Anatomy of upper airway -

1. Anatomy of upper airway: Nose,
Oral cavity , Pharynx-Its anesthetic
implications
Presented by- Dr. Maninder Singh
Nehria

2. Airway is defined as a passage through
which the air/ gas passes during
respiration
OR
In practice of airway management it is
described as any artificial device with
a lumen to aid ventilation &/orserve
as a conduit to endotracheal
Intubation. These include intubating
laryngeal mask airway (LMA),
oropharyngealairway, nasopharyngeal
airway or several varieties of laryngeal
mask airway

3. ASA DEFINITION
• 1)DIFFICULT AIRWAY –It is defined as “ the clinicalsituationin which a
conventionallytrainedanesthesiologistexperiences difficulty with mask
ventilation,difficultywith trachealintubationor both .”
• 2)DIFFICULT MASK VENTILATION-”The inabilityof a trained
anesthesiologistto maintainthe oxygen saturation> 90% using a face mask
for ventilationand 100% inspired oxygen, provided that the pre-ventilation
oxygen saturationlevel was within the normal range.
• 3)DIFFICULT LARYNGOSCOPY-”It is not possible to visualize any portion
of vocal cord with conventional laryngoscope.Correspondsto cormack &
lehane’s grade IV laryngoscopic view
• 4)DIFFICULT ENDOTRACHEAL INTUBATION-When proper insertion of Tracheal
tube with conventional laryngoscopyrequires
▪ More than 3 attempts
▪ Longer than 10 minutes
▪ Failure of optimal best attempt

4. ASA DEFINITION
• 5)OPTIMAL /BEST ATTEMPT AT LARYNGOSCOPY Can
be defined as ‘laryngoscopy performed by a reasonably
experienced laryngoscopist with the patient in optimal
sniff position having no
significant muscle tone & the laryngoscopist has an
option of change of blade type & length(one time
each)
• 6)INTUBATION ATTEMPT-Defined as “Intubation
activities occurring during a single continuous
laryngoscopy maneuver

5. CLASSIFICATION OF AIRWAY
UPPER AND LOWER AIRWAY
• 1)UPPER AIRWAY-
• – Mouth , oral cavity, oropharynx,
• – Nostrils, nose ,nasal cavity, nasopharynx
pharynx ,larynx
• MOST VULNERABLE AREA FOR
OBSTRUCTION
• 2)LOWER AIRWAY –
– Trachea,bronchi,
bronchioles, alveoli
• SIGNIFICANCE-
– Upper airwayserves to
Warm , filter, humidifythe air/gas
before it enters the lower airway
Bypassingthese structures during
ETT Intubation,makes it essential to
provide warm humidified air/gas
while patient breath spontaneously
– Lower airwayserves in exchange of
gases

6. ORAL CAVITY
- EXTENSION
LIPS TO OROPHARYNGEAL ISTHMUS
I.E. UPTO LEVEL OF ANTERIOR
PILLARS OF TONSIL
• BOUNDARIES -
▪ ROOF Hard and soft palates.
▪ FLOOR Soft tissues, which
include a musculardiaphragm and
the tongue.
▪ LATERAL WALLS Cheeks
▪ POSTERIOR aperture of the
oral cavity is the oropharyngeal
isthmus

7. FUNCTION
1) Inlet for the digestive system
2) Manipulates sounds produced by the larynx and
one outcome of this is speech
3) Can be used for breathing because it opens into
the pharynx, which is A common pathway for food
and air.
4)Due to relatively small size of nasal passage and
significant risk of trauma mouth is often used as
conduit for airway devices.

