Surgical management of difficult adult airway

2. SURGICAL MANAGEMENT
OF DIFFICULT ADULT
AIRWAY
DR.ASHWIN MENON M

3. CLINICAL ANATOMY

4. CLINICAL ANATOMY
• Depth from skin: 18 mm to 32 mm
• Length: 11 cm
• Levels: C6 to Upper border of T5
• Rings: 16 to 20
• 2nd, 3rd, 4th rings are covered by thyroid isthmus
• Cartilaginous ring C-shaped i.e. incomplete posteriorly.
• The edges of the C are connected by trachealis muscle
which helps in narrowing the tracheal lumen during
coughing-Thus higher velocity of air is generated.

7. Definition
No universally accepted definition of the difficult airway
exists, but in broad terms, difficult airway control may be defined
as problematic ventilation using a face mask, incomplete
laryngoscopic visualization, or as a difficult intubation with
standard airway equipment.

8.  The incidence of difficult intubation in the operating room
ranges between 1.15% and 3.80% , with failed attempts in
0.05% to 0.35% of cases.
 In the emergency department, difficult intubation occurs
in 3.0% to 5.3% of cases with failure rates ranging from 0.5%
to 1.1%.

9. Hypoxia from the difficult airway is commonly
due to:
1. Excessive number of attempts performed by different
operators unsuccessfully.
2. Subsequent attempts with the same devices.
3. Inadequate oxygenation between attempts.
4. Aspiration of gastric contents during face mask
ventilation.
5. Traumatic oedema of the laryngeal aditus.

10. SIGNS & SYMPTOMS
• Dyspnoea at rest or on exertion.
• Stridor
• Neck swelling
• Voice changes
• Haemoptysis
• Dysphagia
• Odynophagia
• Cough

11. CAUSES OF DIFFICULT AIRWAY
Pierre Robin Syndrome Cleft soft palate, glossoptosis,
retrognathia
Treacher Collins Syndrome Auricular & ocular defect, molar &
mandibular hypoplasia
Goldenhar’s Syndrome Auricular and ocular defects, molar
and mandibular hypoplasia;
occipitalization of atlas.
Down’s Syndrome Poorly developed or absent bridge of
the nose, macroglossia
Kilppel-Feil Syndrome Congenital fusion of a variable
number of cervical vertebrae;
restriction of neck movement.

12. Pierre Robin Syndrome Treacher Collins Syndrome
Goldenhar’s Syndrome Down’s Syndrome

13. Kilppel-Feil Syndrome

14. ACQUIRED
Infections
Supraglottitis
Croup
Abscess
Ludwig’s angina
Laryngeal oedema
Laryngeal oedema
Distortion of the airway and trismus
Distortion of the airway and trismus.
Arthritis Larynx Rheumatoid
Arthritis
Ankylosing
spondylitis
TMJ ankylosis, cricoarytenoid, deviation of
restricted mobility of Cervical spine.
Ankylosis of cervical spine, less commonly
ankylosis of TMJ; lack of mobility of
cervical spine.
Tumor Benign Tumor
Malignant Tumor
Stenosis or distortion of the airway
Fixation of larynx to adjacent tissues.
Trauma Oedema of airway, unstable#, haematoma
Obesity Short thick neck, sleep apnoea
Acromegaly Macroglossia, Prognanthism
Acute Burns Oedema of airway

16. AIRWAY ASSESSMENT INDICES
1. Individual indices.
2. Group indices - Wilson’s score
- Benumof’s analysis
- Saghei & safavi test
- Lemon assesment
3. Radiological indices.

18. EVALUATION OF MANDIBULAR SPACE
THYROMENTAL DISTANCE (PATIL’S TEST)
• Distance from the tip of thyroid cartilage to the tip of
inside of the mentum.
• Neck fully extended / mouth closed
Significance
• Negative result – the larynx is reasonably anterior to the base
of tongue
>6.5 cm No problem with
laryngoscopy & intubation
6 – 6.5 cm Difficult laryngoscopy but
possible
<6 cm Laryngoscopy may be
impossible

19. HYO MENTAL DISTANCE
• Distance between mentum and hyoid
bone
• Grade I : > 6cm
• Grade II: 4 – 6cm
• Grade III : < 4cm – Impossible
laryngoscopy & Intubation

20. STERNOMENTAL DISTANCE
(SAVVA TEST)
• Distance from the upper border of the manubrium to the
tip of mentum, neck fully extended, mouth closed
• Minimal acceptable value – 12.5 cm
• Single best predictor of difficult laryngoscopy and
intubation ( Has high sensitivity & specificity).

