contains information about airway anatomy & its evaluation required for anaesthesiologists

1. AIRWAY ANATOMY
and
EVALUATION
Presented By - DR. SANSKRUTI PUROHIT
Ist year PG student
Guided by - DR. LAKSHMI KANTA PANIGRAHI
Assistant Proffesor
Dept of Anaesthesiology
VIMSAR, Burla

2. WHY IS IT IMPORTANT FOR ANAESTHESIOLOGISTS?
It is the fundamental responsibility of an anaesthesiologist
to establish airway patency & to ensure adequate
ventilation and oxygenation.

3. WHAT IS AIRWAY?
Airway is the passage through which air passes into our body
during respiration.
or
In the practice of airway management, airway is an artificial device with a
lumen to aid ventilation or to serve as a conduit to endotracheal intubation.

5. CLASSIFICATION OF AIRWAY
Upper Airway
Oral Cavity
Nasal Cavity
Pharynx
Larynx
Lower Airway
Trachea
Bronchi
Bronchioles
Alveoli
Upper Airway
Lower Airway
Oral Cavity

6. 1. ORAL CAVITY
• Boundaries :
Anteriorly - Lips
Laterally - Cheeks
Posteriorly - Faucial Pillars
Roof - Hard & Soft Palate
Floor - Tongue
Posteriorly it communicates with
oropharynx
UPPER AIRWAYS

7. Anaesthetic importance of oral cavity:
Difficult laryngoscopy & intubation - Contracture of mouth & lips
Loose or buck teeth
Loss of buccal pad of fat
Large tongue
During sleep, unconciousness or general anaesthesia, muscle tone
decreases —> tongue can fall backwards —> obstruct the airway.
Tongue is connected to mandible by Genioglossus muscle. Jaw
thrust maneuver —> mandible & attached tongue anteriorly —>
relieving the airway obstruction
Ludwig’s Angina(cellulitis of sublingual tissues) —> elevation &
posterior displacement of tongue —> airway obstruction

8. 2. NASAL CAVITY
• Extends from naris (external openings) to choana (posterior openings)
• Narrowest portion of upper airway
• 2 nasal passages (right & left) by a nasal septum
• External nose - formed by bones & cartilages
Alae nasi(margins of nostrils) flare during airway obstruction &
may be infolded while introduction of nasal tracheal tube.
Distance from alae nasi to tragus used to estimate length of
nasopharyngeal airway.

9. • Boundaries :
Roof - Cribriform plate of ethmoid
Floor - Palatine process of maxilla
Horizontal plate of palatine bone
Floor of nasal cavity is perpendicular to plane of face, so nasal tracheal
tube/NG tubes should be inserted at right angles to face.
Fracture of cribriform plate of ethmoid is a contraindication for
nasal tracheal intubation & Ryle’s tube insertion.

10. Medial wall - Nasal septum (formed by septal cartilage anteriorly &
ethmoid and vomer posteriorly)
Lateral wall - 3 bony turbinates/conchae dividing the nasal passage
into 3 meatuses - inferior, middle and superior
Septal deviation is a common finding in adults, so more patent side should be
used for instrumentation.
Little’s area in anterior 1/3rd of nasal septum is highly vascular, so topical
vasoconstrictor should be applied before insertion to minimise bleeding.
Inferior meatus is the preffered pathway for passage of nasal airway devices.
Conchae may obstruct passage of nasal airways leading to trauma.
During nasal intubation, bevel of ETT should face medially to avoid
injury to turbinates

11. LATERAL WALL MEDIAL WALL, ROOF & FLOOR

12. 3. PHARYNX
• It is a muscular tube extending from base
of skull to the level of cricoid cartilage.
• Boundaries:
Sup - base of skull
Inf - continuous with esophagus
Post - prevertebral fascia separating it
from vertebral bodies
Ant - communicates with nasal cavity,
oral cavity & larynx
• Divided into 3 parts:
Nasopharynx
Oropharynx

13. NASOPHARYNX
• Extends from base of skull to soft palate
• Ending of nasopharynx at soft palate
is called Velopharynx
Velopharynx is a common site of airway
obstruction in both awake & anaesthetized
patients.
Adenoids in roof of nasopharynx can cause
chronic nasal obstruction & difficulty in
passage of airway devices if enlarged.

