3. INTRODUCTION
Awake fibreoptic intubation (AFOI) is an essential skill in
the management of a patient with a known difficult airway,
or who has an anticipated difficult airway as found during
the airway assessment preoperatively
It is important to know the anatomy of the normal upper
and lower airways, from the nasal passage to the
carina/bifurcation of the trachea
4. It is also essential to have a good knowledge of the
mechanisms of action and maximum dosages of various
local anaesthetic agents and vasoactive drugs, as these are
used widely in this technique.
Recognition of the signs, symptoms and treatment of local
anaesthetic toxicity is essential.
5. DEFINITION....
AFOI is a technique which allows a flexible oral or
nasal route to provide a clear visualisation of the
vocal cords, and subsequent passage of an
endotracheal tube into the trachea under direct
vision.
6.
7.
8. INDICATIONS
Previous difficult airway or AFOI
Previous difficulty in mask ventilation
Anticipated difficult airway
Known or suspected C-spine instability
Progressive airway obstruction
10. CONTRA-INDICATIONS
Patient refusal
Allergy to local anaesthetic agents
Difficult airway with impending airway obstruction
Infection/contamination of the upper airway
Fractured base of skull
Severe Coagulopathy
uncooperative patient
11. PROCEDURE
AFOI can be performed in the following scenarios…
Awake FOI
Asleep FOI
Oral FOI
Nasal FOI
12. REQUIREMENTS FOR THE PROCEDURE..
Ensure that you are familiar with using the fibreoptic scope
Explain the procedure to the patient and obtain consent.
Make sure that you have all the appropriate resuscitation equipment to hand
Emergency Drugs(LAST)
The patient should be fully monitored throughout the procedure (capnography)
A well trained assistant
Calculation of your local anaesthetic dose beforehand is essential
Obtain intravenous access
antisialagogue premedication
Connect IV fluids
Administer O2 by nasal cannalue or by Hudson type of face mask
Communication with your patient throughout the procedure is of vital importance.
15. Position of the Anaesthetist
Sniffing position not essential for FOI.
Stand tall, relaxed at the head end of the patient or in front
of the patient.
Ensure operator can readily see patient monitor, infusion
pump and video screen
Chin lift and jaw thrust maneuvers [in anaesthetized pt.]
16.
17. There are 3 phases to Fibreoptic
intubation
TOPICALISATION OF THE AIRWAY
FIBREOPTIC ENDOSCOPY
RAILROADING THE TRACHEAL TUBE
18. TOPICALISATION OF THE AIRWAY
Position the patient on the trolley for administration of local
anaesthetic
Patient sitting up at 45°. Operator facing the patient.
Specifc nerve blocks (sphenopalatine, ethmoid,
glossopharyngeal, superior laryngeal nerve, recurrent
laryngeal nerve)
Topical anaesthesia
19. Nose and nasopharynx:
Assess nasal passages for patency (history and examination) and history of
epistaxis.
Vasoconstriction:
Co-phenylcaine (5% Lignocaine + 0.5% Phenylephrine) (2.5ml = 125 mg)
Xylocaine (2% Lignocaine + 1:200000 Adrenaline) (5ml = 100mg
Alternatively, if Co-phenylcaine and mucosal atomiser device (MAD) are available,
administer to selected nostril via MAD (125mg)
Topical 4% lidocaine with gauze or cotton buds.
Alternative is serial dilation: hegar cervical dilators coated in lidocaine gel (or
nasopharyngeal airways)
4 puffs 10% Lignocaine to nose and post nasal space
20. Tongue and oropharynx:
Lidocaine 10% spray (ten sprays) or gargle lidocaine gel.
Benzocaine 100mg lozenges can be sucked half an hour
beforehand.
Pharynx and Larynx above cords
1-4% Lignocaine via metered spray
21. Larynx below the vocal cords, and tracheo-
bronchial tree
“Spray as you go” technique during endoscopy
Cricothyroid (trans-tracheal) injection,
Nerve blocks (glossopharyngeal, superior laryngeal and recurrent laryngeal nerve
blocks
22. The total dose of Lidocaine should not exceed
9mg/kg
Test topicalisation atraumatically
Treatments for LAST must be immediately available
23. FIBREOPTIC ENDOSCOPY
Basic principles:
Know the anatomy
Where am I?
