Assessment of Airway

1. : ‫م‬1 2051 ‫م‬ 1
Wesam Farid Mousa
Assist prof Anesthesia
& ICU
Dammam University ,

2. Why it is a basic requirement ??
Difficult intubation results in significant morbidity and mortality
Prediction of the difficult airway allows time
for proper selection of equipment, technique
and personnel experienced in difficult airways

3. ASA definition of difficult airway
“The clinical situation in which a conventionally
trained anaesthetist experiences difficulty with
mask ventilation, difficulty with tracheal
intubation or both.”

4. definition of
Difficult ventilation
The inability of a trained anesthetist to maintain
the oxygen saturation > 90% using a face mask
for ventilation and 100% inspired oxygen,
provided that the pre-ventilation oxygen
saturation level was within the normal range.

5. definition of
Difficult intubation
• More than 3 attempts in 10 minutes time
• Failure of optimal best attempt
The canadian Society of Anesthesiologists
(CSA) definition:
• It is not possible to visualize any portion of
the vocal cords with conventional
laryngoscopy –
• Intubation requires more than one attempt, a
change in the blade, an adjunct to direct
laryngoscopy or use of alternative devices

6. Prevalence
• Difficult face mask
– 0.1% - 5%
• Difficult intubation
– 1-2% of normal surgical population
– 50% of rheumatic cervical disease

7. Airway assessment
• History
– Patient/notes/chart: Surgery/burns Concurrent disease
• General examination
– Do they just look difficult? Obese or pregnant - Beards
– Airway examination
•Dentition (prominent upper incisors, receding chin)
•Distortion (edema, blood, vomits, tumor, infection)
•Disproportion (short chin-to-larynx distance, bull neck,
large tongue, small mouth)
•Dysmobility (TMJ and cervical spine)
• Specific tests/indices
• Investigations.
- Nasoendoscopy X-ray - CT/MRI - Flow volume loop
• Mask ventilation precedes laryngoscopy

8. 1.Obese (body mass index >30kg/m2)
2.Bearded
3.Elderly (older than 55 y)
4.Snorers
5.Edentulous
1)Bearded
2)Obese
3)No teeth
4)Elderly
5)Snorers

9. 1)Mask seal difficult
2)Obesity
3)Advanced age
4)No teeth
5)Snorer
1)Bearded
2)Obese
3)No teeth
4)Elderly
5)Snorers

10. Predictors of difficult intubation
Individual indices
-Physical examination indices- radiological indices-
advanced indices
1. Atlanto-occipital movement
2. Warning sign of DELIKAN
3. Prayer sign
4. Palm Print test
5. Assessment of TMJ function
6. Assessment of mandibular space: thyrohyoid, thyromental, hyomental
7. Inter-incisor gap
8. Sternomental distance (SAVVA TEST)
9. Upper lip bite /catch test
10.Mallampati Score
11.Grading at direct laryngoscopy CORMACK - LEHANE

11. Predictors of difficult intubation
Group indices
-Physical examination indices-radiological indices-advanced indices
1. Wilson’s score
2. Saghei & safavi test
3. Lemon assesment
4. Arne’s simplified score
5. Magboul’s 4 M’s

12. Predictors of difficult intubation
Individual indices
-Physical examination indices- radiological indices-
advanced indices
1. Atlanto-occipital movement
2. Warning sign of DELIKAN
3. Prayer sign
4. Palm Print test
5. Assessment of TMJ function
6. Assessment of mandibular space: thyrohyoid, thyromental, hyomental
7. Inter-incisor gap
8. Sternomental distance (SAVVA TEST)
9. Upper lip bite /catch test
10.Mallampati Score
11.Grading at direct laryngoscopy CORMACK - LEHANE

13. It assessesfeasibility to makesniffing or
Magill position for intubation i.e. alignment of
oral, pharyngeal and laryngeal axesinto an
arbitrary straight line.
: ‫م‬1 2051 ‫م‬ 13

14. The patient is asked to hold head erect, facing directly to the
front, then he is asked to extend the head maximally and the
examiner estimates the angle traversed by the occlusal surface
of upper teeth
Visual assessment or using a goniometer
• Grade I >35 degrees
• Grade II 22-34 degrees
• Grade III 12–21 degrees
• Grade IV <12 degrees
Grades 3 and 4 : Difficult laryngoscopy