14. OROPHARYNX
• Extends from soft palate to epiglottis
• Includes tonsil, uvula & epiglottis
• Lateral walls contain palatoglossal &
palatopharyngeal folds aka anterior &
posterior tonsillar pillars.
Palatine tonsils present between these folds
can cause airway obstruction if
hypertrophied
Space between base of tongue & epiglottis is
called Vallecula - tip of laryngoscopic blade
lies in vallecula during direct laryngoscopy

16. LARYNGOPHARYNX
• Extends from epiglottis to the level
of cricoid cartilage where it is continuous
with esophagus
• Deep depression in lateral walls of
laryngopharynx is called Piriform fossa
Piriform fossa is a catch point for foreign body.

17. 4. LARYNX
• Situated in anterior midline of neck
• Extends from upper border of
epiglottis to lower border of
cricoid cartilage (C3-C6 in adults,
C1-C4 in children)
• Made up of cartilages, muscles
& ligaments.

18. • Cartilages of larynx : 9 in no.- 3 paired & 3 unpaired
UnPaired cartilages - Epiglottis (leaf-like)
Thyroid (shield-like)
Cricoid (ring-like)
Paired cartilages - Arytenoid (cup-shaped)
Corniculate (horn-shaped)
Cuneiform (wedge-shaped)

20. EPIGLOTTIS
• Thin, leaf-like cartilage in anterior wall of
upper part of larynx
• Upper end- free, broad & projects upwards
• Lower end- long, narrow & attached to
thyroid cartilage by
Thyroepiglottic ligament
• Lateral margins -Aryepiglottic folds
Thyroepiglottic muscle (to
thyroid cartilage)
• Ant surface - Median Glossoepiglottic fold
(to tongue)
Hyoepiglottic ligament
(to hyoid bone)

21. THYROID CARTILAGE
• Largest of all cartilages, V shaped in c/s.
• Consists of 2 quadrilateral lamina
• Ant borders of lamina
- Make 90o in males & 120o in females
- Lower part fuse & form median
projection called Laryngeal Prominence
- Upper part separated by Thyroid notch
• Post borders
- Free & prolong upwards & downwards as
Superior & Inferior cornu.
Thyroid notch & Laryngeal prominence serve as important landmarks for
percutaneous airway techniques & larngeal nerve blocks

22. BURP - Used during laryngoscopy to improve view of glottis.
- Backward Upward Rightward Pressure on Thyroid cartilage .

23. CRICOID CARTILAGE
• Inferior limit of larynx.
• Only complete cartilagenous ring in airway
• Narrow anterior Arch & broad posterior Lamina.
• Lamina projects upwards behind thyroid
cartilage to articulate with Arytenoid cartilages
superiorly.
• Inferior cornu of thyroid cartilage articulates
with cricoid cartilage at the junction of arch &
lamina.
Sellick’s maneuver - pressure over cricoid cartilage prevents passive regurgitation
without airway obstruction in patients at risk of gastric aspiration

24. ARYTENOID CARTILAGE
• Small pyramidal shaped cartilages
on upper border of lamina of cricoid.
• Apex - articulates with Corniculate
• Base - prolonged to form Vocal process to
which Vocal fold is attached &
Vestibular fold is attached above
Vocal process
CORNICULATE CARTILAGE
• Small, conical attached to apex of Arytenoids.
• Present in post part of Aryepiglottic folds.
CUNEIFORM CARTILAGE
• Small rod-shaped cartilages in Aryepiglottic
folds just anteior to corniculate cartilages

25. LIGAMENTS & MEMBRANES OF LARYNX
• Extrinsic
Thyrohyoid membrane
Hyoepiglottic ligament
Cricotracheal Ligament
• Intrinsic
Quadrate membrane-lower free
border forms Vestibular fold
and its upper border forms
Aryepiglottic fold
Cricovocal membrane-upper free
border forms Vocal Fold and

26. CAVITY OF LARYNX
• Extends from inlet of larynx to lower
border of cricoid cartilage.
• Inlet - open backwards & upwards
- Boundaries :
Ant - Epiglottis
Post - Interarytenoid fold
Sides - Aryepiglottic fold
• Within the cavity, 2 folds :
Upper fold - Vestibular fold
Lower fold - Vocal fold

