Oral Review Flashcards
Components of the upper airway:
Nasal passages Oral cavity: teeth, tongue, soft and hard palate Pharynx Tonsils Uvula Epiglottis Vocal cords
Components of the lower airway:
Trachea Carina Bronchi Bronchioles Terminal bronchioles Respiratory bronchioles Alveoli
Boundaries of the pharynx:
Nose to cricoid cartilage
Naso/oropharynx divided by soft palate
Oro/laryngopharynx divided by epiglottis
Innervation of the airway:
Sensory:
Glossopharyngeal: posterior 1/3rd tongue, oropharynx to vallecula
Internal branch of SLN: vallecula to vocal cords
Recurrent LN: subglottic mucosa
Motor:
Recurrent LN: posterior cricoarytenoid, arytenoid, lateral cricoarytenoid, vocalis, thyroarytenoid
External branch of SLN: cricothyroid
Muscles that close and open glottis:
Posterior cricoarytenoid (abducts; Pulls Cords Apart)
Arytenoid
Lateral cricoarytenoid
Muscles that put tension on vocal cords:
Cricothyroid
Vocalis
Thyroarytenoid
S/s of esophageal intubation:
No breath sounds
No ETCO2
Low SpO2
S/s of endobronchial intubation:
High peak airway pressures
Uneven chest rise
No breath sounds on left
Low SpO2
Describe the cricoid cartilage:
Only complete ring of of cartilage in the trachea
Signet-shaped
Narrowest part of peds airway
Located inferior to the thyroid cartilage and cricothyroid membrane
Sellick’s Maneuver:
Used for rapid sequence intubation to prevent aspiration of gastric contents
Have an assistant hold pressure on the cricoid cartilage as you induce patient and hold firm until ET tube placement is confirmed
Advantages of an LMA:
Less anesthesia requirements for airway tolerance
Improved hemodynamic stability for induction/emergence
Easier and faster to insert
Can be woken up with LMA in place
Disadvantages of an LMA:
Does not protect against aspiration
Lower seal pressure
Cannot mechanically ventilate
Increased risk for gastric insufflation
Contraindications for an LMA:
Full stomach: bowel obstruction, GERD, gastroparesis Non-fasting Pregnant Trauma Acute abdomen Thoracic injury Autonomic neuropathy Low pulmonary compliance
Extubation criteria:
TV > 6ml/kg
VC > 10 ml/kg
RR 90%
Sustained head lift for 5+ seconds
When is an ETT necessary?
Pregnant Aspiration risk Long case Can't access airway during case Head/chest/neck/abd surgery Need for controlled ventilation Airway compromise or disease
What are airway adjuncts for difficult airways?
LMA Lightwand Transtracheal jet ventilator Glidescope Bullard Bougie
What are potential hazards of airway management?
Damage to teeth, lips or soft tissue Laryngospasm Bronchospasm Aspiration/vomiting Endobronchial or esophageal intubation SNS stimulation Hypercarbia/hypoxemia
What triggers laryngospasm?
Foreign objects (vomit, blood, secretions) in the airway
Pain
Pelvic/abdominal visceral stimulation
Loud noises
What muscles cause laryngospasm?
Lateral cricoarytenoids
Thyroarytenoids
Cricothyroid
How do we treat laryngospasm?
Jaw lift
100% FiO2 and positive pressure ventilation
Suction/remove stimulation
Succs 20-40mg
Pre-op airway assessment should include:
Overall appearance of head/neck Mallampati score Range of motion Thyromental distance Dentition Mouth opening H/o difficult airway Planned surgery
When should nasal intubation be avoided?
Epistaxis/anticoagulated
Nasal/basal skull fx
Adenoid hypertrophy
Large turbinates
What are potential hazards of an oral airway?
Bleeding
Tissue damage
Laryngospasm
Causes of obstructed airway:
Tongue Laryngospasm Bronchospasm Mucous plug in ETT Kink in ETT
S/s of obstructed airway:
Low O2 sat
No ETCO2
No chest rise
High pitched, snoring, or no noise
Indications of a good mask case:
Easy airway Good mask seal (no heavy beard) Easy to ventilate No aspiration risk Short case, non-head/neck No repositioning (will have access to airway entire case) No airway bleeding/secretions
Steps if awake intubation is unsuccessful:
Cancel case, consider feasability of other options, or surgical airway
If unable to intubate but have adequate mask ventilation, next steps in difficult airway algorithm are:
- Call for help, consider return to spontaneous breathing, or waking patient up
- Try non-emergency adjuncts: LMA, glidescope, mask case, FO intubation, retrograde, etc
- If still unable to intubate, consider surgical airway, mask case, or local/regional
If unable to intubate or mask ventilate, next steps in difficult airway algorithm are:
- Attempt an emergency non-surgical airway: LMA, combitube, bronchoscope, transtracheal jet ventilation
- Emergency invasive airway: cricothyrotomy, tracheostomy, ETT passed through LMA if able to ventilate
NPO guidelines:
2 hrs: clear liquids
4 hrs: breast milk
6 hrs: light meal/milk/formula
8 hrs: heavy meal
Steps to resolve difficult mask ventilation:
Reposition airway
Oral/nasal airway
Call for help so you can two-hand the mask