About airway management and criteria

1. Airway management
SPEAKER - DR.VINEESHA
MODERATOR – DR.SRILATA MAM

2.  HISTORY
 FUNCTIONAL ANATOMY
 EQUIPMENT
 TECHNIQUE
 DIFFICULT AIRWAY ALGORITHM
 EXTUBATION

3. HISTORY
 Prior to 1874, mechanisms of airway obstruction were poorly understood. Opening the mouth with a wooden
screw and drawing the tongue forward with forceps or a steel-gloved finger was the height of nonsurgical
airway management.
 Not until 1880 was it recognized that most airway obstruction resulted from the tongue falling against the
posterior pharyngeal wall.
 Joseph Thomas Clover - *used a nasopharyngeal tube for the delivery of chloroform anesthesia.
* the first use of SGA
 Ralph Waters – introduced flattened tube oral airway
 Arthur Guedel modified Waters’ concept by fitting his airway within a stiff rubber envelope in an attempt
to reduce mucosal trauma.
 Tracheal intubation was a means of resuscitation of the “apparently dead,” but was not used for the
delivery of anesthesia until almost 100 years later.
 Sir Ivan Magill and Stanley Rowbotham - development of modern tracheal
intubation
During the use of this “Magill” tube, the exhaust lumen would occasionally pass blindly
into the larynx, leading Sir Ivan to describe “blind nasal intubation.”

4.  Cuffed SGAs were initially described in the early part of the 20th century. Three factors led to the
development of these devices:
• (1) the introduction of cyclopropane (which was explosive and required an airtight circuit for appropriate gas
containment)
• (2) appreciation that blind and laryngoscope-guided tracheal intubation remained a difficult task, and
• (3) a need for protection of the lower airway from blood and surgical debris in the upper airway.
 By 1981, two types of airway management prevailed—tracheal intubation and facemask ventilation with or
without a Guedel airway. Although time-tested, both had failings.
• Tracheal intubation - associated with dental and soft tissue injury as well as cardiovascular stimulation
• Mask ventilation - required a prolonged hands-on-the-airway technique. These difficulties led to the
reconsideration of SGAs.
 Dr. Archie Brain conceived the idea of fitting a mask-like structure over the larynx.
• The first prototypes of the LMA were built from the Goldman dental mask, fitted with a tracheal tube. The
LMA Classic (Teleflex, Research Triangle Park, NC) was introduced into practice in the United Kingdom

5. ANATOMY OF AIRWAY
▶ DEFINITION: The airway is defined as a passage through which the air
/gas pass during respiration.
CLASSIFICATION OFAIRWAY
UPPER AIRWAY
Oral cavity, Nasal cavity, Pharynx, Larynx
MOST VULNERABLE AREA FOR OBSTRUCTION
LOWER AIRWAY
Trachea, Bronchi, Bronchioles, Alveoli
SIGNIFICANCE
 The upper airway serves to warm, filter, and humidify the air/gas before it enters the
lower airway. Bypassing these structures during ETT Intubation makes it essential to
provide warm humidified air/gas while the patient breathes spontaneously or is on
assisted/ controlled ventilation.
 The laryngeal structures in part serve to prevent aspiration into the trachea.
 The lower airway serves in the exchange of gases.

6. UPPERAIRWAY
ORAL CAVITY
 Extends from lips to oropharyngeal isthmus (anterior tonsillar pillars)
 Tongue – the muscular organ that makes up most of the floor of the oral
cavity
BOUNDARIES
ROOF – Hard and soft palates
FLOOR – soft tissues which include the muscular
diaphragm and tongue
LATERAL WALLS – cheeks
THE POSTERIOR – aperture of the oral cavity is the oropharyngeal isthmus

7. MUSCLES OF TONGUE
• EXTRINSIC MUSCLES
Functions – protrusion, retraction, and
side-to-side movement.
• GENIOGLOSSUS
• HYOGLOSSUS
• PALATOGLOSSUS
• STYLOGLOSSUS
• INTRINSIC MUSCLES
Functions - lengthening and shortening , curling and uncurling the
tongue
• SUPERIOR LONGITUDINAL MUSCLES
• INFERIOR LONGITUDINAL MUSCLES
• VERTICAL
• TRANSVERSE
GENIOGLOSSUS is most clinically relevant to anaesthesiologists
which connect the tongue to the mandible

