Airway anatomy 2 Flashcards
Which landmark is identified for a superior laryngeal nerve block?
a. greater cornu of hyoid bone
b. superior horn of thyroid cartilage
c. cricothyroid membrane
d. palatoglossal arch
a. greater cornu of hyoid bone
What must be anesthetized for awake intubation?
base of the tongue
oropharynx
hypopharynx
larynx
__________ is commonly selected to topicalize the airway
Benzocaine spray
A key risk of benzocaine spray is __________. The treatment is __________
methemoglobinemia. The treatment is methylene blue
____________ may be used to provide topical anesthesia to the airway, but you should avoid it in the patient with _________, _______________, or if _____________ is a problem.
Cocaine; PChE deficiency, on MAOI drugs, or if increased SNS tone is a problem (i.e. history of coronary artery disease)
What 3 nerves must be blocked to anesthetize the airway?
- glossopharyngeal (bilateral)
- superior laryngeal (bilateral)
- recurrent laryngeal (transtracheal)
To perform a glossopharyngeal block, insert the needle at
the base of the palatoglossal arch (anterior tonsillar pillar) to a depth of 0.25-0.5 cm, and inject 1-2 mL of LA
A risk of the glossopharyngeal block is
seizures 5%(due to intracarotid injection)
To perform a superior laryngeal nerve block, inject LA at
the inferior border of the greater cornu of the hyoid bone
To perform a transtracheal block, insert the needle through the
cricothyroid membrane (in a caudal direction). Ask the patient to take a deep breath, and then inject 3-5 mL of local anesthetic into the tracheal lumen
Is anesthetizing the mouth necessary for an awake intubation?
No
6 topical techniques to anesthetize the upper airway include
- cotton soaked pledgets in the nares-4% lidocaine+vasoconstrictor
- instill topical LA into each nare
- Swish and swallow (4% viscous lidocaine)
- LA spray- 20% benzocaine
- nebulization
- atomization- typically works better than nebulization
3 topical techniques to anesthetize the vocal cords includes
- inject LA through a nasal airway or ETT positioned just above the vocal cords
- spray as you go with a flexible fiberoptic scope
- inject LA through a multi-orifice epidural catheter that’s inserted into the suction port of a flexible fiberoptic catheter
The adult larynx lies anterior to
C3-C6
The essential components of the larynx include:
bone: hyoid
ligaments: thyrohyoid, cricothyroid
unpaired cartilages: epiglottis, thyroid, cricoid
paired cartilages: corniculate, arytenoid, cuneiform
What 2 instances may you need to place a needle through the cricothyroid membrane
cricothyroidotomy (to emergently secure the airway)
transtracheal block (to anesthetize the RLN)
During laryngoscopy, the bumps you see on the aryepiglottic folds are the
corniculates and cuneiforms (not the arytenoids)
The narrowest region in the adult airway is the
glottic opening
The narrowest region in the pediatric airway is
Narrowest “fixed” region= cricoid ring
Narrowest “dynamic” region= vocal cords
The only complete cartilaginous ring in the airway is the
cricoid
The movement of the arytenoids can be significantly restricted by
rheumatoid arthritis and systemic lupus erythematosus
Situations that increase the risk of cricoid edema include
an endotracheal tube that is too large, multiple intubation attempts, prolonged intubation, frequent head positioning while intubated
What maneuver is efficacious for the treatment of laryngospasm?
A. larson
b. valsalva
c. muller
d. bainbridge
A. Larson
Laryngospasm is the
sustained and involuntary contraction of the laryngeal musculature
Complications of laryngospasm include
airway obstruction, negative pressure pulmonary edema, pulmonary aspiration of gastric contents, cardiac dysrhythmias, cardiac arrest, and death
Signs of laryngospasm include
inspiratory stridor
suprasternal and supraclavicular retraction during inspiration
“Rocking horse” appearance of the chest wall (paradoxical movement)
increased diaphragmatic excursion
lower rib flailing
absent or altered EtCO2 waveform
Common causes of laryngospasm include
age <1 year
airway manipulation (particularly during light anesthesia)
airway secretions
surgery in the airway
active or recent respiratory tract infection (<2 weeks)
Treatment of laryngospasm includes
FiO2 100%
remove noxious stimulation
deepen anesthesia
Larson’s maneuver, chin lift, CPAP 15-20 cmH2O
Consider succinylcholine
What is the IV dose of succinylcholine for adult and children?
0.1-1 mg/kg
What is the IM dose of succinylcholine for adult and children?
4 mg/kg
What is the neonate and infant dose of succinylcholine (IV)?
2 mg/kg
What is the neonate and infant dose of succinylcholine (IM)?
5 mg/kg
__________________ should be given to children <5 years of age when succinylcholine is given.
Atropine 0.02 mg/kg
Valsalva’s maneuver is
exhalation against a closed glottis or obstruction
Examples of Valsalva’s maneuver include
coughing, bucking, or bearing down
Risk of Valsalva’s maneuver include
increased pressure in the thorax, abdomen, and brain
Muller’s maneuver is
inhalation against a closed glottis (or obstruction)
Examples of Muller’s maneuver is
patient bites down on ETT and takes a deep breath
Risk of Muller’s maneuver include
subatmospheric pressure in thorax–> negative pressure pulmonary edema
Pre-anesthetic risk factors for laryngospasm include
active or recent upper respiratory tract infection (<2 weeks)
exposure to second-hand smoke
reactive airway disease
GERD
age <1 year
Risk factors in the OR for laryngospasm include
light anesthesia
saliva or blood in the upper airway
hyperventilation/hypocapnia
surgical procedures in the airway include: tonsillectomy, adenoidectomy, nasal/sinus, laryngoscopy, bronchoscopy, palatal
