difficult airways Flashcards
A difficult airway is:
- Difficulty with mask ventilation or ventilation with SGA
- difficulty with endotracheal intubation (difficult DL)
- Or both
must investigate
a flat capnograph
if mask ventilation and SGA ventilation fail, should exclude
laryngospasm
trachea begins at
level of C6 and extends to about T5
Ophthalmic (V1) nerve
sensory:
- anterior ETHMOID
- anterior MUCOUS MEMBRANES
Maxillary (V2) nerve
Sensory:
- sphenopalatine
- POSTERIOR mucous membranes
Mandibular Nerve (V3)
Sensory:
- anterior 2/3rds of tongue
Motor:
- muscles of mastication
Glossopharyngeal Nerve (CN9)
sensnory:
- Roof of pharynx
- tonsils
- under surface of palate
- Posterior 1/3 of tongue
Superior Laryngeal Nerve (SLN)
Superior Laryngeal Nerve (SLN)
External -
sensory:
- Below epiglottis
motor:
Cricothyroid muscle (cords tense)
Superior Laryngeal Nerve (SLN)
internal -
sensory:
- to laryngeal mucosa - blocked in awake intubation
SLN sensory innervation:
external branch: below epiglottis
internal branch: laryngeal mucosa
Recurrent Laryngeal Nerve
Recurrent Laryngeal Nerve
Sensory:
- below vocal cords
Motor:
- all INTRINSIC muscles of the larynx except cricothyroid muscles (“cords tense” -> SLN”)
- includs posterior cricoarytenoid.
Injury to SLN
- voice hoarseness
- motor: cricothyroidarytenoid “cords tense”
Injury to RLN
- unilateral: hoarseness
- bilateral: r/f partial or total occlusion of vocal cords
Hypoglossal N (CN12)
motor:
- all intrinsic and extrinsic muscles of the tongue
- except PALATOGLOSSUS (vagus)
Complications r/t Pierre-Robin Syndrome
Complications r/t Pierre-Robin Syndrome
- micrognathia
- macroglossia
Treacher-Collin’s Syndrome Airway Effects
Treacher-Collin’s Syndrome
- auricular defects
- ocular defects
- malar/manidublar hypoplasia
Goldenhar’s Syndrome Airway Effects
Goldenhar’s Syndrome Airway Effects
- Auricular defects
- ocular defects
- malar/mandibular hypoplasia
Down’s syndrome airway effects
Down’s syndrome airway effects
- Poorly developed or absent bridge of nose
- macroglossia
- Small mouth
- atlanto-axial instability
- small subglottic diameter - subglottic stenosis
Klippel-Feil Syndrome Airway Defects
Klippel-Feil Syndrome Airway Defects
- congenital fusion of a variable number of cervical veretebrae - cervical spine abormality
- limited ROM
- small-underdeveloped mandible
Turner Syndrome Airway Effects
Turner Syndrome Airway Effects
- frequent/complex abnormality affecting women.
- short neck
- maxillary/mandibular hypolasia
epiglottitis
- bacterial infection of epiglottis,
- may lead to emergent airway,
- potentially life threatening.
Croup
- viral mediated inflammation
- may see “steeples sign” on CXR
- laryngeal edema
- airway irritabiltiy
Ludwig’s Angina
- Abcess in the floor of the mouth under the tongue
- edema/obstruction/distortion of airway/trismus
Acromegaly Airway Considerations
- macroglossia
- hypertrophy of laryngeal tissue
Hemtoma an airway risk with
- thyroidectomy
- tonsillectomy
- neck dissection
short thyromental distance
<6 cm = anterior airwa, difficult intubation
class IIa is associated with
4.3-13.4% risk of difficult intubation
class IIb is associated with
class III is associated witih
80-87% chance of difficult intubation
glossopharyngeal nerve block abolishes
airway reflexes
Glossopharyngeal Nerve Block Anesthetizes
Glossopharyngeal Nerve Block Anesthetizes
- the posterior 1/3 of the tongue
- oropharynx
- laryngopharunx up to the valleculae
- anterior surface of epiglottis
- ABOLISHES GAG REFLEX.
Glossopharyngeal Block
intra-oral approach
Glossopharyngeal Block
intra-oral approach
- block at the base of the palatoglossus and palatopharyngeal folds
- need sufficient mouth opening
- need 25 g needle, position INFERIOR to tonsillar pillars
- 1-2 mls of 2% lidocaine
Glossopharyngeal Nerve Block
Peristyloid Approach:
Glossopharyngeal Nerve Block
Peristyloid Approach:
- posterior to styloid process (external)
- close proximity to INTERNAL carotid
- 5-7 mL of 2% lidocaine
“peristyloid approach aims to infiltrate LA just porior to the styloid process where the glossopharyngeal nerve lies”
Superior Laryngeal Nerve Block
anesthetizes
Superior Laryngeal Nerve Block
- anesthetizes
- external SLN: sensory below epiglottis above vocal cords
- internal: laryngeal mucosa
SLN block approach
Direct RLN blocks are
not performed as these would result in bilateral vocal cord paralysis and airway obstruction as botht motor and sensory fibers run together.
