Airway Assess & Equipment Flashcards
Mallampati I
Class 1
Pillars, uvula, soft palate, & hard palate
Mallampati II
Class 2
Uvula, soft palate, & hard palate
Mallampati III
Class 3
Soft & hard palate ± partial uvula
Mallampati IV
Class 4
Only hard palate
Inter-Incisor Gap
Normal 4-6 cm
What factors contribute to limited mouth opening?
Buckteeth
Arthritis
Scar tissue
Temporomandibular joint disease
Prior surgery
Thyromental Distance
Helps to estimate the submandibular space
Normal > 6 cm
Submandibular space borders = mentum (superior), hyoid bone (inferior), & neck (lateral)
Mandibular Protrusion Test
Upper lip bite test
Temporomandibular joint function
Mandibular Protrusion Test
Class 1
Patient can move lower incisor past upper incisor & bite the lip vermilion
Mandibular Protrusion Test
Class 2
Patient able to move lower incisor inline w/ upper incisor
Mandibular Protrusion Test
Class 3
Patient cannot move lower incisor past the upper incisor (indicates potential difficult intubation)
Atlanto-Occipital Joint Mobility
Ability to place patient in the sniffing position
What conditions impair atlanto-occipital mobility?
Degenerative joint disease, arthritis, RA
Ankylosing spondylitis
Trauma or surgical fixation
Down syndrome
Klippel-Feil
Diabetes mellitus
Cormack & Lehane
Grade 1
Complete or near complete view of the glottic opening
Cormack & Lehane
Grade 2
Posterior region of the glottic opening
Unable to see the anterior commissure
Cormack & Lehane
Grade 3
Epiglottis only
Unable to see any part of the glottic opening
Cormack & Lehane
Grade 4
Soft palate only
Unable to see any part of the larynx
When to consider a bougie?
Grade 2B or 3
Difficult Mask-Ventilation Indicators
BONES
- Beard (mask seal)
- Overweight/obese BMI > 26 kg/m^2
- No teeth (edentulous)
- Elderly > 55 yo
- Sleep apnea OSA
Difficult Laryngoscopy & ETT Intubation Indicators
LEMON
Small mouth opening
Long incisors
Prominent overbite
High, arched palate
Mallampati class 3 or 4
Retrognathia
Inability to sublux jaw
Short, thick neck (obesity)
Reduced cervical mobility
Short thyromental distance
Difficult Video Laryngoscopy Indicators
Neck pathology - radiation, tumor, or previous surgery
Short thyromental distance
Limited cervical ROM or mouth opening
Class 3 upper lip bite test
Difficult Supraglottic Airway Placement Indicators
Limited mouth opening
Upper airway obstruction
Altered pharyngeal anatomy
C-spine
Poor lung compliance
↑airway resistance
Lower airway obstruction
Difficult Invasive Airway Placement
Abnormal neck anatomy - tumor, hematoma, abscess, radiation history
Surgery or previous scar
Obesity
Short neck
Laryngeal trauma
Limited access to the cricothyroid membrane (Halo or neck flexion deformity)
NPO Guidelines
Clear liquids 2 hours
Breastmilk 4 hours
Non-human milk, infant formula, or solid food 6 hours
Fried or fatty foods 8 hours
Mendelson Syndrome
Gastric content aspiration → pneumonia
Risk factors include gastric volume > 25 mL or 0.4 mL/kg + pH < 2.5
RSI Cricoid Pressure
Apply pressure to the cricoid ring C5 vertebrate
How much pressure to apply during RSI?
Before LOC 20 Newtons or ≈ 2 kg
After induction 40 Newtons or ≈ 4 kg
What are cricoid pressure complications?
Airway obstruction
Difficult DL and/or intubation
Impaired glottic visualization
↓LES pressure
Esophageal rupture (w/ active vomiting)
Angioedema
↑vascular permeability → face, tongue, & airway swelling
1° concern = upper airway obstruction
Angioedema Cause
Anaphylaxis
ACEi prevent bradykinin breakdown
Hereditary C1-esterase inhibitor deficiency
Angioedema Treatments
- Anaphylaxis mast-cell mediated → Epi, antihistamines, & steroids
- Discontinue ACEi → bradykinin receptor antagonist, plasma kallikrein inhibitor, FFP, & C1 esterase concentrate
- C1-esterase inhibitor deficiency → C1 inhibitor concentrate, FFP, & prophylaxis prior to upper airway procedures or tracheal intubation
Ludwig’s Angina
Bacterial infection characterized by rapidly progressing cellulitis in the floor of the mouth
Inflammation & edema compress the submandibular, submaxillary, & sublingual spaces
What’s the 1° concern w/ Ludwig’s angina?
