Difficult airways Flashcards
1
Q
First four steps of the dificult airway algorythm
(stop at the algorithm)
A
- Asssess the likelyhood of basic management problems
- Difficult ventilation
- Difficult intubation
- Difficulty with consent or cooperation
- Difficult tracheostomy
- Deliver supplimental oxygen throughout
- Consider merits and feasible management choices:
- Awake vs intubation after general anesthesia
- Non-invasive vs invasive technique to intubation
- Preservation vs Ablation of spontaneious ventilation
- Develop primary and alternative strategies
2
Q
Develop primary and alternative strategies
Side A
A
-
Awake intubation
- invasive or non-invasive approach to intubation
-
If this FAILS
- Cancel case
- consider feasibility of other options
- if you attempted a non-invasive approach - you can attempt an invasive approach
3
Q
Develop primary and alternative strategies
Side B
Non-emergency pathway
A
- The initial intubation was unsucessful
-
Consiter from here on:
- Calling for help
- Returning to spontaneous ventilation
- awakening the pateint
-
If you are ABLE to mask ventilate it is the NON-EMERGENCY pathway
- this means the intubation failed but ventilation is adequate
-
Alternate approaches to intubation
- try a different blade
- use the LMA as a conduit
- Use and intubating stylet
- Retrograde intubation
- Light Wand
- Blind oral/nasal intubation
-
Still fail after multiple attempts
- Consider invasive airway access (tracheostomy, cricothyrotomy)
- Consider other feasible options
- Awaken the patient
4
Q
Develop primary and alternative strategies
Side B
Emergency pathway
A
- The initial intubation was unsucessful
-
Consiter from here on:
- Calling for help
- Returning to spontaneous ventilation
- awakening the pateint
- If facemask ventilation is not adequate
- Consider/Attempt an LMA
- If the LMA is not feasible and you are UNABLE to mask ventilate it is the EMERGENCY pathway
- this means the intubation failed unable to provide adequate ventilation
- CALL FOR HELP!!!
-
Emergency NON-Invasive airway ventilation
- Rigid bronchoscope
- Esophageal-tracheal combitube ventilation
- Transtracheal jet ventilation
-
If this fails go to INVASIVE airway ventilation
- tracheostomy
- cricothyrotomy
5
Q
Difficult Airway Management
Pink one
A
6
Q
ASA Difficult Airway Algorythm
A
7
Q
Radiological studies have shown this maneuver is the most improtant to maintain space between the pharyngeal soft tissues
A
Head extension
(it stretches the anterior neck structures and move the hyioid bone and attached structures anteriorly)
8
Q
Four principals central to the prevention of complications during tracheal intubation
A
- Maintinence of oxygenation
- Trauma must be prevented
- Must have a sequence of backup plans before staarting the primary technique
- sometimes the safest plan is to stop attempts, awaken the patietn and postpone the surgery
- Call for help as soon as difficult tracheal intubation is experienced
9
Q
Five predictors of difficult mask
A
- Age
- Facial hair
- Snore (Apnea)
- Edentulous (No teeth)
- BMI >26
10
Q
Four things you can do if you are having difficulty initially
A
- Pull back
- ventilate
- re-group
- change positions
11
Q
Two techniqes for preoxygenation.
What does this do?
A
- Tidal volume breathing
- Four deep breaths within 30 seconds
(both increase arterial oxygen tension, and provide a longer time to desaturation)
12
Q
What is the goal of preoxygenation?
A
TO fill the FRC(alveoli), arterial compartment and tissue compartment to increase the duration of safe apnea time
13
Q
What is the barrier between the upper and lower airway?
A
Glottis
14
Q
Normal mouth opening distance
A
3 - 4 cm (2-3 FB)
15
Q
Precautions for nasal airways
A
Epistaxis and anticoagulants
Nasal and basilar skull fractures
Adenoid hypertrophy
16
Q
Big caution with oral airways
A
LARYNGOSPASM
bleeding
soft tissue damage
17
Q
What should we remember to do before placing a nasal airway?
A
Lube that sucker up
18
Q
When is a mask case ok?
A
- 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
19
Q
When in the induction sequence can an LMA be placed?
A
After loss of lash reflex and confirmation of mask ventilation
20
Q
Who should not have an LMA placed?
A
Anyone considered a full stomach
(non-fasting, parturients 34+ weeks, uncontrolled GERD, trauma, acute abdomens, diabetics d/t autonomic neuropathy, low pulmonary complience)
21
Q
LMA advantages
A
- ↑ 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
22
Q
LMA disadvantages
A
- Lower seal pressure
- Higher frequency of gastric insufflation → risk for aspiration
- Esophageal reflux more likely
- Inability to use mechanical ventilation at higher pressures
23
Q
LMA - when do you deflate the cuff
A
Keep the cuff inflated until the patient is awake → DO NOT DEFLATE at END OF CASE
Keeps secretions from getting on vocal cords
24
Q
ETT indications
A
- 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
25
How far to insert the ETT
males - 23 cm
females 21 cm
26
RSI Sequence of Events
1. Adjuncts → aspiration prophylaxis
* Bicitra, reglan, protonix
2. Monitors, suction on & placed at head of bed
3. Supine “sniffing” position
4. Sedation (Versed) if applicable
5. Pre-Oxygenate 5 minutes or Minimum 4-5 VC Breaths!
6. Sellick’s Maneuver = Cricoid pressure
7. Induction agent followed by succinylcholine
* Wait 60 seconds → **watch the clock** NOT the block!
