Transcript Airway Management

Endotracheal Intubation in the
ICU
David Oxman, MD
July 12, 2013
Objectives
• Discuss Airway Assessment
– Assessing for difficult bag mask ventilation
– Assessing for difficult intubation
– Specific conditions of critically-ill.
• Discuss 4 Ps of Pre-intubation:
– Preparation
– Pre-oxygenation
– Positioning
– Planning.
Objectives
• Discuss obtaining intubating conditions
–induction
–paralytics
• Discuss Direct Laryngoscopy and tube
placement
• Post-intubation care
• Overview Rescue Devices
Why Intubate
• Indications for endotracheal intubation
1. inadequate oxygenation or ventilation
2. airway protection in a patient with altered
mental status
3. expectation 1 or 2 will develop soon!!
• Contraindications
1. Laryngeal Trauma
2. Obstructed Airway
Who should intubate in the ICU?
Chest, December
2012
Why Intensivists Should Intubate
• It’s the A in ABC.
• Competent to perform vast majority
of intubations.
• Will be expected in many settings.
• Complications mostly not related to
airway itself.
Airway Assessment
• Can be more challenging in critically ill.
• Must avoid the “cannot intubate, cannot
ventilate” scenario.
• Must assess
1) Risk for difficult mask ventilation
2) Risk for difficult intubation
Bag Mask Ventilation
• Crucial airway management skill.
• Takes practice to perform correctly.
• Gives time for well-planned approach to
definitive airway management.
• 3 keys:
– Patent airway
– Good mask seal
– Proper ventilation
Bag Mask Ventilation:
Opening Airway
Head Tilt and Chin Lift
• One hand applies downward
pressure to forehead and index and
middle finger of the second hand
lift at chin.
• Lifts tongue from posterior pharynx
Jaw Thrust
• For unstable cervical spine
• Place heels of hands on parieto-occipital area
• Grasp angles of mandible with fingers, and
displace jaw anteriorly.
Adjuncts for Opening Airway
• Need to size properly
• Avoid pushing tongue into posterior pharynx.
• Start with curve of OPA inverted and rotate 180 degrees as tip
reaches posterior pharynx.
• Avoid in awake patient  aspiration risk
Bag Mask Ventilation
One-handed technique
Three facial landmarks that must be covered by mask:
1.
Bridge of the nose
2.
Two malar eminences
3.
Mandibular alveolar ridge
Two-handed techniques
Small tidal volumes
Squeeze steadily – don’t force air too
quickly
10-12 breaths/minute
Assess for rise and of fall chest
Airway Assessment:
Difficult Bag Mask Ventilation
• Incidence approx 5%
• MOANS
• M ask seal: cant approximate
mask
• O besity: redundant tissues
impede airflow
• A ge >55: loss of elasticity tissues
• N o teeth: mask doesn’t sit
properly
• S tiff (lungs/body): need
increased pressure
Airway Assessment:
Identification Difficult Intubation
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Incidence difficult intubation varies.
No clear definition. Approximately 5%
Corresponds to glottic view
Can’t intubate/can’t ventilate = 1 in 10,000
Strongly associated with adverse outcomes
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Airway trauma
Aspiration
Hypoxemia/Anoxic brain injury
Hypotension
Cardiac arrest and death
Assessing the Airway:
Identification Difficult Intubation
LEMON
–L ook
–E valuate 3-3-2
–M allampati
–O bstruction/Obesity
–N eck mobility
Assessment for Difficult Intubation
“Look”
• External
– Facial trauma
– Unusual anatomy
• Internal
– Foreign body
– Obstructing mass
• Sensitive but not specific
Assessment for Difficult Intubation:
Evaluate: 3-3-2 Rule
Mouth opening
Access to airway
and obtaining glottic
view
Tip of mentum to hyoid bone
Can tongue be deflected
to accomdate
laryngoscope
Thyromental distance
Predicts location larynx to
base of the tongue. If larynx high
angles difficult
Assessment for Difficult Intubation:
Mallampati Score
• Validated but not as
solitary predictor.
• Relates amount of
mouth opening to size of
tongue.
• Provides estimate of
space for oral intubation
by direct laryngoscopy.
• Class I or II : easy
laryngoscopy
• Class III difficult
• Class IV: extreme
difficulty. (10%failure).
Assessment for Difficult Intubation:
Obesity
• Redundant tissue in upper airway may
obscure glottis.
• Controversial about how often difficult airway.
• Proper positioning key.
Assessment for Difficult Intubation:
Neck Mobility
• Decreased cervical spine mobility
compromises sniffing position.
• Impairs alignment of axises and glottic view
• Degenerative or rheumatoid arththritis
• Cervical immobilzation
• Test: extending neck/touching chest
Additional Considerations in
Critically Ill
• Complications intubation higher than ICU (2040%.)
– Limited physiologic reserve
– Pre-existing hypoxemia or hemodynamic instability.
– Inability to properly assess airway.
• Special Considerations in ICI: Three Hs:
– Hypoxemia
– H+
– Hemodynamics (hypotension/pulmonary
hypertension)
Steps for Endotracheal Intubation
1. The 4Ps:
– Preparation
– Pre-oxygenation
– Positioning
– Premedication
2. Achieving Intubating Conditions:
Laryngoscopy/Intubation
3. Post-intubation Care
Preparation
• Airway assessment
– Signs of difficult bag mask ventilation
– Signs of difficult intubation
• Assembling necessary equipment and
medications.
