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Advanced Principles- Fall 2018 > Difficult Airway- Lots of Review > Flashcards

Flashcards in Difficult Airway- Lots of Review Deck (27)
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What is the NAP4 study?

  • Study done in the UK in 2008 that looked at airway complications
  • 3 million GA administered each year
    • 56% LMA, 38% ETT, 5% face mask
  • 20% of malpractice claims were respirtory
    • problems with inadequate ventilation, esophageal intubation, aspiration
    • 2/3 of problems happened during induction


What were the issues identified by the NAP4 study?

  • poor airway assments followed by failure to act on the assessment
  • poor evaluation of aspiration risk
  • failure to use awake technique d/t lack of skill and confidence
  • more than 2 DVL attempts
  • failure to communicate with head and neck surgeon
  • lack of training and equipment
  • failure to plan for difficult airway


What recommendations came out of the NAP4 study?

  • perform an airway assessment
  • assess risk of aspiration
  • Have Plan A,B,C, and D regarding airway management
  • know the difficult airway algorithm
  • use capnography ALWAYS- troubleshoot if flat
  • limit number of intubation attempts
  • know skill of fiberoptic intubation
  • if the airway is at risk, secure BEFORE induction
  • if LMA or masking fails, rule out laryngospasm
  • pt should have adequate neuromuscular function at extubation


What is the function of the nose?

Where is the pharynx?

  • Nose- warms and humidifies air; is the primary path for breathing, unless there is obstruction
    • tissue is friable, prone to bleeding, and harbors bacteria
  • Pharynx extends from the posterior aspect of the nose down to the epiglottis
    • divided into nasopharynx, oropharynx, and hypopharynx


What is CN 9?

What does CN 9 innervate?

  • CN9 is the glossopharyngeal nerve
  • provides sensory innervation from the posterior 1/3 of tongue and oropharynx down to the Vallecula


Where is the Larynx located?

What is its function?

What is it composed of?

  • Located between C3-C6 vertebrae and extends from the epiglottis to the lower level of the cricoid cartilage
  • Function- phonation and as a valve to prevent aspiration
  • Composition-
    • 3 unpaired cartilages: epiglottic, cricoid, and thyroid
    • 3 paired cartilages: arytenoid, corniculate, and cuneiform


Visualize and label in your brain the airway anatomy as viewed from above.


What innervates the Larynx?



  • Sensory:
    • the Internal branch of the Superior Laryngeal nerve innervates vocal cords and above
    • the Recurrent Laryngeal nerve innervates below the vocal cords
  • Motor
    • Cricothyroid muscle (adduction of vocal cords) innervated by External branch of the Superior Laryngeal nerve
    • All other intrinsic muscles of the larynx innervated by the recurrent Laryngeal nerve


What are the actions of the intrinsic Laryngeal muscles?


Describe the trachea.

  • begins at level of C6 or thyroid cartilage
  • Bifurcates at T5 or carina
  • 9-15 cm in length and 22 mm diameter
  • located in front of the esophagus and behind the thyroid gland in the superior and middle mediastinum
  • made up of 16-20 incomplete hyaline cartilaginous U rings that are open posteriorly


What are the components of an airway assessment used to determine difficulty?

  • History: anesthesia, medical, surgical
    • If pt has history of difficult airway:
      • Was there sore throat or dental damage?
      • were you advised to have awake or fiberoptic intubation?
      • Do you have any records or documentation?
  • Observation/inspection
  • Physical exam
  • Questions related to airway
  • previous documentation


What comorbidities may be associated with difficult airway?

  • Lesions/infections of the larynx
  • Thyroid disease
    • hypothyroidism causes large tonge
  • cancer (radiation)
  • GERD
  • diabetes
  • sleep apnea/snoring
  • obesity
  • genetic disorders
  • RA
  • musculoskeletal
  • scleroderma


What are some congenital syndroms associated with difficult intubations?


What kind of surgical history would you want to take not of when assessing for a difficult airway?

  • Tracheostomy scar
  • neck dissection
  • radiation
  • UVPP (surgery that removes tissues in throat to help with sleep issues)
  • cervical neck instrumentation (fusion)


What general appearance observations might indicate a difficult airway?

  • facial deformities, burns, radiation scars
  • large neck circumference
  • goiter
  • receding mandible
  • facial hair
  • cervical collar
  • mouth breathing or nasal flaring


What should you note on the physical exam of the airway?

  • mouth opening
  • size and mobility of tongue
  • if palate is high or arched
  • any masses
  • size and shape of mandible
  • TMJ- degree of motion, dislocations
  • ability to advance lower incisors in front of upper?
  • neck circumference


What are the different classes of the Mandibular protrusion test?


What is the 3-3-2 rule?


What does the thyromental distance indicate?

What are the measurements?

  • A short thyromental distance indicates an anterior larynx
  • >7 cm = usually an easy intubation
  • 6.5 cm is normal
  • <6 cm = difficult intubation


What is the normal hyoid-mental distance

2 fb or > 4 cm


What are the Mallampati classifications?


How does Mallampati correlate to Cormack and Lehane classification?

  • Cormack and Lehane:
    • Class 1: vocal cords are visible
    • Class II: vocal cords partly visible
    • Class III: only epiglottis is seen
    • Class IV: no epiglottis is seen


What are the normal values for cervical ROM?



lateral (L&R)

rotation (L&R)


What causes cervical spine subluxation in a pt with RA?

  • The C1 and C2 move abnormally into the cord during extension of the neck


What are the two different methods of pre-oxygenation?

  • Tidal volume breathing of 100% FiO2 for 3-5 minutes
  • Deep vital capacity breaths 4 times within 30 seconds
  • **both are effective in increasing arterial oxygen tension but longer time to desaturation is achieved with 3 min of O2


What is in a difficult airway cart?


What is the difficult airway algorithm?