1° concern = posterior tongue displacement resulting in complete, supraglottic airway obstruction
How to secure the airway in a patient w/ Ludwig’s angina?
Best way to secure the airway = AWAKE nasal intubation or tracheostomy
Retrograde intubation contraindicated in patients w/ an infection above the trachea***
What congenital conditions are associated w/ difficult airway management?
Beckwith syndrome
Trisomy 21
Pierre Robin
Goldenhar
Treacher Collins
Cri du chat
Klippel-Feil
What nerve injury can result from an aggressive jaw thrust or excessive traction at the mandibular angle?
Facial nerve stretch
What nerve injury can result from face straps being too tight?
Facial nerve 7
- Buccal branch
What nerve injury can result from an ETT connector resting on the patient’s face?
Supraorbital nerve compression
How does facial nerve stretch present?
Affected side sagging, drooling, & mastication affected
How does facial nerve compression to the buccal branch present?
Patient has difficulty opening & closing lips
Orbicularis oris muscle function impaired
How do OPA & NPAs function?
Open the airway by displacing the tongue & epiglottis from the posterior wall
How to measure OPAs:
Measure from the mouth corner to the earlobe or mandibular angle
The flange should protrude outside the lips & the pharyngeal end should rest at the tongue base
OPA Types
- Guedel
- Berman
- Williams
- Ovassapian
How to measure NPAs:
Measure from the are to the earlobe or mandible angle
What are contraindications to NPAs?
Cribiform plate injury
- LeFort 2 or 3 fracture
- Basilar skull fracture
- CSF rhinorrhea
- Raccoon eyes
- Periorbital edema
Coagulopathy
Previous trans-sphenoid hypophysectomy
Previous Caldwell-Luc procedure
Nasal skull fracture
BURP Maneuver
Backward
Upward
Rightward
Pressure
High-Volume, Low-Pressure Cuff
High cuff compliance
Manometer to measure internal pressure
Easy to pass things around the cuff (esophageal stethoscope, OT tube, temp probe)
Less protection against aspiration
Low-Volume, High-Pressure Cuff
Low cuff compliance
Better protection against aspiration
Lower sore throat incidence
Easier visualization during intubation
Prolonged intubation → tracheal ischemia
Pediatric ETT Equations
Cuffed ETT = [Age (years) / 4] + 3.5
Uncuffed ETT = [Age (years) / 4] + 4
Video Laryngoscopy Types
Non-channeled
Channeled
Acute-angle blade
Non-Channeled Video Laryngoscopes
Glidescope
C-MAC
McGrath
Channeled Video Laryngoscopes
Airtraq avant
Pentax AWS
King vision
Acute-Angle Blade Video Laryngoscopes
Glidescope LoPro
C-MAC D-blade
McGrath X-blade
LMA Types
Classic
ProSeal or Supreme
Fastrach
C-Trach
Flexible
iGel
Classic LMA
Max Pressures
MAX PIP pressure = 20 cmH2O
MAX cuff pressure = 60 cmH2O
What most commonly causes nerve injury w/ LMAs?
Cuff overinflation
Also increases sore throat & pharyngeal necrosis risk
What nerves are at risk for injury w/ LMA use?
- Lingual
- Hypoglossal
- RLN
What do the aperture bars on LMAs prevent?
2 aperture bars prevent the epiglottis from obstructing the airway
LMA Anatomical Borders
Superior = tongue base
Lateral sides = piriform sinus
Inferior = upper esophageal sphincter
LMA 1
< 5 kg
Cuff 4 mL
ETT 3.5 mm
Flexible endoscope 2.7 ID mm
LMA 1.5
5-10 kg
Cuff 7 mL
ETT 4.0 mm
Flexible endoscope 3.0 ID mm
LMA 2
10-20 kg
Cuff 10 mL
ETT 4.5 mm
Flexible endoscope 3.5 ID mm
LMA 2.5
20-30 kg
Cuff 14 mL
ETT 5.0 mm
Flexible endoscope 4.0 ID mm
LMA 3
30-50 kg
Cuff 20 mL
ETT 6.0 mm
Flexible endoscope 5.0 ID mm
LMA 4
50-70 kg
Cuff 30 mL
ETT 6.0 mm
Flexible endoscope 5.0 ID mm
LMA 5
70-100 kg
Cuff 40 mL
ETT 7.0 mm
Flexible endoscope 5.5 ID mm
LMA ProSeal
Double lumen LMA
Gastric drain tube, large mask, & built-in bite block
Max PIP < 30 cmH2O
LMA supreme = disposable version
LMA Fastrach
Intubating LMA w/ specially designed ETT (uses high-pressure cuff)
Metal handle
Tube pusher
Epiglottic elevating bar
LMA C-Trach
Similar to Fastrach but includes a camera
LMA Flexible
Flexible airway tube
Wire-reinforced
Longer & narrower than LMA classic
Used w/ head & neck surgery
iGel
Supraglottic airway alternative to the LMA
No inflatable cuff
Gastric port
No aperture bars
MRI safe
iGel Complications
Tongue trauma
Cricoid cartilage mucosal erosion
Trachea compression
Nerve injury
Airway obstruction
Regurgitation & aspiration
Most to least stimulating airway device placement & SNS stimulation
- Combitube (most)
- DVL
- Fiberoptic intubation
- LMA (least)
LMAs + Laparoscopy
Select an LMA that allows gastric drainage
Normal BMI
Avoid light anesthesia
< 15° tilt < 15 cmH2O intraabdominal pressure < 15 minutes insufflation
Combitube
Supraglottic double lumen device
Blindly placed in the hypopharynx
Combitube Cuffs
Proximal oropharyngeal cuff (blue port) occludes the hypopharynx 50-85 mL
Distal cuff (white port) occludes the esophagus 5-15 mL air INFLATE 1st!