8. Nerve supply
 Palate(sensory)-
The palatinenerves provide sensoryfibersfrom the trigeminal
nerve (V) to the superior and inferiorsurfacesof the hard and soft
palate
 Tongue
Sensory supply
General sensations
Anterior 2/3 rd –lingual nerve
Posterior 1/3 rd-
Glossopharyngeal nerve
Motor supply
All muscles-supplied by the hypoglossal
nerve, with the exception of
the palatoglossus, which is innervated by
the vagus nerve
Taste sensations
Anterior 2/3rd –
Chordatympani nerve
Posterior 1/3rd-
Glossopharyngeal nerve

9. SIGNIFICANCE
Mallampati grading helps in the assessment of the airway during PAC
JAW THRUST MANEUVER
This Maneuver uses the sliding component of the temporomandibular joint to
move the mandible and the attached tongue anteriorly relieving airway
obstruction caused by posterior displacement of the tongue into the
oropharynx (during sleep, decreased consciousness, during general 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

10. NOSEAND NASAL CAVITY
▶ Nose is divided into two regions :
▶ 1. External nose and 2. Internal nose
▶ 1. (A)External nose: Bony part and cartilaginous part
▶ 2. (B) Internal nose: Vestibule and nasal cavity proper
.
 Nerve supply
- olfactory nerves
-nerves of common sensation
• anterior
ethmoidal nerve
• sphenopalatine
nerve
• infraorbital
nerve

11. SIGNIFICANCE
 Endotracheal intubation- nose is bypassed so to maintain the
humidity of inspired air, humidifiers should be used
 Normal inhaled gases in the OT room are administered at room
temperature with or no humidification. So gases should be
warmed to body temperature and saturated with water vapor
 Tracheal intubation and high fresh gas flow bypass this
humidification system exposing lower airways to dry room
temperature gases
 Prolonged exposure of the lower respiratory tract to this
non-humidified air leads to dehydration
Altered ciliary function
Inspissation of secretion
Atelectasis
Ventilation perfusion mismatch

12. PHARYNX
▶ Extends from the base of the skull to cricoid cartilage anteriorly and to the
inferior border of the sixth cervical vertebra posteriorly
▶ The pharynx divided into –NASOPHARYNX, OROPHARYNX,
LARYNGO/HYPOPHARYNX
▶ 12-14cm long,3.5cm wide at its base
▶ 1.5cm at pharyngoesophageal junction (the narrowest part of the
digestive tract apart from the appendix which is the most common
site of obstruction with foreign body aspiration.
▶ Posterior pharyngeal wall is made up of buccopharyngeal fascia which
separates pharyngeal structures from retropharyngeal space. Improper
placement of gastric or tracheal tube can result in laceration of fascia
The wall of the pharynx contains
Internal layer – stylopharyngeus, salpingopharyngeus, palatopharyngeal
they elevate the pharynx and shorten the larynx during
deglutition
External layer – superior, middle, and inferior constrictor
.

13. Nerve supply
 Internal layer - Glossopharyngeal nerve
 External layer - pharyngeal plexus formed by
• 1) vagus
• 2) glossopharyngeal
• 3)external branch of superior laryngeal
nerve
• The inferior constrictor also innervated by the recurrent
laryngeal nerve
•
Blood supply
 ascending pharyngeal artery
 ascending palatine artery
 tonsillar artery
 pharyngeal artery
 superior thyroid artery
 and the inferior thyroid artery.
The pharyngeal plexus is responsible for the venous
drainage of the entire region

14. NASOPHARYNX
 It extends from the posterior nasal aperture to the posterior
pharyngeal wall above the soft palate.
 Consists of - nasal cavity, septum, turbinates, and adenoids.
APPLIED ANATOMY:
 Ends at the soft palate – the area is called the velopharynx – a common
site for airway obstruction in both awake and anesthetized patient
 The roof of the nasopharynx forms an acute angle with the posterior
pharyngeal wall – while passing any tube through the nose into the
oropharynx a simple maneuver of extension of the head will straighten
out this angle & facilitates the passage of the tube.
 Adenoids – located in the roof when hypertrophied(commonly in
children )causes obstruction