27. • Vestibular & Vocal folds divide
laryngeal cavity into 3 parts :
1. Supraglottis / Vestibule -
part above Vestibular fold
2. Ventricle / Sinus - part
between Vestibular &
Vocal fold
3. Infraglottis / Subglottis -
part below Vocal cords

28. • Rima Vestibuli - space between right &
left Vestibular folds
• Rima Glottidis / Glottis - space between
right & left Vocal folds
- narrowest part of larynx in adults
- Length = 24mm(males)
16mm(females)
- Ant 3/5 = intermembranous part
(between vocal folds)
- Post 2/5 = intercartilagenous part
(between arytenoid cartilages)
*Sensory supply - upto Vocal cords by Internal Laryngeal N
- below Vocal cords by Recurrent Laryngeal N

29. • Intrinsic muscles - attaches laryngeal
cartilages to each other
Acting on Vocal cord -
Abductor - Posterior Cricoarytenoid
Adductor - Lateral Cricoarytenoid
Transverse & Oblique
Arytenoid
Tensor - Cricothyroid
Relaxor - Thyroarytenoid
Vocalis
Acting on Laryngeal Inlet -
Opener - Thyroepiglottic
MUSCLES OF LARYNX

30. • Extrinsic Muscles - attach laryngeal cartilages to nearby structures
Elevators - Thyrohyoid.
- Mylohyoid
Depressors - Sternothyroid
- Sternohyoid
*All muscles supplied by Recurrent laryngeal N except Cricothyroid
which is supplied by Superior laryngeal N

31. LARYNGEAL NERVE PALSY

32. DIFFERENCE BETWEEN ADULT & PEDIATRIC AIRWAY
Epiglottis Shape
(High up larynx)

34. TRACHEA
• From lower border of cricoid cartilage(C6) &
ends at Carina (T4 in supine,T6 in standing
posteriorly and Sternal angle anteriorly)
• Length - 10-11mm
• Internal Diameter - 12mm in adults
- 3mm in newborns-3yr then
by 1mm/yr till 12yr
LOWER AIRWAYS

35. • Trachea is made up of 16-20 C-shaped
hyaline cartilage connected by
fibroelastic membrane.
• Posterior deficit part contains
involuntary Trachealis muscle.
• Trachea divides into Right and Left
Bronchus at Carina at angle of 20-25o
and 45-55o respectively
ET Tube should be just above carina for equal ventilation of both lungs
More chances of foreign body entry , aspiration or one lung ventilation in Right lungs b

36. Trachea
Right & Left Bronchus
Segmental Bronchioles
Terminal bronchioles
Respiratory bronchioles
Alveolar Ducts
Alveoli
BRONCHI, BRONCHIOLES & ALVEOLI
Cartilagenous
No Cartilage
Smooth Muscle+

38. Why is it necessary?
To diagnose the potential for difficult airway for :
1. Optimal patient preparation
2. Proper selection of equipments & techniques
3. Participation of personnel experienced in difficult airway management

39. 1)FACIAL ANOMALIES - Maxillary hypoplasia,
- Mandibular hypoplasia &hyperplasia
2)TMJ PATHOLOGY - Ankylosis or reduced movement
3)MOUTH & TONGUE ANOMALY - Microstomia (due to burns, trauma)
- Tongue swelling in Ludwig’s angina
- Tumors of mouth & tongue
- Macroglossia (due to Down’s Syndrome)
4)TEETH PROBLEMS - Missing or Protruding upper incisors(buck tooth)
5)NOSE PATHOLOGY - Choanal atresia
- Hypertrophied turbinate
- Tumors & foreign bodies
6)PALATE PATHOLOGY - Narrow arched palate
- Large cleft palate
- Soft palatal swelling
CAUSES OF DIFFICULT AIRWAY

40. 7) PHARYNX PATHOLOGY - Hypertrophied tonsils & adenoids
- Tumors & abscesses
8) LARYNX PATHOLOGY - Epiglottitis & Laryngomalacia
- Foreign bodies & tumors
- Congenital/traumatic stenosis & Edema
9) TRACHEAL PATHOLOGY- Tracheitis, tracheoesophageal fistula, tracheal
stenosis & webbing, tracheomalacia
- Foreign bodies
- Tracheal deviation due to mass/lung pathology
10) BRONCHIAL TREE PATHOLOGY- Mediastinal mass
- Foreign body aspiration & bronchial tumors
11) NECK - Large goitre, skin contracture, ankylosing spondylitis
12) SPINE - Limitation of movement
- Cervical spine instability

