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The Emergency Airway
National Review Course in Emergency Medicine
Kirk Magee MD, MSc, FRCPCAssociate Professor
Dalhousie Department of Emergency Medicine
Outline:
• Recognition: is this an airway question?
• Cases
Case
• A 35 year old female presents to the ED with an altered LOC. She was found surrounded by empty pill bottles
• Vital Signs: HR 130, BP 115/78, sats 98%, GCS 6/15
• Is this an airway question?
Types of Airway questions
• Recognition of the need for an airway• Description of RSI and recognition of
relative contraindications• Recognition and management of a
difficult airway• Post intubation management• Approach to the failed airway
How to drive an examiner nuts…
• “I would perform an RSI with a double set-up”
Exam triggers to the difficult airway:
• Morbidly obese• Trauma to head or neck• Burns• Stridor• Prior unsuccessful attempts• Asthma• Anaphylaxis
Beware…
BMV
Laryngoscopy
Difficult Mask Ventilation
• Beard mask seal issues
• Obese lung/chest wall compliance
• Older head/neck position
• Toothless mask seal
• Snores/Stridor obstruction‘BOOTS’
Predicting Difficult Laryngoscopy and Intubation
MMAP the airway:• Mallampati and Measure
3-3-1
• A-O extension
• Pathologic conditions
‘MMAP’
Lets get ready to rumble!
Cases
Case 1
• 34 yo asthmatic presents with severe respiratory distress
• Normal airway
• VS: 122, 32, 156/90
Special Considerations
• Percipitating causes:– Pneumothorax, mucous plug– Role of epinephrine
• Difficult/impossible to BMV• Permissive hypercapnea• Ketamine• Apneic oxygenation
Apneic Oxygenation
Pre-oxygenation combining high flow nasal canula and a non-rebreather mask• Measured inspired oxygen NRBM @ 15 lpm only
60-70%– Pt’s expired gasses are mixing with applied O2 in
nasopharynx
• High flow nasal O2 flushes the nasopharynx with O2
– When pt inspires, inhale higher percentage of inspired O2
• Small changes in FiO2 create dramatic changes in the availability of O2 at the aveolus
Apneic Oxygenation
• Alveoli will continue to take up O2 even without diaphragmatic movments
• Optimal circumstances: PaO2 can be maintained at > 100 mmHg for up to 100 minutes without a single breathe!
“NO DESAT”
Nasal Oxygen During Efforts Securing A Tube
“If you enter the exam as a resident, that is how
you will leave, but if you enter as a consultant…”
Be decisive!
Case 2
• 4 yo presents with a 3 day hx of fever and “flu-like” symptoms
• Unable to arouse• VS: 139, 6, 60/40
Special Considerations
• Not just “little adults”
The Pediatric Airway
• Smaller airway• Large occiput• Tongue is larger• Larynx is relatively cephalad in position• Epiglottis is more floppy• < 10 yrs, narrowest portion of airway is
below vocal cords• Higher basal metabolic rate• bradycardia
Important pediatric numbers:• ET Tube size:
• ET Tube depth:
Age
4
Age
2
+ 4
+ 4
Breslow Tape
Case 3
• 26 yo Type 1 diabetic
• Florid DKA, not protecting his airway
• VS: 127, 28, 95/66, 95%
Special Considerations
• Hyperkalemia• Post-intubation still need high
respiratory rate– DKA– ASA overdose
Contraindications to Sux
• Hyperkalemia• Burns > 10% BSA• Crush injury• Denervation• Neuromuscular disease
– ALS, MS• Malignant hyperthemia
Case 4
• 50 yo pulled from burning car
• Significant burns to face, stridor
• VS: 112, 28, 132/88, 88%
Special Considerations
• Difficult airway• Toxicology
– CO– CN
MMAP: Pathological Obstructing Conditions…
e.g. Periglottic edema
e.g. Glottic trauma
MMAP: Pathologically Obstructing Conditions…
…with deep sedation may be impossible to BMV or intubate !!
Two Possible Scenarios
• Can’t Intubate• Can Ventillate
• Can’t Intubate• Can’t ventillate
What are your options?
• If not contraindicated, RSI may actually improve success rate– Double set-up
• Are you the right person, is the ED the right location?
• Awake intubation
‘Awake’ intubation
Advantages• Airway maintained
• Breathing continues• Stable
hemodynamics
Disadvantages• Can be difficult• Cooperation• Adverse reflexes
(GI/CNS/CVS)
…Intubation with topical airway anesthesia and light sedation.
Rescue device: Glide Scope®
Rescue ventilation devices: I-LMA
Rescue devices: Lighted Stylet
Rescue techniques
• Glide Scope®
• LMA• I-LMA• Lighted Stylet• Esophagotracheal Combitube• Retrograde Intubation• Fiberoptic Intubation
Can’t ventilate, Can’t intubate
Cricothryotomy Contraindications:
• Distorted neck anatomy• Pre-existing infection• Coagulopathy
• +++ difficult in pts < 10 yrs of age
Relative Contraindications!
What equipment do you need?• Scalpel• Tracheal dilator (Trousseau dilator) or
spreader• Tracheal hook• Portex or Shiley tube (No. 5-6 in
adult)
Decribe how you would perform a cricothyrotomy
Case 5
• 72 yo with altered LOC and urosepsis
• Normal airway
• VS: 124, 20, 70/40
Special Considerations
• CBA not ABC!– Maximize BP first
• Relative contraindication for etomidate?
“If only I had been a vet…”
Case 6
• 26 yo mountain biker “clothes-lined” on wire fence at high speed
• Pt is unable to talk; obvious respiratory distress
• Edema and echymosis evident at his neck
• VS: 115, 26, 160/85, 88%
Special Considerations
• The “most difficult” airway!• Patent airway may be lost with deep
sedation/paralysis• How does the scenario change with:
– Time from injury– Community vs Urban ED– “stable” vs. “unstable”
Your 1st attempt should not be in Ottawa at the exam centre!
Putting it all together
• Preparation – predictors of difficult BMV/laryngoscopy
• Preoxygenate – no BMV• Paralysis and induction agent• Placement of tube and confirmation• Post tube management
Putting it all together…Assess predictors of
difficult BMV/laryngoscopy
Pre-oxygenate
Paralytic/Induction Agent
Reposition
BURP
Bougie
Blade/ETT Change
Confirm Tube Placement
Rescue Techniques
Post Intubation Management
Cricothyrotomy
Unsuccessful
Unsuccessful
Unsuccessful
Difficult Laryngoscopy and Intubation: Putting it all together…
QuickTime™ and aCinepak decompressor
are needed to see this picture.