its combination of all latest guidellines regarding difficult airway management perticularly in critical care setting.

2.  INTRODUCTION
 DEFINATION
 PREDISPOSING FACTORS
 AIRWAY ASSESSMENT
 TECHNIQUES FOR DIFF. AIRWAY
MANAGEMENT
 PRINCIPLES AND GUIDILINES

3.  Difficult intubations are common in the Intensive Care Unit
(ICU), emergency department (ED), and prehospital settings,
with the incidence ranging being between 8% and 13%.
 Compromised cardio respiratory physiology, risk of aspiration,
and the presence of specific factors related to the environment
and inadequately trained operators render tracheal intubation
(TI) in the ICU more likely to be associated with complications
compared to that in the operating room (OR).

4.  The Royal College of Anaesthesiologist and Difficult Airway
Society found that more than 60% airway complications in the
ICU led to death or brain damage compared with 14% in
anesthesia.
 Unlike in the OR, postponing airway management is not an
option in critically ill patients.
 Primary indications for intubation in 417 patients in one North
American emergency department (ED) were: mechanical
ventilation 57.4%, airway protection 41.3%, and cardiac arrest
1.3%.
 The incidence of complications during intubation in critically ill
patients in the ICU and ED ranges from 22% to 54%
-Critical Care and Resuscitation 2003; 5: 43-52
-Indian Journal of Critical Care Medicine ¦ Volume 21 ¦ Issue 3 ¦
March 2017

5.  Two or more attempts at TI significantly increase the risk of
complications. In one study, complication rates compared to
those in whom intubation was successful at the first attempt,
were aspiration (22% vs. 2%), hypoxemia (70% vs. 12%), and
cardiac arrest (11% vs. 1%).
 The occurrence of aspiration and hypoxemia during
emergency intubations increased the risk of developing a
cardiac arrest by 22 and four times, respectively.
 An oesophageal intubation was the most common cause of
cardiac arrest and was associated with a seven-fold increase
in the risk of death.

6.  DIFFICULT AIRWAY: The American Society of
Anesthesiologist (ASA) defined a difficult airway as “the
situation in which conventionally trained anesthesiologist
experience difficulty with mask ventilation difficulty with
tracheal intubation, or both”.
 DIFFICULT MASK VENTILATION: The ASA Task force
defined it as occurring when “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
and/or It is not possible for the unassisted anaesthesiologist to
prevent or reverse signs of inadequate ventilation during
positive pressure mask ventilation”.

7.  DIFFICULT LARYNGOSCOPY: The ASA Task force defined it
as occurring when “It is not possible to visualize any portion of
the vocal cords with conventional Laryngoscopy”.
 DIFFICULT ENDOTRACHEAL INTUBATION: The ASA Task
force defined it as occurring when “proper insertion of the
tracheal tub with conventional Laryngoscopy requires more
than 3 attempts or more than 10 minutes”.

9.  Anesthesiologist :
-Inadequate assessment
-Inadequate equipment preparation
-Inexperience
-Poor technique
 Equipment : Malfunction / Unavailability
 Patient : Congenital & acquired causes.

10. Indian Journal of Critical Care Medicine ¦ Volume 21 ¦ Issue 3 ¦ March 2017

11.  EVALUATION OF DIFFICULT MASK VENTILATION:
I. Individual indices:
- presence of beard: diff in effective seal
- obesity: BMI > 26 kg/m2, decreased FRC
- abnormality of teeth: irregular/artificial teeth, edentulous
- elderly pt: >55 yrs
- snorers: apply CPAP 5-10 cm of water
- hair bun: difficulty in sniffing position
- jewelry and facial piercing

12. II. Group indices:

13.  EVALUATION OF DIFFICULT LARYNGOSCOPY
AND INTUBATION:
I. Individual indices:
A. Cervical & a-o joint assessment:
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.
(DELILKEN’S TEST)

14. PRAYER SIGN:
A positive "prayer sign" can be elicited
on examination with the patient unable
to approximate the palmer surfaces of
the phalangeal joints while pressing
their hands together; this represents
cervical spine immobility and the
potential for a difficult endotracheal
intubation.

15. PALM PRINT SIGN:
Patient’s fingers and palms painted with blue ink and pressed
firmly against a white paper
 Grade 1- all phalangeal areas visible
 Grade 2- deficient interphalangeal areas of 4th and 5th digits
 Grade 3- deficient interphalangeal areas of 2nd to 5th digits
 Grade 4- only tips seen.