41. COMPONENTS of AIRWAY ASSESSMENT
1. History taking - H/O difficult airway in previous surgeries
- H/O previous surgery, tumor, trauma, burns in &
around the oral cavity, neck or cervical spine
2. General Examination - to rule out anatomic/pathologic factors that
can lead to difficult airway
3. Assessment Tests/Indices - Individual Indices
- Group Indices
Mask Ventilation —> Laryngoscopy —> Intubation

42. PREDICTORS OF DIFFICULT MASK VENTILATION
O B E S E - Obese ( BMI > 26kg/m2 )
Bearded individual
Elderly ( age > 55yrs )
Snorers
Edentulous
M O A N S - Mask seal difficulty in patients with receding mandible,
facial abnormalities, burn strictures etc
Obesity ( BMI > 26kg/m2 )
Advanced age
No teeth

43. PREDICTORS OF DIFFICULT LARYNGOSCOPY &
TRACHEAL INTUBATION
I. Individual Indices - 1.Physical examination indices
2.Radiological indices
3.Advanced indices
II. Group indices - individual indices grouped & scoring systems done

44. INDIVIDUAL
INDICES

45. A. ASSESSMENT OF CERVICAL & ATLANTO-OCCIPITAL FUNCTION
1. Direct Assessment
a) Assessment of Neck Flexion & A-O Extension
Asking patient to touch his manubrium with his chin
( If done => Neck flexion of 25-30o )
Asking patient to look at the ceiling without raising
eyebrows( If done => A-O joint extension 85o )
*Grade III & IV
Difficult Laryngoscopy
GRADES
REDUCTION OF A-O
EXTENSION
Grade I No Reduction
Grade II 1/3rd reduction
Grade III 2/3rd reduction
Grade IV Complete reduction
PHYSICAL EXAMINATION

46. b) Delilkan’s Test
To assess movement of occiput on atlas during extension.
Patient asked to look straight
Place the index finger of left hand under the chin &
the index finger of right hand on occipital tuberosity
Patient is asked to look at the ceiling
If the Left index finger higher than the Right => Normal
If level of both fingers remains same or the Left finger
remains lower than the Right => Abnormal extension

47. 2. Indirect Assessment
a) PRAYER SIGN
- A positive sign can be elicited if patient is
unable to approximate their palms & cannot
bend their fingers backwards
- Seen in Diabetics with stiff joint syndrome
- +ve Prayer sign => cervical spine stiffness
limited A-O movement
difficult laryngoscopy
& intubation

48. b) PALM PRINT TEST
- Joint rigidity in Diabetics also involve Laryngeal & Cervical joints leading to
difficult larngoscopy.
- Patient is asked to give their palm print on a white sheet of paper on a firm
surface. Scoring is done as:
GRADES PALM PRINTS
Grade 0
Phalangeal area completely
visible
Grade I
Interplangeal areas of 4th-5th
digits partly visible
Grade 2
Interplangeal areas between 2nd-
5th digits hardly visible
Grade 3 Only fingertips printed
* Higher the Score, more
difficult is the Laryngoscopy

49. B. ASSESSMENT OF TEMPORO-MANDIBULAR JOINT (TMJ) FUNCTION
• TMJ exhibits 2 functions :
1. Rotation of the condyle in the synovial cavity - 2-3cm mouth opening
2. Forward displacement of the condyle - further 2-3cm mouth opening
• Tests :
a) Interincisor Gap/Mouth Opening
Mouth wide open
Index, middle & ring finger in mouth vertically
If > 5cm / > 3 fingers => Adequate for laryngoscopy

50. b) Sliding of Mandible Test
Index finger in front of tragus &
Thumb in front of lower part of
mastoid process
Asked to open his mouth as wide
as possible
Index finger in front of the tragus can
be indented in its space and the thumb
can feel the sliding of condyle
Good Sliding function of mandible
c) Calder Test
Patient is asked to protrude the mandible
Look for lower incisors alignment
with respect to upper incisors

51. d) Upper Lip Bite test
- Tests the range & freedom of mandibular movement & architecture
of the teeth
Class III of this test expected to have C-L Grade III & IV
CLASS I
Lower incisors can bite upper lip above
vermilion line
CLASS II
Lower incisors can bite upper lip below
vermilion line
CLASS III Lower incisors cannot bite upper lip

