Exam I: The Difficult Airway Flashcards
What are the 3 reasons the ASA states that may create the impossibility of the Anesthesiologist to perform mask ventilation?
- Inadequate mask
- Excessive gas leak
- Excessive resistance to the ingress or egress of gas
A ______ occurs when there is no visualization of the vocal cords or there are mutilple failed attempts.
Difficult laryngoscopy
What are the 3 different methods by which various entities qualify a “difficult tracheal intubation”?
- Attempts & Time
- Experience of Provider
- Multiple attempts
Many studies use what, metric as a primary criterion for the finding it difficult intubation?
C&L Grade III
What is the approximate rate of difficult intubation’s and difficult laryngoscopy’s?
1.5-8.5%
What is the approximate rate of field intubation?
0.13-0.3%
What is the approximate rate of impossible mask ventilation?
0.15%
What is strongly recommended to be performed before as well as between intubation attempts?
Mask Ventilation
There is very strong correlation between difficult mask ventilation and ______.
Difficult intubation
What may be done pharmacologically if a provider is experiencing a difficult mask ventilation
Push muscle relaxant
What are some guidelines for mask ventilation?
- High flow, oxygen: 10L/min or greater
- Patent Airway: sniffing position.
- Proper mask size and seal (check bag for refilling)
- Lift Chin Pad with jaw thrust (may require two hands)
- Early use of an oral or nasal airway.
- Reposition had laterally if need be/ reposition patient
- 2 Person Techniques
What is the difference between the traditional and maximum (novel) approach to mask ventilation?
traditional:
- Bagger: focuses on ventilations and monitors
- Masker: focuses on 2-handed E-C technique (face away from monitors)
Maximum: (3 hands on mask total)
- Primary: Masker & Ventilator (1 hand each)
- Secondary: 2-handed masking
What are 3 major factors that could cause a difficult intubation?
- Limited access to the oropharynx or nasopharyngeal (Dz or condition)
- Inability to see larynx
- Diminished cross-sectional area of the larynx and trachea (narrowing)
Cormack-Lehane Epiglottic Views
Optimal sniffing position requires the external auditory meatus to be lined up with the ______. sniffing position
Eternal notch
If the patient has observable tone, it will likely be required to administer ______.
Muscle relaxant (this will provide optimal relaxation of the airway)
The BURP maneuver is a technique performed by a support person blindly, while ______ is choreographed by the Laryngoscopist in order to optimize laryngoscopy.
OELM
______ may be performed to the patient in order to raise the EAM to the level of the sternal notch.
Ramping
Receding chin
Micrognathia
difficult airway sign
Signs of Difficult Airway
- Trauma/deformity
- Stridor (“air hunger”)
- Intolerance of the supine position
- Hoarseness or abnormal voice
- Mandibular Abnormality (decreased mobility, decreased mouth opening, <6cm thyromental distance, retrognathia/micrognathia: Treacher Collins, Pierre Robin)
- Laryngeal Abnormalities
- Macroglossia
- Deep, Narrow, High-Arched oropharynx
- Protruding Teeth
- Mallampati 3 or 4
- Neck abnormalities (short & thick, decreased ROM, Fracture, obvious trauma)
- Thoracoabdominal Abnormalities (kyphoscoliosis prominent chest/breasts, morbid obesity, Term or near term Pregnancy)
- Age: 40-59
- Males
Disorders associated with airway complications
- Known history of difficult airway.
- Diabetes mellitus.
- TMJ
- Morbid obesity.
- Down syndrome.
- Fetal alcohol syndrome.
- Pierre Robin syndrome.
- Sleep apnea syndromes
- Prior long-term intubation.
- Premature infants. 
What test can be performed to rule out TMJ abnormalities?
Upper Lip Bite Test
What technological innovation precipitated the formulation of the 2013 revision of the “ASA difficult airway Algorithm ”?
Video laryngoscopy
Prior was 2003 after distribution of LMA
What year was the most recent ASA difficult airway Algorithm formulated?
2022
ASA difficult airway Algorithm 2022 diagram
ASA difficult airway Algorithm 2022 diagram
What is a key component that is stressed in the most recent difficult airway algorithm that was not as prominent in past algorithms?
“ optimize oxygenation throughout”
N.O.D.E.S.A.T.
What are the two variables that can be manipulated in order to ensure optimal oxygenation intraoperatively?
- Patient positioning.
- Supplemental oxygen administration (hi-flo nasal oxygen administration: up to 70 L/min)
What does N.O. D.E.S.A.T. Stand for and what is its relevance?
Nasal Oxygen During Efforts Securing A Tube
- whenever a difficult airway is expected, the patient should begin receiving high flow nasal oxygen to assist with oxygen therapy during intubation*
The ASA difficult airway Algorithm (2022) ultimately provides guidance for what paths of treatment?
- Awake vs Asleep Intubation
- Awake vs Non-Awake Management
- Emergency vs Non-Emergency Pathways
Which pathway is concerned with establishing mask-ventilation?
- emergency or non-emergency*
Emergency
Which pathway is primarily concerned with establishing an airway?
- emergency or non-emergency*
Non-emergency
(we have already demonstrated the ability to mask-ventilate and therefore this is not an emergency situation - IOW ventilation is key)
_______ is the determining factor between difficult intubation being an urgent matter and a life or death medical emergency.
