2. OVERVIEWOVERVIEW
Anatomy of the AirwayAnatomy of the Airway
Evaluation of the AirwayEvaluation of the Airway
Basic Airway ManagementBasic Airway Management
Indications for Endotracheal IntubationIndications for Endotracheal Intubation
Equipment for Airway ManagementEquipment for Airway Management
Difficult Airway AlgorithmDifficult Airway Algorithm
4. Innervation of theInnervation of the
Nasopharynx and OropharynxNasopharynx and Oropharynx
CN V - Trigeminal Nerve
• V1 - Ophthalmic Division
(anterior ethmoidal n.)
• V2 - Maxillary Division
(sphenopalatine n.)
• V3 - Mandibular Division
(lingual n.)
5. Innervation of theInnervation of the
Nasopharynx and OropharynxNasopharynx and Oropharynx
CN VII – Facial Nerve
Taste to posterior 1/3 of tongue
CN IX – Glossopharyngeal Nerve
Sensation to posterior 1/3 of tongue,
tonsils, pharynx
6. Nerve Supply to the LarynxNerve Supply to the Larynx
CN XCN X – Vagus Nerve– Vagus Nerve
• Superior Laryngeal NerveSuperior Laryngeal Nerve
- Motor to cricothyroid muscle- Motor to cricothyroid muscle
- Sensory to above the vocal- Sensory to above the vocal
cordscords
• Recurrent Laryngeal NerveRecurrent Laryngeal Nerve
- Motor to all intrinsic muscles- Motor to all intrinsic muscles
exceptexcept cricothyroidcricothyroid
- Sensory to below the vocal- Sensory to below the vocal
cordscords
7. Clinical SignificanceClinical Significance
Acute bilateral RLN injuryAcute bilateral RLN injury stridor,stridor,
respiratory distressrespiratory distress
Need for topical anesthetics for nasalNeed for topical anesthetics for nasal
intubationintubation
Nerve blocks for awake intubationNerve blocks for awake intubation
– Glossopharyngeal nerve blockGlossopharyngeal nerve block
– Superior laryngeal nerve blockSuperior laryngeal nerve block
– Transtracheal blockTranstracheal block
8. Anatomy of the LarynxAnatomy of the Larynx
C4-C6 levelC4-C6 level
3 single cartilages3 single cartilages
• epiglottisepiglottis
• thyroidthyroid
• cricoidcricoid
3 paired cartilages3 paired cartilages
• arytenoidsarytenoids
• corniculatescorniculates
• cuneiformscuneiforms
11. Anatomy of the AirwayAnatomy of the Airway
TracheaTrachea
– 15 cm long ( adult)15 cm long ( adult)
– 16-20 C shaped16-20 C shaped
cartilagescartilages
– Bifurcates to R and LBifurcates to R and L
bronchus at T5bronchus at T5
– R bronchus appears toR bronchus appears to
be a verticalbe a vertical
continuation of tracheacontinuation of trachea
Aspiration more commonAspiration more common
R mainstem intubationR mainstem intubation
more commonmore common
12. Evaluation of the AirwayEvaluation of the Airway
Historical InterviewHistorical Interview
Prior difficult intubation?Prior difficult intubation?