What am I looking at?
What do I hope to see next?
Be gentle, avoid forcing the fibrescope, and avoid mucosal trauma,
at all costs.
Ensure laryngeal activity is lost before approaching with the
fibrescope
Lubricate the fibrescope with aqueous gel/KY jelly
load it with the uncut Endotracheal Tube (ETT) (size 6.0 to 7.0)
24. Tips for performing endoscopy:
Orientate the fibrescope and white balance before starting
Using an FOB, ‘black’ is the airway, and ‘pink’ the airway wall. Aim
for ‘black’.
A good view may be spoilt by blood = red out, secretions = white out,
no cavity = pink out
If negotiating the oropharynx is difficult: ask the patient to protrude
their tongue and jaw; ask an assistant to pull the tongue forwards
with gauze and provide gentle jaw thrust; or insert a laryngoscope.
If an area is not anaesthetised, pull the fibrescope back by 1-2cm,
advance the epidural catheter
25. Endoscopy:
Introduce the fibrescope through the nostril, into the lower
nasal meatus (inferior, largest).
Steer the fibrescope into the oropharynx,
Once in the oropharynx, you may see the epiglottis, the 1st
landmark.
Advance the fibrescope into the laryngeal opening.
Advance the fibrescope until it enters the subglottic space, and
identify the trachea, 2nd landmark.
Advance the fibrescope again into the trachea, identifying the
carina, 3rd landmark.
26. RAILROADING THE TRACHEAL TUBE
Lubricate the tip of the ETT, and the fibrescope
ask your assistant to hold fibrescope in position, as you perform
intubation.
Release the ETT and advance it with a gentle rotating motion
Alert the patient of discomfort as the tube is passed through the
nose
If any resistance is felt, do not force the tube, but withdraw
slightly, rotate the ETT 90 degrees anti-clockwise, and advance
gently again.
Keep the carina in the field of vision at all times to prevent
dislocation of the fibrescope out of the larynx into the oesophagus
27. Remove the fibrescope whilst visualising, to ensure tip of the
ETT is in the trachea, and maintaining the ETT in place, with
the tip at 3-5cm above the carina
Fix the ETT in place and connect to the anaesthetic breathing
circuit
Confirm the ETT position
Induce the patient using appropriate anaesthetic
agents and inflate the ETT cuff
30. SEDATION…
Sedation can help anxiety, discomfort and intolerance
Critical airway: may need to avoid sedation.
But can cause airway obstruction, cardiorespiratory depression
and hypoxia
Sedation is not a substitute for effective LA.
Low doses of sedative drugs should be use
Remifentanil, dexmedetomidine, midazolam or propofol
can be use
Another anaesthetist monitoring sedation improves safety
Antagonists must be immediately available if using opioids
and benzodiazepines
31. The failure rate of fiberoptic under general anaesthesia is reported
as 2.5% even under experienced hands.
Lack of experience.
Presence of secretions.
Fogging of the objective / focusing lens.
Poor topical anaesthesia.
Epiglottis touching the pharyngeal wall.
Distorted airway anatomy.
Causes of failure
32. POSTOPERATIVE CARE
At the end of surgery, before extubation is performed,
ensure that;
The patient has been oxygenated with 100% for 3-5min
Any muscle relaxants have been adequately reversed
The upper airway is free of all secretions –
The patient is breathing spontaneously with adequate
tidal volumes
The patient is awake
Keep the patient starved until airway sensation and
reflexes have returned
33. Have all the necessary equipment for
potential reintubation at hand
Reusable FOB, VLs and other instruments must be
decontaminated and disinfected
35. CONCLUSION
AFOI Success depends on setup, skill, cooperation,
and effective LA
Sedation is optional but has risks
Oxygenation remains the priority.
Have backup plans for airway obstruction and
inadequate ventilation, including postponement,
high-risk GA and eFONA.
36. REFERENCES
World Federation of Societies of Anaesthesiologist
“Anaesthesia tutorial of the week”Tutorial 201
18th october, 2010
MCU_2022_Morgan_and_Mikhail's_Clinical_An
esthesiology,_7th_Edition.
