Airway Management Flashcards
Definition of difficult mask ventilation
Inability to maintain O2sat > 90%
Inability to prevent/reverse signs of inadequate ventilation
Definition of difficult intubation/laryngoscopes
Successful intubation requiring more 3 attempts or taking longer than 10min
What innervates the hard and soft palate?
Palantine nerves
Innervation of the anterior 2/3 of tongue
Lingual n.
From mandibular branch of trigeminal
Innervates the posterior 1/3 tongue, soft palate, and oropharynx
Glossopharyngeal
What demarcates the border between the oropharynx and the hypopharynx?
Epiglottis
What separates the nasopharynx from the oropharynx
Soft palate
What innervates the hypopharynx?
Vagus via superior laryngeal n
Tongue obstruction during anesthesia is due to relaxation of which tongue muscle?
Genioglossus
Between what levels of cervical vertebrae does the larynx reside?
C3-C6
What is the function of the larynx?
Separate trachea from esophagus
Describe the areas of the larynx
Epiglottis Supra glottis Vocal cords Glottis Subglottis
What ligaments form the vocal cords?
Thyroarytenoid ligaments
What is the narrowest part of the adult airway
Vocal cords
Anatomical points where the trachea starts and ends
From C6 to carina
Carina overlies T5
10-15cm long
Nonreassuring interincisor distance?
<3 cm
Difficult Airway Algorithm:
Assess the likelihood and clinical impact of basic management problems: (A-D)
A. Difficult ventilation
B. Difficult intubation
C. Difficulty with pt cooperation or consent
D. Difficult tracheostomy
Difficult Airway Algorithm:
What’s step 2?
Actively pursue opps to deliver supplemental O2
What is Step 3 of the Difficult Airway Algorithm?
Consider the relative merits/feasibility of basic mgt choices:
A. Awake or GA intubation?
B. Noninvasive or invasive?
C. Spontaneous ventilation or not?
You induce GA and still can’t intubate. What now?
Difficult Airway Algorithm:
- Call for help
- Consider returning spontaneous V
- Awaken pt
You induce GA and can’t intubate and now can’t bag mask. What now?
Difficult Airway Algorithm:
Consider/attempt LMA
Induce GA and can’t intubate and now can’t place LMA now what?
Call for help if haven’t already
Emergency pathway!
Either noninvasive or invasive
How do you confirm successful intubation or LMA placement?
EtCO2
Watch for awhile in case it was a puff of gastric gases could imitate
PCO2 > 30 for 3-5 consecutive breaths
Symmetrical chest rise
Bilateral equal breath sounds
Fogging of tube
How to check neck ROM?
“Can you touch your chin to your chest?”
“How far can you bend your neck back?”
Mallampati System
System to correlate the oropharyngeal space with ease of intubation
How do you check Mallampati score?
Eye level
Open mouth maximally w/ head in neutral position
Protrude tongue W/O phonating
Class I Mallampati
TONSILLAR PILLARS visible
+ soft palate, uvula
Class II Mallampati
No tonsillar pillars but can still see uvula
Class III Mallampati
Only base of uvula visible
Class IV Mallampati
Soft palate not visible
What is the Cormack and Lehane score?
Correlate laryngoscopic view with oropharyngeal space
Why should you never use nasotracheal intubation in basilar skull fractures?
Can result in intracranial tube placement
Airway considerations for lower airway tumors (trachea, bronchi, mediastinal)
Airway obstruction may not be relieved by tracheal intubation
Airway considerations for radiation management
Fibrosis may distort the airway or make manipulation difficult
Airway considerations for Rheumatoid Arthritis
TMJ arthritis Immobile cervical vertebra Laryngeal rotation Cricoarytenoid arthritis Mandibular hypoplasia
Why do you need flexion of the NECK and extension of the HEAD?
Flex neck to align pharyngeal and laryngeal axes
Extend head on AA to align oral and pharyngeal
= sniffing position
Less than ideal thyromental distance
< 6-7cm
Receding mandible
Short neck
= more acute angle between oral and pharyngeal axes, harder to bring to alignment
What is the end point of the difficult airway algorithm?
Emergency invasive access
Cricothyrotomy
Describe anatomical landmarks for a cricothyrotomy
Find thyroid cartilage
Slide down to locate membrane right below
Inability to intubate is not the biggest problem. What is?
Inability to oxygenate or ventilate
Aspiration complications
Combo of these factors
Predictors of Difficult Facemask Ventilation:
What age?
> 55 yo
Predictors of Difficult Facemask Ventilation:
What BMI?
> 26 BMI
Predictors of Difficult Facemask Ventilation:
What gender?
Make
Predictors of Difficult Facemask Ventilation:
What facial factors?
Beard
Lack of teeth
Limited ability to protrude mandible
Predictors of Difficult Facemask Ventilation:
List 4 more factors
History of snoring
Repeated attempts at laryngoscopy
Mallampati III and IV
Neck radiation
Describe the placement of the facemask during bag ventilation
Upper border of the facemask should align with the pupils
Sides seal nasolabial folds
Bottom between lower lip and chin
DAWD
Preoxygenation allows for Duration of Apnea Without Desaturation
What is the ideal minute ventilation for O2 in an adult with IBW?
3mL/kg/min
T or F: DAWD is a function of MVO2 and the O2 reservoir of the FRC (~30-35 mL/kg)
T
What parameter indicates sufficient preoxygenation?
EtO2 > 90%
Ideally 3min
A healthy non-obese patient can maintain a SaO2 >90% for how long after preoxygenation?
~8.5min
Obesity can severely decrease DAWD. What measures can you take to address this?
100% O2 head up
10cm CPAP
Followed by PPV
(Set at peak P 14cm, PEEP 10)
This can increase DAWD another min or so
Decreases atelectasis and improves mismatch
Grabbing mask and face and doesn’t seem like air is passing through? What issue with hand placement
Make sure your L hand is not compressing airway (not mashing mask into face) instead using fingers to pull up
What is your R hand doing during bag mask ventilation?
Generating positive pressure by compressing reservoir bag
ventilating P should not exceed 20 to not insufflate stomach
List indications for endotracheal intubation
Patent airway Prevent aspiration Facilitate positive P ventilation Operative position other than supine Operative site near upper airway Mask airway difficult Need for frequent suctioning
Ideal height of table for intubation
Bottom of table at belly button
Face near your xiphoid when standing
Describe Sellicks Maneuver
Cricoid pressure
Downward pressure with your THUMB and INDEX finger
Compress esophagus to prevent aspiration
30 Newtons of Force
Endotracheal tube sizes are based on what?
Internal diameter
Available in 0.5 increments
Indications for fiber optic intubation?
When difficult intubation by direct laryngoscopy is anticipated
- can be done awake to elim risk of failed intubation and ventilation
Unstable cervical spines
- allows for assessment of neuro fxn
Upper airway trauma
Contraindications of fiber optic intubation?
Lack of time
Anything that impinges size of airway to prevent visualization
Excessive blood and secretions
Pharyngeal abscess
- don’t want aspiration of purulent material
Style points for fiber optic intubation
Antisialogogue (Glyco 0.2mg IV) Lidocaine spray GP nerve blocks (2 mL 2% lido inject @ depth 0.5 cm)
In tracheal extubation what are some signs of light anesthesia?
Disconjugate gaze
Breath holding or coughing
Not responsive to commands
= inc risk of laryngospasm
