Transcript Serotonin syndrome: A literature review of therapeutic

Advanced Emergency
Airway Management
Core Rounds July 22, 2004
Rob Hall MD, PGY5
FRCPC Emergency Medicine
Arun Abbi MD, FRCPC
Outline
• Some basics and motherhood statements
• An approach to emergency airway
management
• Minimal literature review
• Procedures are not the focus
• Case examples
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–
–
–
Approach
Focus on difficult airways
Selected Controversies
Pediatric airway mx
Case
• picture
MVC vs Trailer, two reds, one needs intubation
How do you prepare?
Intubation = flight:
preflight, flight, post-flight
Pilot picture
APPROACH TO THE AIRWAY
Think of an intubation like a pilot flying a plane!
Consider the following approach to
ED airway management.
PREFLIGHT
FLIGHT
POST-FLIGHT
Prep equipment (SOLESD)
Preoxygenate
Think of 4 back ups!!!!
Back up equipment nearby
Tube 'em Danno
Check placement
CXR
Sedation +/- paralysis
Tx hypotension, hypoxia
Part of being prepared is knowing
your equipment
Know your equipment
Pre-oxgenation is an important step
in preparation for intubation
• Desat curve
APPROACH TO THE AIRWAY
Does the patient need to be intubated? ABCDEs
Quckly evaluate the situation and the patient?
What type of airway?
CRASH AIRWAY
EASY AIRWAY
DIFFICULT AIRWAY
Cardiac arrest
Apneic
Near death
Not a crash airway
No anticipated difficulty
Difficult anatomy
Difficult pathology
Cases
• 2yo drowning, PEA arrest
– What type of airway?
– Any drugs?
• 77yo female, MVC, as you are
assessing, GCS drops, BP 60 palp, HR
40, teeth a bit clenched
– What type of airway?
– Any drugs?
THE CRASH AIRWAY
JUST DO IT!
Direct laryngoscopy with no drugs
Unsuccessful
TIME
(can bag, sats ok)
NO TIME
(can't bag, sats dropping)
Repeat attempts (up to 3)
Add succinylcholine prn
Go to failed airway algorithm
Go to failed airway algorithm
Case: Motorbike vs Car
• 45yo male, Motorbike vs car
• Hemodynamically stable: BP 175/50, HR 70,
face ok
• GCS 6 (E1V1M4)
• Bilateral decorticate posturing
• Anatomy looks normal
• What type of airway?
• What drugs would you use?
THE “EASY” AIRWAY
RAPID SEQUENCE INTUBATION
Prepare, preoxy, pretreat, induction, paralysis,
pass the tube, check placement
Unsuccessful
TIME
(can bag, sats ok)
NO TIME
(can't bag, sats dropping)
Repeat attempts (up to 3)
Go to failed airway algorithm
Go to failed airway algorithm
Case: Motorbike vs Car
• Pretreatment
– Lidocaine
– Fentanyl
– ? Defasiculator
• Induction
– Etomodate or
Pentothal
• Paralytic
– Succ
• How does lidocaine
work?
• What is the evidence for
lidocaine?
• When should we use
lidocaine?
• Why use fentanyl here?
• Is there any role for
defasiculation?
Lidocaine Pretreatment
• How does it work?
Blocks the direct
reflex which increases
ICP
– Laryngoscopy ------------ increased ICP via
direct reflex from laryngoscopy stimulation
“Local” anesthetic
Effect which decreases
The response to laryngoscopy
– Laryngoscopy ------------- sympathetic
release which increases MAP and ICP
– May also decrease brain’s oxygen utilization
Lidocaine Pretreatment
• How does it work?
“Local” anesthetic
effect which decreases
the airway response to
laryngoscopy
– Laryngoscopy ------------ stimulation of
“airway reflexes” which increases
bronchoconstriction +/- secretions
Lidocaine pretreatment: what is the
evidence?
• Evidence for “tight heads”
– Vallancourt C. CJEM. Mar 2002. 4(2).