Surgical history – head and neckSurgical history – head and neck
Congenital and Acquired SyndromesCongenital and Acquired Syndromes
– Down syndrome, Pierre Robin syndrome, Ludwig’sDown syndrome, Pierre Robin syndrome, Ludwig’s
anginaangina
Medical condition that may predisposeMedical condition that may predispose
to difficult intubationto difficult intubation
-- Morbid Obesity, TMJ dysfunction, TumorsMorbid Obesity, TMJ dysfunction, Tumors
Review of previous anesthetic recordsReview of previous anesthetic records
14. Evaluation of the AirwayEvaluation of the Airway
Ancillary TestsAncillary Tests
RadiographsRadiographs (cervical x-ray)(cervical x-ray)
CT ScanCT Scan
MRIMRI
Pulmonary Function TestsPulmonary Function Tests
Direct Fiber-optic ExaminationDirect Fiber-optic Examination
16. Evaluation of the AirwayEvaluation of the Airway
Physical ExamPhysical Exam
General assessmentGeneral assessment
- cachexia, need for O2 support, cyanosis,- cachexia, need for O2 support, cyanosis,
morbid obesity, VS including SpO2morbid obesity, VS including SpO2
Focused Airway ExamFocused Airway Exam
19. Thyromental DistanceThyromental Distance
estimates theestimates the
displacement ofdisplacement of
the tonguethe tongue
notch of thyroid cartilage
tip of the mandible
Normal = 6.5 cm
neck fully extended
20. Thyromental DistanceThyromental Distance
Questioned the most re: predictive valueQuestioned the most re: predictive value
Sensitivity : 60-80%
Specificity : 80-90%
Arne and El-Ganzouri : highly insensitive
but very specific (17% and 99%)
Chou and Wu : adjust this measure to pt’sChou and Wu : adjust this measure to pt’s
heightheight
21. Mouth Opening/Incisor GapMouth Opening/Incisor Gap
< 3 cm< 3 cm – reduces– reduces
prevalence of easyprevalence of easy
intubation fromintubation from
95% to 62%95% to 62%
25. Multivariate Predictors of DifficultMultivariate Predictors of Difficult
Tracheal IntubationTracheal Intubation
1996, El-Ganzouri1996, El-Ganzouri
Prospective analysis of 10,507 consecutive adultProspective analysis of 10,507 consecutive adult
patients presenting for surgery under generalpatients presenting for surgery under general
anesthesiaanesthesia
A multivariate model for stratifying the riskA multivariate model for stratifying the risk
Compared to Mallampati Class I as a singleCompared to Mallampati Class I as a single
predictor. A risk index score of threepredictor. A risk index score of three
demonstrates a higher sensitivity (59 vs 44)demonstrates a higher sensitivity (59 vs 44)
26. Multivariate Predictors of DifficultMultivariate Predictors of Difficult
Tracheal IntubationTracheal Intubation
Mouth openingMouth opening
Thyromental distanceThyromental distance
Mallampati ClassMallampati Class
Neck MovementNeck Movement
Ability to Protrude theAbility to Protrude the
MandibleMandible
Body WeightBody Weight
History of DifficultHistory of Difficult
IntubationIntubation
27. Maneuvers for Opening the AirwayManeuvers for Opening the Airway
Head Tilt orHead Tilt or
Chin LiftChin Lift
28. Maneuvers for Opening the AirwayManeuvers for Opening the Airway
JawJaw
ThrustThrust
33. INDICATIONS FOR ENDOTRACHEALINDICATIONS FOR ENDOTRACHEAL
INTUBATION (operative)INTUBATION (operative)
1.1. Need to deliver positive pressureNeed to deliver positive pressure
ventilationventilation
2.2. Protection of the respiratory tractProtection of the respiratory tract
3.3. Head, neck, chest surgeryHead, neck, chest surgery
4.4. GA in nonsupine positionGA in nonsupine position
5.5. Neuromuscular paralysis institutedNeuromuscular paralysis instituted
6.6. Need to treat intracranial HTNNeed to treat intracranial HTN
7.7. Lung isolationLung isolation
34. INDICATIONS FOR ENDOTRACHEALINDICATIONS FOR ENDOTRACHEAL
INTUBATION (non-operative)INTUBATION (non-operative)
1.1. Decreased consciousnessDecreased consciousness
2.2. Tracheobronchial toiletTracheobronchial toilet
3.3. Severe pulmonary and multi-systemSevere pulmonary and multi-system
injury associated with respiratory failureinjury associated with respiratory failure
Severe sepsisSevere sepsis
Airway obstructionAirway obstruction
Hypoxemia/hypercarbia of various etiologiesHypoxemia/hypercarbia of various etiologies
35. Objective MeasuresObjective Measures