8. Attempt Laryngoscopy → visualize vocal cords → place ETT inflate cuff
9. Confirm tracheal tube placement:
* Chest rise
* BBSE
* Confirm presence of EtCO2
10. Give assistant permission to release cricoid pressure
11. Ventilate
12. Start inhaled anesthetic or anesthetic infusion
13. Ventilator on
14. Secure ETT/tape eyes
27
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
28
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
29
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
30
when is it allowed not to test-ventilate a patient before insertion of the ETT/LMA?
in RSI
31
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
32
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
33
This is the only muscle that ABDUCTS the vocal ligaments
Posterior cricoarytenoid muscles
34
What is the most narrow part of the adult and pediatric airways?
Pediatric - cricoid cartilage
Adults - glottis (6 - 9 mm)
35
Posterior cricoarytenoid
what do they do
who innervates it
Only abductor of the cords!! Opens the glottis
Recurrent laryngeal nerve
intrinsic muscle
36
Lateral cricoarytenoid
function
nerve
Adducts the cords
Recurrent laryngeal nerve
intrinsic muscle
37
Arytenoids
function
nerve
Closes the glottis (esp the posterior)
Recurrent laryngeal nerve
intrinsic muscle
38
Crycothyroid
function
nerve
Produces tension and elongates the cords
## Footnote
**superior laryngeal nerve**
39
Thyroarytenoid & Vocalis
Shortens and relaxes the cords
recurrent laryngeal nerve
40
Sensory and Motor Function of the Superior Laryngeal Nerve (Internal branch)
Sensory only!!
## Footnote
Base of tongue
Epiglottis
Supraglottic mucosa
2 joints (thyroepiglottic and cricothyroid joints)
41
Sensory and Motor Function of the Superior Laryngeal Nerve (External branch)
* Sensory:
* Anterior subglottic mucosa
* Motor:
* Cricothyroid muscle (adductor/tensor)
42
Sensory and Motor Function of the recurrent laryngeal nerve
* Sensory
* Subglottic mucosa
* Muscle spindles
* Motor
* Thyroarytenoid
* Lateral cricothyroid
* Interarytenoid
* Posterior arytenoid
43
Proper Snifing position
pillow under the head (not soulders)
35° neck flexion and 15° head extension (angles relative to horizontal planes)
44
Difficult Airway Management
Pink one
45
ASA Difficult Airway Algorythm
46
Ten airway assesment concerns,
1. Length of **Upper Incisors** → Long
2. Relation of **maxillary** & **mandibular** incisors during normal jaw closure → Prominent Overbite
3. **Interincisor** distance → Less than 3 cm (2 FB)
4. Visibility of **uvula** → Mallampati \> II
5. Shape of **palate** → Highly arched or very narrow
6. Compliance of **mandibular space** → Stiff, occupied by mass, non-resilient
7. **Thyromental** distance → Less than 3 ordinary finger breadths
8. **Length** of **neck** → Short
9. **Thickness** of **neck** → Thick
10. **Range of motion** of head & neck → Cannot touch chin to chest or extend neck
47
What is the 3-3-2 Rule
* 3 fingers fit in mouth → Inter incisor distance
* 3 fingers fit from mentum to hyoid
* 2 fingers fit from the floor of the mouth to top of thyroid cartilage
48
Thyro-Mental Distance significance
* Measure from **upper edge of thyroid cartilage** **to** **chin** with the head fully extended
* A short thyromental distance = anterior larynx
* **\> 7 cm** is usually = easy intubation
* **\< 6 cm** = difficulty airway
49
Medical History and potential difficult airway considerations
## Footnote
**Thyroid disease**
* Does the patient have **goiter** or **enlarged** **thyroid** **mass**?
* Check for **tracheal deviation**
* possible **tracheomalacia**
* which would be more problematic for **extubation** criteria rather that **intubation**.
50
Medical History and potential difficult airway considerations
## Footnote
**Cancer**
* **Head and Neck cancer**
* may involve previous **surgical** intervention or **medical** intervention for chemo and radiation.
* **Radiation** **to** **neck** is known to cause **tissue to become fibrotic**
* leading to **stiff neck structures internally and** **externally**.
51
Medical History and potential difficult airway considerations
## Footnote
**Asthma**
* If moderate to severe = want to optimize respiratory status before surgery.