Combitube Sizing
Based on patient height
4-6’ = size 37
> 6’ = 41
Combitube Benefits
Provides a secure airway (aspiration protection)
Ability to decompress the stomach
Useful in the obese population
Does not require neck extension
Allows high ventilatory pressures
Does not need to be taped
Combitube Contraindications
Intact gag reflex
Use > 2-3 hours (ischemia risk from the oropharyngeal balloon)
Esophageal disease = Zenker diverticulum
Caustic substances ingestion
King Laryngeal Tube
Similar to Combitube
Inserted blindly
Single ventilation lumen
Child-size devices are available
- Minimum weight 10 kg
King LTS-D (disposable) 2nd lumen allows gastric tube to suction the stomach
King Laryngeal Tube Cuffs
Only one inflation port
Simultaneously inflates both the proximal & distal cuffs
Flexible Fiberoptic Bronchoscope
Difficult airway gold standard = awake fiberoptic
Non-dominant hand = holds the scope near the proximal end & thumb controls the lever
Dominant hand = holds the cord
Pushing the lever ↓down flexes the tip ↑UP
Pushing the lever ↑up extends the tip ↓DOWN
Rotation L or R allows to control the scope in the horizontal plane
What are the best drug choices to facilitate awake fiberoptic bronchoscopy?
Short DOA and/or minimal respiratory depression
Midazolam
Dexmedetomidine
Ketamine
Remifentanil
Bullard Laryngoscope
Rigid fiberoptic device
Indirect laryngoscopy
Adult & pediatric patients
Disposable tip extender available (tall patients)
Maintain head in neutral or slightly flexed position
Lubricate the stylet
Lift handle to straight up (90° angle to the spine) to expose the glottic opening
What patients are ideal candidates to use the Bullard laryngoscope?
Small mouth openings (minimum 7 mm)
Impaired cervical spine mobility - do not need to align OPL axes
Short, thick neck
Congenital airway syndromes (Pierre Robin or Treacher Collins)
What are absolute contraindications to the Bullard Laryngoscope?
NONE
Rigid Fiberoptic Laryngoscopes
Bullard
WuScope
UpsherScope
Intubating Stylet
Eschman introducer
Gum elastic BOUGIE
Coudé angled tip
When to use bougie?
Cormack & Lehane 2B or 3 view
How to confirm bougie placement?
Tracheal rings
Advance the tip into the trachea 23-25 cm
What does encountering resistance w/ the bougie indicate?
Hold-up sign at the carina
35-40 cm
Lighted Stylet
BLIND intubation technique
Illuminates the anterior neck
Lighted Stylet (+) Pros
Anterior airway
Small mouth opening
Minimal neck manipulation
Less stimulating than DVL
Sore throat less common
Cervical spine abnormality
Pierre Robin
Severe burn contractures
Lighted Stylet (−) Cons
Difficult to use in patients w/ short, thick neck
Obese patients ↑adipose tissue
More false positive possible in children
NOT an emergency airway technique
Blind technique - do not use w/ tumor present, foreign body, airway injury, or epiglottitis
Traumatic laryngeal injury
What angle should be used w/ a lighted stylet for pediatric patients?