– Systematic review of lidocaine and ICP
– 348 studies, 25 RCTs included
– Only one paper regarding intubation
– 3 papers regarding tracheal suctioning
– 24 papers looking at MAP changes with
lidocaine
Lidocaine Pretreatment
• Vallancourt C. CJEM. Mar 2002. 4(2)
– Bedford 1980 looked at intubations
• N=20, elective brain tumor surgery
• Lidocaine 1.5 mg/kg decreased ICP rise with
intubation by 12 mmHg vs placebo
– 3 Suctioning papers: decr ICP by 5 mmHg
– 24 MAP papers: decrease MAP by average
of 7 mmHg with lidocaine 1-3 mg/kg
Lidocaine Pretreatment
• Summary
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CPP = MAP – ICP
Lidocaine decrease MAP and ICP
What happens to CPP is unknown
Neurologic outcomes not studied
• Take home points
– We really don’t know if lidocaine is effective
– Most people currently are using lidocaine for head
injuries and some are using in asthma/copd
– Don’t waste time with lidocaine if the patient
needs rapid airway control
Case: Motorbike vs car; head
trauma, normotensive
• Why fentanyl pretreatment?
• Is there any role for defasciculation?
• What is the induction agent of choice
for hypotensive, head injured patients?
Fentanyl Pretreatment
• When is it indicated?
– Elevated ICP
– Anyone where you don’t want and increase in HR
and BP (cerebral aneurysm or AVM, aortic
dissection, active ischemic heart dz, penetrating
vascular injury)
• What is the evidence?
– Many studies documenting the blunting of
sympathetic response to laryngoscopy and
intubation but no outcome studies
Pretreatment: defasiculation
• What? 1/10 the intubation dose of
rocuronium, vecuronium, pancuronium
• Why?
– Prevents fasciculations from increasing your ICP
and intraocular pressure
• Is this necessary?
– Debatable: no evidence for
– Reasons why NOT to do this
• Adds another step, another drug
• May cause apnea, paralysis at wrong time
Pretreatment Medications Summary
MED
INDICATIONS
L
Lidocaine
Tight heads
Tight lungs
O
Opiate
Tight heads
Anyone where you don’t want incr
HR/BP (Ao dissection, MI, SAH, etc)
A
Atropine
Kids < 10 yo (some say 6yo)
Second dose of succinylcholine
F
Fluids
Hypotension
Anyone where you expect decr BP
D
Defasiculator
Tight heads (controversial)
Tight eyes (controversial)
Induction agents in hypotensive +
head injured
• Midazolam: NO
• Propofol: NO
• Ketamine
– Debatable: likely will increase MAP and ICP
– Most think ketamine is contraindicated with high
ICP (limited evidence)
• Pentothal: generally NO, could use at ½ the
dose (1-2 mg/kg vs 3-5 mg/kg)
• Etomodate
– Drug of choice
– Decrease the dose from 0.3 to 0.15 mg/kg
Case: Addy is sick
• 40 yo female
• Known Addison’s
• Abdo pain +
hypovolemic +
septic + ARDS
• BP 85/50, HR 130
• Anatomy easy
• What type of
airway?
• What drugs?
• ? Etomidate for
induction
• You give etomidate
and she has a
seizure, why?
Etomidate: will become the drug of
choice for RSI!
• Hemodynamically stable
– Average decrease in SBP is 10%
– Average decrease in SBP is 20% if already
hypotensive
– CAN DROP YOUR BP!!: decrease dose from 0.3
mg/kg to 0.15 mg/kg if concerned re hypotension
• Decreases ICP
• Very rapid onset (20-30sec): some give after
succ
Etomidate
• Side-effects
– N/V at emergence in 30%
– Adrenal suppression: decreases serum cortisol,
only reported with ICU infusions, never reported
after single ED dose
– Myoclonus
•
•
•
•
? Brain stem disinhibition
Commonly mistaken for seizure
30% incidence quoted (? Reporting bias)
Treat with benzo if prolonged/severe
Etomidate
• Contraindications
–P
–P
–P
–P
Pregnant
Pediatrics < 10 yo
Prior seizures
Poor adrenal function
Case: globe rupture
• On the exam, maybe!