15. 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 & extension movement if within the normal range, three axes
(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
Again

16. Predictors of difficult intubation
Individual indices
-Physical examination indices- radiological indices-
advanced indices
1. Atlanto-occipital movement
2. Warning sign of DELIKAN
3. Prayer sign
4. Palm Print test
5. Assessment of TMJ function
6. Assessment of mandibular space: thyrohyoid, thyromental, hyomental
7. Inter-incisor gap
8. Sternomental distance (SAVVA TEST)
9. Upper lip bite /catch test
10.Mallampati Score
11.Grading at direct laryngoscopy CORMACK - LEHANE

17. 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.

18. Predictors of difficult intubation
Individual indices
-Physical examination indices- radiological indices-
advanced indices
1. Atlanto-occipital movement
2. Warning sign of DELIKAN
3. Prayer sign
4. Palm Print test
5. Assessment of TMJ function
6. Assessment of mandibular space: thyrohyoid, thyromental, hyomental
7. Inter-incisor gap
8. Sternomental distance (SAVVA TEST)
9. Upper lip bite /catch test
10.Mallampati Score
11.Grading at direct laryngoscopy CORMACK - LEHANE

19. 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.
Seen in diabetics
This represents:- cervical spine
immobility and the potential for a
difficult endotracheal intubation

20. Predictors of difficult intubation
Individual indices
-Physical examination indices- radiological indices-
advanced indices
1. Atlanto-occipital movement
2. Warning sign of DELIKAN
3. Prayer sign
4. Palm Print test
5. Assessment of TMJ function
6. Assessment of mandibular space: thyrohyoid, thyromental, hyomental
7. Inter-incisor gap
8. Sternomental distance (SAVVA TEST)
9. Upper lip bite /catch test
10.Mallampati Score
11.Grading at direct laryngoscopy CORMACK - LEHANE

21. The palm and fingers of the dominant hand of the
patient is painted with black writing ink using a brush.
The paTienT then presses the hand firmly against
a white sheet of paper on a hard surface. Scoring is
done as:
Grade 0 - All phalangeal areas visible.
Grade 1 - Deficiency in the inter-phalangeal areas of 4th and/or 5thdigit.
Grade2 - Deficiency in the inter-phalangeal areas of 2nd to 5th digit.
Grade 3 - Only the tips of digits seen.
Which grade you see?

22. Predictors of difficult intubation
Individual indices
-Physical examination indices- radiological indices-
advanced indices
1. Atlanto-occipital movement
2. Warning sign of DELIKAN
3. Prayer sign
4. Palm Print test
5. Assessment of TMJ function
6. Assessment of mandibular space: thyrohyoid, thyromental, hyomental
7. Inter-incisor gap
8. Sternomental distance (SAVVA TEST)
9. Upper lip bite /catch test
10.Mallampati Score
11.Grading at direct laryngoscopy CORMACK - LEHANE

23. TM joint exhibits 2 functions.
*Rotation of the condyle
*Forward displacement of the condyle
First movement is responsible for 2-3cm
mouth opening &the second is responsible
for further 2-3cm mouth opening.
SUBLUXATION OF THE MANDIBLESUBLUXATION OF THE MANDIBLE
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.

24. Significance-Class B and C:
difficult laryngoscopy

25. Predictors of difficult intubation
Individual indices
-Physical examination indices- radiological indices-
advanced indices
1. Atlanto-occipital movement
2. Warning sign of DELIKAN
3. Prayer sign
4. Palm Print test
5. Assessment of TMJ function
6. Assessment of mandibular space: thyrohyoid, thyromental, hyomental
7. Inter-incisor gap
8. Sternomental distance (SAVVA TEST)
9. Upper lip bite /catch test
10.Mallampati Score
11.Grading at direct laryngoscopy CORMACK - LEHANE

26. Assessment of mandibular space
Thyromental distance: ”PATIL’S TEST”
Patient seated,
head extended
mouth closed,
distance that exists between the
thyroid cartilage (upper recess)
and the lower border of the chin
is evaluated

27. Thyromental Distance
If the thyromental distance is short, <6 cm or <3
finger widths, the laryngeal axis makes a more
acute angle with the pharyngeal axis and it will be
difficult to achieve alignment.Less space to
displace the tongue

