Transcript Airway Management - Calgary Emergency Medicine

Airway Management
Philip Ukrainetz, MD, PGY5
Gord McNeil, MD, FRCPS
Core Rounds, July 18, 2002
Case

6 year old girl, MVA victim. She is stuporous,
has a suspected head injury and is
hypotensive. You have an IV and are giving a
20cc/kg NS bolus. What do you want to do?
Three indications to intubate
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Failure to protect airway
Failure to oxygenate or ventilate
Anticipated course
Anatomy
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Pediatric Airway Differences
– Larger tongue
– Large occiput
– Anterior larynx
– Larger epiglottis/floppier
– Subglottic area narrowest
– Less musculature
– Shorter trachea
– Narrower airway
Pediatric Pointers
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Broselow tape
Avoid 2nd dose of sux
– infants/children exquisitely sensitive 
intractable brady/arrest
Pierre Robin and Treacher Collins’ syndrome
– Small mandibles and posteriorly fixed tongues

Down syndrome - large tongue
Four Types of Airways
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BVM
Crash - intubate
RSI – the “8 P’s”
Difficult – no paralytic, have a backup
8 Steps to a Successful RSI

RSI 8 p’s:
– Preparation
– Peruse
– Preoxygenate
– Pretreatment
– Paralysis
– Protection
– Placement
– Post intubation management
Basic Airway Management - 8 P’s
“Prepare” – SIGMA D
What do you need for intubation?
 SIGMA D
–
–
–
–
–
S = Suction
I = Intravenous
G= Gas
M = Mask/Bag
A =airway equipment (oral airway, laryngoscope,
tubes, alternative)
– D= Drugs
“Peruse” - LEMON LAW
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L = Look: face, neck, chest
E = Examine: mouth, thyromental, floor of
mouth to thyroid
M = Mallampatti: huge tongue?, back of
throat?
O = Obstruction: tumor, epiglottitis
N = Neck mobility: OA, RA, syndromic
LEMON - Look

Look
– Evaluate the pt.
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Obesity
Micrognathia
High arched palate
Narrow face
Short or thick neck
Neck trauma
Large tongue
Presence of facial hair
Dentures
Large teeth
LEMON –Evaluate 3-3-2
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Evaluate 3-3-2
– Evaluate the anatomy
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3 fingerbreadths of mouth opening
3 fingerbreadths between front of chin and
hyoid
2 fingerbreadths from mandible to thyroid
cartilage
CAN I DISPLACE TISSUE SUB-MENTALLY?
LEMON – Mallampati score

Mallampati score
– Grade 1: entire post.
Pharynx, visualized to
tonsillar pillars
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No difficulty
– Grade 2: hard palate,
soft palate and top of
uvula only

No difficulty
– Grade 3: hard and soft
palate only

Moderate difficulty
– Grade 4: no
visualization post
pharynx or uvula (hard
palate only

Severe difficulty
LEMON -Obstruction
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Obstruction
– Look for upper and lower airway
obstruction
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foreign body aspiration
Epiglottitis
croup
Abscesses
others: surgery,tumors, radiation
LEMON –Neck Mobility
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Neck Mobility
– Collar, RA, degenerative arthritis, history of
surgery
– Note: get significant movement with
BVM ventilation also!!
“Pre-oxygenate” - no bagging

Preoxygenate (nitrogen washout)
– Saturate O2 reservoir, tissues and blood
– 100% NRB (70%)
 5 min healthy adult
 2.5 min children
 8 VC breaths
How much time do I have?
70kg adult maintains O2 sat >90% for 8
min
–From 90% - 0% = < 120 seconds
 Obese adult (>120kg) desaturate to 0%
in less than 3 min
 10kg child desaturate <90 in 4 min
–From 90% to 0% in 45 seconds
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Walls graph
“Pre- medicate” - LOAD
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Lidocaine: tight heads, tight lungs
Opioid: for blunting sympathetic response
(ICP, IOP, aortic dissection, aneurysm, IHD)
Atropine: children <= 10
Defasiculate: for increased ICP
Lidocaine ?
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Premise
– Laryngoscopy and Intubation
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afferent stim. in post pharynx/ larynx
increased central stim
increased ICP
stim of autonomic system
– increased HR / BP
– upper and lower resp. tract leading to increased
airway resistance
Lidocaine ?

