiration, spasm)
Major Morbidity
permanent disability or complication (anoxic brain injury, spinal injury)
Airway types
Routine, anticipated difficult, unanticipated difficult, failed
Most difficult airways are unanticipated - usually due to inflamed or swollen lingual tonsils undetected on assessment.
Considerations for airway mgmt
Thorough airway history/exam
Consideration of ease of intubation
Form mgmt plan for mask ventilation or supraglottic airway
Estimate relative risk of periods of apnea
Aspiration risk
Review the Difficult Airway Algorithm
Induction Mgmt Plan
provide oxygen the entire time!! (new).
Patient can tolerate a longer apneic period if you’re oxygenating the whole time
Consideration in induction Mgmt Plan
Aspiration risk
Likeliness to obstruct
Difficulty in masking
Difficulty with SGA/intubation
Toleration of apneic period
Comorbidities
Anesthesia history
Make extubation part of your plan. Unless you decide to leave ETT in.
Nose & Nasopharynx (Turbinates)
Large surface area, very vascular
Relevant for placement of nasal trumpet
Risk for bleeding increases if enlarged.
Nose Bleeds
Inc vascularity with pregnancy, allergies, and prolonged prone positioning
_________ stimulation usually constricts blood vessels, but we block that with anesthesia
Sympathethic
Where do 90% of nose bleeds occur?
Anterior (littles area): ICA/ECA branches
How should you stop nose bleeds
hold pressure on cartilaginous part of nose, not on nasal bone! (many branches of anterior ethmoid artery here)
Tx of Posterior Nose bleed
hard bleed to treat (may require embolization, surgery, silver nitrate, ballooning, packing), further back, profuse, sphenopalatine artery, greater risk of airway compromise, blood in both nostrils & posterior pharynx.
Apply pressure, gauze, neo on gauze. If doesn’t stop → CALL ENT
What causes a person to be more susceptible to nose bleeds?
allergies, dryness, chemical exposure, prone position, blood thinners, broken nose
Location of the Oropharynx
Starts at the mouth and meets the nasopharynx posteriorly. Soft palate → epiglottis, contains the palatine & lingual tonsils
Tongue
Large muscle, relaxes when it falls back
Soft Palate
Raises during swallowing
Uvula
protects passageway from oral cavity to nasopharynx
What happens to the oropharynx with increasing age?
With increased age (>50), muscle tissues stretch/relax → increases obstruction
Enlargement of the pharyngeal adenoids tonsils can cause obstruction of what structure in the nasopharynx?
Eustachian tubes
T/F: Palatine tonsils which are located in the oropharynx can cause enlargement w or w/o infection?
True
What are the most common cause of enlargement and are compensatory mechanisms after tonsillectomy or with auto-immune disorders. These are also located on posterior ⅓ of tongue.
Lingual Tonsils
Lingual Tonsil enlargement
CANNOT see with airway assessment; unanticipated difficult airway!!!
Laryngeal skeleton
3 unpaired cartilage (thyroid, cricoid, epiglottis)
3 paired cartilages (arytenoid, corniculate, cuneiform)
Hyoid bone
chief support for the larynx
Fxn of the Larynx
Protect patency between hypopharynx (part of throat that lies behind the larynx; entrance to the esophagus) & trachea
Phonation
Gag/cough reflexes
Location of Larynx in adults
C4-C6
Location of Larynx in infants
C3-C4 & more anterior
Differences b/w Male and Female Vocal Cords
Male vocal folds are longer (17mm-25mm) - deeper voice
Female vocal folds are shorter (12.5-17.5) - higher pitch voice.
Review Netter’s plates 54, 60, 70-74 for airway anatomy
Thyroid cartilage
Largest of the 9 cartilages
Superior cornu attaches to lateral thyrohyoid ligament
Inferior cornu attaches to cricoid cartilage
Cricoid Cartilage
Anatomical lower limit of the larynx
Wraps completely around larynx (only complete ring in upper airway!)
Narrowest part of larynx in a child
Attaches to the thyroid cartilage by the cricothyroid membrane (1-1.5 cm past laryngeal prominence)
Cricoid Pressure
Used in RSI, controversial. Apply light pressure until they fall asleep, then firmer. If vomiting, let go
Epiglottis anatomy
Unpaired leaf-shaped projects obliquely upward (free extremity is broad & rounded with a stem connected to the thyroid cartilage),
Epiglottis fxn
protect the glottis from aspiration (when swallow, it folds backward)
Vallecula
pouch-like area found between the median & lateral folds of epiglottis
Epiglottis attachments
INFERIORLY to posterior aspect of thyroid cartilage
SUPERIORLY into the hypopharynx
POSTERIORLY is free & visualized with laryngoscopy
ANTERIOR attached the hyoid bone
What are the paired cartilages of larynx?