28. Limitations
• Little reliability in prediction
• Variation according to height, ethnicity
Modification to improve the accuracy
Ratio of height to thyromental distance (RHTMD)
Useful bedside screening test
RHTMD > 23.5 – very sensitive predictor of difficult laryngoscopy

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

30. Predictors of difficult intubation
Individual indices
-Physical examination indices- radiological indices-
advanced indices
1. Atlanto-occipital movement
2. Warning sign of DELIKAN
3. Prayer sign
4. Palm Print test
5. Assessment of TMJ function
6. Assessment of mandibular space: thyrohyoid, thyromental, hyomental
7. Inter-incisor gap
8. Sternomental distance (SAVVA TEST)
9. Upper lip bite /catch test
10.Mallampati Score
11.Grading at direct laryngoscopy CORMACK - LEHANE

31. 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

32. Predictors of difficult intubation
Individual indices
-Physical examination indices- radiological indices-
advanced indices
1. Atlanto-occipital movement
2. Warning sign of DELIKAN
3. Prayer sign
4. Palm Print test
5. Assessment of TMJ function
6. Assessment of mandibular space: thyrohyoid, thyromental, hyomental
7. Inter-incisor gap
8. Sternomental distance (SAVVA TEST)
9. Upper lip bite /catch test
10.Mallampati Score
11.Grading at direct laryngoscopy CORMACK - LEHANE

33. STERNOMENTAL DISTANCE (SAVVA TEST)STERNOMENTAL DISTANCE (SAVVA TEST)
• 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).

34. Predictors of difficult intubation
Individual indices
-Physical examination indices- radiological indices-
advanced indices
1. Atlanto-occipital movement
2. Warning sign of DELIKAN
3. Prayer sign
4. Palm Print test
5. Assessment of TMJ function
6. Assessment of mandibular space: thyrohyoid, thyromental, hyomental
7. Inter-incisor gap
8. Sternomental distance (SAVVA TEST)
9. Upper lip bite /catch test
10.Mallampati Score
11.Grading at direct laryngoscopy CORMACK - LEHANE

35. : ‫م‬1 2051 ‫م‬ 35
Class zero (0): The lower lip gliding over the upper lip positioning itself
at any point above midway between the vermilion line and the
columella: class I: The lower lip reaching a point midway between the
vermilion and the columella; class II: The lower lip catches the upper lip
at the level of the vermillion line or positioning itself just above it (2
mm); class III: The lower lip just caresses the upper lip, but falls short of
obliterating the vermillion line
Significance:
*Assessment of mandibular movement and dental architecture
**Less inter observer variability

36. Predictors of difficult intubation
Individual indices
-Physical examination indices- radiological indices-
advanced indices
1. Atlanto-occipital movement
2. Warning sign of DELIKAN
3. Prayer sign
4. Palm Print test
5. Assessment of TMJ function
6. Assessment of mandibular space: thyrohyoid, thyromental, hyomental
7. Inter-incisor gap
8. Sternomental distance (SAVVA TEST)
9. Upper lip bite /catch test
10.Mallampati Score
11.Grading at direct laryngoscopy CORMACK - LEHANE

37. Test for assessing adequacy of the oropharynx for
laryngoscopy and intubation
Mallampati grading (samsoon and young’s modification)

38. Mallampati Score
Roughly corresponds to Cormack and Lehane’s laryngoscopy views
Class I (easy)—visualization of the soft palate, fauces, uvula, and
both anterior and posterior pillars
Class II —visualization of the soft palate, fauces, and uvula
Class III —visualization of the soft palate and the base of the
uvula
Class IVClass IV (difficult)—the soft palate is not visible at all(difficult)—the soft palate is not visible at all
Sensitivity: 44% - 81%
Specificity: 60% - 80%

40. SIGNIFICANCE OF MMP SCORE
• Class III or IV: signifies that the angle between the base
of tongue and laryngeal inlet is more acute and not
conducive for easy laryngoscopy
• Limitations
– Poor interobserver reliability
– Limited accuracy
• Good predictor in pregnancy, obesity, acromegaly