Literature (supports)
– suppresses cough reflex
– attenuates increase in airway resistance
(from ET tube irritation)
– prevents increased ICP
– prevents increased IOP
– decreases dysrhythmias by 30-40%
Lidocaine ?

Literature (?doesn’t support)
– use to attenuate sympathetic response to
laryngoscopy
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Use: tight lungs / tight brains
– 1.5mg/kg 3 min prior
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Topical 4% lidocaine and ICP ????
Drugs to Decrease Sympathetic
Response to Intubation (LOAD)
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Fentanyl
– high dose 5-10 ug/kg (will unequivocally
block sympathetic response - hypotension,
apnea , chest wall rigidity)
– 1.5-3ug/kg (2 min prior) blocks increase BP
but no effect on HR

Beta-blockers
– will decrease sympathetic response
– prob: neg ionotrope, bronchoconstriction
Drugs to Decrease Sympathetic
Response to Intubation

Helfman et al
– compared 200 lido, 200 fentanyl, 150
esmolol
– esmolol only reliably agent in preventing
rise in HR and BP

Chung et al
– combination esmolol and fentanyl (2ug/kg
and 2mg/kg) best combo with limited sideeffects
LOAD - Atropine

Use with SUX in children under the age
of 8 and when giving repeat doses
– Sinus brady, junctional, sinus arrest usually
after a second dose
– Reason: Sch mimicks action of Ach at the
cardic muscarinic receptors
– Dose 0.02mg/kg (no less than 0.1mg), 3
min prior to induction
LOAD - Atropine

Literature
– Prevents brady in children
– Reduces BUT doesn’t eliminate them in
infants
– No effect on older children
– Anesthesia literature: volatile anesthetics in
combination with atropine - increased risk
of arrhythmias
– Bottomline: Use atropine on children in the
ED
Defasiculation
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Decrease the rise in ICP from Sch induced
fasciculation (animal data, limited human)
Does not attenuate the sympathetic response
to intubation
Does not attenuate the increase in airway
resistance with intubation
1/10 intubating dose
RSI in Adults With Elevated Intracranial
Pressure: A Survey of Emergency
Medicine Residency Programs

Am J Emerg Med :1995
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–
–
–
–
–
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100 programs surveyed
67 responses, 65 used RSI in their programs!!!
Top NMB agents – Sux and vecuronium
Top induction agents - midazolam and thiopental
Lidocaine - was routine
Fentanyl - other pretreatment agent
Defasciculating dose used by most programs
“Paralysis with induction”
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Rapid sequence - “intubation before
aspiration”
Do not titrate
Midazolam, ketamine or thiopental
Succinylcholine
Case

A 6 year old has been seizing for 30 minutes
and you have a vial of etomidate in your hand
- should you use it?
Etomidate
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Ultrashort acting non-barbiturate hypnotic
agent (no analgesic effects)
Adv:
– rapid onset and rapid recovery
– hemodynamic stability
– minimal resp depression
– cerebral protection
Induction Dose: 0.3 mg/kg
Etomidate
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Onset : one arm-brain circulation (within 1
min)
Duration : 3-5 min
Cerebral
– decreases CBF by 35% - decr ICP
– no change MAP
– CPP increases (increased cerebral
oxygen/demand ratio) - decr ICP
Etomidate
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Resp
– minimal effects
– doesn’t release histamine
CV
– no change in HR/ MAP/ CI/ PAWP
Endocrine
– concern re: steroid depression
Etomidate
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Dose dependant reversible inhibition of 11beta- hydroxylase (converts 11-deoxycortisol
to cortisol)
Studies:
– transient drop in cortisol levels with
induction of anesthesia (6hrs), back to
normal in 20 hrs
– no reported adverse outcomes
Etomidate
CI: < 10, known seizure disorder, pregnant
 Adverse effects
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– nausea and vomiting (30-40%)
– pain on injection (similar to propofol)
– myoclonic movement
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Pregnancy category C
– embryocidal in rats
Case
A brittle asthmatic comes in obtunded
and has a silent chest - you needed to
intubate him yesterday?
 What inductionagent shall you use?
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Ketamine
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Phencyclidine derivative (similar to Angel
Dust)
Dissociative anesthetic (dissociation between
the thalmus and limbic system)
Sympathomimetic (increased HR and BP)
Increases cerebral blood flow by 60%
potentially elevating ICP!
Reduces airway resistance
Dose 1-2mg/kg IV, 4-5mg/kg IM
Onset: within 60s
Case

