Leo- Eval of Airway Flashcards
What are the 3 unpaired larynx cartilages?
Cricoid
Thyroid
Epiglottis
What are the 3 paired larynx cartilages?
Arytenoids
Cuneiforms
Corniculate
What is the function of the PosteriorCricoArytenoids muscle?
Pull Cords apart (PCA) ***
Cricothyroid
Lengthen and stretch
VOCALIS (vocal ligament)
part of muscle that help with voice
Larynx all nerves come from
Vagus
***Most of motor function comes from the
Recurrent LARYNGEAL nerve
➢ Difficult mask ventilation
“Not possible for the unassisted anesthesiologist to prevent or reverse signs of inadequate ventilation during positive pressure mask ventilation
➢Difficult intubation
The proper insertion of an endotracheal tube using conventional laryngoscopy requires more than 3 attempts, or greater than 10 minutes”
➢Failed airway is defined as
⚫ 3 failed attempts at orotracheal intubation by a skilled provider
⚫ Failure to maintain acceptable saturations (> 90%) in otherwise normal individuals
ASA Closed Claims Database: single most important factor leading to fail airway
“Failure to evaluate the airway and predict difficulty is the single most important factor leading to a failed airway”
Incidence of Difficult Intubation by Rigid Laryngoscopy
⚫ Failed intubation 1 in 280
➢ Parturient 2.7%
Parturient and intubation
Almost 10x greater than in the nonparturient patient
➢ Major cause of injury in anesthetic practice
➢ Inadequate ventilation—largest class of adverse events
_____is especially important in patients at high risk for aspiration
Anticipation
Factors preventing a snug mask fit,
interfering with positioning of head and neck, limited opening of mouth, and narrow or distorted airway
Difficult Intubation Predictors:➢ External anatomic features
- ↓ Head/neck movement (atlanto-occipital joint)
- Jaw movement (temporo-mandibular joint), mouth opening, and subluxation of the mandible
- Receding mandible
- Protruding maxillary incisors
- Obesity
More Predictors o difficult airway
Thyromental distance <6cm or 3 fingerbreaths.
• Sternomental distance
• Visualization of the oropharyngeal structures
• Anterior tilt of the larynx
• Radiographic assessment
Mouth opening (distance between incisors) limited to
3.5 cm or less will contribute to difficult intubation
Mouth opening is limited by
Limited by: ⚫ TMJ dysfunction ⚫ Congenital or surgical fusion of the joints/ vertebrae ⚫ Trauma ⚫ Tissue contracture around the mouth ⚫ Trismus (lock jaw)
Protruding maxillary incisors can interfere with
laryngoscope placement and ETT passage
Mouth opened maximally normal
normal opening 5-6cm
➢ Class II–
base of tongue obscures tonsillar pillars, posterior pharyngeal wall visible below soft palate, uvula
➢ Class III–
only soft palate visualized (7.58 x greater chance of difficult intubation than class I)
➢ Class IV–
essentially nothing visualized, not even soft palate (11.2x greater chance of difficult intubation than class I)
Don’t Forget . . .
➢ Overbite
➢ Mobility of and ability to displace mandible
– can patient push jaw to place lower teeth
past the top teeth
⚫ May not be able to pull mandible forward far
enough to see larynx - TMJ
➢ Tongue Size
➢ Loose, chipped, or missing teeth, or dental
work
Micrognatia
No room to displace the tongue and epiglottis forward
➢ Anterior airway associated wtih ______
Micrognatia ; with the laryngoscope, the structures will be anterior to your field of view
Neck ➢ Limited Mobility -
Neck touch chin to chest, both shoulders, and extend back (normal 55 degrees) Harder to push tongue and epiglottis forward
➢ Neck circumference
> 27 inches is suggestive of difficult management
Neck: With trachea check
➢ Trachea mobility and alignment
➢ TM Less than
3 fingerbreadths is considered a receding mandible and may contribute to difficulty with intubation
➢ Rigid laryngoscopy may be impossible if
<6cm
➢ TM Measured with the
head fully extended,
between the bony part of the mentum of
the mandible and the thyroid notch
➢ TM Measured with the
head fully extended, between the bony part of the mentum of the mandible and the thyroid notch
Atlanto-occipital Mobility
Alignment of the oral, pharyngeal, and laryngeal axis required for visualization of the glottis during rigid laryngoscopy
Head has to be above the
Breast
What is responsible for the sensory and motor innervation of the larynx?
The vagus nerve (cranial nerve X), via the superior and recurrent laryngeal nerve, is
Has the highest density of touch receptors
The posterior half of the vocal cords
During bedside evaluation of Atlanto occipital mobility?
Bedside evaluation: have the patient sit straight and extend their head while maintaining a neutral cervical spine
With Atlanto occipital mobility ↓ degree of head extension indicate→
↑ possibility
for difficult intubation