22. CORMACK - LEHANE
(Grading at direct laryngoscopy)
Grade 1: Full exposure of glottis (anterior + posterior
commissure)
Grade 2: Anterior commissure not visualized
Grade 3: Epiglottis only
Grade 4: No glottic structure visible.

24. ASSESSMENT OF TMJ FUNCTION
TM joint exhibits 2 function.
1. Rotation of the condyle in the synovial cavity.
2. Forward displacement of the condyle.
First movement is responsible for 2-3cm mouth opening & the
second is responsible for further 2-3cm mouth opening.
Index finger is placed in front of the tragus & the thumb is
placed in front of the the lower part of the mastoid process.
patient is asked to open his mouth as wide as possible. Index
finger in front of the tragus can be intented in its space and
the thumb can feel the sliding movement of the condyle as the
condyle of the mandible slides forward.
SUBLUXATION OF THE MANDIBLE

26. INTER-INCISOR GAP
• Inter-incisor distance with maximal mouth opening
• Normal value > 5 cm / admits 3 fingers.
Significance :
• Positive results: Easy insertion of a 3 cm deep flange of the
laryngoscope blade
• < 3 cm: difficult laryngoscopy
• < 2 cm: difficult LMA insertion
• Affected by TMJ and upper cervical spine mobility

28. Significance-
Class B and C: difficult laryngoscopy

29. UPPER LIP BITE /CATCH TEST
• Class I: Lower incisors can bite the upper lip above
vermilion line
• Class II: can bite the upper lip below vermilion line
• Class III: cannot bite the upper lip
Significance
• Assessment of mandibular movement and dental architecture
• Less inter observer variability

30. Evaluation of Neck Mobility
Patient is asked to hold the head erect, facing directly to
the front  maximal head extension  angle traversed
by the occlusal surface of upper teeth( can also
measured by goniometer).
Minimum 35⁰ extension is possible at AOJ in normal
individuals.

31. Grade Reduction of A.O.Extension
1 none
2 One third
3 Two third
4 complete
Grades 3 and 4 : Difficult laryngoscopy
Grading of reduction in
A.O.Extension
Grade I : > 35°
Grade II : 22-34°
Grade III : 12-21°
Grade IV : < 12°

32. ASSESMENT OF A.O. EXTENSION
• Flexion movement of the cervical spine can be assessed by
asking the patient to touch his manubrium sternii with his
chin. If done, the above maneuver assures a neck flexion of
25- 35 degree. Flexion and the extension movement if within
the normal range ,three axis ( oral,pharyngeal & laryngeal
axis) can be brought into a straight line.
can also be done by asking the patient to look at the floor
and at wall after fully flexing and fixing the neck as shown

33. Warning sign of DELIKAN
Place the index finger of each hand, one underneath the chin and
one under the inferior occipital prominence with the head in
neutral position. The patient is asked to fully extend the head
on neck. If the finger under the chin is seen to be higher than
the other, there would appear to be no difficulty with
intubation. If level of both fingers remains same or the chin
finger remains lower than the other, increased difficulty is
predicted.

34. PALM PRINT & PRAYER SIGN
Palm print sign:
Patient’s fingers and palms painted with blue ink and pressed
firmly against a white paper
• Grade 1- all phalangeal areas visible
• Grade 2- deficient inter phalangeal areas of 4th and 5th digits
• Grade 3- deficient inter phalangeal areas of 2nd to 5th digits
• Grade 4- only tips seen.
Prayer sign:
Limited-mobility joint syndrome (stiff-joint sydrome) 30-40% of
Type I diabetics positive "prayer sign“. TM joint and C-spine (e.g.
atlanto-occipital joint) may be involved

35. Palm Print as a Predictor of
Difficult Airway in DM

36. PRAYER SIGN
A positive "prayer sign" can be
elicited on examination with the
patient unable to approximate the
palmar surfaces of the phalangeal
joints while pressing their hands
together; this represents cervical spine
immobility and the potential for a
difficult endotracheal intubation.

37. 1. SAGHEI & SAFAVI’S
• Weight
• Tongue protrusion
• Mouth opening
• Upper incisor length
• Mallampati class
• Head extension
Any 3 indices if present -
>80kg
< 3.2cm
<5cm
>1.5cm
>1
<70 degree
Prolonged laryngoscopy
GROUP INDICES

38. 2.“LEMON” Assessment
• Look externally.
• Evaluate the 3-3-2 rule.
• Mallampati.
• Obstruction.
• Neck mobility.