• 30yo female
• In real life, NO!
• Facial smash
– IOP increases 5-10 mmHg with succ
• Suspect globe
– IOP increases 10-15 mmHg with
blinking
rupture
– Think what rough intubation will do!
• Is
– Airway control more important
– What to do?
succinylcholine
• Defasiculation can prevent increase
contraindicated?
in IOP with succ
• Rocuronium is an option
Contraindications to Succ
• Absolute
– Airway skills lacking
– Allergy
– Burn > 48hrs
– Crush > 48hrs
– CNS dz > 48hrs
– CRF with
hyperkalemia
– Malignant
hyperthermia
– Myopathies
• Relative
– Pseudocholinesterase
deficiency
– Organophosphate toxic
– Foreign body in airway
– Cardiac tamponade
– Globe rupture
(debatable)
– Abdo sepsis > 1 week
Succ and hyperkalemia
• Study of normal patients
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•
•
•
•
46% with K+ increase
46% with K+ decrease
8% with no change
Max change was 1 mEq/L
Myopathies are the worst!
Don’t forget about rhabdomyolysis
If in doubt, use rocuronium
Arrest after succ, think hyperkalemia
Case: Aspirator
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•
•
•
75yo female
CVA 3 months ago
Dysphagic
Aspiration, resp failure,
BP 150/70
• Anatomy easy
• Easy airway approach
• Can’t use
succinylcholine
• What is the timing
principle?
Timing Principle
• If you are using rocuronium as the
paralytic, it has a longer time to action
(1-2 min) than the induction agent
– Give rocuronium
– Wait 30 – 45 seconds
– Give etomidate
– Wait 30 seconds
– Intubate
Case: I hate myself.
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•
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•
25yo female
Benzo, Etoh overdose
GCS 8, BP 120/70, anatomy easy
Type of airway?
Do you need to add an induction agent
to your RSI?
Is an induction agent necessary if
you are paralyzing a patient?
• Controversial, no absolute right/wrong
• Advantages of adding full induction
– Improved patient comfort and decreased recall
– Blunts rise in ICP, HR, BP, airway resistance
– Decreases time to ideal intubation conditions
• Peak effect of succ doesn’t occur until 3 min (despite
onset at 45 sec) when given alone
• You don’t want the pt to be apneic for 3 minutes and
you don’t want to bag in between unless you have to
• Several studies documenting that IDEAL INTUBATION
CONDITIONS are present 45-60 seconds after induction
agent + succinylcholine
Case: Pneumonia, oops!
• 80yo female
• Resp failure from
pneumonia, Pmhx
hypertension and
seizures
• HR 110, BP
110/30, easy
anatomy
• What type of
airway?
• What drugs?
• After intubation her
BP is 80/40, HR 110
– What is the ddx?
– Why hypotensive?
– What is the
treatment?
Post-intubation Hypotension
• Tension pneumo, Myocardial ischemia,
Acidosis, high intrathoracic pressures are all
on the differential dx
• Volume depletion
– Common in anyone with respiratory or critical
illness that necessitates intubation
• Sympathetic tone
– Anyone that is critically ill has a maximal
sympathetic output; deep induction takes away
the stimulus ----------- end result is that they drop
their pressure
– Treat with fluids, pressors (be prepared!)
Case: head to pavement
• 3 yo male
• Fall off deck, head
to pavement
• GCS 5
• Bagged by EMS
• RSI by you
• After intubation,
patient desaturates
and is difficult to
bag. AE equal.
– Why?
– Differential?
– Management?
Post intubation Hypoxia
•
•
•
•
•
D
O
P
E
G
Dislodged tube (must r/o)
Obstructed tube
Pneumothorax
Equipment failure (wall to pt)
Gastric distension
more common in kid, ++ gastric
distension leads to compression of the
lungs
Case: I can’t breath
•
•
•
•
16yo female
Hx asthma
Sudden SOB, wheezing, distress
RR30, tired, sats 93%, BP 140,
anatomy easy
• Type of airway?
