The document discusses difficult airway assessment and management. It defines a difficult airway as situations involving difficult mask ventilation, difficult intubation, difficult placement of a supraglottic airway device, or difficult surgical airway access. It describes predictors of a difficult airway related to patient characteristics and anatomy. It also discusses the importance of assessing the airway and having appropriate equipment and personnel prepared when encountering an anticipated or unanticipated difficult airway.

1. Dr ASHISH NAIR
MD ANAESTHESIA

2. What is Difficult Airway?
 Clinical Situation in which conventionally trained anaesthesiologist
experiences difficulty in
1. Mask ventilation
2. Tracheal intubation
3. Placement of supraglottic airway device(SAD)
4. Creating Surgical airway

3. DIFFICULT TO MASK VENTILATE
PATIENTS
Definition:
 A situation in which it is not possible for the
unassisted anaesthesiologist to maintain SPO2 >90
% using 100 % O2 and positive pressure mask
ventilation in a patient whose SPO2 was 90%
before anaesthetic intervention.

4. Difficult Bag Mask Ventilation(BMV)
• Bearded individual
• Obesity
• No teeth
• Elderly
• Snorer

5. SIGNS OF INADEQUATE MASK VENTILATION:
 Absent or inadequate chest movement
 Absent breath sounds
 Gastric insufflation
 Decreasing oxygen saturation
 Absent or inadequate ETCO2

6. What is Difficult Intubation?
 Conventionally trained anaesthesiologist needs more than
1. 3 attempts
2. 10 minutes
for a successful tracheal intubation
 Best attempt at laryngoscopy –Laryngoscopy performed with patient in optimal
sniff position having no significant muscle tone and laryngoscopist has an option
of change of blade type and length

7. Difficult placement of SAD
 Predictors of difficult placement /subsequent ventilation with SAD
1. Restricted mouth opening
2. Obstructions of the Upper airway
3. Disrupted upper airway following trauma, burns etc
4. Stiff lung

8. Difficult Surgical airway access
 Presence of any of following factors predict difficulty in performing
surgical airway –cricothyrotomy or tracheostomy
1. Bleeding tendency inherent or as a result of anticoagulants
2. Agitated patient
3. Neck scarring,neck flexion deformity
4. Growth or vascular abnormalities in the region of surgical airway

9. WHY TO ASSESS ??
 Optimal patient preparation
 Proper selection of equipments and techniques
 Participation of personnel experienced in the difficult airway
management.

10.  Difficult intubation
 Airway trauma
 Broken tooth
 Airway surgery
 Radiation
 Burns
 Tumor
 Joint pathology(Rheumatoid arthritis,TMJ).
 Cervical spine pathology.
 Difficulty in positioning the patient for laryngoscopy(Ankylosing spondylitis).
 Congenital syndromes & facial dysmorphism.

11. c.

12. 1.MOUTH
OPENING:
 Inter-incisor distance should be
5 cm or more ( > 3 fingers) in
adults.
 For easy insertion of 3cm deep
flange of laryngoscope blade.
 <3 cm:Difficult laryngoscopy
 <2cm:Difficult LMA insertion.

13. 2.MALLAMPATTI CLASSIFICATION:
 Frequently performed.
 To examine the size of tongue in relation to the oral cavity.
 Describes the relationship between mouth opening, tongue size and
pharyngeal space.
 More the tongue obstruct the view of pharyngeal structures, more difficult
the intubation will be.

14.  Test for assessing the adequacy of oropharynx for laryngoscopy.
 MP GRADE I : Faucial pillars, uvula,soft and hard palate are visible.
 MP GRADE II : uvula ,soft and hard palate are visible
 MP GRADE III : Base of uvula or none, soft and hard palate are visible
 MP GRADE IV : Only hard palate is visible.

15. MP grade
0(zero) :
when epiglottis is visualized during
examination of oropharynx.

16. 3. ASSESSMENT OF MANDIBULAR SPACE
:
a) Thyromental distance
b) Hyomental distance
c) Sternomental distance

17. a) THYROMENTAL DISTANCE :
 Measured by Patil's test.
 Distance between mentum and thyroid
notch.
 Ideally done with neck fully extended.
 Helps determine how readily laryngeal
axis will fall in line with pharyngeal axis.
 >6.5 cm ( > 3 finger bridth) - normal
 6- 6.5 cm - less difficult airway
 < 6 cm - difficult airway

18. b) HYOMENTAL DISTANCE :
Distance between mentum and
hyoid bone.
GRADE I : > 6 cm
GRADE II : 4-6 cm
GRADE III : <4 cm
GRADE III associated with difficult
laryngoscopy & intubation.