39. L: Look Externally
• Obesity or very small.
• Short Muscular neck
• Large breasts
• Prominent Upper Incisors (Buck Teeth)
• Receding Jaw (Dentures)
• Burns
• Facial Trauma
• Stridor
• Macroglossia

40. E Evaluate the 3-3-2 rule
 3 fingers fit in mouth
 3 fingers fit from mentum
to hyoid cartilage
 2 fingers fit from the floor
of the mouth to the top of
the thyroid cartilage

42. Cormack & Lehane Grading
(Grading at direct laryngoscopy)
Grade 1: Full exposure of glottis (anterior +
posterior commissure)
Grade 2: Anterior commissure not visualized.
Grade 3: Epiglottis only.
Grade 4: No glottic structure visible.

44. O Obstruction
 Blood
 Vomitus
 Teeth
 Epiglottis
 Dentures
 Tumors

45. N Neck mobility -Measurement of
Atlanto-Occipital Angle

46. Grading of reduction in A.O.Extension
Grade I : > 35°
Grade II : 22-34°
Grade III : 12-21°
Grade IV : < 12°

47. 3. WILSON SCORING SYSTEM
5 factors - Weight, upper cervical spine mobility, jaw
movement, receding mandible, buck teeth
• Each factor: score 0-2
• Total score < 5 – Easy laryngoscopy.
6 to 7 - Moderate difficulty.
> 7 - Severe difficulty.

48. 4. BENUMOF’S 11 PARAMETER ANALYSIS
Parameter
1. Upper inciors length
2. Buck teeth
3. Subluxation
4. Interincisor gap
5. Palate configuration
6. Mallampati class
Minimum acceptable value
<1.5cm
Absent
Yes
>3cm
No arching/narrowness
<2
7. TM distance
8. SMS compliance
9. Neck thickness
10. Length of neck
11. Head /neck mvt
> 5cm
Soft to palpation.
Qualitative ( >33cm DI)
>8cm
Normal range
2 for mandibular space
3 for neck examination.
4-2-2-3 rule
4 for tooth
2 for inside of mouth

49. Rule of 1-2-3
• 1 finger breadth for subluxation of mandible.
• 2 finger breadth for adequacy of mouth opening.
• 3 finger breadth for hyomental distance.
Significant difficulty in 2 or more of these components requires detailed
examination.
• 4 finger breath for thyromental distance
• 5 movements- ability to flex the neck upto the manubrium sterni, extension
at the AOJ, rotation of the head along with right & left movement of the
head to touch the shoulder.
Rule of 1-2-3-4-5
• 3 finger in the interdental space.
• 3 finger between mentum and hyoid bone.
• 3 finger between thyroid cartilage & sternum.
Significant difficulty in 2 or more of these components requires detailed
examination.
Rule of Three’s

50. 1. X-Ray neck (lateral view) :
• Occiput - C1 spinous process
distance< 5mm.
• Increase in posterior mandible
depth > 2.5cm.
• Ratio of effective mandibular
length to its posterior depth
<3.6.
• Tracheal compression.
RADIOGRAPHIC PREDICTORS

51. 2. CT Scan:
• Tumors of floor of mouth, pharynx, larynx
• Cervical spine trauma, inflammation
• Mediastinal mass
3. Helical CT (3D-reconstruction):
• Exact location and degree of airway compression
• Flow volume loop
• Acoustic response measurement
• Ultra sound guided
• CT / MRI
• Flexible bronchoscope
ADVANCED INDICES

52. Surgical Airway Procedures

53. Types of Surgical Airway Procedures
1. Laryngotomy (cricothyrotomy)
2. Elective Temporary Tracheostomy:
– This is performed as a planned procedure, usually under G/A, as a
temporary stage in patients management
3. Permanent Tracheostomy:
– In an operation involving removal of larynx. Tracheal remnant is
brought to surface as a permanent stoma.

54. 4. Emergency Tracheostomy
– Nowadays there ought to be very few indications for this. On occasion
a patient will be seen first with a large laryngeal tumor and require an
emergency tracheostomy.
– To have to do an emergency tracheostomy in conditions such as acute
epiglottitis, respiratory failure, coma etc is a sign of poor forward
planning in the management of the patient.
– It is to be done under L/A.
5. Micro Laryngeal tube placement for airway management
of tracheal stenosis
6. Percutaneous Tracheostomy

56. 1. Laryngotomy (cricothyrotomy)
“Laryngotomy is opening the airway through the
cricothyroid membrane”
• It is used for acute complete airway obstruction when
endotracheal intubation/ ventilation is not possible.
• The procedure can be accomplished in 15 to 30
seconds.