15. OROPHARYNX - includes tonsils, uvula, and epiglottis
 A most important area in terms of airway obstruction & management as it is
made of collapsible soft tissue all around
APPLIED ANATOMY:
 The laryngoscope blade tip lies in the vallecula during classical Macintosh
laryngoscopy.
 The vallecula is a common site of the impaction of foreign bodies, such as
fish bones, in the upper airway.
WALDEYER’S RING
 The ring includes masses of lymphoid tissue or tonsils
 Enlarge tonsils (kissing tonsils)- prone for obstruction
 Lingual tonsillar hypertrophy - usually asymptomatic, has been
reported as a cause of unanticipated difficult intubation and fatal
upper airway obstruction

16. LARYNGOPHARYNX
Extends from the superior border of the epiglottis to the
inferior border of the cricoid cartilage.
APPLIED ANATOMY
1) Pyriform fossa - part of the lateral wall of the
laryngopharynx(on two sides)
 Acts as a catch point for foreign body
 The internal laryngeal nerve runs submucosally in the
lateral wall of the pyriform sinus and thus is easily
accessible for local anesthesia.
2)Postcricoid area - part of the anterior wall of the
laryngopharynx
 It is a common site for carcinoma in females suffering
from Plummer–Vinson synd.

17. SIGNIFICANCE
 Pharyngeal musculature - awake patients help in maintaining
airway patency – loss of pharyngeal muscle tone is one of the
primary causes of upper airway obstruction during anesthesia
 A chin lift with mouth closure increases tension in pharyngeal
muscles, counteracting the tendency of the pharyngeal airway to
collapse
 Along the superior and inferior walls of the nasopharynx are adenoid
tonsils which can cause chronic nasal obstruction-difficulty in passing
airway devices
 Nasopharynx - a common site for obstruction both in the awake
and anesthetized patient
 Oropharynx – contains palatine tonsil which can hypertrophy and
cause obstruction
 Hypopharynx/laryngopharynx - two pyriform recesses on either
side

18. LARYNX
 Larynx - made of muscles, cartilage, and ligaments
serves as an inlet to the trachea and performs various functions
including phonation and airway protection
 3 unpaired cartilages – thyroid cricoid and epiglottis
3 paired cartilages - arytenoid corniculate and cuneiform
 Thyroid cartilage – largest cartilage- superior thyroid notch associated with
laryngeal prominence is appreciated from the anterior neck and serves as an
important landmark for percutaneous airway technique and laryngeal nerve
blocks
 The cricoid cartilage at the level of the 6th cervical vertebrae is the inferior
limit of the larynx and is connected anteriorly to the thyroid cartilage by the
cricothyroid membrane, it is the only cartilaginous ring in the airway.
 Arytenoid cartilage articulates with the posterior cricoid and is the posterior
attachment for the vocal cords
 When viewed from the pharynx as during direct laryngoscopy, the larynx begins at
the epiglottis which is the cartilaginous flap that serves as the anterior border of
the laryngeal inlet – it directs food away from the larynx

19. ▶ Anterior surface of the epiglottis is attached to the upper border of the hyoid bone by the
hyoepiglottic ligament
▶ Laryngeal inlet is bounded by aryepiglottic folds and posteriorly by corniculate cartilage and the
inter arytenoid notch. Space inferior to the laryngeal inlet down to the inferior border of the
cricoid cartilage is the laryngeal cavity
▶ Ventricular folds (vestibular folds are false vocal cords) are the most superior structure within
the laryngeal cavity
LARYNGEALCAVITY
UPPER(SUPRAGLOTTIC)
MIDDLE(GLOTTIC)
LOWER(SUBGLOTTIC)
Upper fold: Vestibular fold(FALSE VOCAL CORD) Pink in color
Lower fold: Vocal fold(TRUE VOCAL CORD) Pearly white in color- attach posteriorly to arytenoids and
anteriorly to the thyroid cartilage
▶ Space between the vocal cords is termed as glottis, the portion above the glottis is known as the
vestibule and the portion below is known as the subglottis
GLOTTIS
It is the narrowest part of the laryngeal cavity.
It is an elongated space b/w the vocal cord anteriorly and the Vocal process and base of the
arytenoid posteriorly.
▶ In adults.A-P length: - Male –24mm Female –16mm
▶