52. C. ASSESSMENT OF MANDIBULAR SPACE
This space determines how easily the laryngeal and pharyngeal axis
will fall in line when the A-O joint is extended.
1. Thyromental distance - Distance between thyroid notch & symphysis
menti when neck fully extended
DISTANCE DIFFICULTY
>6.5 cm
NO PROBLEM WITH
LARYNGOSCOPY &
INTUBATION
6-6.5cm
DIFFICULT
LARYNGOSCOPY &
INTUBATION
>6.5cm
LARYNGOSCOPY MAY BE
IMPOSSIBLE

53. 2. Hyomental Distance - Distance between mentum & hyoid bone
3. Thyroid to floor of mouth distance
- Indicates position of larynx in neck
- Larynx position is normal if patient can place 2 fingers between top
GRADES Distances
GRADE I > 6cm
GRADE II 4-6 cm
GRADE III
<4 cm
Impossible laryngoscopy &
intubation

54. 4. Sternomental Distance
- Measured with head in full
extension & closed mouth
- Distance from sternal notch
to mentum < 12.5 cm
Difficult laryngoscopic
intubation

55. D. TEST FOR ASSESSING ADEQUACY OF OROPHARYNX FOR
LARYNGOSCOPY AND INTUBATION
1. Mallampatti grading
- MC used test for predicting airway difficulty
- Indicates amount of space within oral cavity to accomodate
laryngoscope & ETT
- Prerequisites - patient in sitting position & head neutral postion
- mouth wide open
- tongue protruded out without phonation
- observer's eye at the level of patient's open mouth
- Observe for structures visible

56. GRADES STRUCTURES VISIBLE
GRADE I FAUCIAL PILLARS, UVULA, SOFT PALATE & HARD PALATE
GRADE II BASE OF UVULA, SOFT PALATE & HARD PALATE
GRADE III SOFT & HARD PALATE - DIFFICULT LARYNGOSCOPY
GRADE IV ONLY HARD PALATE - DIFFICULT LARYNGOSCOPY

57. E. ASSESSMENT FOR QUALITY OF GLOTTIC VIEW
DURING LARYNGOSCOPY
1. Indirect mirror laryngoscopic view
- complete vocal cords visible
- posterior commissure visible
- epiglottis visible
- no glottic structures visible
2. Direct laryngoscopy “awake look”
- possible with sedation
- gives estimate of forthcoming laryngoscopy & intubation
- Cormack Lehane graded the laryngoscopy view

58. GRADE I ▪ The entire laryngeal aperture
GRADE II ▪ Only the posterior laryngeal aperture
GRADE III ▪ Only the epiglottis
GRADE IV ▪ Only the soft palate
CORMACK LEHANE GRADING

59. 3. Cook’s Modification of Cormack-Lehane’s grading
GRADES LARYNGOSCOPIC VIEW
GRADE 1 GLOTTIC OPENING CLEARLY VISIBLE ( POST COMMISURE & ENTIRE VOCAL CORDS SEEN )
GRADE 2a GLOTTIC OPENING PARTLY VISIBLE ( POST COMMISURE & PART OF VOCAL CORDS SEEN )
GRADE 2b POST COMMISURE SEEN BUT VOCAL CORDS NOT SEEN
GRADE 3a ONLY EPIGLOTTIS SEEN & LIFTABLE
GRADE 3b ONLY EPIGLOTTIS SEEN BUT NOT LIFTABLE
GRADE 4 ONLY ROOT OF TONGUE SEEN

60. 4. Grading Ease of Intubation
5. POGO Scoring ( Percentage Of Glottic Opening )
GRADE I NO EXTRINSIC MANIPULATION OF LARYNX NEEDED
GRADE II EXTERNAL MANIPULATION NECESSARY TO INTUBATE
GRADE III INTUBATION POSSIBLE ONLY WHEN AIDED BY STYLET
GRADE IV FAILED INTUBATION
100% ENTIRE GLOTTIC STRUCTURES VISIBLE
33% ONLY LOWER 1/3rd OF VOCAL CORD & ARYTENOID VISIBLE
0% NO GLOTTIC STRUCTURES VISIBLE