Ventilation
“LEMON” pertains to:
Difficult Intubation
- look externally
-
evaluate 3-3-2
(3 FB Oral opening/3FB Mandibular Space”/2FB Sub-Mental–Thyroid Cartilage Space) - Mallamati
-
Obstruction/Obesity
(Muffled or “Hot Potato Voice”/Dyspnea/Stridor/Difficulty Swallowing) - Neck (C-spine immobility/Sniffing Position)
MOANS pertains to:
Difficult BMV
- Mask Seal (Beard, facial debris)/Male/Mallampati
- Obstruction/Obesity
- Age (>55) (Loss of Tissue & Muscle)
- No Teeth (Leave Dentures In/Pack Gauze in Cheeks)
- Stiff Lungs/Snores
(Airway Dz increases ventilation resistance/Asthma,COPD,ARDS, Pneumonia, P. Edema)
RODS pertains to:
Difficult EGD
- Restricted Mouth Opening
- Obstruction (upper airway)/Obesity
- Disupted/Distorted Airway “seat & seal”
- Stiff Lungs/C-Spine
SMART pertains to:
Difficult Cricothyrotomy
- Surgery (recent wounds or scarring)
- Mass (hematoma or abscess)
- Access/Anatomy (Halothoracic Brace/edema/infection)
- Radiation (distort tissue planes)
- Tumor (tumor: chronically hoarse patient)
LEMON Diagram
BVM Connector Options to AngioCath Hacks Picture
Percutaneous Translaryngeal Ventilation Diagram
Cricothyroid Membrane Diagram Adult vs Pediatric
Cricothyroid Membrane Diagram
What gauge catheter should be used for percutaneous translaryngeal ventilation?
14ga
After failed intubation, which rescue technique is most successful according to studies?
Video laryngoscopy (92%)
SGA Conduit (78%)
Flexible Fiber Optic (78%)
Lighted Stylet (77%)
Optical Stylet (67%)
What size ET tube is recommended for scalpel cricothyrotomy?
Size 6
What size scalpel blade is recommended for a scalpel cricothyroidotomy?
A size 10 blade
What does the UK DAS Guidlines recommend if you are unable to palpate the cricoid or thyroid cartilage, in preparation of a cricothyroidotomy?
Make a vertical incision with the scalpel and then palpate the cartilages with your fingers until you’re able to locate the cricothyroid membrane.
What are the most common locations of C-spine injury?
C2, C6 or C7
When should C-spine precautions be put in place?
- slight neck discomfort
- Not fully alert
- head first falling
- motor vehicle accident in excess of 35 mph
With regard to a cervical spine injury, the neck should be immobilized as soon as possible and remain as such until ______.
Injury is excluded or repaired
What immediate stabilizing equipment is recommended for a patient suffering from a potential cervical spine spine?
- hardboard
- Rigid collar
- Sandbags on either side of the neck for stabilization
In order to facilitate the mouth opening, the C-spine collar may have to be removed, and ______ performed to maintain stability.
In-line stabilization
All airway maneuvers _______ to some degree.
Widen disk space
- despite the potential for neurologic deficit, the actual instance is very rare or nonexistent with manual stabilization*
What is the greatest risk to a C-spine patient?
Provider not recognizing the potential C-spine injury
- missed enough to 8% of CSI fractures (even after 3 views)*
What anatomical manifestation after CSI may be indicative of difficult intubation as a result of airway encroachment?
Soft tissue widening at C1-C2
Many studies have demonstrated, even in the presence of CSI with in-line stabilization precautions, intubation is ______.
Safe
What % carboxyhemoglobin is usually fatal?
50%
What is the half-life of carboxyhemoglobin, and what can be done to increase its offloading/removal?
- 4 hours
- 100% O2 treatment via ETT or Non-rebreather
will reduce half-life to 40 minutes
What BMI is considered “morbidly obese”?
> 35
BY how much can FRC decrease for an obese patient when supine?
Up to 50% reduction in FRC (vs 20% non-obese)
FRC = “Respiratory Reserve”
What airway-related complications occur in obese patients that effectively cause a the development of Restrictive Lung Disease?
- Increased Work of Breathing (due to increase chest wall & airway resistance)
- Increased Metabolic Demand (need for higher minute ventilation)
- Increased intra-abdominal & Intravascular-thoracic pressures (aspiration risk)
- Decreased FRC
Administration of what post-operatively should be avoided for the OSA patient?
Opioids
drug induced sleep and deep sleep can induce life-threatening apnea
What mode of anesthesia is optimal, if possible, for a patient with OSA?
Regional
avoids both opioids and sedation
OSA is a severe form apnea of hypopnea that has episodes lasting longer than ____ seconds during sleep.
10
What is the acronym that helps identify OSA patients?
STOP BANG
Snore loudly
Tired
Observed pt stop breathing during sleep
Pressure (high BP)
BMI over 35
Age over 50
Neck circumference > 15.75”
Gender: Male
E. All of the above are options
B. Mask Ventilation
C. Awake Intubation
Pt will be difficult intubation, rapidly de-sat
Labeled cartilaginous structures