Artyenoids
Cuneiform
Corniculate
Arytenoids
pyramidal shaped, attached to posterior portion of vocal cords, articulates with the cricoid cartilage forming a synovial joint (problem w rheumatoid arthritis- vocal cord fatigue)
Cuneiform & Corniculate
connected to the arytenoids by laterally placed aryepiglottic ligaments & folds, embedded in the aryepiglottic folds, reinforce & support the aryepiglottic folds & may help the arytenoids move
Vocal Cords & Glottis
Fibromembranous folds attached anteriorly to the thyroid cartilage and posteriorly to the arytenoids, alteration in tension on the vocal cords determines the pitch of the voice
Intrinsic muscles
TENSION of vocal cords control the glottic opening, moves the cartilages in relation to each other
Extrinsic muscles
move the larynx as a whole, connects larynx, hyoid, & neighboring structures, adjusts the POSITIONING of the larynx
Pharyngeal Muscles
Posterior Cricoarytenoids- abduction
Lateral Cricoarytenoids - adduction
In an awake patient muscle tension is maintained by…
Tensor palatini m (nasopharynx)
Genioglossus m (oropharynx)
Hyoid m (laryngopharynx)
Importance with correction of sleep apnea
Many surgeries to correct: hyoid suspension, genioglossal advancement, upper airway stimulators)
Motor innervation of the tongue
CN XII Hypoglossal N
CN IX Glossopharyngeal N
Complications of CN XII Hypoglossal N
Risk of injury during vigorous manipulation of airway
Risk of nerve palsy with LMA/use of nitrous oxide. Complications can lead to Dysphagia
CN IX Glossopharyngeal
Sensory innervation to: vallecula, base of the tongue, roof of the pharynx, tonsils, undersurface of soft palate)
Stimulation of CN IX Glossopharyngeal N will result in what?
Gag reflex and increased coughing
Glossopharyngeal Nerve Block
Anesthetize the tongue with topical anesthesia
Inject in the gutter where tongue meets palatoglossal arch using a 23 or 25g needle →
Inject 1-2 cc lido on both side
MUST ASPIRATE! Risk of intracarotid injection!
Which nerves share nuclei in the medulla?
Glossopharyngeal, vagus, & spinal accessory nerves
Gag reflex MOA
stimulation such as suctioning back of oropharynx sends afferent impulse via CN IX to medulla → vagus nerve sends efferent impulse for all muscles to contract → GAG
Innervation of the Larynx
CN X Vagus nerve
Supplies sensory & motor innervation, 2 main branches
What nerve supplies sensory innervation above the VC (supraglottic)?
Superior Laryngeal N (2 Branches)
What are the 2 branches of the SLN?
Internal Branch
External Branch
What does the External branch of the SLN do?
Motor innervation to cricothyroid muscles
Tenses the VC
T/F: Unilateral injury to the larynx indicates an immediate need for repair.
False: usually no treatment, over time the VC will move medial, changes in voice or voice tiring
Bilateral injury to the larynx
(rare) aspiration risk
Possible need for tracheostomy
Loss of sensation above cords (inability to adduct-close)
Floppy cords
Route of the Recurrent Laryngeal N
Right RLN loops around Brachiocephalic innominate artery; Left RLN wraps around Aorta
Sensory innervation for the Recurrent Laryngeal N
Sensory below VC (Subglottic)
Motor innervation for the Recurrent Laryngeal N
Motor innervation to all intrinsic muscles EXCEPT cricothyroid
Motor innervation to the cricoarytenoids (ONLY ABDUCTORS of VC)
Unilateral damage to the RLN will cause what?
Hoarseness
Bilateral injury to the RLN will cause what?
* worst scenario
Unopposed adduction by the cricothyroid via the SLN → inability of the cords to abduct
Aphonia
Stridor can lead to death
IMMEDIATE REINTUBATION & laryngoscopy to evaluate cord function
Damage to either the SLN or the RLN may cause the larynx to become incompetent with a potential for _________ or _____________!!
Aspiration or Airway obstruction
Superior Laryngeal Nerve Block
→sensory above vocal cords, supraglottic region
Find the hyoid bone & greater cornu of hyoid bone at angle of mandible
Walk off hyoid bone to thyrohyoid membrane
Inject a small amount of local
Go 2-3mm deep & inject 2 mL lido
Repeat on the other side
What risk is associated with a Transtracheal Block?
Risk of tearing mucosa with needle
This block is contraindicated if aspiration risk
Transtracheal Block Procedure
Find cricothyroid membrane & find middle
Do a skin wheel of local 22g angiocath w 5mL syringe attached
Add about 3-5 mL of lidocaine
Aspirate constantly (want air bubbles)
When get bubbles, remove needle while advancing catheter & inject lido
Tell patient to take a deep breath while injecting → cough spreads local
What are the laryngeal muscles?
Vocal cords
Glottis
Vocal cords movement
Lengthened by cricothyroid muscles (tension)
Shortened by thyroarytenoid muscles (relaxation)
Glottis movement
Abducted by posterior cricoarytenoid (opens) - “Pulls Cords Apart”
Adducted by lateral cricoarytenoids (closes )
How many cartilaginous rings are located in the trachea?
15-20 rings
The last ring produces the bronchial bifurcation also known as what?
Carina
Lies at the angle of louis formed by the articulation of the manubrium with the body of the sternum
Why are the tracheal rings incomplete?
Allow for esophageal expansion
The length from the VC to carina is about________
10-15cm
Right mainstem bronchi
Diverges from trachea at 20 degree angle, 2 cm long
Left mainstem bronchi
Diverges from trachea at 45 degree angle, 5 cm long