21. MUSCLES OF LARYNX
EXTRINSIC MUSCLES OF LARYNX
Suprahyoid muscles – geniohyoid muscles, stylohyoid, mylohyoid, thyrohyoid,
digastric, and stylopharyngeus

Infrahyoid muscles – strap muscles - lowering the larynx can modify the internal
relationship of laryngeal cartilage and folds into one another
Strap muscles – sternohyoid, sternothyroid, omohyoid, and thyrohyoid
INTRINSIC MUSCLES OF THE LARYNX
 They modify the length and tension of the vocal cords as well as the shape rima
glottidis during breathing, swallowing, and vocalization
I –ACTING ON VOCAL CORD
Abductor – Posterior cricoarytenoid
Adductor – Lateral cricoarytenoid, Transverse & oblique arytenoid
Tensor (Elongation) – Cricothyroid, Partly Vocalis
Relaxer (Shortening) – Thyroarytenoid, Partly Vocalis
II –ACTING ON LARYNGEAL INLET
Openers – Thyroepiglottic,
Thyroarytenoid Closer – Aryepiglottic,
Oblique arytenoid

22. Nerve supply
Vagus nerve
Superior laryngeal Recurrent laryngeal
Internal External
BLOOD SUPPLY
The cricothyroid artery – a branch of the Superior thyroid artery - crosses
the upper cricothyroid membrane (CTM) The superior thyroid artery is
found along the lateral edge of the CTM.
Cricothyroid membrane
 joins the superior aspect of the cricoid cartilage and the inferior edge of the
thyroid cartilage.
 identified 1 to 1.5 fingerbreadths below the laryngeal prominence (thyroid
notch).
 The membrane has a central portion known as the cone elastics and two
lateral thinner portions. Directly beneath the membrane is the laryngeal
mucosa.
 Because of anatomic variability in the course of veins and arteries and the
membrane’s proximity to the vocal folds it is suggested that any incisions or
needle punctures to the CTM be made in its inferior third and be directed
posteriorly during cricothyroidotomy.

23. SIGNIFICANCE
▶ Glottis - narrowest part in adults,
Subglottis -is the narrowest part in children up to the age of
5 years- that’s why in children uncuffed endotracheal tubes can be used
▶ Burp technique (backward upwards rightwards pressure maneuver) – which is used to improve the view of
the glottis during laryngoscopy and tracheal intubation. It requires a clinician to apply pressure on
thyroid cartilage posteriorly, then upwards, and finally laterally towards the patient’s right
▶ Sellick’s maneuver – in patients who are at risk of gastric aspiration, during airway management downward
pressure over cricoid cartilage will prevent passive regurgitation without subsequent airway obstruction
Burp technique
Sellick’s maneuver

24. DIFFERENCES BETWEEN ADULT AND INFANT
LARYNX
• ADUL
T LARYNX
• ▶ LARGER
• ▶ LOCATION- C4-C6
• ▶ NOT PLIABLE
• ▶ POSTERIOR ANGLE WITH
RESPECT TO THE PERPENDICULAR
AXIS OF THE LARYNX
• ▶ ARIEPIGLOTTIC FOLDS LIE
FAR FROM THE MIDLINE
• ▶ EPIGLOTTIS – RELATIVELY
SMALLER BROADER
• ▶ MUCOSA IS NOT EASILY INJURED
INFANT LARYNX
▶ SMALLER
▶ C3-C5
▶ PLIABLE LARYNGEAL CARTILAGE
▶ ANTERIOR ANGLE WITH RESPECT TO THE
PERPENDICULAR AXIS OF THE LARYNX
▶ ARIEPIGLOTTIC FOLDS CLOSER TO
THE MIDLINE
▶ EPIGLOTTIS –RELA
TIVEL
Y LONGER
NARROWER AND STIFFER
▶ MUCOSA IS VULNERABLE TO
TRAUMA