Head injured, hemodynamically stable
34 year old. Needs to be intubated
what will you pre-medicate with and
what is currently your induction agent
of choice?
Thiopental
Barbituate, potentiates GABA
 Cerebroprotective
 Dose related potent venodilator and
myocardial and resp depressant
 Adult 1-4 mg/kg, child 1- 6 mg/kg
 Onset 15 - 30 secs, duration 3- 5 min
 Do not use in hypotension

Case

One hour ago a zoo keeper was welding
in the elephant cage when the elephant
panicked, sat on him, and they were
both burnt severely. The patient has
been crushed, paralyzed, head injured,
has an open globe injury, but manages
to squeak out that he had a stroke 4
days ago. You cannot get an IV - can
you use succinylcholine?
Succinylcholine CI
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History of MH
Burns > 24 hrs old until healed
Muscle damage (crush) > 7 days - completely
healed
Spinal cord injury, stroke (denervation UMN,
LMN) > 7 days - 6 months
Neuromuscular disease, myopathies:
indefinately as long as disease is active
Intra-abdominal sepsis > 7 days - resolution
of infection
Succinylcholine
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Depolarizing NM agent
– Onset:
– Duration:

30-45s
5-10 min
Dosage (IV):
– 1-1.5mg/kg adult
– 2mg/kg child
– 3mg/kg neonate
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Can give IM at twice the dose
Succinylcholine
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Side-effects?
– Incr IOP, ICP
– Bradycardia
– Trismus-masseter muscle spasm
– Fasciculations
– Malignant Hyperthermia
– Hyperkalemia
– Prolonged blockade
Sux - Hyperkalemia
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Literature
– Case reports since 1960’s
– No case reports of hyperkalemia in the ED
(multiple trauma, burns, neurological disease)
– Literature poor with chronic renal failure
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Zink et al
– 100 pts (no risk factors)
– Max increase 1.0 meq/L (K increased in 46pts,
dropped in 46 pts and unchanged in 8)
– 1 pt found to be in a wheelchair!, K dropped from
4.6 to 4.1
Sux - Hyperkalemia
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Mechanism: ? Increased receptor density
(extra-junctional), more sensitive, depolarize
for long periods, release of K
? Increased K of approx 0.5 meq/L
Risk factors/guidelines :
– Burn victims >24hrs to 1-2 yrs post healing?
– Crush injuries >7 days post lasting up to 60-90
days
– Spinal cord injury/ stroke (denervation injury) >7
days to 6 months
– Neuromuscular disorders (MS, ALS) indefinitely
Sux - Hyperkalemia
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Conclusion
– Non high risk pts
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No problems with administration
– High risk pts
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CRF probably okay
Others : literature is not great but we have
good NDNM blockers, therefore no point to
take risk
Sux – Raised IOP
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Thought to be a contraindication to an open
globe injury!
Pressure elevations do occur, are transient,
maximal for 2-4 min post administration
– Pressure elevations of 3-8mmHg (never been
shown to worsen globe injury
– Comparison: normal blink – increases IOP by 1015mmHg, forceful closure of the eyelid >70
mmHg
– Anesthesia continues to use Sux in OR with globe
injuries
– Chiu et al:

if you want to prevent increase in IOP, can give
defasciculating dose of a NDNM blocker (rocuronium 2
Case