59. Techniques
1. Standard technique
2. Rapid four step technique
3. Seldinger technique

60. 1. Standard technique
Step 1: Immobilize the larynx and
palpate the cricothyroid
membrane.
Step 2: Incise the skin vertically.
Step 3: Incise the cricothyroid
membrane horizontally.

61. Step 4: Insert the tracheal
hook.
Step 5: Insert the Trousseau
dilator and open it to enlarge
the incision vertically.

62. Step 6: Insert the tracheostomy tube. Step 7: Remove the obturator.

63. Step 8: Insert the inner cannula.
Step 9: Attach the tracheostomy
tube to the mechanical ventilator
or a bag valve device.

64. 2. Rapid four step technique
The rapid four-step technique (RFST) can be done quickly and
requires only a number 20 scalpel, hook, and cuffed tracheostomy
tube. For this technique, stand at the head of the patient in the
same position as when performing endotracheal intubation. Next,
perform the following four steps in sequence:
Step 1: Identify the cricothyroid membrane by palpation.
Step 2: Make a horizontal stab incision through both skin and
cricothyroid membrane with the scalpel. The size of the skin
incision is approximately 1 to 2 cm.

65. STEP 2

66. Step 3: Prior to removal of the scalpel, the hook is placed and
directed inferiorly. Caudal traction is used to stabilize the larynx.
This marks a significant change from the standard method, in
which the tracheal hook is placed under the thyroid cartilage.
Also in contrast with the Standard technique, this step does not
require an assistant to manage the hook.
Step 4: Insert the tracheostomy tube into the trachea
STEP 3 STEP 4

67. 3. Seldinger technique
Commercial cricothyrotomy kits are available that contain all
essential equipment to perform the Seldinger technique.
As an example, the Cook® Melker kit includes the following:
a. 6 ml Syringe
b. 18 Gauge Needle With Overlying Catheter
c. Guide Wire
d. Tissue Dilator
e. Modified Airway Catheter
f. Tracheostomy Tape.

69. Technique
Step 1: Be certain all equipment is present and functioning. Insert
the dilator into the airway catheter. Palpate the cricothyroid
membrane with the index finger of the non dominant hand while
immobilizing the larynx with the thumb and middle finger.
Step 2: Attach the introducer needle to the syringe, and, if time
permits, fill it with a small amount of saline or water. Apply a
small amount of negative pressure on the syringe and insert the
needle carefully into the cricothyroid membrane at a 45 degree
angle with the needle oriented caudaly.

71. Be careful not to insert it too far as this may damage the posterior
wall of the trachea. Watch for the appearance of bubbles in the
water, or feel for the free flow of air into the syringe, indicating
the needle is in the airway.
Step 3: When bubbles appear, remove the syringe and then
remove the needle, leaving the catheter in place, with its distal tip
in the trachea. Thread the guide wire through the catheter into the
trachea. Remove the catheter, sliding it over the guide wire.
Step 4: Make a 1 to 2 cm incision in the skin at the entrance point
of the guide wire with a number 15 scalpel blade. The
cricothyroid membrane must also be incised at this point.

73. Step 5: Thread the combined tissue dilator-airway catheter over
the guide wire and advance it into the skin incision. Following
the curve of the dilator, advance the dilator-catheter unit through
the subcutaneous soft tissue and into the trachea until the cuff of
the catheter is flush against the skin of the neck. A slight twisting
motion may be needed.
Step 6: Remove the tissue dilator and guide wire as a unit,
leaving the airway catheter in the trachea.
Step 7: Secure the airway catheter to the neck with the 'trach
tape' provided in the kit or other appropriate means.

75. COMPLICATIONS
Emergency surgical cricothyrotomy has a much higher
complication rate than elective cricothyrotomy.
Early complications
• Bleeding.
• Laceration of the thyroid cartilage, cricoid cartilage, or
tracheal rings.
• Perforation of the posterior trachea.
• Unintentional tracheostomy.
• Passage of the tube into an extra tracheal location (ie, false
tract).
• Infection.

76. • Long-term complications include subglottic stenosis
and voice changes.
• Rapid Four Step Technique (RFST) involves cricoid
injury.