25. NERVE EFFECTS OF NERVE INJURY
SUPERIOR LARYNGEAL NERVE
UNILATERAL
BILATERAL
MINIMAL EFFECTS
HOARSENESS , TIRING OF VOICE
RECURRENT LARYNGEAL NERVE
UNILA
TERAL
BILATERAL
ACUTE
CHRONIC
HOARSENESS
STRIDOR, RESPIRA
TORY DISTRESS
APHONIA
VAGUS NERVE
UNILA
TERAL
BILATERAL
HOARSENESS
APHONIA

26.  The tracheameasures approximately 15 cm in adults
and is circumferentiallysupported by 17 to 18-C-shaped
cartilages,with a membranousposterioraspect
overlying the esophagus.
 In adults, the first tracheal ring isanterior to the sixth
cervicalvertebra.The trachea ends at the carina
(opposite the fifth thoracic vertebra), whereit bifurcates
intothe principal bronchi.
 The right principal bronchus islarger in diameterthan
the left and deviates fromthe sagittal plane of the
trachea at a less acute angle.For these reasons,
aspirated materials, as wellas a deeply inserted
endotrachealtube (ETT), tend to gainentry intothe right
principal bronchus, although left-sided positioning
cannotbe excluded.
 Cartilaginous ring support continues through the first
seven generationsof the bronchi.
TRACHEA

27.  Airway management always begins with a thorough airway-relevant history and physical
examination, including a search for documentation of previous airway-related anesthetic
events.
 When a patient requires more than routine care (anticipated or unanticipated), the patient
should be made aware of diagnostic evaluations and therapeutic interventions that were
employed.
 It is becoming common practice for a dedicated “difficult airway note” to be incorporated into
electronic medical records and for a “difficult airway letter” to be given to, and reviewed with,
patients and their families, describing critical and unanticipated airway events.
 In the absence of such documentation, the clinician should seek the anesthetic records of past
surgical visits, which in some cases may involve contacting other institutions. When this
information is not available, adopting a low threshold for using a more conservative approach to
airway management (e.g., awake intubation) will mitigate risk.

28.  Until recently, there was limited data on external airway findings that may indicate failure of indirect
laryngoscopy.
 Studies comparing DL with a Macintosh laryngoscope and VL with the Glidescope indicate that, though no single
examination finding may predict the success or failure with each device, the failure to visualize the larynx with
the Glidescope was characterized by higher multivariate risk scores of the same clinical finding.
 Others have found that the following preoperative findings contribute to the failure of VL:
• Scarring
• radiation
• masses or thickness of the neck
• a thyromental distance of less than 6 cm
• limited cervical motion
• and operator experience.
 In 2016, based on a secondary analysis of 1,100 VL intubations, identified four distinct predictors of difficult
acute-angle VL. Of note, the “supine sniffing” position was associated with more difficult VL than the “supine
neutral” position (Odds Ratio: 1.646), suggesting that this common position may be best avoided when initial
plans include VL.
 In general, tracheal intubation should be considered nonroutine under the following conditions: (1) the presence
of equally important priorities to the management of the airway (such as a “full stomach” or emergency
surgery); (2) abnormal airway anatomy; or (3) direct injury to the upper airway, larynx, spine, and/or trachea.
Although the finding of abnormal anatomy is not synonymous with difficult airway management, it should kindle
heightened suspicion.

29.  Ultrasound (US) technology is widely used, portable, and provides rapid, real-
time, dynamic images.
 Bedside US can confirm endotracheal intubation with both a sensitivity and
specificity of 0.9832 and can be used to identify the CTM, rule out esophageal
intubation and verify ventilation in the absence of CO2 detection (assuring
bilateral lung excursion).
 Subglottic hemangiomas, papillomas, laryngeal cysts, and stenosis have also
been identified by the US.
 Another use for US imaging is the estimation of ETT (including double lumen)
size. Although it may be possible to examine the upper airway for changes such
as hypertrophic lingual tonsils, the clinical relevancy (e.g., impact on
laryngoscopy and ventilation) of ultrasonography has not been studied33 and the
applications of US in preoperative airway evaluation are still limited.