16. B. Assessment of TM joint function:
 Subluxation of 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.
 CALDER TEST (JAW SLIDE TEST): the pt is asked to
protrude the mandible as far as possible. The lower incisor will
lie either anterior to aligned with or posterior to the upper
incisors. The later two suggest reduced view at Laryngoscopy.
-Grade A: lower teeth in front of upper teeth
-Grade B: lower teeth equal to upper teeth
-Grade C: lower teeth behind upper teeth

17. C. Assessment of the mandibular space:

18.  Hyomental distance:
Distance between mentum and hyoid bone
 Grade I : > 6 cm
 Grade II: 4 – 6cm
 Grade III : < 4cm – Impossible Laryngoscopy & Intubation

19. D. Assessing the adequacy of the oropharynx for Laryngoscopy:
Mallampati grading

20. E. Assessment for quality of glottic viewing:
Cormack and Lehane’s laryngoscopic view:

21. II. Group indices:
- wilson’s score
- Benumof’s analysis
-Saghei & Safavi
- LEMON law
III. Radiological indices:
- lateral X ray of head and neck
- CT scan
IV. Advanced indices:
- Flow volume loop
- Acoustic response measurement
- Ultra sound guided
- CT / MRI
- Flexible bronchoscope

23.  Rule of 1-2-3
 1 finger breadth for subluxation of mandible.
 2 finger breatdh for adequacy of mouth opening.
 3 finger breathd for hyomental distance.
In emergency situation, above test can be rapidly performed
within 15sec to assess the TMJ function, mouth opening and
SM Space. Significant difficulty in 2 or more of these
components requires detailed examination.
 Rule of 1-2-3-4-5
• 4 finger breath for thyromental distance
• 5 movements- ability to flex the neck upto the manubrium
sterni, extension at the AOJ, rotation of the head along with
right & left movement of the head to touch the shoulder.

24.  Rule of THREE
• 3 finger in the interdental space.
• 3 finger between mentum and hyoid bone.
• 3 finger between thyroid cartilage & sternum.
Significant difficulty in 2 or more of
these components requires detailed examination.

25.  The most commonly described tests are
-the Mallampati test
-the ‘jaw slide’
-the thyromental distance
-Wilson’s score

27. 1. at the time of administration of anaesthetic
agents (most importantly when the loss of airway
muscle tone might cause complete airway
obstruction),
2. with facemask inflation,
3. when attempting Laryngoscopy, and
4. when intubating.
One then has to make rational primary and
backup plans for airway management.

30.  SNIFFING POSITION:

31.  3 AXISES FOR AIRWAY:

32.  LARYNGOSCOPY:

33.  a difficult laryngoscopic view is found (i.e. Cormack and
Lehane Grade III or IV), then it is reasonable to have one
further “best” attempt at Laryngoscopy which should consist of
the following components:
• an attempt by an experienced laryngoscopist,
• an optimal patient head and neck position (e.g. “sniffing-the-
morning-air” or “sipping a full pint of beer”16),
• external laryngeal manipulation,
• consider adjuncts to Laryngoscopy,
• consider a single change of laryngoscope blade size and
type,
• consider using a smaller sized endotracheal tube.

34.  EXTERNAL LARYNGEAL MANIPULATION (BURP
MANEUVER):
-Backward
-upward
-rightward pressure
Helps to increase laryngoscopic view.
Different from Sellick’s manuever

40.  History
 Physical examination
 Additional evaluation
 Preoperative airway assessment should be
performed routinely in order to identify
factors that might lead to difficulty with face-
mask ventilation, SAD insertion, tracheal
intubation, or front-of-neck access.
- British Journal of Anaesthesia, 115 (6): 827–48 (2015)

41. 1. availability of equipment for management of a
difficult airway (i.e., portable storage unit),
2. informing the patient with a known or suspected
difficult airway,
3. assigning an individual to provide assistance
when a difficult airway is encountered,
4. preanesthetic preoxygenation by mask, and
5. administration of supplemental oxygen throughout
the process of difficult airway management.

43.  Noninvasive interventions intended to manage a
difficult airway include, but are not limited to:
a. awake intubation,
b. video-assisted laryngoscopy,
c. intubating stylets or tube-changers,
d. SGA for ventilation (e.g., LMA, laryngeal tube),
e. SGA for intubation (e.g., ILMA),
f. rigid laryngoscopic blades of varying design and size,
g. fiberoptic-guided intubation, and
h. lighted stylets or light wands.

