Airway Management Flashcards
The upper airway consists of the _____.
pharynx, nose, mouth, larynx, trachea, and mainstem bronchi
Functions of the upper airway
warms and humidifies air, filters particulates and prevents aspiration
The nose leads to ____.
the nasopharynx
The mouth leads to ____.
the oropharynx
The epiglottis prevents _____.
aspiration by covering the glottis during swallowing
The larynx is composed of _____.
nine total cartilages
3 unpaired
3 paired
What are the 3 unpaired cartilages of the larynx?
- Thyroid
- Cricoid
- Epiglottis
What are the 3 paired cartilages of the larynx?
- Arytenoids
- Corniculates
- Cuneiforms
The thyroid cartilage shields the _____.
conus elasticus, which forms the vocal cords.
The trigeminal nerve provides ____.
general sensation to the anterior two-thirds of the tongue
The glossopharyngeal nerve is AKA ____ and provides ____.
cranial nerve IX and provides general sensation to the posterior one-third of the tongue, the roof of the pharynx, the tonsils and the undersurface of the soft palate.
The vagus nerve is AKA __ and provides ___.
cranial nerve X and provides sensation to the airway below the epiglottis.
What are the branches of the vagus nerve?
1) The superior laryngeal
2) The recurrent laryngeal nerve
The superior laryngeal is a branch of the _____ divides into ____.
branch of the vagus nerve
an external (motor) nerve and an internal (sensory) branch.
*The internal branch provides sensory supply to the larynx between the epiglottis and the vocal cords.
The recurrent laryngeal nerve innervates ____.
the larynx below the vocal cords and the trachea.
The muscles of the larynx are innervated by the ___.
recurrent laryngeal nerve, with the exception of the cricothyroid muscle, which is innervated by the external (motor) superior laryngeal nerve
Muscles that tense and relax the vocal cords
CricoThyroid: “Cords Tense”
ThyroaRytenoid: “They Relax”
Muscles that abduct and adduct the vocal cords
Posterior CricoArytenoid: “Please Come Apart”
Lateral CricoArytenoid: “Let’s Close Airway”
Damage to the External Branch of the Superior Laryngeal Nerve
Damage to the external laryngeal nerve may paralyze the cricothyroid muscle.
This impacts the vocal cords’ ability to tense and produces a raspy voice.
Unilateral Recurrent Laryngeal Nerve Damage
This injury is characterized by hoarseness and a paralyzed cord that assumes an intermediate position (midway between abduction and adduction).
This is the most common injury after subtotal thyroidectomy.
Bilateral Recurrent Laryngeal Nerve Damage
This injury results in paralyzed cords and aphonia.
Each paralyzed cord assumes an intermediate position (midway between abduction and adduction).
The cords can flop together causing airway obstruction during inspiration which requires immediate intubation.
The trachea begins ____.
beneath the cricoid cartilage and extends to the carina, the point at which the right and left mainstem bronchi divide.
How many cm above the carina should an ETT be placed?
5-7 cm
The ETT is more likely to advance in the ___.
right bronchus than the left bronchus
Anteriorly, the trachea consists of ____.
cartilaginous rings; posteriorly, the trachea is membranous.
Components of GA airway management
- Preanesthetic airway assessment
- Preparation and equipment check
- Patient positioning
- Preoxygenation (denitrogenation)
- Bag and mask ventilation
- Intubation or placement of a laryngeal mask airway (if indicated)
- Confirmation of proper tube or airway placement
- Extubation
Standard Preanesthetic Assessment includes
- Mouth opening: an incisor distance of 3 cm or greater is desirable in an adult.
- Thyromental distance: This is the distance between the mentum (chin) and the superior thyroid notch. A distance greater than 3 fingerbreadths is desirable.
- Neck circumference: A neck circumference of greater than 17 inches is associated with difficulties in visualization of the glottic opening.
- Prominent overbite, neck ROM, shape of palate
- Mallampati classification: a frequently performed test that examines the size of the tongue in relation to the oral cavity. The more the tongue obstructs the view of the pharyngeal structures, the more difficult intubation may be.
Mallampati classification
Class I - The entire palatal arch, including the bilateral faucial pillars, is visible down to the bases of the pillars.
Class II - The upper part of the faucial pillars and most of the uvula are visible.
Class III - Only the soft and hard palates are visible.
Class IV - Only the hard palate is visible.
Indications of Difficult Bag Mask Ventilation
- Mask seal impeded by beards, anatomy, or nasogastric tube
- Obstruction of upper or lower airway
- Obesity with redundant upper airway soft tissue
- Age greater than 55 r/t loss of upper airway elasticity
- Absence of teeth
- Decrease lung elasticity
- Obstructive sleep apnea or snoring
Pneumonic = “BONES” Beard, obstruction, no teeth, elderly, sleep apnea
Indications of Difficulty with Direct and Video Laryngoscopy with Tracheal Intubation
- Evaluate the 3-3-2 rule
- Mallampati score (classes III and IV indicating increased difficulty)
- Obstruction of the upper airway
- Obesity with increased neck circumference and redundant soft tissue
- Scarring, radiation, or masses on the neck
- Neck mobility that is impaired by disease of immobilization
“LEMON”
Look externally face shape, obesity, face and neck pathology
Evaluate 3 3 2
Mallampati
Obstruction
Neck mobility
Indication of Difficulty With Supraglottic Airway Device Placement and Ventilation
Restricted mouth opening
Obstruction of the upper airway
Distortion of airway anatomy preventing an adequate seal
Stiff lungs (e.g., increases in airway resistance or decreases in pulmonary compliance)
Pneumonic = RODS
Indication of Difficulty With Cricothyrotomy Airway Placement
- Distortion of neck anatomy (e.g., hematoma, infection, abscess, tumor, scarring from radiation)
- Obesity or a short neck limiting cricothyroid identification
- Trauma in or around the cricothyroid area
- Impediments causing limited access to the neck (e.g., halo device, fixed flexion abnormality)
- Surgery causing limited access to anatomic landmarks
Pneumonic = SHORT (surgery, hematoma, obesity, radiation, tumor/trauma)
What equipment should be routinely available for airway management?
- An oxygen source
- Capability to ventilate with bag and mask
- Laryngoscopes (direct and video)
- Several ETTs of different sizes with available stylets and bougies
- Other (not ETT) airway devices (eg, oral, nasal, supraglottic airways)
- Suction
- Pulse oximetry and CO2 detection
- Stethoscope
- Tape
- Blood pressure and electrocardiography (ECG) monitors
- Intravenous access
Preoxygenation before anesthetic induction and tracheal intubation
designed to increase the body oxygen stores and thereby delay the onset of arterial hemoglobin desaturation during apnea.
the need for preoxygenation is desirable in all patients
routine preoxygenation before the tracheal extubation has also been recommended
End points of maximal preoxygenation (efficacy) would be ____.
an end-tidal oxygen concentration of 90%
The sniffing position can help ____.
align the oral, laryngeal and pharyngeal axises
Patients with morbid obesity may have ____.
redundant tissue of the back and require a ramp to align these axises
Which patients must remain in a neutral position?
Those with unstable cervical spines and/or in c-collars
Which scenarios would NOT include bag mask ventilation?
patients undergoing rapid sequence intubation or elective awake intubation
Effective mask ventilation requires both ____.
1) a sealed mask fit, and 2) a patent airway; and will result in chest rise, end-tidal CO2 detected condensation in the clear mask