60-80°
Retrograde Wire Intubation
Blind procedure
Retrograde Intubation STEPS
- Puncture the cricothyroid membrane w/ 14-18 G needle
- Aspirate 3 cc syringe w/ air to confirm placement in the tracheal lumen
- Pass a wire through the needle & advance it cephalad
- Wire should travel b/w vocal cords & exit via the mouth
- Secure the wire at the cricothyroid membrane w/ clamp
- Load the ETT over the wire & advance it into the trachea
Withdraw the wire & advance the ETT into position
Retrograde Intubation Indications
Unstable cervical spine
Upper airway bleeding (unable to visualize the glottis)
*Possible to perform on awake patient
Retrograde Intubation Contraindications
Poor anatomy - neck deformity or mass
- Unable to access the cricothyroid membrane
- Severe obesity
- Pretracheal mass (thyroid goiter)
Laryngotracheal disease
- Tracheal stenosis
- Tumor that obstructs wire path
Coagulopathy
Infection (pre-tracheal abscess)
Retrograde Intubation Complications
Bleeding
Pneumothorax
Trigeminal nerve trauma
Surgical Invasive Airways
Percutaneous cricothyroidotomy
Cricothyroidotomy
Tracheostomy
Percutaneous Needle Cricothyroidotomy
EMERGENT surgical airway
- Insert large-bore needle through the cricothyroid membrane
- Ventilate w/ jet & high-pressure oxygen source ≈ 50 psi
How does expiration occur w/ percutaneous needle cric?
PASSIVE
What conditions limit or prevent exhalation w/ percutaneous needle cric?
Upper airway obstruction limits or prevents exhalation → barotrauma, pneumothorax, subcutaneous emphysema, and/or mediastinal emphysema
Unable to control ventilation → hypercapnia
Percutaneous Needle Cricothyroidotomy Complications
Hemorrhage, aspiration, tracheal injury, & esophageal injury
Cricothyroidotomy
EMERGENT surgical airway
- Small horizontal incision made through the cricothyroid membrane
- Insert cuffed ETT via hole
Cricothyroidotomy Contraindications
Children < 6-10 years old more pliable & mobile laryngeal/cricoid cartilages
Laryngeal fracture or neoplasm
Cricothyroidotomy Complications
Tracheal stenosis, tracheal or esophageal injury, hemorrhage, dysphagia, subcutaneous or mediastinal emphysema
Tracheostomy
Usually controlled surgical airway
Requires more time than cricothyroidotomy
Chosen when a patient requires a definitive airway (failure to wean from mechanical ventilation)
- Incision made b/w 2nd & 3rd tracheal rings
- Pull back ETT when surgeon enters the trachea (ensure not to puncture the cuff)
Tracheostomy ABSOLUTE Contraindications
NONE
Tracheostomy Complications
Acute
Airway obstruction, hypoventilation, pneumothorax, & bleeding
Tracheostomy Complications
Long-Term
Tracheal stenosis, tracheomalacia, tracheoesophageal fistula, & tracheal necrosis
Difficult Airway Algorithm
- Pre-airway management decision-making
- Awake airway management
- Airway management after anesthesia induction
a. Able to ventilate → non-emergent pathway
b. Unable to ventilate → emergent pathway HELP!!!
Guedel Anesthesia Stages
- Awake - airway reflexes intact
- Light anesthesia - airway reflexes are hyperreactive
- Deep anesthesia - airway reflexes are attenuated
Extubation AWAKE (+) Pros
- Airway reflexes intact
- Ability to maintain airway patency
- ↓aspiration risk
Extubation AWAKE (−) Cons
↑CV & SNS stimulation
↑Coughing
↑ICP/IOP
↑intra-abdominal pressure
How to prevent complications associated w/ awake extubation?
β blockers, Ca2+ channel blockers, & vasodilators to minimize cardiovascular & SNS stimulation
Lidocaine IV or inside the ETT cuff & opioids to minimize coughing
Extubation DEEP (+) Pros
↓CV & SNS stimulation
↓coughing
Extubation DEEP (−) Cons
Airway reflexes are ineffective
↑airway obstruction risk
↑aspiration risk
Extubation Risk Factors
Difficult airway
Aspiration risk
OSA
Obesity
Cardiopulmonary disease
Neuromuscular disease
Metabolic abnormalities including acidosis, electrolyte imbalance, hypothermia
Airway Exchange Catheter
Long, thin, flexible, & hollow tube that maintains direct access to the airway following tracheal extubation
- Able to measure ETCO2
- Provide jet ventilation via Luer-lock adaptor
- Oxygenation insufflation via 15 mm adaptor
How to use an airway exchange catheter?
- Insert the airway exchange catheter into the ETT
- Keep the distal end in the trachea ≈ 25-26 cm at the lip
- Remove ETT
- Maintain airway exchange catheter in place up to 72 hours
Airway Exchange Catheter Complications
Jet ventilation w/ obstructed upper airway → barotrauma/pneumothorax