30. AIRWAY ASSESSMENT
▶WHY IS IT NECESSARY ??
PURPOSE – TO DIAGNOSE THE POTENTIAL FOR DIFFICULTAIRWAYS FOR
▶ Optimal patient preparation
▶ Proper selection of equipment and technique
▶ Participation of personnel experienced in difficult airway management

31. ▶ History
• Patient /notes/chart/previous
anesthesia records
Surgery/burns/trauma/tumor in
and around d oral cavity
Concurrent disease
• Reflux/recent meals
• GENERALEXAMINATION
• Do they just look difficult?
• Recognition of anatomic factors that
can cause difficult airway
• Investigations

32. CAUSES OF DIFFICULTAIRWAY
1)FACIALANOMALIES - Maxillary hypoplasia (Apert syndrome, Crouzon ds) Mandibular hypoplasia(Gierre Robin
syndrome, Treacher Collins syndrome, Goldenhar syndrome) Mandibular hyperplasia(acromegaly)
2)TMJ PATHOLOGY - Ankylosis or reduced movement
3)MOUTH & TONGUE ANOMALY - Microstomia (burns, trauma), tumor of mouth & tongue macroglossia (down’s
syndrome, hypothyroidism)
4)TEETH PROBLEMS - Missing left upper incisors, protruding upper incisors
5)NOSE PATHOLOGY - Hypertrophied turbinate, polyps, gliomas, foreign bodies, DNS
6)PALATE PATHOLOGY - Narrow arched palate, large cleft palate
7)PHARYNX PATHOLOGY - Hypertrophied tonsils & adenoid, tumors, abscess (retropharyngeal / parapharyngeal
abscess)
8)LARYNX PATHOLOGY – Epiglottitis , laryngomalacia, foreign body, papillomas, congenital stenosis, edema
9)TRACHEAL PATHOLOGY – Tracheitis, tracheoesophageal fistula, tracheal stenosis & webbing, foreign body ,
tracheomalacia
10)BROCHIAL TREE PATHOLOGY - Mediastinal mass, foreign body aspiration, bronchial tumors
11)NECK– Large goiter
, skin contracture, ankylosing spondylitis
12)SPINE- Limitation of movement( congenital Klippel-Feil syndrome,Acquired - surgical fusion , fracture of
cervical vertebrae) ; cervical spine instability (down’s syndrome)

33. INDIVIDUAL INDICES
 Presence of beard – Difficulty in creating an
effective seal by mask leading to loss of
ventilated volume
 Obesity - Large body mass index(>26kg/m2 )
Abnormality of teeth – Irregular teeth,
artificial denture
 edentulous
 Elderly >55years
Snorers
 Hair bun
 Jewelry and facial piercing GROUP INDICES
(OBESE) (MONAS
GROUP INDICES
 Obese (BMI > 26 kg/m2) This is identical to BONES,
except M
 Bearded Mask seal difficult due to receding
mandible
 Elderly (older than 55 y) syndrome with facial
abnormalities, burn,
 Snorers stricture, etc
 Edentulous
 Obesity (BMI >26 kg/m2
 upper airway Obstruction
 No teeth
 Advanced age
 Snorers
 Patients having ≥2 of the predictors likely to have
difficult mask ventilation

34. A )CRITERIAFOR DIFFICULT MASK VENTILATION
▶ Inability for one anaesthesiologist to maintain oxygen saturation greater than 92%
▶ Significant gas leak around face mask
▶ Need for greater than 4 litre per min gas flow(or use of fresh gas flow button more
than twice)
▶ No chest movement
▶ T
wo-handed mask ventilation needed
▶ Change of operator needed
B) INDEPENDENT RISK FACTORS FOR DIFFICULT MASK VENTILATION
RISK FACTORS
▶ Presence of a beard
▶ Body mask index >26 ng/m2
▶ Lack of teeth
▶ Age >55 years
▶ History of snoring

35. Predictors for difficult laryngoscopy and tracheal intubation
INDIVIDUAL INDICES GROUP INDICES
Physical examination indices
Radiological indices
Advanced indices
Bellhouse’s criteria
 Wilson’s scoring system
 Benumof’s 11-parameter analy
 Saghei & Safavi test
 Arne’s simplified score method
 Magboul’s
Lemon trial

