Transcript sugameddex - Jennifer Ranieri Professional Portfolio

AWAKE INTUBATION
Techniques and Tips
Jennifer Ranieri
N 747
Fall 2014
Indication for Awake Intubation
• Safety! “If they do not inspire, they expire”
• Thorough preoperative history and physical evaluation
• Assess difficulty with direct laryngoscopy or difficulty
ventilating the patient when ablating reflexes or
relaxing tissue
Why Awake Intubation?
• Maintenance of natural airway structure
– Optimized gas exchange
• Maintenance of muscle tone to keep relevant
airway structures separated and easier to
identify
• Avoids anterior laryngeal movement that occurs
during induction of anesthesia that potentially
worsens visualization of airway structures
Conditions
• Tumors
• Infections
• Congenital Abnormalities
• Foreign Body
• Trauma
• Obesity
• Inadequate Neck Extension
• Anatomic Variations
Choices and Preparation
• Preparation is key- awake intubation often more time consuming
• Inform the patient
• Oral versus nasal approach
• Equipment selection
• Anesthetizing the airway
• Sedation and anxiolysis
• Back up plan
– Difficult airway supplies
– Additional anesthesia providers
– Otolaryngology at the ready
– Surgical airway
Techniques & Equipment
• Blind nasal intubation
– Uses breath sounds as a guide
• Awake direct laryngoscopy
– Video versus traditional
• Awake optical stylets
• Fiberoptic scope
• Transtracheal jet ventilation
Flexible Bronchoscope
•
Not a requirement for an awake intubation, but a frequent choice
•
Nasal or oral
•
Warm tube to soften, lubricate scope, keep it straight
– Stepstool may help
•
Insufflation of O2 via the suction port allows for increased FiO2 administration
during procedure
– Prevents fogging, may assist in removing secretions from scope tip
•
Grasping tongue with gauze may assist with visualization as well as jaw thrust
forward or cricoid pressure
•
Ovassapian airway is specially designed for FOB intubation
– Protects scope from damage from biting
– Patient must be well topicalized to tolerate
– Disconnect ETT adapter because it will not fit through airway
Relevant Airway Innervation
• Nose
– Greater and lesser palatine nerves
– Anterior ethmoidal nerve
• Mouth and proximal airway structures
– Glossopharyngeal
– Branches of facial nerve
• Larynx and distal airway structures
– Vagus
• Superior Laryngeal Nerve
• Recurrent Laryngeal Nerve
Topicalization of the Airway
• Mucosal application of local anesthetic to
facilitate local uptake and neural blockade
• May be sufficient airway anesthesia alone
• Adequate application time required
• May be inadequate due to pressure receptors
at base of tongue causing gag reflex
– Submucosal, not blocked topically
Topicalization Continued
• Viscous lidocaine - swish and spit
• Lidocaine ointment 4% “lollipop” (blob on stick), onset ~15 minutes
• Nebulized lidocaine 2-4%
– Highly variable results, limit inhalation to 15-30mins, well tolerated
• 10ml syringe with 2-4% lidocaine to atomize oral or nasal passages
– Safe even if large amount swallowed
• Local anesthetic soaked cotton swabs and pledgets
– Cocaine excellent for this methodology but difficult to obtain plus concern
about cocaine toxicity
– Can add epinephrine or phenylephrine to lidocaine to achieve similar
vasoconstriction
• Must vasoconstrict nasal passages
• Cetacaine spray: contains benzocaine, tetracaine and butamben in
pressurized container
•
Consider risk of methemoglobinanemia with benzocaine use, 1 sec spray recommended
Airway Blockade
• Unfortunately, no single nerve can be blocked for
adequate anesthesia to the airway
• Glossopharyngeal Block (CN 9)
– Anesthesia to oropharynx, tonsils, soft palate, posterior portion
of the tongue, and the pharyngeal surface of the epiglottis
• Superior Laryngeal Nerve Block (Branch of CN 10)
– Anesthesia to base of tongue, posterior surface of epiglottis,
aryepiglottic fold, and the arytenoids
• Recurrent Laryngeal Nerve Block (Branch of CN 10)
– Anesthesia to glottis and subglottic structures
– Transtracheal Block
Glossopharyngeal Block
• Bilateral blockade of the pharyngeal, lingual and
tonsillar branches of the CN 9
– Eliminates gag reflex and facilitates nasal intubation by
blockade of posterior pharynx
– Not adequate alone
– Patient opens their mouth, 22-25 gauge needle used to
inject 2-4 mL of local anesthetic bilaterally at the base of
the palatoglossal arch (also called the anterior tonsillar
pillar)
– High risk intravascular injection: aspirate and/or consider
epinephrine as marker of intravascular injection
Glossopharyngeal Block
Superior Laryngeal Nerve Block
• Mucosal application of local anesthetic may
anesthetize SLN, but if saturation time not available
bilateral SLN regional blockade can be effective
• The internal branch originates from the superior
laryngeal nerve lateral to the greater cornu of the
hyoid bone, passes approximately
2-4 mm inferior to the greater
cornu of the hyoid bone
SLN Block Continued
• Palpate outward from the thyroid notch along the
upper border of the thyroid cartilage until the greater
cornu is encountered just superior to its posterolateral
margin
• Displace the hyoid bone with contralateral pressure by
no dominating hand
– This brings the ipsilateral cornu and the internal branch of
the superior laryngeal nerve toward the anesthetist
• Pulsation of the carotid artery being displaced deep to
the palpating finger tip
SLN Block Continued
• 22-25g needle is inserted until lateral aspect of the greater cornu is
contacted
• Walk needle downward toward the midline (1-2 mm) off the inferior
border of the greater cornu
– If thyrohyoid membrane is pierced then the internal branch alone is blocked
– If the needle is retracted slightly after contacting the hyoid, both the internal
and external branches of the superior laryngeal nerve are blocked
• May result in cricothyroid muscle weakness due to lack of function as an airway dilator,
but motor function of the RLN is spared and therefore does not result in clinically
significant change in laryngeal inlet diameters
• Negative for blood for air aspiration, inject 2ml solution and repeat on
other side
• Noninvasive methodology:
pledget placement in pyriform fossa
Recurrent Laryngeal Nerve Block
• Avoidance of coughing during endotracheal tube
manipulation between and below the cords
• Abolition of hemodynamic responses, may help avoid
vagal responses that can occur
• Accomplished via the transtracheal block
• Why not direct RLN blockade?