Oxford Handbook of Anaesthesia 4th and 5th
editions.
Smith and Aitkendhead’s textbook of anesthesia
7th edition
40. Q1…SBA
A 48yr old female with temporomandibular joint
dysfunction and associated limited mouth
opening is scheduled for a thyrodectomy for
goiter. Due to concern for challenging
laryngoscopy, the anaesthesiologist elects to
perform an awake fibreoptic intubation. In order
to anesthetize the posterior third of the tongue,
the anesthesiologist should perform a nerve
block of the
A. Cranial nerve V
B. Cranial nerve VII
C. Cranial nerve IX
D. Cranial nerve XII
41.
42. ANSWER TO Q1
C
The glossopharyngeal nerve (CN IX) is a mixed motor and
sensory nerve. Its sensory fibers carry information about
general sensation and taste from the posterior third of the
tongue. Of note, the glossopharyngeal nerve does not
provide sensory innervation to the epiglottis; it is provided
by the superior laryngeal nerve. The trigeminal nerve (CN
V) (choice A) carries general sensory information from the
anterior two-thirds of the tongue. The facial nerve (CN VII)
(choice B) is a mixed motor and sensory nerve. It carries
taste sensation from the anterior two-thirds of the tongue
and oral cavity. The hypoglossal nerve (CN XII) (choice D)
is a purely motor nerve that innervates the muscles of the
tongue
43. Q2….SBA
A 48yr old female with temporomandibular joint
dysfunction and associated limited mouth opening is
scheduled for a thyrodectomy for goiter. Due to concern
for challenging laryngoscopy, the anaesthesiologist elects
to perform an awake fibreoptic intubation. To reliably
blunt the afferent limb of the cough reflex, the
anesthesiologist should perform a bilateral block of the…
A. Superior laryngeal nerve and the recurrent laryngeal nerve
B. Glossopharyngeal nerve and the internal branch of the superior
laryngeal nerve
C. Glossopahryngeal nerve and the external branch of the superior
laryngeal nerve
D. Internal and external branches of the superior laryngeal nerve
44.
45. ANSWER TO Q2
A.
A cough occurs through the stimulation of a complex
reflex arc. This is initiated by the irritation of cough
receptors, which are found in the pharynx, larynx, trachea,
carina, branching points of large airways, and more distal
smaller airways. When triggered, impulses travel via the
internal branch of the superior laryngeal nerve and the
recurrent laryngeal nerve, which stem from the vagus
nerve, to the medulla of the brain. This is the afferent
neural pathway. The efferent neural pathway then follows,
with relevant signals transmitted back from the cerebral
cortex and medulla via the vagus and superior laryngeal
nerves to the glottis, external intercostals, diaphragm, and
other major inspiratory and expiratory muscles.
46. A patient is listed for a temperomandibular joint
replacement. Preoperative assessment reveals limited
mouth opening and the decision is taken for an awake
fibreoptic intubation. Which of the following is true
regarding anesthesia to the larynx for AFOI.
A) Topical anesthesia using a spray as you go technique with 4% lidocaine
can provide effective anesthesia
B) Topical anesthesia using a spray as you go technique with 2% lidocaine
can provide effective anesthesia
C) Nebulized 4% lidocaine for 15min can provide effective anesthesia
D) Superior laryngeal nerve block is adequate as a solo technique to
provide adequate anesthesia for intubation
E) Translaryngeal block with 2%lidocaine can provide effective analgesia
Q3….T or F
47.
48. ANSWER TO Q3
TTTFT
A Spray –as-you-go technique allows local anaesthetic to be applied under
direct vision to the airway (either via the side port of the scope or through
an epidural catheter threaded out of the scope) as its visualized with the
fibrescope. Studies comparing the use of 2% and 4% lidocaine for this
technique have found that both produced adequate intubating conditions
for awake-fibreoptic intubation. Nebulized lidocaine 2-4% for 15-30
minutes can also produce effective anesthesia of the oral cavity and trachea,
although the density of the anesthesia produce can be quit variable, and
some patient will maintain a cough reflex. The SLN supplies sensory
innervation to the base of the tongue, the posterior surface of the epiglottis,
the aryepiglottic fold and the arytenoids. Blockade of the SLN alone is not
noormally adequate as a solo technique to allow awake intubation, but is
very effective when used in combination with topical anaesthetic technique.