Upsher laryngoscope blade
- is for adults only
- fits 7-8 ETT
- fixed curve with lighted channel
- good for small mouth openings (15 mm)
- requires MINIMAL head manipulation
- can be used for awake intubation
- insert horizontal then turn vertical
- RIGID, fiberoptic laryngoscope
criteria for “difficult mask” ventilation
- inability for one anesthesia provider to maintain saO2 >92%
- Significant gas leak around mask
- Need for >4L of gas flow
- or need of FGF button more than 2x
- No perceptible chest rise
- Two handed mask required
- >20-25 cm H2O pressure to inflate the lungs
- Change of operator required
“Incidence of DMV varies from 0.08 to 0.15%, varies due to absence of universally accepted defintion of DMV”
- varies due to absence of accepted defintition, provider experience, reporting, diverse populations
Risk factors for DMV
- prence of beard
- edentulous
- Higher BMI
- Male gender
- Age >55
- Hx of snoring/OSA
- Increased neck circumferences
- Hx of difficult intubation
- Mallampati 3/4
- severely limited jaw portrusion
combitube
“king tube”
- ONLY for ADULTS
- twin lumen device designed for emergency situations and difficult airways (EMTs in field)
- Can be inserted without the need for visualization into the oropharynx
- Usually enters the esophogus
- Low volume inflatable distal cuff
- Much larger proximal cuff designed to occlude the oro-pharynx
- If the tube has entered the trachea, ventilation is achieved through distal lumen.
- Enters the esophogus and ventilation is achived through multiple proximal aperatures situated above the distal cuff-proximal and distal cuffs have to be inflated to prevent air from esacping through the esophogus or back out of the oro and nasopharynx.
- Does not allow for long term airway control
combietube sizes
- 37F: patient below 5’
- 41F: patient above 5’
combitube balloons
- distal, small, 15 mLs of air - WHITE
- proximal (blue), large, 85 mLs of air
Insertion of combietube
- pt supine with neutral head alignment
- use left hand for chin life and insert the combietube until the upper incisors are between the two black lines
- Inflate the distal (white) cuff with 12 mLs of air.
- attempt to ventilate, if breath sounds - tracheal
- no breath sounds, inflate proximal cuff, 50-75 ml of iar
- listen for breath sounds
- confirm with capnography
Complications of combietube
- sore throat
- dysphagia
- upper airway damage
- esophogeal rupture (rare)
- increased stress response
- needs to be replaced with ETT to fully protect airway
Relative Contraindications to Emergent Airways
- fracture to larynx
- Laryngotracheal disruptions
- Transection of the trchea
- Young children <12
Transtrachel jet ventilation
- connect to O2 osurce, to DISS not machine
- open flow regular 1/2 turn
- adjust pressure regulator to 20-20 PSI
- attach catheter airway device,
- 15-20 breaths perminute, 1:3 or 1:4 ratio
Increased extubation complications associated with
- Paradoxical Vocal Cord movement
- Thyroid surgery
- Tracheomalacia
- Diagnostic Laryngoscopy
- Uvulopalatoplasy
- Sleep apnea
- Maxillofacial trauma
- parkinson’s disease
- RA
- inadequate protective airway reflexes
- prolonged prone or trendelenberg
- anaphylaxis
extubation criteria
- vital capacity >10mL/kg
- peak negative IF -20 cm H2O
- Tidal volume > 6mL/kg
- TOF ratio >70%
- Aa gradient <350
retrograde intubatino is C/I in pts
with infection above the level of the trachea
syndromes with macroglossia
- big -> Beckwith
- tongue -> Trisomy 21
Syndromes with small mandibles
Micrognathic:
- “Please” - Pierre-Robin
- “Get” - Goldenharr
- “That” - Treacher Collins
- “Chin” - Cru di chat
Syndromes with Cervical Spine Anomaly
- “kids” - Klippel-Fiel
- “Try” - trisomy 21
- “Gold” - Goldenhar
Complicatoins r/t Treacher Collins
- micrognathia - manidublar hypoplasia
- small mouth
- nasal airway is blocked - choanal atresia
- ocular and auricular anomalies
Cri du Chat airway effects
- small, underdeveloped mandible, mandibular hypoplasia
- laryngomalacia
- stridor
Max PPV pressure with LMA
20 cm H2O
Max LMA cuff pressure
40-60 cmH2o
tendency of airway device placement to activate the SNS
- combitube (most likely)
- DVL
- Fiberoptic intubation
- LMA
when to use a bougie
- with grade III CL view - best time
- with grade IIb CL view - next best time
Should NOT use bougie wiht grade IV CL view - success rate is unacceptably low
palattoglossus muscle is innervated by
vagus nerve