19. C) STERNOMENTAL DISTANCE :
Assessed by SAVVA test.
Distance between mentum and sternal notch
> 12.5 cm is normal.
< 12.0 cm associated with difficult intubation.
Measured when neck is fully extended and mouth closed.

20.  Class I : Visualisation of entire vocal cords
 Class II a : Visualization of posterior part of vocal cord.
 Class II b:Visualisation of arytenoids only.
 Class III a : Epiglottis liftable
 Class III b:Epiglottis adherent or only tip visible.
 Class IV : No glottic structures seen

21. 4. TEMPOROMANDIBULAR JOINT
Put the middle finger of each hand inferior and posterior to patient's earlobe.
Place the index finger just anterior to tragus.
Instruct the patient to open mouth widely.
TWO distinct movement should be felt :
1. The first is rotational
2. The second is advancement of condylar head .
If presence of clicks or crepitus, suggest TMJ dysfunction.

22. 5) NOSE & ORAL CAVITY
Deformities of nose
Patency of nostrils
 Macroglossia
 High arched palate/ cleft palate
 Micrognathia / retrognathia
 Large central incisors ,edentulous,loose or poor dentition

23.  Neck circumference > 40 cm predicts 5% difficult intubation
 > 60 cm predicts 35% difficult intubation.
 Laryngoscopic view becomes easier when neck is flexed on chest by 25-35̊ and atlanto
occipital joint extended by 85̊- Magills sniffing position.
 Assess flexion by asking the patient to touch his manubrium sternii with his chin, this
assures flexion of 25-35̊
 Extension assessed by asking the patient to look at ceiling without raising eyebrows.

24. A- Neutral head position: OA, PA and LA are at greater angle.
B- Pillow under head - flexing lower cervical spine and aligning PA and LA
C- Head has been extended over cervical spine aligning OA, PA and LA and creating optimum
“SNIFFING “ position.

25. L : Look externally
E : Evaluate 3-3-2-1
rule
M : Mallampati score
O : Obstruction
N : Neck mobility

26. EVALUATE 3-3-2-1 RULE :
Mouth opening : < 3 fingers
Hyo-mental distance : < 3 fingers
Thyro-mental distance : < 2 fingers
Lower jaw anterior subluxation : < 1 finger

27. Difficult
Airway
Anticipated Unanticipated

28. Concerns of Unanticipated DA
 Expert help may not be available
 Special equipment non availability
 General anesthesia and long acting muscle relaxant may have been given
 Backup airway management plan may not be thought of

30. Unanticipated difficult airway

32. DIFFICULT AIRWAY CART

33. Organisation,design & standardisation of
Difficult airway trolley
• According to four plans of Difficult airway algorithm of DAS guidelines.
• Helps in improving the adherence to step wise progression to alternative airway rescue plan
• Immediate availability of equipments.
• Movable,portable storage space with 4-5 drawers
• Individual drawers clearly labelled
• Contents checked once daily, or after every use.
• Individual variations can be made according to local availability and requirement.
• Laminated charts of algorithm or printed images to be displayed on side of trolley.
• Familiarity with equipment
• It can be a cart/trolley/grab bag with essential equipments for remote locations.

34. Top of trolley
• Difficult airway algorithm flow
chart
 Direct access phone numbers to
ENT
and anaesthesiology, icu physician
 Stopwatch
 Monitors for videolaryngoscope /
fibreoptic brochoscope
 Side of trolley
 Introducers,
bougie/ventilating bougie
 Videobronchoscope
 Airway exchange catheter

35. Drawer 1- (Plan A) Intubation
Contents
 Laryngoscope handles-standard, stubby handle,
Howland lock
 Laryngoscope blades-Macintosh sizes 3 & 4, Miller sizes 2 & 3,
McCoy .
 Videolaryngoscope blades
 ETT of assorted sizes
 Stylet: Shroders stylet / light wand
 Lubrication gel
 Syringe 5, 10 ml
 Magill forceps
 Adhesive tape, wide and narrow
 Cognitive aid indicating the importance of continous waveform
capnography.
 Printed labels “Rocuronium”
• Aspiration cannula