A translaryngeal block, which involves a cricoid puncture through 2-3ml of
2-4% lidocaine is injected provides a further technique for effectively
anaesthetizing the larynx
49. Q4…T or F
Regarding assessment of a patient’s airway
A) A Mallampati class III view means that the hard
palate, soft palate and uvula are visible
B) A sternomental distance of <12.5cm predicts a
difficult intubation
C) A thyromental distance of <6.0cm predicts a
difficult intubation
D) The thyromental distance is measured with the
patient’s head fully flexed
E) A horizontal mandibular length of >5cm suggests a
good laryngoscopic view
50.
51. A) FALSE
B) TRUE
C) TRUE
D) FALSE
E) FALSE
ANSWER TO Q4
52. Q5… T or F
The following are indications for an Awake
Fibreoptic Intubation:
A) A patient with atlanto-axial instability of their
cervical spine, secondary to Rheumatoid Arthritis
B) Impending airway obstruction secondary to acute
epiglottitis
C) A history of difficulty in mask ventilation
D) A predicted difficult airway in an uncooperative
patient
E) A patient with severe facial injuries and active intra-
oral haemorrhage
53.
54. ANSWER TO Q5
A) TRUE
B) FALSE
C) TRUE
D) FALSE
E) FALSE
55. Q6..T or F
Regarding Awake Fibreoptic Intubation:
A) The maximum topical dose of Lignocaine for an 80kg patient is
880mg
B) When a trans-tracheal injection of Lignocaine is performed to
anaesthetise the subglottic region, the patient is asked to exhale
prior to injection of the Lignocaine
C) Trans-tracheal injection is performed between the 2nd and 3rd
tracheal rings
D) The fibrescope is passed along the superior nasal meatus
E) A white out of the view with the fibrescope is caused by
secretions
F) The patient can be safely extubated deep at the end of the
surgery
56.
57. ANSWER TO Q6
A) FALSE
B) TRUE
C) FALSE
D) FALSE
E) TRUE
F) FALSE
58. Q7…SBA
A 55yr old woman with severe anxiety and rheumatoid
arthritis is scheduled for thyroidectomy for medullary
thyroid cancer. Her airway exam in the upright position
is notable for a nonvisible uvula with a tongue
protruded, a 2 finger-breadth mouth opening, a
thyromental distance of 2.5 finger-breadths, and neck
range of motion at the atlanto-occipital joint of about 70
degrees. Examination of her neck reveals an enlarged
fixed and nonmobile mass that appears to be
contagious with the thyroid gland when the patient
swallows. The trachea cannot be palpated. The patient
is highly anxious and tells you under no circumstance
will she let you insert a breathing tube inside my airway
while im awake. The next best step in anesthetic
management is…...
59. Q7…..
A) Induction of GA followed by fibreoptic
bronchoscopy
B) Induction of GA followed by rigid bronchoscopy
C) Induction of GA followed by laryngeal mask
airway placement
D) Cancel the case
60.
61. ANSWER TO Q7
D
This patient has multiple risk factors for difficult intubation, including
Mallampati class of >2, thyromental distance of <3 fingerbreadths, mouth
opening <3 fingerbreadths, and total atlanto-occipital range of motion <80
degrees. Patients with inflammatory rheumatoid arthritis (RA) have an
increased incidence of temporomandibular joint disease (and associated
limited mouth opening) and immobile cervical vertebra (associated with
limited neck range of motion). Additionally, patients with RA can have occult
airway abnormalities not apparent on physical exam, such as laryngeal
rotation, cricoarytenoid arthritis, and cervical spine instability. The patient’s
thyroid malignancy may result in other airway abnormalities including
tracheal deviation and/or compression. Were such a patient to be induced
and mask ventilation turn out to unsuccessful, there would be no reliable
backup method of airway management. The safest way to secure this patient’s
airway would be an awake fiberoptic intubation. Since the patient has refused
this option and the case is not urgent, the anesthesiologist should cancel the
operation and discuss the options for airway management with the patient so
that a mutually acceptable plan can be reached
