Airway (2) Flashcards
What are the components of the internal nasal cavity?
Divided by septum
Cribriform plate
Turbinates
What can be used to vasoconstrict vessels in the nose?
Phenylephrine
Afrin
Lidocaine jelly
What makes up the roof of the mouth vs the floor of the mouth?
Roof:
Maxilla and palatine bones
Hard palate
Soft palate
Teeth
Floor:
Tongue
Mandible
Teeth
What is one of the primary causes for upper airway obstruction during anesthesia?
Loss of pharyngeal muscle tone
What is the pharynx?
Muscular tube (AKA throat)
Base of skull to lower border of cricoid cartilage
What are the different sections that the pharynx is divided into?
Nasopharynx
→Ends at soft palate
Oropharynx
→Soft palate to epiglottis
Hypopharynx
→Epiglottis to cricoid cartilage
Larynx is the gateway to the trachea and stretches from ___________ to lower end of _______ __________.
Epiglottis, Cricoid cartilage
Which laryngeal cartilages are unpaired?
Thyroid
Cricoid - complete ring
Epiglottis
Which laryngeal cartilages are paired?
Arytenoid
Corniculate
Cuneiform
Which laryngeal cartilage is the only one to have complete ring?
Cricoid cartilage
Trachea extends from ________ _______ _________ to ________
Inferior cricoid membrane, carina
The average adult trachea is _____cm
10-15 cm
How is tracheal cartilage shaped?
C-shaped
→Closed posteriorly by longitudinal trachealis muscle
→Anteriorly bounded by tracheal rings
What might you consider if you are worried you wont be able to adequately ventilate the patient?
Awake intubation
What is the most valuable part of patient pre assessment in regards to airway assessment?
Patient history: ask direct questions
Hx of difficult airway may report as: sore throat/jaw from prior anesthesia
What things would be concerning when asking patient history?
Past difficult intubation – most predictive factor
Report of excessive sore throat
Report of cut lip/broken tooth
Recent onset of hoarseness: subglottic stenosis
History of OSA
Lesions intra-orally…. base of tongue, lingual tonsils
Why is it important to assess submandibular space?
That is where the tissue is displaced when intubating
If the patient can slide their mandible _______, then its a good sign for intubation.
anteriorly (bottom teeth over top lip)
Neck circumference greater than ______ is a concern for difficult intubation.
> 43cm
Better predictor than BMI
Inter-incisor distance of ____ suggests possibility of difficult intubation.
2 finger breadths (<6cm)
What is the ideal inter-incisor distance we want to see?
> 6cm (3 finger-breadths)
Which common drug could cause airway issues and difficulty with intubation? How can this be treated?
ACE inhibitors–angioedema, massive tongue
Treat with FFP/TXA
What is macroglossia?
Enlarged tongue
What’s a consideration for patient that dont have teeth?
Difficult mask ventilation
25% of closed insurance claims against anesthesia providers are from ________ injuries
Dental
When do dental injuries commonly occur during anesthesia delivery?
75% occur during tracheal intubation
Difficult or emergency airway management
Laryngoscope blade
Rigid suction catheters
Oropharyngeal airway placement
Rigorous removal of airways
Biting down on ETT/LMA/airways during emergence
What is the Sniffing position? What the purpose?
Cervical flexion and atlanto-occipital extension
Aligns oral, pharyngeal, and laryngeal axis
What is being measured when assessing head/neck mobility with sternomental distance? What distance is preferred?
Distance between notch and chin
Head in full extension, mouth closed
> 12.5cm preferred
What is thyromental distance? What is the preferred distance?
Measuring from tip of chin to thyroid notch–looking at submandibular compliance
> 6.5cm (3 finger-breadths) preferred
What is prognathic ability measuring?
Extension of lower incisors beyond upper incisors (bitting upper lip)
What is the gold standard of airway tests?
Mallampati Test–external airway eval
visibility of oropharyngeal structures
What position is the patient in for the mallampati assessment?
Pt seated upright
Mouth open, tongue protruded
No phonation
How many mallampati classes are there?
1-4: 4 is the hardest airway
What is visualized in Mallampati class 1?
Fauces, pillars, entire uvula, and soft palate
What are fauces?
Arched opening at the back of the mouth leading to the pharynx
What structures are visualized with mallampati class 2?
Fauces, portion of the uvula, and soft palate
What structures are visualized with mallampati class 3?
Base of uvula and soft palate
What is seen with mallampati class 4?
Only hard palate
What mallampati class is this?
Class 1
What mallampati class is this?
Class 2
What mallampati class is this?
Class 3
What mallampati class is this?
Class 4
What is BURP laryngeal manipulation?
External pressure
B: backward
U: upward
R: rightward
P: pressure
How is optimal external laryngeal manipulation (OELM) achieved?
One person guiding the position of the tube and assistant to put pressure on the larynx
How is the Cormack-Lehane classification different from mallampati?
Cormack lehane: internal airway eval–laryngeal view
How many grades are involved with cormack-lehane classification?
Grade 1-4
CL-Grade 1:
Visualization of the entire glottis
How do pediatric airways differ from adults?