8. SIGNIFICANCE
• • JAW THRUST MANUEVER
• This maneuveruses the slidingcomponent of
temporomandibularjointto movethe mandible and
attached tongue anteriorlyrelievingairway
obstruction caused byposteriordisplacement of
tongue into oropharynx (Duringsleep,decreased
consciousness,duringgeneral anesthesia)
• • Caution should be maintained during
laryngoscopy as lips can be injured
• Loose/bucked tooth can lead to
difficult intubation
• Depletion of buccal fat ( old age ) –
Difficult mask ventilation

9. NOSE AND NASAL CAVITY
• Airway functionally begins at nostril, the
external opening of nasal passage
• Only externally visible part of the respiratory
system

10. • Nose is divided into two regions
– External nose
– Internal nasal cavity
• EXTERNALLY ALAE NASI
• Lateral margins of the nostrils
• Flaring of ala nasi- Airway obstruction
• Infolded while introducingany tube via the nostril
• Distance from alae nasi to variouspointson external
ear(tragus ,meatus)- Estimate the length of airway device

11. NASAL CAVITY
• Extends from external nares to the post. nasal
aperture
• Divided by nasal septum into rt. & lt. Halves
• Each half has a roof, floor, lateral wall &
medial wall.

12. NASAL CAVITY
• ROOF –
• Cribriform plate of ethmoid bone
• Fracture leading to CSF rhinorrhea, is a contraindication
for passing nasogastric tube or nasotracheal tube
Positive pressure mask ventilation is also a
contraindication as it may leads to entry of infection
• FLOOR
• Palatine process of maxilla in its anterior 3/4th and
horizontal part of palatine bone in posterior 1/4th
Almost perpendicular to the plane of the face
• So the tube should be inserted perpendicular to the plane
of face
• LATERAL WALL
• 3 bony turbinates or conchae , 3 meatus
• Easily damaged by force during passage of nasotracheal
tube
• Paranasal sinuses opening & its drainage may be impaired
by prolonged nasotracheal intubation.
• INFERIOR MEATUS IS THE PREFERRED
PATHWAY FOR PASSAGE OF NASAL
AIRWAY DEVICES.IMPROPER
PLACEMENT IN NOSE CAN RESULT IN
AVULSION OF A TURBINATE

13. MEDIAL WALL
▪ NASAL SEPTUM
▪ Principal constituents are-
• Perpendicular plate of ethmoid & vomer
Septal cartilage
- NASAL SEPTUM DEVIATION is
common in adults therefore the
more patent side should be
determined before passing
instrumentation through nasal
passage
- Has highly vascular area
• (LITTLE’S AREA) in anterior 1/3rd of
nasal cavity.
• Vasoconstrictor should be applied
usually topically before
instrumentation to avoid epistaxis

14. FUNCTION OF NOSE
• Inspired air is:
– Humidified by the high water content in the nasal
cavity
– Warmed by rich plexuses of capillaries
• Ciliated mucosal cells remove contaminated
mucus
• Turbinates increase mucosal area(166cm2) for
humidification & enhance air turbulence & help
filter air
• During exhalation these structures:
– Reclaim heat and moisture
– Minimize heat and moisture loss

15. Significance
• In endotracheal intubation, nose is bypassed so to maintainthe humidity of
inspired air, humidifiers should be used.
- At 37°c & 100% relative humidity absolute humidity is 44mg/ml,
- At room temperature i.e. 21°c & 100%humidity) it is 18mg/l.
-Normal inhaled gases at OT room are administered at room temperature with
little/ no humidification.So gases should be warmed to body temperature and
saturated with water vapor
• Tracheal intubation & high fresh gas flow bypasses this humidification system
exposing lower airway to dry(<10cm h2o/l)room temperature gases
• Prolonged exposure of lower respiratory tract to this non – humidified air
leads to:
1) dehydration of mucus
2)altered ciliary function
3)inspissationof secretion
4)atelectasis
5)ventilation-perfusion mismatch

16. PHARYNX
• Extends from base of skull to cricoid
cartilage anteriorlyand to inferior border
of sixth cervical border posteriorly
• 12-14 cm long
• 3.5cm wide at its base
• 1.5cm at pharyngoesophageal
junction(narrowestpart of digestive
system
• Posterior pharyngealwall made up of
buccophayngeal fasciawhich separates
pharngealstructures from
retropharyngeal
space.Improper placement of gastric or
tracheal tube can result in lacerationof
fascia
Pharynx is further subdividedinto :
• Nasopharynx
• Oropharynx
• Laryngopharynxor hypopharynx.