77. Tracheostomy
• A tracheotomy is an incision into the trachea (windpipe) that
forms a temporary or permanent opening which is called a
tracheostomy.
• Best performed as an elective procedure under endotracheal
anesthesia, in an adequately equipped operation theatre and
aseptic measures.
• Position:
o Supine position with a sandbag under patient’s shoulders
to give extension of head and prominence to the trachea
and larynx.
o Under local anesthesia a compromised position of
extension will have to be found.

79. • Anaesthesia:
– Endotracheal anaesthesia or
– Local anaesthesia (in
obstructive pathologies)
obtained by injection of skin
and subcutaneous tissues
with Xylocaine 2%
1:200000 adrenaline
solution.
– Drugs which depress resp.
system better avoided.

80. • Incision:
– A Transverse/vertical 5 cm incision 2 cm below the lower
border of cricoid cartilage, through skin, S/C fat and deep
cervical fascia.
– Flaps are raised by undermining with blunt dissection to
expose ant. Jugular veins and infrahyoid muscles.

81. • Separation of Infra hyoid
Muscles:
• The fibrous median raphe
b/w the sternohyoid
muscles is defined and
separated with blunt
dissection
– The sternothyroid muscles
on a deeper plane are
identified and retracted
laterally.

82. • Identification of Thyroid Isthmus:
• Anatomical variations in size and
position of thyroid isthmus should
be expected
• The thyroid isthmus may be small
and not interfere with the approach
but in most patients it is of
sufficient size to need dividing.
• A small horizontal incision is made
in the pre tracheal fascia
• Pull thyroid isthmus up or down or
• Divide the thyroid isthmus b/w
large haemostats and ligate or are
over sewn

84. • Opening of the Trachea:
• Trachea is retracted in an
anterio-superior direction by
a tracheal hook below the
cricoid.
• A transverse incision into
intercartilaginous membrane
below the 2nd or 3rd ring and
converted into a circular
opening.

85. • Insertion & fixation of Tracheostomy
tube:
• The type of tracheosomy tube should
be selected prior to surgery.
• A Soft cuffed tube (ported) will be
needed if anaesthesia is to be
continued or positive pressure
ventilation required or if entry of
secretions and blood into trachea are
to be avoided.
• Position of tube is retained by tapes
passed around the neck and tied to
each other on one side of neck.

86. • Wound Closure and Dressing:
– Wound loosely approximated with
skin sutures and sterile sponge
trachesotomy dressing is done
around the tube.
– There should be sufficient space
remaining around the tube to
minimize the danger of
subcutaneous emphysema.

88. Complication
• Intraoperative Complications
 Bleeding and injury to big vessels
 Injury to tracheoesophageal wall
 Pneumothorax
• Early Complications
 Bleeding
 Tracheostomy tube obstruction
 Tracheostomy tube displacement
 Infection

89. • Late Complications
 Tracheal Stenosis
 Granulation tissue
 Tracheocutaneus fistula
 Tracheo - inominate fistula

90. Micro Laryngeal tube placement for airway
management of tracheal stenosis

91. Percutaneous Tracheostomy
Percutaneous tracheostomy is a bedside procedure requiring a
small surgical field and avoiding the need for an operating room.
It was popularised in the 1990’s as a minimally invasive
technique requiring only a small skin incision.
Anatomical factors: Laryngeal and tracheal anatomy may vary
widely depending on the patient and his/her age. A larynx situated
in the thoracic inlet (laryngoptosis) makes all kinds of
tracheostomy difficult and one gets critically close to big
mediastinal vessels. In such cases open dissection under direct
surgical vision is required.

92. TECHNIQUE
Percutaneous tracheostomy is similar to using a
Seldinger technique to cannulate veins and arteries.
 The trachea is entered percutaneously with a thin needle
through which a guide wire is advanced into the trachea.
 A bougie is passed over the guide wire and the tract
between the skin and trachea is dilated until a
tracheostomy tube can be advanced into the trachea.
Unlike with conventional surgical tracheostomy, the
trachea, thyroid gland and vascular structures cannot be
visualised during placement of the tracheostomy or to
achieve haemostasis should bleeding occur.

94. Difficult airway:
The patient must be easy to intubate in the event that alternative
techniques of ventilation by oro- or naso-tracheal intubation is
required should the patient’s airway obstruct following removal
of the endotracheal tube e.g. with in-correct placement of the
percutaneous tracheostomy, accidental decannulation, bleeding
etc.