61. 6. Symmetry of Upper & Lower Face
- Upper face : from bridge of nose to just below nasal septa at upper lip
- Lower face : from just below nasal septa to chin
- If lower face longer than upper face
difficulty in straightening of
airway structures during
laryngoscopy

62. 1. X-RAYS
- Lateral X-Ray of head & neck done.
- Measurements predicting difficult laryngoscopy :
1. Effective mandibular length/Posterior depth of mandible < 3.6
2. Reduced distance between occiput & spinous process of C1 < 5mm
3. Increase in posterior depth of mandible >2.5cm
2. CT SCAN
3. MRI
RADIOLOGICAL EXAMINATION

63. 1. FLOW VOLUME LOOPS
- Helps to diagnose small airways vs large
airways obstruction & intrathoracic vs
extrathoracic obstruction
- Helps to locate site of large airway
obstruction
- Helps to distinguish between fixed or
variable obstruction
ADVANCED INDICES

65. 2. ULTRASONOGRAPHY
- Useful in airway assessment by :
a) Identification of cricothyroid membrane
b) Identification of intraoperative pneumothorax
c) Localisation of trachea
d) Quantifying anterior neck soft tissues -
distance from skin to ant aspect of trachea measured at 3 levels:
- vocal cords (zone I)
- thyroid isthmus (zone II)
- suprasternal notch (zone III)
*Soft tissue thickness > 25mm in Zone I or > 28mm in avg of 3 zones
indicates difficult laryngoscopy
3. ESOPHAGOGRAM

66. GROUP
INDICES

67. BELLHOUSE’S CRITERIA
- 3 parameters - Restricted A-O joint extension < 35 degree
Reduced Mandibular space
Enlarged tongue size with respect to pharynx
WILSON’S SCORING SYSTEM
- 5 parameters analysed simultaneously
- Score 0, 1, 2 given to each
- Easy / difficult laryngoscopy & intubation predicted from
their sum total - 5 or less => easy laryngoscopy
6-7 => moderate difficulty
8-10 => severe difficulty

68. WILSON’S SCORING SYSTEM
PARAMETER 0 1 2
WEIGHT(KG) < 90 90-110 >110
HEAD & NECK MOVEMENT >90o 90o <90o
JAW MOVEMENT
(INTER-INCISOR GAP)
>5cm 5cm <5cm
SLIDING MANDIBULAR
BEYOND MAXILLARY INCISORS
>0 0 <0
RECEDING MANDIBLE None Moderate Severe
BUCK TEETH None Moderate Severe

69. BENUMOF’S 11 PARAMETER ANALYSIS
- 11 step airway examination
- Follows line of sight from upper incisors to glottis
- 4-2-2-3 rule : 4 steps focusing on teeth
2 steps for oral cavity
2 steps for mandibular space
3 steps in neck examination

70. BENUMOF’S 11 PARAMETER ANALYSIS
PARAMETER MIN ACCEPTABLE VALUE
INTER-INCISOR GAP > 3cm
BUCKED TOOTH no overriding
LENGTH OF UPPER INCISORS short <1.5cm
MANDIBLE PROTRUSION TEST mandibular teeth beyond maxillary teeth
MALLAMPATI CLASS Class II or less
PALATE CONFIGURATION no arching or narrowing
THYROMENTAL DISTANCE >5cm or >3 finger breadth
MANDIBULAR SPACE COMPLIANCE soft to palpation
NECK LENGTH not too short
NECK THICKNESS not too thick
HEAD /NECK MOVEMENT neck flexion 35o & head extension 80o

71. ROCKE ET AL COMBINED MALLAMPATI GRADING
- Rocke et al combined Mallampati grading with various other factors
and showed correlation between classification of airway &
laryngoscopic blade
- Combined Mallampati with obesity
short neck
teeth abnormality
facial edema
swollen tongue
NC/TMD RATIO
- If >/= 5 —> cutoff point for difficult intubation in obese patients