44. 1. Two operators: recommendation for the presence of two
operators during ICU intubations, with one being experienced
in airway management.
2. Call for help: In addition to the two operators present during
intubation, recommendation for calling for additional help at
the earliest, when the first difficulty in airway management is
encountered.
-also a recommendation for calling for additional help when the
final attempt at rescue mask ventilation fails and emergency
cricothyroidectomy is planned.

45. 3. Preoxygenation and preintubation oxygenation:
-Oxygen desaturation is the most common complication
occurring during intubation in the ICU and is the most
common reason for aborting intubation attempts.
-Three minutes of preoxygenation using noninvasive positive
pressure ventilation (NIPPV) delivered by an ICU ventilator
using a face mask
-mask is more effective at reducing desaturation than by face
mask with bag and reservoir.
-High-flow nasal cannula (HFNC) oxygen delivered at 70 L/min
through a device capable of providing heated, humidified
oxygen has been compared with standard methods of
preoxygenation with mixed results.
-apneic oxygenation through HFNC
-Recently, the addition of supplemental oxygen through a nasal
cannula in the presence of mask leaks has been shown to
improve the end-tidal O2 during preoxygenation

46. 4. Hemodynamic stabilization:
-Hypotension after intubation is reported in nearly half of the
intubated patients in ICU, with cardiovascular collapse
occurring in 30% patients.
-preintubation fluid bolus
-prompt treatment of postintubation hypotension with
vesopressors and additional fluid therapy.

47. 5. Selection of pharmacological agents:
-Drugs such as benzodiazepines, propofol, and thiopental may
be used in reduced doses; however, they decrease the
systemic vascular resistance, produce myocardial depression
and may cause precipitous fall in blood pressure, especially in
the ASA III-IV patients and those with hypotension.
-etomidate and ketamine are preferred in comparison in ICU.
-transient adrenal insufficiency with etomidate, especially in
septic patients,
-Ketamine may cause hypertension, tachycardia, increased
airway secretions, raised intracranial and intraocular pressure.
-Other agents such as opiates, dexmedetomidine, and
lignocaine can be used as adjuncts

48. -use of the neuromuscular blocking agents improve overall
intubating conditions.
-Suxamethonium has been the conventionally used
neuromuscular blocking agent of choice, unless
contraindicated
-rocuronium at a dose of 1.2 mg/kg has comparable speed of
action and intubating conditions to suxamethonium.

49. 6. Device selection:
-video laryngoscopy has been shown to increase first-attempt
success and improve glottis visualization during intubation in
the ICU.
-fiberoptic bronchoscope.

50. 7. Rapid sequence induction:
-for pts with full stomach
-Either suxamethonium (if not contraindicated) or rocuronium
may be used for neuromuscular blockade.
-Application of cricoid pressure may make the laryngoscopic
view unfavourable. So should be partially or completely
released
-Gentle mask ventilation while applying cricoid pressure before
TI can prolong the time to desaturation and may be useful in
patients with poor respiratory reserve and sepsis.
-A second-generation supraglottic airway device (SAD) offers
greater protection against aspiration.

51. 8. Confirmation of tracheal intubation:
-strongly recommends the use of capnography for confirmation
of TI in all critically ill patients, irrespective of location.
9. Proper training:
Indian Journal of Critical Care Medicine ¦ Volume 21 ¦ Issue 3 ¦ March 2017

52. 10. Intubation bundle: 10 components

53.  Step 1: Preoxygenation and induction of
anaesthesia
 Step 2: Laryngoscopy and tracheal intubation
 Step 3: Insert supraglottic airway device to
maintain oxygenation
 Step 4: Rescue face mask ventilation
 Step 5: Emergency cricothyroidectomy

58. 1. All clinical areas should be equipped with face mask
ventilation and direct Laryngoscopy for tracheal intubation
and their alternatives.
2. Be familiar with and well practiced in alternative techniques.
3. In actual difficult airway situation, remain calm yourself.
4. Call for early assistance
5. Keep track off time
6. If 1st intubation fails, think what to do differently 2nd time to
succeed.
7. Lastly, in the difficult airway management success is lauded,
but failure can be disastrous.