36. HOWLAND LOCK LIGHT WAND

37. Drawer 2- (Plan B) Oxygenation via a
Supraglottic Airway Device
Contents
 Two different types of second generation SADs(IGEL,
Proseal), sizes 3,4,5
 Lubrication gel
 Syringe 20 ml(cuff inflation)
 Orogastric tubes size 12 & 14

39. Drawer 3 –(Plan C) mask ventilation
 Contents
 Neonatal facemask size 0
 Facemaks- Various sizes
• Oropharyngeal airways – various sizes
• Nasopharyngeal airways – various sizes
• Syringe 10 ml
• Aspiration cannula
• Prepinted labels “sugammadex”

40. Drawer 4 –(Plan D)Emergency invasive airway
access
 Surgical cricothyroidotomy
Contents
 Emergency Cricothyroidotomy catheter set
 Endotracheal tube size 6
 Scalpel blade 10

41. Drawer 5- Optional , customized equipment
 Specialized equipments, pertinent to specific areas of hospital
 Contents
 Equipment for management of tracheostomies
 Left hand laryngoscope blades:
 Mirror image version of macintosh blade for use with right hand
 Reverse configuration of the flange
 Used for patients with right sided facial or oropharyngeal abnormalities, when ETT
should be located on left side of mouth.
• Combitube

42. Left handed laryngoscope
 Mirror image version of macintosh blade for use with right
hand.
 Identical to the regular macintosh blade except for the
reversed configuration of flange.
 Used for procedures in those with right sided facial
abnormalities , in which ETT should be located on the left
side of the mouth.

43. COMBITUBE

44. Combitube
 Large proximal oropharyngeal cuff inflated with 100 ml air.
 Distal esophageal/tracheal cuff inflated with 15 ml air.
 Two lumens, one opens beyond the distal cuff , while the other lumen ends
between two cuffs and has 8 ventilating ports.
 Used for emergency airway management.
 Primarily used as an alternative airway device in pre hospital setup in CPR,in
difficult airway.
 Can be inserted blindly , mostly enters esophagus (95% cases)

45. Front of neck
access(FONA)
 Cricothyrotomy-
 Needle cricothyrotomy
 Percutaneous cricothyrotomy
 Surgical cricothyrotomy
 Immediate preparation of FONA to be done as soon as it is declared as “CICO”
 Equipment-Scalpel(10), Bougie, ETT 6

46. Laryngeal Handshake

47. Needle
cricothyroidotomy
 Equipment-14 G cannula, 5 ml syringe,
saline,O2 source
 Laryngeal handshake
 Insert cannula at 45 degree while aspirating
 Advance cannula of trocar
 Remove trocar
 Reattach syringe to confirm aspiration
 Supply O2 and secure cannula

48. Ventilating with cricothyroid cannula
 Bag valve assembly with oxygen
 Modified oxygen tubing- hole near the end of
oxygen tubing, connect to 50 psi oxygen source
,ventilate by intermittenly opening and closing
the hole.
 Jet ventilation.

49. Scalpel/Bougie
1. Palpable membrane
 Transverse stab
 Turn blade 90 degree
 Slide bougie tip along blade into trachea
 Railroad 6mm ETT into trachea
 Ventilate ,inflate cuff and confirm position
 Secure tube

50. Pre oxygenation
 Pre oxygenation and face mask ventilation are primary methods to preserve
oxygenation until airway is secured
 Pre oxygenation should be done for a min of 3 to 5 min with tidal volume
breathing
8 vital capacity breaths for 60 s is more effective method
Target End Tidal Oxygen>90% and End tidal nitrogen<4%

51. Positioning for intubation
 Best position-
Sniffing position( Flexion at the neck and
extension at the atlanto occipital
joint)achieved by keeping a pillow of 10
cm thickness under the head, C/I in
suspected cervical spine injury.
Ramped position / HELP - In obese
patients sniffing position is achieved by
placing blankets or towel below
scapula,shoulder,neck,head until
external auditory meatus and sternum
are in horizontal line

52. Other Equipments
1)AMBU(Artificial manual breathing unit)
 Ventilating device used for resuscitation,transport,standby for non functioning of
anesthesia machine
2) Functioning suction machine
3)Emergency drugs
4)Extra set of batteries.
5) Pillows and towels for positioning of patient.