36. PHYSICAL EXAMINATION INDICES
(A) ASSESSMENT OF CERVICAL & ATL-ANTO-OCCIPITAL JOINT FUNCTION:
• DIRECT ASSESSMENT – Assess the neck movement by asking the patient to touch his manubrium sternum with his chin. If done
this assures neck flexion of 25-30°. Then ask the patient to look at the ceiling without raising their eyebrows to test a-o joint
extension
GRADE 3 & 4 INDICATE DIFFICULT LARYNGOSCOPY
The warning sign of DELIKAN:
Place the index finger of the left hand, one underneath the chin, and the
index finger of the right hand under the inferior occipital prominence with
the head in a neutral position. The patient is asked to fully extend the head
on the 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 the level of both
fingers remains the same or the chin finger remains lower than the other, the
increased difficulty is predicted. The warning

37. • INDIRECT ASSESSMENT –
• 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.
• Seen in Diabetes
 This represents:- cervical spine immobility and the potential for difficult endotracheal intubation.

38. (B) ASSESSMENT OF TEMPOROMANDIBULAR JOINT
FUNCTION:
TMJ exhibits 2functions –
1. Rotation of the condyle in the synovial cavity.
2.Forward displacement of the condyle. The first movement is responsible
for a 2-3cm mouth opening & the second is responsible for a further 2-3cm
mouth opening.
1) SUBLUXATION OF THE MANDIBLE ( CALDER TEST )
 The index finger is placed in front of the tragus & the thumb is placed in
front of the lower part of the mastoid process behind the ear
 The patient is asked to open his mouth as wide as possible
 The index finger in front of the tragus can be indented in its space and
the thumb can feel the sliding movement of the condyle as the condyle
of the mandible slides forward

39. 2) UPPER LIP BITE /CATCH TEST
Class I: Lower incisors can bite the upper lip above the
vermilion line
Class II: Lower incisors can bite the upper lip below the
vermilion line
Class III: Lower incisors cannot bite the upper lip
Significance
 Assessment of mandibular movement and dental
architecture
 Less inter observer variability
3) SYMMETRY OF UPPER AND LOWER FACE
 The upper face should be measured from the bridge of
the nose to just below the nasal septa at the upper lip
while the lower face is measured from just below the
nasal septa to the chin.
 If the lower face is longer than the upper part of the
face, then some degree of difficulty in lining up
structures should be anticipated

40. C) ASSESSMENT OF MANDIBULAR SPACE
- Thisspacedetermineshoweasilythelaryngealandpharyngealaxiswillfallinlinewhenthea-ojointisextended
THYROMENTALDISTANCE/PATIL’STEST: Measurefrom theupperedgeofthethyroidcartilageto thechinwith the
headfullyextended
▶ >6.5cm -NoProblem withLaryngoscopy&Intubation
▶ 6-6.5cm-DifficultLaryngoscopy&Intubation
▶ <6cm - laryngoscopymaybeimpossible
INTER-INCISORGAP-Inter-incisordistancewith maximal mouthopening
Normalvalue>5cm/admits3fingers.
Significance:
Positiveresults:Easyinsertion ofa3cm deepflangeofthelaryngoscopeblade
<3cm:difficultlaryngoscopy
<2cm:difficultLMAinsertion
AffectedbyTMJ anduppercervicalspinemobility

41. STERNOMENTALDISTANCE(SAVVATEST)
Distance from the upper border of the manubrium to the
tip of the mentum, neck fully extended, mouth closed
 Minimal acceptable value - 12.5cm
 single best predictor of difficult laryngoscopy and
intubation(Has high sensitivity & specificity)
HYOMENTAL DISTANCE
Distance between mentum and hyoid bone
 Grade I: >6cm
 Grade II: 4 –6cm
 Grade III : < 4cm (Impossible laryngoscopy & Intubation)

42. (D) TEST FOR ASSESSING ADEQUACY OF THE OROPHARYNX FOR
LARYNGOSCOPY AND INTUBATION
Mallampaticlassification
A frequently performed test that examines the size of the tongue in
relation to the oral cavity. The greater the tongue obstructs the view
of the pharyngeal structures, the more difficult intubation may be
■Class I: the entire palatal arch, including the
bilateral faucial pillars, are visible down to their
bases.
■Class II: the upper part of the faucial pillars
and most of the uvula are visible.
■ Class III: only the soft and hard palates are visible.
■ Class IV: only the hard palate is visible
Although the presence of all the above-mentioned
findings may not be particularly sensitive for
detecting difficult intubation, the absence of these
findings is predictive of the relative ease of
intubation