During the G8 summit a cocaine addict
comes in SLUDGING. Is it safe to use
succinylcholine?
Sux – Prolonged blockade
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Pseudocholinesterase Deficiency
– Congenital
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Heterozygous : up to 25 min, homozygous up to 5 hrs
after a single dose
Homozygous : 1 in 3000 pts
– Acquired
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Organophosphate poisoning
Cocaine use
CRF, severe liver disease, hypothyroidism,malnutrition,
pregnancy, cytotoxic drugs, metoclopramide,
bambuturol(long acting beta 2 anonist)
– Note: above none have prolonged blockade over 20-25
min
Sux – Trismus/Masseter
muscle Spasm
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Occasionally can get spasm
Especially in children
Transient
If prolonged, severe and other muscle
involved should think of MH
Malignant Hyperthermia
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Genetic skeletal muscle membrane
abnormality - never been an ED case
reported
Onset acute or delayed - 60% mortality
Clinically
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–
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–
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Muscle rigidity
Autonomic instability
Hypoxia
Hypotension
Hyperkalemia
Lactic acidosis
Temp. elevation is a late sign
Case
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You need a paralytic, however the
patient was severely burnt 48 hours ago
ago. You can see the epiglottis but you
need just a little more relaxation - what
would be your paralytic of choice?
Rocuronium
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Aminosteroid, non-depolarizing
neuromuscular blocker
Agent of choice when sux is CI
Onset: 1.2-1.8 min (sux 0.8-1.2)
Dose: 0.6 mg/kg
Duration of action: 30 -45min
Rocuronium
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Cannot depend on neostigmine in failed
intubation - time to recovery will be too long
Histamine related hypotension
Primary use of non-depolarizing agents is for
defasiculation and paralytic maintenance
post-intubation
Rapacuronium1.5 mg/kg, onset 60 sec,
neostigmine could reverse from 24min
duration to 11min looked ideal, however….
Rapacuronium
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HOLD THE PRESSES!!!
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March 27, 2001
– “Injectable Anesthesia Drug Being
Withdrawn From The Market:
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Bronchospasm in 3.4%
5 case reports of death (? severe
bronchospasm)
Other drugs also given
Voluntary withdrawal by the company pending
investigation
Paralytics (table)
Agent
Class
Dose(mg/kg)
Onset
Duration
Vecuronium
Intem.
0.1
3-5
30-45
Atracurium
Intem.
0.5
3-5
30-45
Pancuronium
Long
0.1
3-5
60-90
Rocuronium
Intem.
0.6
1-2
30-45
Mivacurium
Short
0.15
2.5-4
10-20
Rapacuronium
Short
1.5
1-2
10-15
Case

You are ready to intubate the RT is screaming
in your ear to push all the meds and get the
!@#$%^&* tube in. The RT is bagging the
patient and the nurses have drawn up the
appropriate medications for this head injured,
hemodynamically stable patient - what is your
timeline to intubate?
Timing
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10 minutes out:
– Prepare (SIGMA D) Peruse (LEMON)
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5 minutes out: Pre-oxygenate
3 minutes out: Pre-treat (LOAD)
Zero: Paralysis with induction
Zero +30 sec: Pressure and position
Zero +45 sec: Pass tube - jaw flaccidity
Zero +1 minute: Post-tube mngmt
RSI Sequence
Case

As you go to intubate a child, you get a
beautiful view of the cords and then it
disappears. You cannot seem to direct the
RT to give the right amount of BURP to get
the same view. What can you do?
“Pressure and position”
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Sellicks maneuver “BURP”
Sniffing position - cervical extension and
atlanto-occipital flexion
BURP

The Efficacy of the "BURP" Maneuver
During a Difficult Laryngoscopy.
Takahata O Anesth Analg - 1997 Feb;
84(2): 419-21
[The difficult intubation. The value of BURP and 3 predictive tests of difficult intubation] Ulrich B - Anaesthesist - 1998 Jan; 47(1): 45-50
Case

You have somewhat blindly intubated a
cardiac arrest patient. You are quite
confident it went in. However, the end tidal
CO2 monitor is not registering wave form. By
all other measures the tube appears in should you yank it?
“Pass tube with proof”
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Thru cords
Misting
ETCO2
Chest rising and falling
Esophageal detector
Basic Airway Management
Positioning
Pass tube with proof
Position of Tube During Intubation
End Tidal CO2
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Qualitative
– Colorimetric
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When color change (yellow = yes) virtually 100%
specific
False negative with cardiac arrest
Quantitative
– Capnography
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Measures amount of CO2 in the expired air (direct
indicator of CO2 elimination by the lungs)
Again false negative with cardiac arrest
Esophageal Detection Devices
(EDD)
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Premise
– Esophagus will collapse with suction
– Trachea rigid structure with lots of air (no
collapse
Not as reliable as end tidal CO2 therfore
should be used as a 2nd line device to confirm
tube placement
Bulb Aspiration
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“Turkey baster”
– Round compressible ball
– Deflate the bulb and attach to end of ETT
– Esophagus: delayed or sluggish inflation
– Trachea: expands rapidly (within 2
seconds)
Syringe Technique
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Same principle
Use larger volume of air
Withdraws 30 cc of air
Use rapid aspiration os syringe
Case