41. Predictors of difficult intubation
Individual indices
-Physical examination indices- radiological indices-
advanced indices
1. Atlanto-occipital movement
2. Warning sign of DELIKAN
3. Prayer sign
4. Palm Print test
5. Assessment of TMJ function
6. Assessment of mandibular space: thyrohyoid, thyromental, hyomental
7. Inter-incisor gap
8. Sternomental distance (SAVVA TEST)
9. Upper lip bite /catch test
10.Mallampati Score
11.Grading at direct laryngoscopy CORMACK - LEHANE

42. CORMACK - LEHANE
Grading at direct laryngoscopy
• Grade 1: Full exposure of glottis (anterior + posterior
commissure)
Grade 2: Anterior commissure not visualised
Grade3: Epiglottis only
Grade 4: No glottic structure
visible.
Grade I =Grade I = ↑↑ success & ease of intubationsuccess & ease of intubation

44. Predictors of difficult intubation
Individual indices
-Physical examination - radiological indices-
advanced indices
1. Atlanto-occipital movement
2. Warning sign of DELIKAN
3. Prayer sign
4. Palm Print test
5. Assessment of TMJ function
6. Assessment of mandibular space: thyrohyoid, thyromental, hyomental
7. Inter-incisor gap
8. Sternomental distance (SAVVA TEST)
9. Upper lip bite /catch test
10.Mallampati Score
11.Grading at direct laryngoscopy CORMACK - LEHANE
indices-

45. Group indices
1. Wilson’s score
2. Saghei & safavi test
3. Lemon assesment
4. Upper and lower face
5. Arne’s simplified score Magboul’s 4M’s
6. 4 D’s

46. : ‫م‬1 2051 ‫م‬ 46
Mobility of the head and neck
(Angle formed between the positions of greatest extension and greatest
flexion of the neck)

47. Group indices
1. Wilson’s score
2. Saghei & safavi test
3. Lemon assesment
4. Upper and lower face
5. Arne’s simplified score Magboul’s 4M’s
6. 4 D’s

48. 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

49. Group indices
1. Wilson’s score
2. Saghei & safavi test
3. Lemon assesment
4. Upper and lower face
5. Arne’s simplified score Magboul’s 4M’s
6. 4 D’s

50. • Look externally
• Evaluate internally
• Mallampati
• Obstruction
• Neck mobility
Difficult ETT Prediction
LEMON

51. Look Externally
• Beard
• Small jaw, receding chin
• “Buck” teeth
• Craniofacial deformity or trauma

52. Evaluate Internally
• 3-3-2
– 3 fingers of mouth opening
– 3 fingers mentum to hyoid
– 2 fingers hyoid to thyroid

53. Mallampati

54. Obstruction
• Pre-glottic
obstructions
– Tongue enlargement
– Airway edema

55. Neck Mobility
• Ideally the neck should be able to extend
back approximately 35°
• Problems:
– Cervical Spine Immobilization
– Ankylosing Spondylitis
– Rheumatoid Arthritis
– Fixation

56. Group indices
1. Wilson’s score
2. Saghei & safavi test
3. Lemon assesment
4. Upper and lower face
5. Arne’s simplified score Magboul’s 4M’s
6. 4 D’s

57. Upper & Lower Face
Measure size of the upper face as compared to the lower face.
Should be roughly the same.
If the lower face is longer than the upper face then you should
anticipate some degree of difficulty lining up the structures

58. Group indices
1. Wilson’s score
2. Saghei & safavi test
3. Lemon assesment
4. Upper and lower face
5. Arne’s simplified score Magboul’s 4M’s
6. 4 D’s

59. Arne’s simplified score model
• The points of simplified score were obtained by multiplying the points of the exact
score by 3.15 and then rounding the results to the nearest whole number.
Risk factor simplified score
1/ Previous knowledge of difficult intubation
No 0
Yes 10
2/ Pathologies associated with difficult intubation
No 0
Yes 5
3/ Clinical symptoms of airway pathology
No 0
Yes 3
4/ Inter-incisor gap (IG) and mandible luxatum (ML)
IG > 5 cm or ML >0 0
IG 3.5-5cm and ML=0 3
IG<3.5 cm and ML<0 13

60. 5/ Thyromental distance simplified score
>6.5cm 0
< 6.5cm 4
6/ Maximum range of head & neck movement
Above 100° 0
About 90° (90° ± 10°) 2
Below 80° 5
7/ Mallampati’s modified test
Class 1 0
Class 2 2
Class 3 6
Class 4 8
Total...... 48
Score of >11 is predictive of difficult tracheal intubation
Arne’s simplified score model