44. (E) ASSESSMENT FOR QUALITY OF GLOTTIC VIEWING
DURING LARYNGOSCOPY
 Indirect mirror laryngoscopic view- closely relates to
Cormack & Lehane grading
 Direct laryngoscopy ‘awake look’-Cormack and Lehane
grading
 Grading ease of intubation
 POGO (percentage of glottic opening)scoring
CORMACK –LEHANE GRADING
Grading at direct laryngoscopy
• Grade1: Full exposure of glottis (anterior + posterior
commissure)
• Grade2: Anterior commissure not visualized
• Grade3: Epiglottis only
•Grade 4: No glottic structure visible.
Grade I = success & ease of intubation

45. GRADING EASE OF INTUBATION
Grade 1- Extrinsic manipulation of larynx not required
Grade 2- Extrinsic manipulation of the larynx required
Grade 3- Intubation possible with stylet guided
Grade 4- Failed intubation
POGO SCORING
Percentage of glottic opening during direct
laryngoscopy
 100%- entire glottis structures visible
 33%- only the lower third of vocal cords &
arytenoid are visible
 0% - no glottic structure visible
USEFUL WHEN A NEW INTUBATING DEVICE TO RECORD THE EXACT % OF GLOTTIC OPENING THAT CAN BE
VISUALISED BY THIS DEVICE

46. RADIOLOGICAL INDICES
 X-Ray neck (lateral view) :
 Occiput and C1 spinous process distance <
5mm.
 Increase in posterior mandible depth >
2.5cm.
 The ratio of effective mandibular length to its posterior
depth
 CT Scan: Tumors of the floor of the mouth, pharynx, larynx, and Cervical spine trauma,
inflammation
 Helical CT (3D-reconstruction): Exact location and degree of airway compression
ADVANCED INDICES
 Flow volume loop
 Acoustic response
measurement Ultrasound-
guided
 CT / MRI
 Flexible bronchoscope

47. GROUP INDICES
 BELHOUSE’S CRITERIA:
• Three parameter criteria for predicting difficult
tracheal intubation are as follows-
 The restricted atlantooccipital joint extension
(less than 35 degrees)
 Reduced mandibular space
 An enlarged tongue( versus pharyngeal ) size

48.  SAGHEI & SAFAVI’S TEST:
•
 1 – 2 – 3 FINGER RAPID ASSESSMENT TEST
• 1 finger breadth for subluxation of the mandible.
• 2 finger breadth for adequacy of mouth opening.
• 3 finger breadth for hyomental distance.
In emergency situations, the above test can be rapidly
performed within 15 sec to assess the TMJ function,
mouth opening, and hyomental distance. Significant
difficulty in 2 or more of these components requires
detailed examination.

49. LEMON TRIAL

50.  MAGBOUL’S :
 Mallampati
 Measurement
 Movement
 Malformation of the skull, teeth, obstruction)
 Skull (Hydro and Microcephalus)
 Teeth (Buck protruded, & loose teeth, macro, and micro mandibles)
 Obstruction (due to obesity, short Bull Neck, and swellings around the head and neck)
 Pathology (Craniofacial abnormalities & Syndromes: Treacher Collins, Goldenhar's, Pierre
Robin, Waardenburg syndromes) .
 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

51. CONDITIONS WHERE AIRWAY MANAGEMENT IS IMPLICATED
1)Increased risk mask ventilation, laryngoscopy, or SGA ventilation
 History of failed or traumatic airway management ~ Dental damage or prolonged airway soreness
 History of head and neck surgery or radiation therapy
 Congenital and acquired syndromes
 Supraglottic pathology
 Acute airway pathology
 Cervical spine injuries
 T
emporomandibular joint diseases
2)Risk of aspiration
 Recent trauma
 Acute meal
 Acute gastrointestinal pathology and significant gastroesophageal reflux Acute narcotic
therapy
 Recent ICU admissions
pregnancy
postpartum
pneumonia
 History change in voice, vocal cord polyp, coughing after eating or drinking
 Systemic disorders ~diabetes, gastroparesis, collagen vascular diseases etc