You have successfully intubated a CormackLehane grade IV airway while telling the
trauma team about a 67 foot putt you
drained at McCall Lake. As you are doing
your end-zone dance the patient grabs for his
tube. The nurse screams “Dr. Hotshot - what
would you like for maintenance of sedation
and paralysis?”
“Post-intubation”
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Use a one third therapeutic dose of benzo
and non-depolarizing paralytic when any
signs of patient awareness detected
Appropriate vent settings: PEEP, rate, volume
Post-intubation bradycardia is an esophageal
intubation until absolutely proven otherwise.
Case

You have successfully intubated a child. Sixty
seconds later the child becomes hypotensive.
What could be the cause?
Postintubation Hypotension
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Tension pneumothorax:
– Incr PIP, difficulty bagging, decr B/S, poor
sats
– Rx: Chest tube
Induction agents:
– Exclude other causes
– Rx: Fluid bolus, expectant
Postintubation Hypotension
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Decreased venous return:
– High PIPS secondary to high intrathoracic pressure
– Rx: Fluid bolus, bronchodilator, incr exp time, decr
tidal volume and rate

Cardiogenic:
– Usually in compromised patient; EKG: exclude
other causes
– Rx: cautious fluid bolus. pressors
Post-tube complication
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A patient becomes hypoxemic 2
minutes after you intubate him. What
is your differential?
Post-intubation Hypoxia
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
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D: Dislodged
O: Obstruction
P: PTX
E: Equipment failure
Mr. Pierre Robin

Your called to a 2 year old child who is “flat”,
mom says he has been unwell for a few days.
She found him unresponsive. You note he
has a tiny mandible and a large tongue. How
are you going to prepare for this airway?
Difficult Airway

Emergency Physicians
– National Emergency Airway Registry
– 6294 intubations
– 85% successful on first attempt
– 99% ultimately successful
– 1% failed airway requiring rescue
maneuvers
Difficult Airway
Sakles Jc et al Ann Emergency Med
1998
 Intubations over 1 yr in their ED
(N=610)

– 569 (93%)by staff/residents
– 515(84%) used RSI
– 98.9% intubated successfully
Difficult Airway
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Paralytics and Aeromedical Transport
– Program A (RSI) success rate: 93.5%
– Program B (no RSI) : 66.7%
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Same program after institution if RSI
Success: 90.5%
Difficult Airway – BARF
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B(5): Best view, Best person, Bougie, Blade
change, BURP manueuver
Alternative airway: LMA, lighted stylet
Rescue: BMV with BURP
Failed airway: TTJV if <8 years old, crich if >8
Best View
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Cormack-Lehane
laryngoscopy
grading system
Grade 1 & 2 low
failure rates
Grade 3 & 4 high
failure rates
Blade Change
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Macintosh (curved)
– McCoy – articulating tip
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Miller (straight)
– Use with children younger than 8y/o, and
people with anterior larynx (short mentalhyoid distance)
– Wisconsin and Guedel blades
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Larger more rounded barrel
Blade Change
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Laryngoscopy and Intubation
– “the single greatest obstacle to successful
intubation is the tongue… the tongue is the
enemy”
– Paraglossal technique
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
Step 1 (blind) insert blade blindly into the
esophagus
Step 2 (visual) withdraw blade until you
visualize the cords /epiglottis
Alternative Airway technique
LMA
 Orotracheal or nasotracheal
 Lighted stylet
 Digital
 Retrograde
 Fibreoptic

Alternative Airway - Laryngeal
Mask
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
Does not constitute
definitive airway
management
Temporizing
measure in the ED
Size :
– #3 teenagers and
small female adults
– #4 average size
adult
– #5 large adults
Alternative Airway-Laryngeal
Mask