17. NASOPHARYNX
• Extends fromposteriornasal aperture to the
posteriorpharyngeal wall abovethe soft palate.
• Ends at soft palate , this area is called
velopharynx & is common site for airway
obstruction in both awake and anaesthetized
patient
• Roof of nasopharynx forms an acute angle with
the posteriorpharyngealwall – while passing
any tube through the nose into the oropharynx
a simple maneuverof extension ofhead will
straighten out this angle & facilitatesthe
passage of tube
• Adenoids are located in its roof – which are
frequentlyhypertrophiedduringchildhood &
may cause obstructionorhemorrhage while passingany
tube through the nose
• Retropharyngeal & peritonsillar abscess possess
anaestheticchallenges

18. OROPHARYNX
• EXTENSION
Soft palate to epiglottis
Includes tonsil, uvula & epiglottis.
• Most important area in terms of airway obstruction
& management as it is made of collapsiblesoft
tissue all around.
• Previously it has been thought that upper airway
obstruction occur due to tongue fall but now it
shows that airway obstruction occur mostly at the
level of soft palate& epiglottis.
• Jaw thrust & neck extension will helps to create
space between the epiglottis& posterior
pharyngealwall.
• VALLECULA -
The entire space between epiglottis& base of
tongue & has paired depression of the two sides of
median glossoepiglotticfold. Laryngoscope blade
tip lies in vallecula during classical macintosh
laryngoscopy

19. LARYNGOPHARYNX OR
HYPOPHARYNX
• It extends from
epiglottis to the
beginning of esophagus.
• On each side of the
laryngeal inlet, the lateral
wall of laryngopharynx
presents the piriform
fossa which is a deep
depression .It acts as a
catch point for foreign
body.

20. Airway
Assessment
• PURPOSE - TO DIAGNOSE THE POTENTIAL FOR
DIFFICULT AIRWAY FOR
-Optimal patient preparation
-Proper selection of equipment
-Participation of personnel experienced in
difficult airway management.

21. How do you assess ??
• Airway may be assessed for difficult airway
using :-
-Individualindices
-Group indices(with and without scoring)
Mask ventilation precedes laryngoscopy,which
in turn followed by, intubation.
So the assessment should be in a systemic
manner.

22. Predictors of difficulty to face mask
ventilate
• (OBESE)
• 1. The Obese (body mass
• index > 26 kg/m2)
• 2. The Bearded
• 3. The Elderly (older than 55y)
• 4. The Snorers
• 5. The Edentulous
• (=BONES)
• Patient having ≥2 of the
predictors likely to have
difficult mask ventilation
• (MOANS)
• • MOANS
• This is identical to BONES except
‘M’.
• -Mask seal difficult due to
receding
• Mandible , syndromes with facial
• Abnormalities ,burn , stricture
etc.
• -Obesity, upper airway
Obstruction
• -Advanced age
• -No teeth
• -Snorer

23. Predictors of difficulty to face mask
ventilation
• Individual indices
-Physical examination indices
-radiological indices
-advanced indices
• Group indices
- Wilson’s score
- Benumof’s 11 parameter analysis
- Saghei & safavi test
- Lemon assesment
- Arne’s simplified score
- Magboul’s 4 M’s

24. ASSESSMENT OF CERVICAL &
ATLANTO-OCCIPITAL JOINT
• DIRECT ASSESSMENT – Assess the neck movement by
asking the patient to touch his manubrium sternii
with his chin. If done this assures neck flexion of 25-
30°.
• Then ask the patient to look at ceiling without raising
eyebows to test a-o joint extension
• GRADE 3 & 4 INDICATE DIFFICULT LARYNGOSCOPY
• Grade Reduction of A.O.Extension
• 1 none
• 2 1/3RD REDUCTION
• 3 2/3RD REDUCTION
• 4 COMPLETE REDUCTION

25. 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.
• Then 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

26. CALDER TEST
• ASSESSMENT OF TMJ FUNCTION
• TM jointexhibits 2 function.
• 1. Rotationof the condyle in the s.cavity.
• 2. Forward displacementof the condyle.
• First movement is responsible for 2-3cm
mouth opening & the second is responsible
for further 2-3cm mouth opening.
• SUBLUXATION OF THE MANDIBLE
• Index finger is placed in front of the tragus &
the thumb is placed in front of the lower
part of the mastoid process.
• patientis asked to open his mouth as wide
as possible.
• Index finger in front of the tragus can be
indentedin its space and the thumb can
feel the sliding movement of the condyle as
the condyle of the mandibleslides forward