• Drugs?
Intubation of the Asthmatic
• Pretreatment
– Lidocaine 1.5 mg/kg decreases bronchospastic
response to laryngoscopy
– Atropine 0.5 mg adult, 0.02 mg/kg peds to
decrease airway secretions
• Induction
– Ketamine likely induction agent of choice
– Pretreat with atropine to decrease secretions
• Paralysis
– Succinylcholine
Post Intubation Management of
the Asthmatic
LOW AND
SLOW!!!!
RR 8-10 bpm, TV 6-8 ml/kg, Fi02 100%, PEEP ????,
Inspiratory flow rate 100 L/min (usually 60 L/min)
Watch peak inspiratory and plateau pressures
Case: Fast Food Nation
• I’m dead-sexy!
• SOB NYD
• Resp failure
• What type of
airway?
• What drugs?
• What position?
• What back ups?
DIFFICULT AIRWAY ALGORITHM
Is the patient easy to bag? Do a "BVM trial"
Call for help,
Difficult airway cart
Unable to maintain sats at 90%....
Go to Failed Airway Algorithm
Blind NTI
Awake Intubation or
Sedation only
"Triple Set up"
"Quick Look"
Prexoygenation
Lidocaine neb/spray
Light sedation prn
Lidocaine neb/spray
Light sedation and take a look
RSI drugs ready
Cric kit ready
Positioning of the Morbidly obese
• Picture 1
• Picture 2
Intubation of the Morbidly Obese
• Be READY for a difficult airway
• Starting with RSI is DANGEROUS!
• Triple set up probably the best
– Lidocaine neb, lidocaine spray, have RSI
drugs ready, have all your back ups ready,
do laryngoscopy, place the tube if you can
• Why else is this a SCARY patient?
Predictors of difficult BVM
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B
O
N
E
S
Beards
Obesity, OSA
Neck trauma, NO teeth
Expectant (pregnant)
Snores
Be cautious with your RSI as your back-up of
BVM may not be available!
DIFFICULT INTUBATION +
DIFFICULT BAG-VALVE-MASK
VENTILATION
Adam
adam
Wear your “Depends”
•
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•
•
Facial trauma
Neck trauma
Massive obesity
Congenital or acquired airway anatomy
anomalies
Difficult Emergency Airway
Managment
• NEAR data (National Emergency Airway
Registry)
– Registry of 10,000 ED intubations
– 97% of ED intubations are done by EP.s
– RSI used in 85% of non-arrested pts
– BNTI used in 5% of all intubations
– 1-3% are difficult laryngoscopies
– Oral ETT after RSI successful in 99.6%
Back to the Fast
Food Nation…
You do your “awake” laryngoscopy and
all you can see is a hint of the
epiglottis, what do you do??????
What to do when you can’t see S…
B
B.U.R.P.
B
Bouigee
B
Big hockey stick on stylet
B
Blade change
B
“Better” physician
B
Back ups
Case: Face vs Baseball bat
• 30yo male
• Assaulted
• Head injured, facial
smash, airway
bloody, GCS 10,
BP150
• “Underlying
anatomy” looks ok
• What type of
airway?
• What type of
preparation?
• What drugs?
• How do things
change is he is
combative?
Intubation with severe facial trauma
• Can you bag the patient?
• Oral intubation with RSI is usually successful
but is a bit dangerous
• Safest approach is likely “Triple Setup”
– Local, draw RSI drugs, prep back ups, perform
laryngoscopy, tube if you can or back off and do
RSI if it isn’t too bad
• What would your back ups be?
– Bouigee, Trach light, LMA
– BNTI contraindicated with severe facial trauma
Case: I can’t breath
• CHF, hypertensive, • CHF + Cardiogenic shock
• Drugs?
needs intubation
• Pretreatment
• Drugs?