72. ARNE’S SIMPLIFIED SCORE MODEL
RISK FACTOR SCORE
H/O DIFFICULT INTUBATION
NO - 0
YES - 10
DISEASES ASSOCIATED WITH
DIFFICULT INTUBATION
NO - 0
YES - 5
SYMPTOMS OF AIRWAY PATHOLOGY
NO - 0
YES - 3
IG & MANDIBULAR SUBLUXATION
IG >/= 5cm or SLux > 0 —> 0
IG < 5-3.5cm or SLux = 0 —> 3
IG < 3.5cm or SLux < 0 —> 13
TMD
>/= 6.5cm - 0
< 6.5cm - 4
MAX RANGE OF HEAD & NECK
MOVEMENT
> 100% - 0
90 +/- 10% - 2
< 80% - 5
MALLAMPATI SCORE
Class I - 0
Class II - 2
Class III - 6
Class IV - 8

73. RAPID AIRWAY ASSESSMENT TEST
- In emergency situation, 1-2-3 Finger Assessment test used
- To assess - TMJ function
- Mouth opening
- Mandibular space
- Can be done in 15sec
1-Finger Test :
Index finger in front of tragus & Thumb in front of
lower part of mastoid process
Asked to open his mouth as wide as possible
Index finger in front of the tragus can be indented in its
space and the thumb can feel the sliding of condyle

74. 2-Finger Test : Ask patient to open his mouth wide
Place 2 fingers i.e Index & Middle in the opening
If done => >3cm & adequate for
2cm flange of laryngoscope
3-Finger Test : Ask patient to extend head
Place 3 fingers i.e Index, Middle & Ring
in submandibular space
If done => adequate space infront of larynx and

75. LEMON LAW
- represents 5 simple Rapid Assessment methods
Look for anatomic features suggesting difficulties
Examine airway anatomy using 3-3-2 method :
Interincisor distance (3 fingers)
Hyomental distance (3 fingers)
Thyroid to floor of mouth (2fingers)
Mallampati Grade
Obstruction of Airway : location, type-fixed/mobile & progression
Neck mobility - check neck flexion (chin on the chest)
head extension (look at ceiling)

76. CRITERIA SCORE
L
Facial trauma 1
Large incisors 1
Beard/moustache 1
Large tongue 1
E
Mouth opening </= 3 fingers 1
H-M distance </= 3 fingers 1
Thyroid to FoM distance </= 2 fingers 1
M Mallampati Score 3/4 1
O Obstruction of airway present 1
N Neck mobility decreased 1
Total 10
*Higher the score,
more likely
intubation will be difficult

77. 4 M’S WITH STOP SIGN
Mallampati
Measurement
Movement
Malformation of the skull, teeth, obstruction & Pathology
S = Skull (Hydro and Microcephalus)
T = Teeth (Buck, protruded & loose teeth,
Macro and Micro mandibles)
O = Obstruction (due to obesity, short bull neck & swellings
around head & neck)
P = Pathology (Craniofacial abnormalities & Syndromes)
* Score >/= 8 ——> Difficult Intubation

78. SCORE 1 2 3 4
Mallampati Grade 1 Grade 2 Grade 3 Grade 4
Measurement
Mouth open 3
fingers
TMD 3 fingers HMD 2 fingers TMJ 1 finger
Movement Left Right Flexion Extension
Malformation
Skull (Hydro and
Microcephalus)
Teeth (Buck,
protruded & loose
teeth)
Obstruction Pathology

79. FOUR D'S OF 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
LM-MAP RULE
Look externally for deformities
Mallampati grading
Measurements 3-3-2-1
A-O extension 35o
Pathological obstruction

80. SAGHEI & SAFAVI’S test
• For prolonged laryngoscopy time
• Indices : Weight >80kg
Tongue protrusion <3.2cm
Mouth opening <5cm
Upper incisor length >1.5cm
Mallampati class >1
Head extension <70o
Any 3 indices if present => Prolonged laryngoscopy

81. PREDICTORS OF DIFFICULT Supraglottic Airway Device PLACEMENT
R O D S - Restricted mouth opening
Obstructed upper airways
Disrupted upper airway due to trauma & burns
Stiff lungs
PREDICTORS OF DIFFICULT SURGICAL AIRWAY
B A N G - Bleeding tendency
Agitated patient
Neck scarring/flexion deformity
Growth/vascular abnormalities in region of surgical airway

82. REFERENCES
1. Miller’s Anaesthesia 9th edition
2. Morgan & Mikhails Clinical anaesthesiology
3. Airway Management Manual by Rashid M Khan
4. B.D.Chaurasia’s Human Anatomy
5. Google search

83. THANK YOU