Airway Anatomy & Management Flashcards
Pharynx Divisions and Borders (3 items)
- Nasopharynx (nose => soft palate)
- Ororpharynx (mouth => epiglottis)
- Laryngopharynx (epiglottis => trachea)
Nasopharynx Structures and Innervation
- Septum, Turbinates, Adenoids; humidify, warm, filter
2. Trigeminal (CN V)
Oropharynx Structures and Innervation
- Teeth, tongue, hard palate, soft palate; predominate cause of airway resistance
2 a. Trigeminal CN V (hard/soft palate, ant 2/3 tongue)
b. Glossopharyngeal CN IX (soft palate, posterior 1/3
tongue)
Larynx Location
C4-C6
9 Larynx Cartilages (6 items)
3 Paired Cartilages a. Arytenoid b. Corniculate c. Cuneiform 3 Unpaired a. Thyroid b. Cricoid c. Epiglottis
3 Unpaired Larynx Cartilages
- Thyroid: anterior attachment for vocal chords; most
prominent cartilage - Epiglottis: covers opening to larynx
- Cricoid: narrowest part of pediatric airway; ONLY
complete cartilaginous ring
3 Paired Larynx Cartilages
- Arytenoid: posterior attachment for vocal chords
- Corniculate: posterior portion of aryepiglottic fold
- Cuneiform: lateral to corniculates on aryepiglottic fold
Describe
- Vocal Chords
- Glottic Opening
- Pearly white color; formed by thyroarytenoid ligamints; attached anteriorly to thyroid, posteriorly to arytenoid
- Triangular fissure between vocal chords; narrowest portion of adult airway
Lateral Cricoarytenoid Muscle
Controls glottic opening, adducts the vocal cords (Let’s Close the Airway); contracts in laryngospasm
Arytenoid Muscles
Control glottic opening; has oblique and transverse components; adducts the vocal cords
Posterior Cricoarytenoid Muscle
Control glottic opening; only vocal cord abductors (Please Come Apart)
Cricothyroid Muscle
Controls vocal cord length; only muscle that tenses/elongates cords; contracts in laryngospasm
Thyroarytenoid Muscle
Controls vocal cord length; relaxes/shortens vocal cords; contracts in laryngospasm
Vocalis Muscle
Controls vocal cord length; relaxes/shortens vocal cords
Innervation of Laryngeal Muscles
- Cricothyroid: External branch of Superior Laryngeal Nerve (branch of Vagus CN X)
- All Others: Recurrent Laryngeal Nerve (Vagus CN X)
Lower Airway: Anatomical Deadspace (5 items)
- Trachea
- Carina
- Bronchi
- Bronchioles
- Terminal Bronchioles
Lower Airway: Anatomical Respiratory (2 items)
- Respiratory Bronchioles
2. Alveoli
Trachea Anatomy:
- Length
- Diameter
- Cartilage #
- Carina Location
- Right Bronchi (Length/Angle)
- Left Bronchi (Length/Angle)
- 10-20cm
- 22mm
- 16-20 U shaped rings (no cartilage posterior)
- T4
- 2.5cm long, 25 degrees (short/fat)
- 5cm long, 45 degrees (long/lean)
Mallampati Classification:
- Indication
- Technique
- 4 Classes (PUSH)
- Correlates oropharyngeal space and size of tongue with ease of direct laryngoscopy
- Pt sits upright, head neutral, mouth open/tongue protruded maximally (no Ahhhhh)
- Classifications:
Class 1: Pillars at back of soft pallet (Faucial pillars), entire
Uvula, Soft and Hard palate
Class 2: Uvula tip masked by tongue, Soft and Hard palate
Class 3: Soft and Hard palates (uvula base only)
Class 4: Hard palate
Cormack and Lehane Score (4 Grades)
Grade 1: most of glottis visible
Grade 2: Only posterior portion of glottis visible
(corniculate/cuneiform visible)
Grade 3: Only epiglottis visible
Grade 4: No airway structures visible(Grades 3/4 must use
video assisted intubation)
*usually correlates to Mallampati CLASS
Thyromental Distance:
- Technique
- Indications
- Fully extend next; measure from lower border of mandible till the thyroid notch; normal is 6-6.5cm or 4 fingerbreadths
- <3 fingerbreadths indicates receding mandible or “anterior airway”; difficult intubation
Mandibular Protrusion Test (3 Classes)
Class A: lower incisors can be protruded anterior to upper incisors
Class B: lower incisors brought edge to edge with upper
Class C: lower incisors cannot be brought edge to edge with upper incisors
*Test indicates how easy it is to jaw thrust
MSMAID of Induction