61. Magboul’s 4 M’s
Remember the 4(M & Ms) with (STOP) sign
•Mallampati
•Measurement
•Movement
•Malformation We can memorize them with the word (STOP)
S = Skull (Hydro and Microcephalus)
T = Teeth (Buck, protruded, & loose teeth. Macro and Micro mandibles)
O = Obstruction (due to obesity, short Bull Neck and swellings around the head
and neck)
P = Pathology (Craniofacial abnormalities & Syndromes: Treacher Collins,
Goldenhar's, Pierre Robin, Waardenburg syndromes) .

62. Group indices
1. Wilson’s score
2. Saghei & safavi test
3. Lemon assesment
4. Upper and lower face
5. Arne’s simplified score Magboul’s 4M’s
6. 4 D’s

63. What are the 4 Ds?
The following Four D's also suggest a difficult airway:
• Dentition (prominent upper incisors, receding chin)
• Distortion (edema, blood, vomits, tumor, infection)
• Disproportion (short chin-to-larynx distance, bull neck, large tongue,
small mouth)
• Dysmobility (TMJ and cervical spine)

64. 1. X-Ray neck (lateral view) :
: ‫م‬1 2051 ‫م‬ 64

65. 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
RADIOGRAPHIC PREDICTORSRADIOGRAPHIC PREDICTORS

66. 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
ADVANCED PredictorsADVANCED Predictors
•Flow volume loop
•Acoustic response measurement
•Ultra sound guided
•MRI
•Flexible bronchoscope

67. COPUR index assessing airway in paediatric patient
• C-chin From the side view the chin is: score
Normal 1
Small, moderately hypoplastic 2
Markedly recessive 3
Extremely hypoplastic 4
• O-Opening of the mouth(Interdental space)
> 40mm 1
20-40 mm 2
10-20mm 3
<10 4
• P-Previous Intubation or OSA
Previous attempt easy 1
No previous attempt, no hx OSA 2
OSA, previous hx difficult intubation 3
Extremely difficult previous intubation 4

68. COPUR index
• U-Uvula (Mouth open tongue out)
Tip of uvula visible 1
Uvula partially visible 2
Uvula concealed, soft palate visible 3
Soft palate not visible 4
• R Range (estimate range of motion looking up and down)
>120° 1
60°-120° 2
30°-60° 3
< 30° 4
• Prediction Points
• 5-7 Easy normal intubation score >10 predict difficult airway
• 8-10 laryngeal pressure may help
• 12 more difficult, fiberoptic may be less traumatic
• 14 Difficult intubation, fiberoptic or other advanced technique
• 16 Dangerous airway, consider awake intubation, potential trach

69. : ‫م‬1 2051 ‫م‬ 69

70. Structured Approach to Airway Management
ComponentComponent DescriptionDescription Assessment ActivitiesAssessment Activities
MMandibleandible Length andLength and
subluxationsubluxation
Measure hyomental distanceMeasure hyomental distance
and anterior displacementand anterior displacement
of mandibleof mandible
OOpeningpening Base, symmetry,Base, symmetry,
rangerange
Assess and measure mouthAssess and measure mouth
opening in centimetresopening in centimetres
UUvulavula VisibilityVisibility Assess pharyngealAssess pharyngeal
structures and classifystructures and classify
TTeetheeth DentitionDentition Assess for presence ofAssess for presence of
loose teeth and dentalloose teeth and dental
appliancesappliances
HHeadead Flexion, extension,Flexion, extension,
rotation ofrotation of
head/neck andhead/neck and
cervical spinecervical spine
Assess all ranges andAssess all ranges and
movementmovement
SSilhouetilhouet
tete
Upper bodyUpper body
abnormalities, bothabnormalities, both
anterior andanterior and
posteriorposterior
Identify potential impactIdentify potential impact
on control of airway ofon control of airway of
large breasts, buffalolarge breasts, buffalo
hump, kyphosis, etc.hump, kyphosis, etc.

71. While this criteria helps identify difficult airways, it does not
guarantee an easy intubation—
Be PrePared!
Nothing is more expensive than the missed
opportunity