53. Trans tracheal jet ventilation
 Used for percutaneous transtracheal ventilation (PTV)
 Attach jet ventilation assembly to 50 psi oxygen source with
regulator so that pressure can be titrated.
 14G catheter at 50 psi will deliver a gas flow of 1600 ml/s for
normal compliant lung( so keep a longer expiration time).
 Patency of upper airway should be ensured before doing jet
ventilation to avoid barotrauma.
 Avoid jet ventilation whenever there is doubt regarding patency
and also in children < 5 years.
 Delivering breaths without ensuring full expiration will lead to
barotrauma.
 Transtracheal jet ventilation is a rescue and temporary maneuver
until a more secure permanent airway is established.

54. Anticipated Difficult Airway
 Preparation of patient, counselling, explaining procedure and risk of difficult airway.
 Preparation of anesthetic team, familiarity with equipments.
 Back up plan, senior help.
 Consider the merits and demerits of basic management choices-
 Awake intubation Vs Intubation after induction of GA
 Non invasive technique for initial approach to intubation Vs invasive technique.
 Preservation of spontaneous respiration Vs abolition of spontaneous respiration.
 Videoassisted laryngoscopy as an initial approach to intubation.

55. Advantages of Awake Intubation
 Preserves spontaneous respiration.
 Airway potency and tone of pharyngeal muscles maintained
 Options for awake intubation-
 Blind nasal
 Fibreoptic bronchoscope
 Retrograde intubation.

56. Premedication
i)Antisialogogues- inj. Glycopyrrolate 4mcg/kg
 Helps in drying of secretions & visualisation of FOB.
 Minimise the dilution of local anesthetic and
formation of barrier between L.A & Mucosa.
ii)Nasal mucosa decongestants: Vasoconstrictor like
Xylometazoline Spray
 Widens the space and reduces risk of bleeding
iii)Identify risk factors for aspiration and give aspiration
prophylaxis.

57. Premedication
iv)Sedatives :Dexmedetomidine, Midazolam, Fentanyl are Commonly used.
• Aim is to preserve spontaneous respiration
• Given in titrated doses
• Use one or two agents , not more.
• Patient should be co operative and also able to control their airway throughout procedure.
v) Topicalisation of airway: Lignocaine 4% Nebulisation, Lignocaine with adrenaline 2% patties in
nostril, lignocaine 10% spray
Lignocaine dose
Infiltration: Plain lignocaine 5 mg/kg.
Topical:British thoracic society recommends maximum dose of 8.2 mg/kg

58. Glossopharyngeal Nerve Block
 Internal Approach:Bilateral glossopharyngeal nerve block - 2 ml lidocaine can be
injected at base of anterior tonsillar pillar on each side.

59. Extra oral approach of
Glossopharyngeal nerve block

60. Superior laryngeal nerve block
 Sensory supply to epiglottis,
arytenoids, vocal cords
Technique
 1occ syringe with 6 cc 1% lidocaine
attached to 23G needle,inserted
until lateral most part of hyoid bone
and then it is withdrawn and walked
off greater cornu in inferior
direction.
 Needle is then advanced and passed
through thyrohyoid membrane(felt
as slight resistance, aspirated and
then 2 cc of L.A injected.
 Procedure is then repeated on the
opposite side.

61. Transtracheal block
 Provides anesthesia of entire trachea
between carina to vocal cord
 Complications-bleeding,tracheal injury
and subcutaneous emphysema
Technique
 2-4 ml 4% lidocaine in 10 cc syringe with
23G needle
 Cricothyroid membrane is identified,
syringe directed posteriorly
perpendicular to the floor
 Sudden LOR felt when needle in trachea,
position confirmed by aspiration of air
through syringe, lidocaine injected &
needle withdrawn quickly

62. Standard reporting of unanticipated difficult
intubation
 Complete details of nature of difficulty, airway management plan & complication
if any to be documented in standard format.
 Copy should be available in case note and should be given to patient or relative for
future reference.
 A Standard difficult airway alert form ideally , which can be modified according to
requirements of workplace.
 This will be useful to the doctor treating them in future.

64. CONCLUSION
 Examples of equipments given in DAS guidelines should serve only as guide
and should not be considered as absolute recommendations.
• Most Important is
 Right equipment
 Right time
 Right place
• Remember to Plan, communicate, prepare and Train

66. ThankYou