Monitors on and machine check Suction at head of bed Means of PPV Airway setup IV Drugs (emergency and case specific)
Airway Setup Components (LOSTSEAL)
LMA Oral/Nasal Airways Suction Tape/tongue depressor Stylet/Syringe ETT (2 sizes) Amub bag w/ face mask Larygoscope w/ two blades
Face Masks:
- Sizes
- Holding technique
- Size 1 (neonate) => Size 6 (large adult)
2. C/E grip with left hand; put 4/5th finger at angle of mandible for chin lift/ jaw thrust
Pre-oxygenation Goal/Techniques
Goal: complete washing out of nitrogen
Technique:
1. 3-5 minutes @ 100% >6L/min flow (10 mins safe apnea)
2. 4 VC breaths within 30 sec @ 100% >6L/min flow (5 mins safe apnea)
Oral Airways:
- Types
- Sizes
- Measurement
- Complications
- Berman (channels down the side) or Guedel (one
opening in center) - a. Small: BOA 80mm = Guedel #3
b. Medium: 90mm = #4
c. Large: 100 = #5 - Measure from corner of mouth to earlobe
- Unconscious patients only; soft tissue damage,
laryngospasm
Nasal Airway:
- Sizes
- Measurement
- Complications
- Measured in French; 24-36; diameter depends on ease
of insertion - Measure from nares to meatus of ear
- Don’t push if too much resistance, try different size or extra lube; lubricate; can cause epistaxis/fractures; can be used on conscious patients
Laryngoscope Blades:
- Types
- Sizes
- Usage
- Complications
- Mac and Miller
- Mac 1-4 (M 3,4/ F2,3) Miller 0-4 (M 3,4/ F 2,3)
- Mac: scoop R => L, wrist straight, tip @ vallecula
(depression behind root of tongue)
Miller: straight back, better for anterior airway/ peds; tip
on epiglottis - Always check battery in handle and lights on blade
Enodtrachial Tubes:
- Types (6)
- Typical sizes
- Ideal Position
- Cuffed, uncuffed, Oral RAE, Nasal RAE, Double Lumen, Reinforced
- F: 6.5-7mm, M: 7.5-8mm
- 4cm above carina; 2cm below vocal cords; M=23mm, F=21 cm; IDx3 for appx peds; 3 ETCO2 is gold standard for placement confirmation
Sniffing Position:
- Landmarks
- 3 Axis
- Tragus even with sternum
2. Aligns oral, pharyngeal, laryngeal axis
Laryngeal Mask Airway:
- Sizes
- Insertion
- Advantages
- Disadvantages
- a. LMA 3 (30-50kg) b. LMA 4 (50-70kg) c. LMA 5 (70-100kg) d. LMA 6 (>100kg)
- Have 20-50cc syringe; lubricate posterior side only; hold w/ black line facing away and insert midline till resistance; inflate, ventilate, auscultate, tape
- Speed/ease, improved hemodynamic stability, reduced anesthetic requirements, lower coughing; avoids foreign body stimulis in trachea (sits supraglottic)
- No positive pressure, increase risk of gastric insuflation/aspiration, can’t use mechanical ventilation (must be spontaneously breathing)
Mask Case Indications (6 items)
- No difficult airway
- No access to head needed
- No excess secretions
- Short duration
- No position changes
- No NMB (spontaneous ventilation)
LMA Case Indications (6 items)
- No difficult airway
- No access to head needed
- No excess secretions
- Short duration
- Need hands free during case
- No NMB (spontaneous ventilation)
ETT Case Indications (8 items)
- Airway compromise/inaccessible/ difficult to maintain
- Long cases
- Access to head needed
- Controlled ventilation needed
- Alternate positions during surgery
- Aspiration risk
- NMB use
- Airway/lung disease
Concerns Managing Airway and Intubation (8 items)
- Hypertension/Tachycardia/MI
- Laryngospasm
- Brnchospasm
- Broken Teeth
- Airway Trauma
- Aspiration
- Hyopxia/Hypercapnia
- Gastric Insuflation
3 Functions of Larynx
- Phonation
- Respiration
- Airway Protection
Components of Airway Assessment (8 items)
- Surgery/Diagnosis/ PMH (including planned surgery;
previous intubation history) - Body Shape
- ROM of neck
- Thyromental Distance (3-4 fingerbreadths
- Mouth Opening (2-3 fingers or 30-40mm)
- Dentition and condition of mouth, lips, gums
- Mallampati
- Mandibular Protrusion
Upper airway resistance
2/3 from nasal cavity; 1/3 tongue
Common Diseases that affect intubation (8 items)
- Radiation/bunrs
- C-spine injuries
- TMJ
- Arthritis
- Tumors
- Tracheotomy/prior intubation issues
- Sleep apnea
- Dysphagia/stridor