27. 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

28. Test for assessing adequacy of the
oropharynx for laryngoscopy and
intubation
• Mallampati grading (samsoon and young’s
modification)
• Narrownessof the palate- EVALUATED WHILE
PERFORMING MALLAMPATI GRADING. A
NARROW , HIGH ARCHED PALATE MAY HAVE
DIFFICULT LARYNGOSCOPY & INTUBATION

29. MALLAMPATTI GRADING
• Suggest optimaltongue size in relationto
oropharyngealcavitypermitting easy
laryngoscopy.
• Indicateamount of space within the oral
cavity to accommodatethe laryngoscope
& ETT
• Assessed when the patient is
-seated
-upright with head neutral
-the mouth open
-tongue protruded as much as possible
- no phonation.
-The observer’s eye At the level of
patient’sopen mouth
• Higher scores- poor visibilityof the
oropharyngealstructures- Large tongue
relativeto the size of the oropharyngeal
space Difficult laryngoscopy

30. Group indices for oral cavity, nasal
cavity, pharnyx
• - Wilson’s score
• - Saghei & safavi test
• - Lemon assesment
• - Arne’s simplified score
• - Magboul’s 4 M’s

31. Wilson’s risk score
score
Weight 0=<90kg
1=90-110kg
2=>110kg
Head and neck
movement
0=above 90
1=about 90
2=below 90
Jaw movement 0=IG> 5cm SL >0
1=IG= 5 cm SL=0
2=IG <5 cm SL <0
Receding mandible 0-normal
1-Moderate
2- Severe
Buck teeth 0- normal
1- moderate
2- severe
• Head movement assessedwith
pencil
taped to a patient’s forehead.
•IG = Inter incisor gap measured
with
mouth fully open.
•S Lux = Maximalforward protrusion
of
the lower incisors beyond
the
upper incisors.
•score <=5 =easy laryngoscopy
•Score 6-7=moderate difficulty
•Score 8-10 =severe difficulty in
laryngoscopy

32. 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

33. Arne’s simplified score model
• • Risk factor simplified score
• • Previous knowledge of difficult intubation
• No 0
• Yes 10
• • Pathologiesassociated with difficult
intubation
• No 0
• Yes 5
• • Clinical symptoms of airway pathology
• No 0
• Yes 3
• • 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
• • Thyromental distancesimplified score
• >=6.5cm 0
• < 6.5cm 4
• • Maximum range of head & neck
movement
• Above100° 0
• About 90° (90° ± 10°) 2
• Below 80° 5
• • 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

34. LEMON trial
• REPRESENTS 5 SIMPLE RAPID ASSESSMENTMETHODS ON
UNCOPERATIVE & COPERATIVE PATIENT
• Look
-Facial trauma
-Large incisors
- Beard
-Large tongue
• Evaluate 3-3-2
-Interincisor distance (3 fingers)
-Hyoidmental distance (3 fingers)
-Thyroid to floor of mouth (2fingers)
• Mallampati
• Obstruction
• Neck mobility – chin to chest

35. LOOK Externally
• Beards or facial hair
• Short, fat neck
• Morbidly obese patients
• Facial or neck trauma
• Broken teeth (can lacerate
balloons)
• Dentures (should be
removed)
• Large teeth
• Protruding tongue
• A narrow or abnormally
shaped face
• EVALUATE 3-3-2
• Mouth Opens at least 3
finger widths.
• Three finger widths
thyromental distance.
• Two finger widths
hyomental distance.

36. Magboul’s 4 M’s
• • For Intubationremember the 4(M & Ms)
• with (STOP) sign
• • Mallampati
• • Measurement
• • Movement
• • Malformation & STOP
• • M =Malformationofthe skull,teeth,
• obstruction,& Pathology(the Macros and
• Micros). 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, Waardenburgsyndromes).
• • PATIENT SCORE >= 8 DIFFICULT INTUBATION

37. THANK YOU