Inflate cuff
– #3 – 20cc
– #4 – 30cc
– #5 – 40cc
– Or until no leak
Note: no literature
describing the
success rate in the
ED(OR success
>95%)
Alternative Airway - LMA
Zideman D - Ann Emerg Med - 01-Apr-2001; 37(4 Suppl): S126-36
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Not studied in infant/child resuscitation
Complications more frequent in peds
Correct size
– 1 = smallest; 3-4 = adult female; 4-5 = adult
male
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May be dislodged during transport/CPR
Aspiration – little protection
Alternative Airway Combitube
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Double lumen, double cuff airway
Insert in the midline
Inflate proximal large oropharyngeal balloon
( 100mls of air) – via blue pilot balloon
Inflate white distal balloon with 5-15mls air
Ventilate first through the long blue port – if
air in lungs the tube in the esophagus
(majority of time in esophagus)
If air in stomach then tube in the trachea
(rare event) then ventilate through the short
clear port
Alternative Airway Combitube
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Effective airway
management device
Higher success rate
than LMA in the
prehospital setting
High rate of success
and few
complications when
used for prehospital
cardiac arrest
Alternative Airway
Nasotracheal Intubation

Advantages
– Very few over RSI

Disadvantages:
– Takes a long time
– Higher failure rate
– Higher complication
rate
– Use smaller tube size
Alternative Airway
Nasotracheal Intubation

Indication
– A potentially difficult intubation who is
spontaneously breathing - epiglottitis
– Pt you do not want to paralyze

Contraindicated
–
–
–
–
–
–
Combative pts
Anatomically deranged airway
Neck hematomas
Raised ICP
Severe facial trauma
Coagulopathy
Alternative Airway
Nasotracheal Intubation

Pearls
– Sniffing position
– Pull tongue forward by grasping with gauze
– Only 60-70% successful on first attempt
(10-20% of NTI’s are simply not possible
Alternative Airway
Lighted Stylet
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Use if cannot directly
visualize the larynx with
laryngoscopy
Relies on
transillumination of the
soft tissues of the neck
Trachea: well defined
glow
Esophagus: diffuse light
glow
Alternative Airway
Lighted Stylet

Success rates consistent with or exceed that
of conventional laryngoscopy
Alternative Airway
Digital Intubation




Tactile intubation
technique
Use of fingers to direct
the tube into the larynx
Not easy to perform (if
have small hands)
Indications:
– No laryngoscopy
equipment
– Visualization of the larynx
is impossible (blood,
secretions)
– Best for premature and
newborn infants
Rescue Airway
BVM with BURP
BONES - predicts difficult mask ventilation
 B: Beard
 O: Obese
 N: No teeth
 E: Elderly (>55 y/o)
 S: Snores

Failed Airway
Surgical:

Needle crich & TTJV, cricothyrotomy,
retrograde intubation
Difficult crich: SHORT
S: Surgery
H: Hematoma
O: Obese
R: Radiation
T: Tumor
Failed Airway


Cricothyroidodomy not recomm. age <8
– complication rate 10-40%
– Retrograde?
Transtracheal jet ventilation
– surgical method of choice in emergency
– allows ventilation for 45-60 mins
– risk – aspiration, subcutaneous
emphysema, barotrauma, bleeding,
catheter dislodgment, CO2 retention
Failed Airway
Retrograde Intubation




Puncture the cricothyroid membrane then
thread a wire retrograde to the mouth, the
tube is then inserted over the wire
Use as rescue technique
Do not use if infection at the site of the
needle puncture
Note: does take time to do
Failed Airway
Surgical Airway

Cricothyrotomy
– NEAR Study


Only 1% of 4000 Ed intubations required cric.
20% complication rate (mostly minor)
– 4 step process
– Pediatrics age >8 y/o
– #4 Shiley cuffed tube

Needle cricothyrotomy (age <8)
Failed Airway
Surgical Airway

Needle cricothyrotomy/ TTJV
– Temporizing measure
– Surgical airway of choice for age <8 y/o
– Need supraglottic patency (exhalation)
– No airway protection
Failed Airway
Surgical Airway

Needle cricothyrotomy/ TTJV
– 12-16G needle
– <5 y/o ventilation only by bag
– 5-12 y/o 30 psi
– 12 – adult 30-50 psi
Case

A lucid, perfectly well 20 year old has
been hit in the throat with a 67 foot
putt. He is stridorous and sats are fine.
He has a large hematoma externally.
He is slowly getting worse. How would
you like to intubate him?
Awake intubation




Lidocaine spray
4% lidocaine on pledgets
Titrated dose of midazolam and fentanyl
Take a look - can turn into a formal RSI
Thanks
Idan Khan MD, FRCPS
Gord McNeil MD, FRCPS