* Be prepared for **laryngospasm**
* ****choose anesthetic drugs that would not cause reactivity
* ie. Histamine releasing drugs or Beta 2 antagonists
* think about your muscle relaxants and induction agents
52
Medical History and potential difficult airway consderations
## Footnote
**GERD**
Consider
1. rapid sequence intubation
2. pre-treat with prokinetics
3. non-particulate antacids.
53
Medical History and potential difficult airway considerations
## Footnote
**Diabetes**
1. **_Stiff joint syndrome_**
* can patient do the “**prayer’s sign**”
* 1:4 adolescent diabetics present with this.
* Due to **Glycosylation** of collagen tissues.
* Joints involved **TMJ, antlantooccipital joint, cervical spine**
* results in limitation of head and neck mobility
2. **_Autonomic Neuropathy secondary to DM_**
* occurs in approx **1:10** diabetics → this increases **4-5 fold** in patients with **coexisting HTN**.
* Anhydrosis (failure of sweat glands)
* **Gastroparesis**→ predispose patients to N/V, GERD, and aspiration
* impotence, urinary retention, early satiety.
54
Medical History and potential difficult airway considerations
## Footnote
**Obesity**
1. **_redundant tissue_**
* upon induction can cause **obstruction**
* may make **mask ventilation** difficult or impossible.
55
Medical History and potential difficult airway considerations
## Footnote
**Genetic Disorders**
1. **_Down’s syndrome, Treacher collins_**
* **maxillofacial malformations** = large tongues, small mouth, receding chin
* **antlantooccipital** joint instability
56
Medical History and potential difficult airway considerations
## Footnote
**Rheumatoid Arthritis**
1. **_antlantooccipital joint instability_**
* need to keep neck in **neutral** position
* may NOT be able to **align axis’** as well.
57
Medical History and potential difficult airway considerations
## Footnote
**Sclerodema**
* Connective tissue disorder
* **stiff TMJ** may make **mouth** **opening** difficult
58
Medical History and potential difficult airway considerations
## Footnote
**Hypothyroidism**
* Large tongue
* Abnormal soft tissue (myxedema)
* May be difficult to ventilate and intubate
59
Medical History and potential difficult airway considerations
Pierre Robin Syndrome
Airway management usually requires **awake** **fiberoptic** intubation; patients usually present with:
* **Micrognathia**
* Small **mouth**/Large **tongue**
* **U-shaped** cleft palate (50% of patients)
* Airway Obstruction secondary to **glossoptosis**
60
Surgical History and potential difficult airway considerations
## Footnote
**tracheaostomy**
* potential for traceheal stenosis
* may require smaller ETT
61
Surgical History and potential difficult airway considerations
**Neck** **Dissection**
* patient may have had **radiation** therapy
* they may present with **fibrotic/stiff tissue**
62
Surgical History and potential difficult airway considerations
## Footnote
**Uvulopalatopharyngoplasty (UVPP)**
uvulopalatoplasty for **sleep apnea**
* may present with
1. large **tongue**
2. large/short **neck**
3. **obesity**.
* More **emergence** issues
63
Surgical History and potential difficult airway considerations
## Footnote
**Cervical Neck Instrumentation**
* usually secondary to cervical stenosis and depending on level of surgical intervention may present with **decreased extension**
64
What are some potential airway obstructions to be concerned about?
What are some assement signs of obstruction?
**_Potential airway obstructions:_**
* Tongue
* Blood
* Vomitus
* Dentures
* Tumors
* Epiglottis
* Foreign Object?
**_Assessment signs of Obstruction = could be difficutlt AW_**
* stridor when they breathe = likely could be a difficult airway
* Hoarseness
* Recurrent papilloma
* Epiglottis cyst
* Lingual tonsil hyperplasia
65
The most frequent timing of poor outcomes in the operative period
1. **At induction!** When we have controll
* ****they also resulted in brain damage or death
2. Additionally Nearly ALL difficult airway claims that happen in non-OR or PACU result in brain damage or death!
* can't ventilate/can't inubate
66
5 Questions Before You Even Touch the Patient regurding airway management
1. **Does the airway have to be managed**? or is Regional appropriate?
2. Will **DVL** be **difficult?** Mallampati
* Class 1 (**85%** NOT DIFFICULT),
* Class 2 (**9%**)
* Class 3 (**5%**)
* Class 4 (**1%**)
3. Is **Supraglottic airway** use possible? **Mask** or **LMA**?
* Ask the ? Before injecting induction drug → **What if I am wrong, will I be able to ventilate?**
4. **Stomach** empty?
* even though you think it is empty, may be very nervous and increased secretions
5. Can the patient **tolerate apnea**?
67
Five predictors of difficult mask-
1. Age
2. Facial hair
3. Snore
4. Edentulous
5. BMI \>26
68
BURP Maneuver
To help visualize the airway on DVL
1. Backward
2. Upward
3. Right Pressure
