Airway Assessment Flashcards
Exam 2 content
How much do you want the mouth to be able to open for intubation?
An inter-incisor distance of at least 6 cm. 3 of the patient’s finger-breadths.
If you can’t see the airways, what paired structures hint that the vocal cords would be right above them?
The arytenoids
What drug can cause angioedema? Treatment?
ACE inhibitors, and tx = steroids, FFP and TXA
What would your primary concern be if the patient had no teeth?
Loss of structure - easier for the airway to collapse and harder to ventilate the patient. May require on oral airway.
What is the preferred pathway for passage of nasal airway devices?
The inferior meatus (between the inferior turbinate and the floor of the nasal cavity)
What is the primary cause of upper airway obstruction during anesthesia? What maneuver would you use to overcome this and how does it work?
Loss of pharyngeal muscle tone. Chin thrust - it increases longitudinal tension in the pharyngeal muscles countering the tendency of the pharyngeal airway to collapse
What does the larynx encompass?
The epiglottis to the lower end of cricoid cartilage (C6)
What provides the most structural support to the soft tissues of the larynx?
The thyroid cartilage
What do the true vocal cords attach to?
The arytenoids and the thyroid notch
List the paired and un-paired cartilage of the larynx
Unpaired = thyroid, cricoid and epiglottis
Paired = arytenoid, corniculate and cuneiform
What is the most predictive factor of difficult intubation?
A history of past difficult intubation
What anatomical feature is more predictive than BMI at predicting a difficult airway?
A thick neck of greater than 43 cm
What teeth are most frequently injured during intubation? Why?
Upper incisors - this is where we put the laryngoscope in and these are the most prominent teeth
What are you trying to align by getting a patient into the sniffing position?
To get the oral, pharyngeal and laryngeal axis’ to align (specifically, get the LA and the PA to align and have the OA bisect the LA/PA line)
What is the goal strenomental distance?
Greater than 12.5 cm
Describe testing for prognathic ability
Bulldog test - have them stick their lower jaw out and see how far it goes, then see if the patient can bite their upper lip
Describe the basics of Mallampati I - IV (external airway evaluation)
I = fauces, pillars, entire uvula and soft palate visible
II = fauces, portion of the uvula and soft palate visible
III = base of the uvula and soft palate visible
IV = hard palate only
What are two acronyms to help guide laryngeal manipulation?
apply pressure…. BURP (backwards, upwards and rightwards pressure)
OELM (optimal external laryngeal manipulation)
Describe grades I - IV of Cormack-Lehane classification (internal airway evaluation)
I = entire glottis
II = only the posterior portion of the glottis
III = only the epiglottis is visible
IV = epiglottis cannot be seen
When does a Cormack-Lehane classification not apply?
When using fiber optic or glidescope to intubate
What basic factors can help you decide between an awake or post-induction airway strategy?
Suspected difficult laryngoscopy, suspect difficult ventilation, significant risk of aspiration, increased risk of rapid desaturation, suspect difficult emergency invasive airway (if even one of these is relevant to the patient, it may be enough to warrant an awake intubation)
On the difficult airway algorithm, there are 4 points that are highlighted as critical to accomplish, what are they?
Optimize oxygenation throughout, limit attempts (consider calling for help), consider awakening the patient after attempts, and be aware of the passage of time/call for help/ or for invasive access
What 3 scenarios in lecture were presented as examples of when to intubate early?
Neck trauma, anaphylaxis/angioedema and burn injuries.
What are some conditions that could necessitate early intubation not listed in lecture?
Airway concerns - infection, tumors, bleeds, foreign bodies
Breathing - failure to oxygenate or ventilate
Circulation - impaired oxygen delivery by unloading the muscles of respiration (think sepsis)
Disability - CNS catastrophes or CNS depression, seizures
Feral - need for prompt, aggressive sedation to protect patient and others
Describe the awake technique of intubation including drugs
Start with glyco or atropine 15 min prior, then suction/dry the mouth, administer nebulized lidocaine (give atomized into the oropharynx if unable to give via nebulizer. Viscous lidocaine also an option), preoxygenate/position, lightly sedate with versed 2 - 4 mg and/or ketamine 20 mg, then intubate awake
What is the most important factor to keep in mind with a difficult airway?
Time elapsed - your pace on each step is critical, minimize time attempting intubation.
Outline the basic steps of laryngoscopy to intubation
1) ensure all equipment is ready and pt is positioned, 2) instrument airway and identify epiglottis 3) optimize head (sniff and head tilt), 4) set blade in vallecula or on the epiglottis and lift, 5) optimize the larynx and intubate
What does the black stripe on the bougie indicate?
25 cm
What are some contraindications for Sux (there are a ton, try to hit the highlights)?
Suspected Rhabdo, hyperkalemia, neuromuscular disorder(s), burns, muscular dystrophies, patients at risk to fasciculate, MH history
What are the “big 3” that kill during intubation?
Hypoxia, hypotension and acidosis
What dosing ranges have greater than 50% excellent intubating conditions with Roc?
1.2 mg/kg or greater (higher doses = quicker onset)
Roc vs Sux wear off times?
Sux = 5-10 minutes
Roc = 30-90 minutes
Goal SBP for intubation? How can you achieve this?
SBP of 140 or greater. Sedatives low, paralytics high–> this will drive BP.
What are the 2 drugs of choice in intubation in shock?
Ketamine and Roc
What are 2 ways you can provide PEEP to a non-intubated patient?
Peep valve on a BVM, the APL valve on the anesthesia machine
What is delayed sequence intubation? What population is it used for?
Uncooperative/combative patient. Give 1 mg/kg IV ketamine -> preoxygenate -> paralyze -> once apneic, intubate
Why does giving bicarb not truly fix the problem in acidosis? How could it make it worse? What should you do to fix the acidosis?
Because it doesn’t address the underlying cause. The issue with bicarbonate is that it eventually gets turned into CO2 in the blood making acidosis worse. Instead “blow off” some of the CO2 using PPV.