((FOR ENDOTRACHEAL INTUBATIONFOR ENDOTRACHEAL INTUBATION))
RR > 35/minRR > 35/min
Vital Capacity < 15 ml/kgVital Capacity < 15 ml/kg
Inability to generate a negative inspiratory forceInability to generate a negative inspiratory force
of 20 mm Hgof 20 mm Hg
PaO2 < 70 mm Hg on 40% FiO2PaO2 < 70 mm Hg on 40% FiO2
A-a gradient > 350 mm Hg on 100% O2A-a gradient > 350 mm Hg on 100% O2
PaCO2 > 55 mm HgPaCO2 > 55 mm Hg
Dead Space (Vd/Vt) > 0.6Dead Space (Vd/Vt) > 0.6
42. Equipment for Airway ManagementEquipment for Airway Management
ORAL AIRWAYSORAL AIRWAYS
– Relieves obstructionRelieves obstruction
due to tongue fallingdue to tongue falling
backwardbackward
– Initially insertedInitially inserted
towards hard palatetowards hard palate
then rotated 180then rotated 180
degreesdegrees
– Can cause gag /vomitCan cause gag /vomit
reflexreflex
NASAL AIRWAYSNASAL AIRWAYS
43. Equipment for Airway ManagementEquipment for Airway Management
Anesthesia Face MaskAnesthesia Face Mask
– Should fit over the bridge ofShould fit over the bridge of
the nose cheeks and chin tothe nose cheeks and chin to
produceproduce AIRTIGHT SEALAIRTIGHT SEAL
– Increased dead spaceIncreased dead space
therefore larger TV requiredtherefore larger TV required
– Clear mask preferable to seeClear mask preferable to see
vomitus/secretions and colorvomitus/secretions and color
44. Equipment for Airway ManagementEquipment for Airway Management
LaryngoscopesLaryngoscopes
– Consist of handle and bladeConsist of handle and blade
– Handle has the batteries.Handle has the batteries.
Usually rough for better gripUsually rough for better grip
– Blades are designed to enterBlades are designed to enter
mouth, displace the tongue,mouth, displace the tongue,
elevate epiglottis and exposeelevate epiglottis and expose
the Vocal cordthe Vocal cord
STRAIGHT BLADE- MILLERSTRAIGHT BLADE- MILLER
CURVED BLADE- MACINTOSHCURVED BLADE- MACINTOSH
45. Equipment for Airway ManagementEquipment for Airway Management
Endotracheal tubeEndotracheal tube
– Increases resistanceIncreases resistance
to gas flowto gas flow
– Increases dead spaceIncreases dead space
– IT or Z 79 (indicatesIT or Z 79 (indicates
lack of tissue toxicity)lack of tissue toxicity)
– High volume-lowHigh volume-low
pressure cuff preferredpressure cuff preferred
(<25 torr) : prevents(<25 torr) : prevents
tracheal mucosatracheal mucosa
ischemiaischemia
46. Equipment for Airway ManagementEquipment for Airway Management
Endotracheal tubeEndotracheal tube
– Very flexible thus aVery flexible thus a
STYLET maybe neededSTYLET maybe needed
– Can be inserted orally,Can be inserted orally,
nasally or thru thenasally or thru the
tracheostomy stomatracheostomy stoma
– With Murphys eye ( allowsWith Murphys eye ( allows
ventilation even if main portventilation even if main port
is occludedis occluded
StyletStylet
– Malleable metal insertedMalleable metal inserted
thru the tube for difficultthru the tube for difficult
intubationintubation
47. Equipment for Airway ManagementEquipment for Airway Management
LMA (Laryngeal MaskLMA (Laryngeal Mask
Airway)Airway)
– Relatively new deviceRelatively new device
– Alternative to ETTAlternative to ETT
– Aspiration?Aspiration?
– Easier to insertEasier to insert
ILMA (Intubating LMA)ILMA (Intubating LMA)
– An ETT may be inserted thruAn ETT may be inserted thru
the LMAthe LMA
49. Equipment for Airway ManagementEquipment for Airway Management
GLIDESCOPEGLIDESCOPE
50. Equipment for Airway ManagementEquipment for Airway Management
Fiberoptic BronchoscopeFiberoptic Bronchoscope
51. Equipment for Airway ManagementEquipment for Airway Management
Cricothyrotomy KitCricothyrotomy Kit
52. Equipment for Airway ManagementEquipment for Airway Management
Retrograde Intubation KitRetrograde Intubation Kit
53. Equipment for Airway ManagementEquipment for Airway Management
Tracheostomy SetTracheostomy Set
54. Difficult AirwayDifficult Airway
the clinical situation in which athe clinical situation in which a
conventionally trained anesthesiologistconventionally trained anesthesiologist
experiences difficulty with maskexperiences difficulty with mask
ventilation, difficulty with trachealventilation, difficulty with tracheal
intubation, or both.intubation, or both.