– Fluid bolus
• Several induction
– Have pressor ready or
already going
agents can be used
• Induction agents limited
– Ketamine (pretreat
– Etomidate (full or ½ dose)
with atropine)
– Ketamine
– Etomidate
– No induction agent
– Fentanyl/midazolam
Controversies with Intubation of the
CHF patient
• Should you do an “awake” intubation
– Advantages: less problems with hypotension from
RSI drugs
– Disadvantages: intubation is more difficult and
takes longer; they don’t tolerate hypoxia during
prolonged attempts very well
– Recommendations:
• RSI if anatomy looks easy
• Awake if anatomy looks difficult
Controversies with Intubation of the
CHF patient
• Should you leave the patient sitting
– Advantages: avoids the large venous return with
lying them down
– Disadvantages: most people are less familiar with
intubation in the sitting position and intubation
may take longer
– Recommendations:
• Leave sitting if you are good at it
• Otherwise, leave sitting initially, push RSI drugs, wait for
full paralysis, lie down quickly and place the tube
I can’t breath!
Granny arrests just as you do the
laryngoscopy……..
Why?
Bradyasystolic arrests after
intubation of the CHF patient
• Why?
– Large venous return as you lie them down
– Vagal response to laryngoscopy and/or
succinylcholine (patient already has maximal
sympathetic tone and adrenals are “dry”)
– Induction agent crashes their pressure
– The patient was already dying
• Take home points
– Likely a combination of all of the above
– Be ready for the patient to crash
• Crash cart attached, fluid bolus, pressor ready, atropine
ready
Other difficult airways
•
•
•
•
Airway Burns
Anaphylaxis
Angioedema
Neck trauma
– Blunt
– Penetrating
• Oral infections
• Airway foreign
bodies
• Is Immediate transfer to OR
available?
• Is fiberoptic intubation in the
ED available?
• Key points for ED management
– Approach as difficult airways
– Call for back up and set up for
surgical airway
– Start with an “awake” intubation:
RSI is an option if you look and
see that the airway isn’t too bad
Case: Head vs stairs
• 30 yo male, fell down
15 stairs, intoxicated,
vomited after, GCS 6,
failed intubation by
medics, LMA inserted
• LMA in place, Sats 88%,
AE equal, BP 150/70,
prominent incisors,
small chin, anterior
larynx
• What type of
airway?
• What drugs?
• Grade 4
laryngoscopy with
blood and vomit in
the airway.
Management?
Case: Head vs stairs
• Oral intubation
attempts fail X 2
despite B.U.R.P. and
blade change
• Blind insertion of a
gum elastic bouigee
failed
• What type of
airway?
• What is the key
question now?
• Management?
THE FAILED AIRWAY ALGORITHM
The FAILED AIRWAY =
Unable to maintain sats > 90% with BVM
3 failed intubation attempts
"Call for everything"
-difficult AW cart
-anesthesia, 2nd EP
- cric kit +/- surgeon
TIME
(can bag, sats ok)
Bouigee
Trach light
LMA
Retrograde
Fiberoptic
I-LMA
BNTI, combitube
NO TIME
(can't bag, sats dropping,
patient crashing)
Rescue LMA
Surgical Airway
Adults = cric or TTJV
Peds = TTJV
Case
• 2 yo drowning
• Full arrest
• Is this a difficult airway?
Children are different not difficult
(generally)!
Head
Large occiput
Oropharynx
Large tongue, large tonsils, large adenoids, large and floppy
epiglottis, sharp angle b/w epiglottis and glottis,
Neck
Anterior larynx, higher tracheal opening, cricoid ring is the
narrowest part of the airway, small cricothyroid membrane,
soft and flexible neck tissue, good neck mobility
General
More anatomic variation between ages
Less anatomic variation between kids of the same age
Fewer changes in airway with body habitus
Other
Higher metabolic rates, lower FRCs, quicker desaturation,
higher tidal volumes
Pediatric PEARLS
• Intubation tricks
– Inch down slowly: don’t go deep and then
pull back
– Provide your own B.U.R.P.