Vocal cord tissue in kids do not have calcification and will be same color as surrounding tissue (pink)
CL- grade 2:
Can only see the posterior portion of the glottis
CL-grade 3:
Can only visualize epiglottis, no part of the glottis is visible
CL_grade 4:
Epiglottis cannot be seen
CL Statistics
Criteria associated with difficult mask ventilation:
“OBESE”
O: Obesity (BMI > 30 kg/m2)
B: Beard
E: Edentulous
S: Snorer, OSA
E: Elderly, male (Age > 55)
& Mallampati 3 or 4
Predicting a difficult airway:
“BOOTS”
Beard–may need LMA
Obesity
Older
Toothless – “gather” cheek, 2 people
Sounds – snoring, stridor
What is the 3-3-2 rule?
3 finger inter-incisor distance
3 finger thyro-mental distance
2 finger between superior notch and thyroid cartilage
What does the mallampati score relate mouth opening to?
Size of tongue
Assessment to identify difficult intubation:
“LEMON”
L- Look – abnormal face, trauma, unusual anatomy
Evaluate – 3-3-2 rule
Mallampati score – I-IV, relates mouth opening to size of tongue
Obstruction/obesity – tumor, infection
Neck mobility
List of things associated with difficult airway
What factors may be clinically important to warrant an awake intubation?
- Suspected difficult laryngoscopy
- Suspected difficult ventilation with face mask/supraglottic airway
- Significant increased risk of aspiration
- increased risk of rapid desturation
- suspected difficult emergency invasive airway
Optimize ____ throughout the difficult airway algorithm
oxygenation
If an intubation attempt after induction of general anesthesia is a failure, what is the next step according to the difficult airway algorithm?
Limit attempts, consider calling for help
or
Limit attempts, and consider waking the patient up.
In the emergency pathway, if mask ventilation is not adequate and the supraglottic airway is not adequate, what should be considered?
Call for help for invasive access and attempt alternative intubation approaches as you prepare for an emergency invasive airway
What are the important features of a bougie?
- Strategically designed deflection at the tip
- self-confirming
- can intubate epiglottis-only views
- leave the laryngoscope in
- lubricate the tube, pull back and rotate if you get stuck
- black stripe is 25 cm- at lips, mid trachea in an adult male
When would you want to use ketamine for intubating?
- Reactive airways
- IM RSI
- hypotension/sepsis
When would you want to avoid using ketamine for intubating?
- If hypertension/tachycardia undesirable
- contraindication in high ICP (slowly dissolving)
What patients would you not want to use Sux?
- rhabdomyolosis
- existing hyperkalemia
- multiple sclerosis/ALS
- muscular dystrophies/inherited myopathies
- denervating injuries > 72 hours old
- burns > 72 hours old
- crush injuries > 72 years old
- tetanus, botulism, and other exotoxin infections
- severe infections > 72 hours old
- immobilization (patients found down)
What are some other problems from using Sux?
- predisposition to malignant hyperthermia
- bradycardia
- fasciculations - increased ICP, myalgias, hastened desaturation
- masseter spasm
What is the duration of action for sux and roc?
Sux: 5-10 minutes
Roc: 30-90 minutes
What are physiologic killers in intubation?
Hypotension
Hypoxemia
Metabolic acidosis
What can you do to prevent fatal hypotension?
- have at least 2 PIVs or IO if unable to get PIV
- judicious bolus of IVF wide open or vasopressor support (push dose pressors)
- shoot for a higher than normal BP before intubating if possible
(BP rarely goes up with emergent intubation)
What is the induction agent of choice in shock patients and why?
Ketamine - gives sympathetic surge and pain control
*shock itself is a powerful anesthetic
What is the paralytic of choice for shock patients and why?
Rocuronium - gives a longer safe apnea time
What meds can you use as push dose pressors?
- Epi*
- Phenylephrine
- Vasopressin
What is delayed sequence intubation?
When would you use it?
Procedural sedation for preoxygenation
In critically ill, agitated patients who are hypoxemic that need to be intubated
What can you do to prevent a patient from desaturating while trying to secure a tube?
- NC at 15 LPM + BVM at 15 LPM
- PEEP valve at 5 cm H2O
What would you consider if you are preoxygenating and can’t get the sats >95%?
Lung shunt physiology (pulmonary edema, pneumonia, etc.)
What does intervention three - back up head elevated mean?
If they can breathe in that position, leave them there. Not everyone has to lay supine
What is the first intervention to correct acidosis?
Bicarbonate therapy may not be as beneficial as we think→ giving bicarb would potentially increase CO2 levels and making things worse or causing arrythmias
Need to be able to blow off CO2 with adequate ventilation
What is the second intervention to correct acidosis?
Vapox - ventilator associated pre-oxygenation
- start with NC at 15 LPM
- then SIMV+PSV
- Vt 8 ml/kg, 100% FiO2, PS 5-10 cm H2O, PEEP 5
What situations are a high aspiration risk and what can you do to prevent it?
Upper GI bleeding, bowel obstruction, pre-induction vomiting
NGT prior to intubation, intubate in semi-upright position, bag early, but slightly less early
Initiate rescue maneuvers such as ventilation and cricothyrotomy ____ so that the paitnet has enough reserve to allow for calm and effective execution
Early
What are considered “dynamic airways”?
- Bullets (neck trauma)
- Bites (anaphylaxis/angioedema)
- Burns (thermal and caustic airway injuries)
A) Epiglottis
B) Supraglottis
C) Vocal Cords
D) Glottis
E) Subglottis
F) Esophagus
G) Trachea
H) Larynx
A) Trachea
B) Corniculate Cartilage
C) Cuneiform Cartilage
D) Epiglottis
E) Vallecula
