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: LMA

www.lmana.com

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.