Airway Flashcards
What is the barrier between the upper and lower airway?
Glottis
Normal mouth opening distance
3 - 4 cm (2-3 FB)
Precautions for nasal airways
Epistaxis and anticoagulants
Nasal and basilar skull fractures
Adenoid hypertrophy
Big caution with oral airways
LARYNGOSPASM
bleeding
soft tissue damage
What should we remember to do before placing a nasal airway?
Lube that sucker up
When is a mask case ok?
- Pt doesn’t have difficult airway
- Airway obstruction is easily relieved with oral/nasal airway or chin lift
- Short case duration
- Surgeon doesn’t need access to head/neck (exception to the rule: bilateral myringotomy tubes)
- Head will be accessible for the entire case
- No airway bleeding/secretions
- No table position changes
When in the induction sequence can an LMA be placed?
After loss of lash reflex and confirmation of mask ventilation
Who should not have an LMA placed?
Anyone considered a full stomach
(non-fasting, parturients 34+ weeks, uncontrolled GERD, trauma, acute abdomens, diabetics d/t autonomic neuropathy, low pulmonary complience)
LMA advantages
- ↑ speed & ease of placement by inexperienced personnel
- Improved hemodynamic stability at induction & during emergence
- ↓ anesthetic requirements for airway tolerance
- Lower frequency of coughing during emergence
- Lower incidence of sore throats in adults (10% vs 30%)
- Avoids “foreign body” in the trachea
- Patient can be fully emerged prior to removal of LMA → good for asthmatic patients
LMA disadvantages
- Lower seal pressure
- Higher frequency of gastric insufflation → risk for aspiration
- Esophageal reflux more likely
- Inability to use mechanical ventilation at higher pressures
LMA - when do you deflate the cuff
Keep the cuff inflated until the patient is awake → DO NOT DEFLATE at END OF CASE
Keeps secretions from getting on vocal cords
ETT indications
- Airway compromise
- Airway inaccessible
- Long surgical time
- Surgery of head, neck, chest, or abdomen
- Need for controlled ventilation & positive end-expiratory pressure
- Inability to maintain airway with mask/LMA
- Aspiration risk
- Airway disease
- Pregnancy
How far to insert the ETT
males - 23 cm
females 21 cm
RSI Sequence of Events
- Adjuncts → aspiration prophylaxis
- Bicitra, reglan, protonix
- Monitors, suction on & placed at head of bed
- Supine “sniffing” position
- Sedation (Versed) if applicable
- Pre-Oxygenate 5 minutes or Minimum 4-5 VC Breaths!
- Sellick’s Maneuver = Cricoid pressure
- Induction agent followed by succinylcholine
- Wait 60 seconds → watch the clock NOT the block!
- Attempt Laryngoscopy → visualize vocal cords → place ETT inflate cuff
- Confirm tracheal tube placement:
- Chest rise
- BBSE
- Confirm presence of EtCO2
- Give assistant permission to release cricoid pressure
- Ventilate
- Start inhaled anesthetic or anesthetic infusion
- Ventilator on
- Secure ETT/tape eyes
Potential Hazards in Airway Management
- Dental damage
- Soft tissue/mechanical injury
- Laryngospasm
- Bronchospasm
- Vomiting/Aspiration
- Hypoxemia/Hypercarbia
- SNS stimulation
- Esophageal/Endobronchial intubation
- Endobronchial intubation evident by → high airway pressures, unilateral chest rise & breath sounds, ↓ O2 saturation
Extubation Criteria
- TV: >6 mL/kg
- VC: >10 mL/kg
- RR:
- If >30 could mean pain or anxious
- SaO2: >90%
- ETCO2:
- If EtCO2 is too low → can ↓ RR or ↓ VT
- Sustained tetanic contraction
- Closed grip fist for 5 seconds
- Sustained head lift for 5 seconds
Laryngospasm interventions
- Jaw-Lift Maneuver
- Forward displacement of the mandible with O2 administered by mask with positive pressure
- Administration of O2 with continuous positive pressure
- Strong intermittent pressure applied manually to a bag full of O2 can force gas effectively through the upper airway & adducted cords
- Immediate removal of the offending stimulus
- Small dose of short acting muscle relaxant succinylcholine 20-40 mg
when is it allowed not to test-ventilate a patient before insertion of the ETT/LMA?
in RSI
Nasal Tracheal Intubation: Asleep Sequence of Events
- Phenylephrine to nose (AFRIN) or consider Anticholinergic/Antisialogogue (glycopyrrolate)
- Monitors, Supine “sniffing” position, Sedate (Versed)
- Pre-Oxygenate
- Induction Agent
- Confirm loss of consciousness
- Attempt ventilation if able to ventilate →
- Muscle Relaxant
- Consider dilation of nare with sequential sizes of nasal airways → choose nare that is easily able to breathe through in preop
- Consider induction agent may be wearing off
- Insert LUBRICATED ETT through nare (that was dilated)
- Continue to ventilate
- Attempt direct visual laryngoscopy → visualize VC → use Magill forceps to pick up end of ETT & advance through cords
- Inflate cuff
- Confirm tracheal tube placement:
- Chest rise
- BBSE in all lung fields & over stomach
- Confirm presence of EtCO2
- Ventilate
- Start inhaled anesthetic or anesthetic infusion
- Ventilator On
- Secure ETT/tape eyes
Extubation guidelines
- Nearly fully awake extubation is performed when the patient has
- Purposeful movement
- ready to maintain & protect his/her own airway
- Muscle relaxant must be fully reversed & confirmed with PNS
- Anesthetic medications, including anesthetic gases & infusions, turned OFF
- Oropharynx is suctioned
- The patient is self-maintaining an acceptable respiratory rate & depth (see respiratory extubation criteria*)
- Assess for responsiveness / purposeful movement &/or responding to commands
- A sustained (5 second) head lift is an excellent way to assess clinically adequate reversal
- ETT is removed while a positive-pressure breath is given with the anesthesia bag to allow subsequent expulsion or secretions away from the glottis
This is the only muscle that ABDUCTS the vocal ligaments
Posterior cricoarytenoid muscles
What is the most narrow part of the adult and pediatric airways?
Pediatric - cricoid cartilage
Adults - glottis (6 - 9 mm)
Posterior cricoarytenoid
what do they do
who innervates it
Only abductor of the cords!! Opens the glottis
Recurrent laryngeal nerve
intrinsic muscle
Lateral cricoarytenoid
function
nerve
Adducts the cords
Recurrent laryngeal nerve
intrinsic muscle
Arytenoids
function
nerve
Closes the glottis (esp the posterior)
Recurrent laryngeal nerve
intrinsic muscle
Crycothyroid
function
nerve
Produces tension and elongates the cords
superior laryngeal nerve
Thyroarytenoid & Vocalis
Shortens and relaxes the cords
recurrent laryngeal nerve
Sensory and Motor Function of the Superior Laryngeal Nerve (Internal branch)
Sensory only!!
- Base of tongue
- Epiglottis
- Supraglottic mucosa
- 2 joints (thyroepiglottic and cricothyroid joints)
Sensory and Motor Function of the Superior Laryngeal Nerve (External branch)
- Sensory:
- Anterior subglottic mucosa
- Motor:
- Cricothyroid muscle (adductor/tensor)
Sensory and Motor Function of the recurrent laryngeal nerve
- Sensory
- Subglottic mucosa
- Muscle spindles
- Motor
- Thyroarytenoid
- Lateral cricothyroid
- Interarytenoid
- Posterior arytenoid
Proper Snifing position
pillow under the head (not soulders)
35° neck flexion and 15° head extension (angles relative to horizontal planes)