– Beware that cricoid pressure from an
assistant can really move the airway
– Place an NG before: decompresses the
stomach, makes it easier to back, may help
you place the tube
Pediatric PEARLS
• EDD
– Slow expansion is not a reliable indicator of
esophageal intubaion in small kids because
the trachea is too collapsible
• Bouigee
– The smallest tube it will fit through is a #5
Proper BVM in pediatrics:
C-E position, lift the jaw to the mask, light pressure so you don’t
occlude the airway, minor position changes important, properly
sized equipment
• WRONG!
• RIGHT!
C E
What is the dose of midazolam in
a 2 week old neonate?
Braslow is your
FRIEND in Exams
and in Real life
Pediatric Equipment, etc
• Tube size
• Blade size
–
–
–
–
Premie
0-2
2-10
>10
Braslow (age/4 +4)
Braslow
0
1
2
3
• Cuffed
Braslow (>8yo)
• Tube depth Braslow (ETT size X 3)
Cuffed tubes in pediatrics is
controversial
• Several recent studies questioning the
dogma that cuffed tubes are not used <
8yo
• Cuffed tubes
– High ventilation pressures: asthma, ARDS,
post drowning
What is unique about RSI in pediatrics?
• Pretreatment
– Atropine < 10yo, < 6 yo ???
– Preoxygenation important as they will desaturate
quicker
– Defasiculation generally not used
• Paralytic
– Remember that succ dose is higher
• Infants/Children 2 mg/kg, neonates 3 mg/kg
– Should rocuronium be used routinely in pediatric
RSI?
Succinylcholine versus Rocuronium
for pediatric RSI
• Succinylcholine
– Faster onset (45
seconds)
– Shorter duration (8
minutes)
– Risk of hyperkalemia
(especially with
undiagnosed
myopathies)
• Rocuronium
– Slower onset (1-2)
min
– Longer duration (3040 min, may
decrease to 20 with
reversal)
– No hyperkalemia risk
Positioning in pediatrics
Case: “sore throat”, needs amoxil
•
•
•
•
•
•
4yo male
Sore throat today
Febrile, no cough
Looks sick, anxious
Tripod position
Drooling, stridorous
• Type of airway?
• Management now?
• Management after he
completely obstructs?
• ? OR management or
ER management of the
airway
DIFFICULT PEDIATRIC AIRWAY
ALGORITHM
Is the patient easy to bag? Do a "BVM trial"
Unable to maintain sats at 90%....
Go to Failed Airway Algorithm
Blind NTI
Call for help,
Difficult airway cart
Awake Intubation or
Sedation only
"Triple Set up"
"Quick Look"
Prexoygenation
Lidocaine neb/spray
Light sedation prn
Lidocaine neb/spray
Light sedation and take a look
RSI drugs ready
Cric kit ready
Use the same approach to the difficult airway; BNTI is
generally considered contraindicated in kids < 10yo
THE FAILED PEDIATRIC AIRWAY
ALGORITHM
The FAILED AIRWAY =
Unable to maintain sats > 90% with BVM
3 failed intubation attempts
"Call for everything"
-difficult AW cart
-anesthesia, 2nd EP
- cric kit +/- surgeon
TIME
(can bag, sats ok)
BVM and wait for help
LMA
Bouigee if ETT > #5
Other adjuncts not
commonly used in peds
(I-LMA, trach light,
fiberoptics)
NO TIME
(can't bag, sats dropping,
patient crashing)
Rescue LMA
Surgical Airway
> 10yo = cric or TTJV
< 10 yo = TTJV
Should Paramedics intubate kids?
• Gausche. JAMA Feb 2000; 283(6): 783-90
– RCT of BVM vs ETT in pediatrics
– N = 830
– Trends toward worse survival and neurological
outcome in kids in ETT group
– Critique: low rates of intubation, even/odd day
randomization, short transport times
– Take home: bag and drive unless long transport
time
TAKE HOME MESSAGES
• Preparation is key
• Prepare for the worst
• Have a solid approach to the crash,
easy, difficult and especially the FAILED
AIRWAY
• Kids are different, not difficult
The End…