– Motor innervation for all the muscles of the larynx except
the cricothyroid from the RLN
– Blockade will result in obstruction of airway
Transtracheal Block
• Identify the cricothyroid membrane
•
Midline neck, palpate caudad from thyroid cartilage
• Prep skin, local wheal
• 22- 20g needle on a 10-mL syringe with 4mL of 4% lidocaine is
advanced perpendicular to the axis of the trachea and pierces the
membrane
• Aspirate for air, positive air identifies you are in trachea, then inject
• Patient will cough! (You should have warned them of this before
hand)
• Coughing disperses the local anesthetic to sensory nerve endings,
motor function remains intact
• Rapid injection minimizes trauma to airway from needle
placement and coughing, larger gauge needle may be preferable
Transtracheal Block
Intravenous Adjuncts
• Antimuscarinic and antisialagogue
– Glycopyrrolate
• Easy Reversibility and titratability
– Midazolam
– Fentanyl
• Maintenance of Spontaneous Ventilation
– Ketamine
– Dexmedetomidine
• Psychological Preparation
Glycopyrrolate
• Anticholinergic anti-muscarinic
• Antisialagogue
• 0.2-0.4mg IV
– Can be given IM as well
• Allows better application of topic anesthetic agents
– Can double the duration of lidocaine
• Improves visualization
• Prevents laryngovagal reflexes
• Atropine would suffice, but increased risk of tachycardia and
psychosis
Midazolam and Fentanyl
• Midazolam
– Benzodiazepine; produces anxiolysis and amnesia
– 0.25-4mg
– Reversal: Flumazenil, imidazobenzodiazepine competitive antagonist of
benzodiazepines
• 0.2mg over 15 sec, repeat q2min max 1mg (some sources say 3mg)
• Fentanyl
– Opioid agonist; sedation, analgesia, antitussive
– 10-100mcg
– Reversal- Naloxone, competitive opioid receptor antagonist
• 0.4 mg/mL vial diluted in 9 mL saline to 40mcg/ml can be titrated in
increments of 0.5-1 mcg/kg (1-2ml) every 3-5 min until adequate ventilation
and alertness are achieved
Ketamine
• NMDA antagonist, dissociative, provides sedation
• Upper airway reflexes remain largely intact,
ventilatory drive minimally affected
• Best as an adjunct with other amnestics and sedatives
due to hallucinations
• Consider cardiovascular side effects
– Directly proportional to dosage
• Low dose 10-50mg
– GA induction dose is 1-2mg/kg
Dexmedetomidine
• Sedative, centrally acting alpha 2 agonist
– Provides analgesia, anxiolysis, xerostomia, and
some degree of amnesia
• Maintains spontaneous respiratory rate
• Consider hemodynamics
• Loading dose: 0.5-1 mcg/kg over 10 min
Infusion: 0.2–1 mcg/kg/hr
References
•
Benumof, J. (1991). Management of the Difficult Adult Airway With Special
Emphasis on Awake Tracheal Intubation. Anesthesiology, 75(6), 1087-1110.
•
Butterworth, J.F., Mackey, D.C., Wasnick, J.D. (2013). Morgan & Mikhail’s Clinical
Anesthesiology. (5th Ed.). New York, NY: McGraw Hill.
•
Hung, O., Murphy, M.F. (2012). Management of the Difficult and Failed Airway (2nd
Ed.). New York, NY: McGraw Hill.
•
Marcucci, C., Cohen, N.A, Metro , D.G., Kirsch, J. (2008). Avoiding Common
Anesthesia Errors. Philadelphia, PA: Lippincott, Williams and Wilkins.
•
New York School of Regional Anesthesia. (2008). Regional & Topical Anesthesia
for Endotracheal Intubation. http://www.nysora.com/techniques/nervestimulator-and-surface-based-ra-techniques/head-and-neck-blocka/3022regional-topical-anesthesia-for-endotracheal-intubation.html