• Developing an airway management plan
– Back-up plan
– Back-up to back-up plan
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Preparation
Equipment
S uction
T ools (laryngoscope, blade, extra batteries)
O xygen
P ostioning/plan
M onitors (pulse ox, BP, capnography)
A mbu bag, airway devices
I ntravenous access
D rugs (premeds, induction, NMB)
Preparation:
Preoxygenation
• Establishment of oxygen reservoir
– Replace nitrogenous mixture of room air
– FRC = 30ml/kg
– Preferable time = 5 minutes
• Bag mask ventilation not needed if good
preoxygenation.
• Preoxygenation often challenging in ICU
– NIPPV
– Elevating head of bed
Preoxygenation: Apnea Time (VE= 0)
- Time from 90% to
0% MUCH shorter
than time from
100% to 90%.
- Obese and criticallyill desaturate
quicker.
Preparation:
Pretreatment
Drugs to mitigate adverse effects of intubation
•L idocaine (reactive airways or elevated ICP)
•O pioids ( blunts sympathetic response and
increased BP)
•A tropine ( bradycardia – mainly kids)
•D efasiculating Agents (low dose competitive
neuromuscular blocker in elevated ICP)
Preparation:
Head Positioning
Supine
Head Elevated
Head Elevated and Neck
Extending = Sniffing Position
Positioning: RAMP
• In supine patient access to
airway obstructed.
• With patient propped in RAMP
position, access to airway
improved.
• Imaginary horizontal line from
external auditory meatus to
the sternal notch
Preparation:
The Need for a Plan
Main Airway Algorithm
Achieving Intubation Conditions
• Many ICU patients need very little or no drugs.
– Crash airway
– Patient relaxed and unresponsive, similar to
conditions with rapid sequence intubation (RSI).
• May not want to stop spontaneous breathing.
Induction Agents
• Purpose: Blunt sympathetic responses,
provide amnesia and improve intubating
conditions.
– Rapid Sequence Intubation: simultaneous
administration of sedative and a neuromuscular
blocking.
– ICU patients with crash airway or pseudo-crash
airway often need very little induction drug or
none at all.
Induction Agents
• Midazolam: (dosage 0.1-0.3 mg/kg; time to effect
>15 minutes; hypotension)
• Etomidate: (rapid onset; no hypotension; no
analgesia; concerns with sepsis unjustified)
• Propofol: 1.5 to 3 mg/kg; rapid onset; hypotension;
no analgesia.
• Ketamine: sedation and analgesia; no hypotension;
bronchodilator effect; respiratory drive preserved;
good for “awake look.”
• Thiopental: rapid onset; no analgesia; myocardial
depressant; severe hypotension
Neuromuscular Blockade
• Rapid Sequence Intubation
– Goal: quickly obtain intubating conditions and
quickly secure airway.
– Avoid BMV and minimize risk of aspiration.
– NMB standard of care in ED
Neuromuscular Blockade
• Succinylcholine
– Onset 45-60 seconds; duration 6-10 minutes
– 1-1.5 mg/kg
– Contraindications: hx of malignant hyperthermia,
neuromuscular disease with denervation (MD, stroke > 72
hours, burns >72 hours) rhabdomyolysis, hyperkalemia.
• Non-depolarizing neuromuscular blockers
– Rocuronium 0.8 -1.2mg/kg: fast onset, longer duration
than succinylocholine; can be reversed
– Cisatricurium (Nimbex): not for RSI as slow onset
– Vercuronium
Laryngoscopes
Macintosh Blade
Miller Blade
Laryngoscopy Technique
Direct Laryngoscopy
Opening Mouth and Inserting Blade
Opening Mouth with Scissors Technique
Inserting Laryngoscope
Macintosh Blade in Vallecula
Miller Blade Under Epiglottis
Laryngoscopy is a predictable sequence of progressively
visualized structures
“Epiglottoscopy”
• Blade inserted with
laryngoscope handle
pointed at the patient’s
feet.
• Tongue and jaw are
distracted downward to
insert the blade.
• Minimal force required
• Tip of blade gets around •
base of tongue, permitting
change in angle of lifting
and better mechanical
advantage.
• Epiglottis edge lifted off •
pharyngeal wall. (Epiglottis
often camouflaged against •
mucosa of posterior
pharynx).
With full insertion of
curved blade into vallecula
the angle of lifting changes
to ~40 degrees from the
horizontal.
Now the lifting force can be
increased as needed.
Tip position (not force) is
the main determinant of
glottic exposure.
Lifting the Scope
Yes
No
Laryngoscopy:
Optimizing Glottic View
Cormack-Lehane Scoring of Glottic View
Cricoid Pressure
Sellick maneuver or BURP
Avoid regurgutation of
gastric contents
Imaging studies
undermine theory
May worsen glottic view
Optimizing Glottic View:
Bimanual Laryngoscopy
1) Drives tip of blade into proper position
optimizing mechanics of indirect epiglottis
elevation.
2) Moves larynx downward into line of sight.
Inserting Endotracheal Tube
Yes, good
No, bad
Inserting Endotracheal Tube
Proof of Placement
• Unrecognized esophageal
intubation devastating.
• Clinical indicators alone
cannot be relied upon.
• Capnography gold standard.
• Beware
– Esophageal intubation may
give transient color change.
Need >5 breaths.
– Cardiac arrest patients can
give false negative color
change. (Other methods =
syringe test)
Rescue Strategies
• Return to spontaneous breathing
• Videolaryngoscopy
• Extraglottic devices
• Bougie
• Cricothyroidotomy (open vs.
percutaneous)
A
Parting Thoughts
• Airway Management/Intubation in
intensivists’ domain of practice.
• Getting competent requires dedication
• Procedures for intubation at Jeff
– Never without attending
– Anesthesia supervision if not available