55. Prediction of the Difficult AirwayPrediction of the Difficult Airway
Recent data from the Closed ClaimsRecent data from the Closed Claims
Project of the American Society ofProject of the American Society of
Anesthesiologists (ASA)Anesthesiologists (ASA)
Adverse respiratory eventsAdverse respiratory events – largest– largest
source of injurysource of injury
inadequate ventilationinadequate ventilation (38%)(38%)
esophageal intubationesophageal intubation (18%)(18%)
difficult intubationdifficult intubation (17%)(17%)
56. Prediction of the Difficult AirwayPrediction of the Difficult Airway
Of these respiratory eventsOf these respiratory events
death or brain damage -death or brain damage - 85%85%
substandard care -substandard care - 12.5%12.5%
preventable -preventable - 12.5%12.5%
Better prediction and anticipation of theBetter prediction and anticipation of the
difficult airway - lead to reduction in thesedifficult airway - lead to reduction in these
numbersnumbers
57. Definition of Terms – Four conceptsDefinition of Terms – Four concepts
Difficult Mask VentilationDifficult Mask Ventilation
Difficult LaryngoscopyDifficult Laryngoscopy
Difficult IntubationDifficult Intubation
Failed IntubationFailed Intubation
58. Difficult Mask VentilationDifficult Mask Ventilation
No universally acceptable classificationNo universally acceptable classification
(1) inability of unassisted anesthesiologist to(1) inability of unassisted anesthesiologist to
maintainmaintain SpO2 > 90%SpO2 > 90% using 100% oxygen andusing 100% oxygen and
positive pressure mask ventilation in a patientpositive pressure mask ventilation in a patient
whose SpO2 was 90% before anestheticwhose SpO2 was 90% before anesthetic
intervention; orintervention; or
(2) inability of the unassisted anesthesiologist to(2) inability of the unassisted anesthesiologist to
prevent or reverse signs of inadequateprevent or reverse signs of inadequate
ventilation during positive pressure maskventilation during positive pressure mask
ventilation.ventilation.
59. Difficult LaryngoscopyDifficult Laryngoscopy
difficult laryngoscopydifficult laryngoscopy = not being able to see any part of= not being able to see any part of
thethe vocal cordsvocal cords with conventional laryngoscopywith conventional laryngoscopy
Cormack and Lehane ClassificationCormack and Lehane Classification
Four grades of laryngoscopy based on structuresFour grades of laryngoscopy based on structures
visualizedvisualized
Grade three and fourGrade three and four or grade four alone as correlatingor grade four alone as correlating
with a potentially difficult intubationwith a potentially difficult intubation
60. Difficult IntubationDifficult Intubation
Less straightforwardLess straightforward
In 1993, The ASA Committee on PracticeIn 1993, The ASA Committee on Practice
Guidelines for Management of the DifficultGuidelines for Management of the Difficult
Airway defined it as intubation when “theAirway defined it as intubation when “the
proper insertion of the ET tube withproper insertion of the ET tube with
conventional laryngoscopy requiresconventional laryngoscopy requires moremore
than three attempts and/or …more than 10than three attempts and/or …more than 10
minutesminutes
61. Failed IntubationFailed Intubation
The inability to place the endotrachealThe inability to place the endotracheal
tube into the airwaytube into the airway
0.05% or0.05% or 1:22301:2230 of surgical patientsof surgical patients
0.13% to 0.35%, or 1:750 to0.13% to 0.35%, or 1:750 to 1:2801:280 ofof
obstetric patientsobstetric patients
62. DIFFICULT AIRWAY
GENERAL ANESTHESIA
+/- PARALYSIS
RECOGNIZED
PROPER
PREPARATION
ASA DIFFICULT AIRWAY ALGORITHMASA DIFFICULT AIRWAY ALGORITHM
UNRECOGNIZED
AWAKE
INTUBATION
CHOICES
SUCCEED
FAIL
SURGICAL
AIRWAY
MASK
VENTILATION
NO
YES
EMERGENCY
PATHWAY
NON -EMERGENCY
PATHWAY
LMA
COMBITUBE
TTJV
INTUBATION
CHOICES
INTUBATION
CHOICES
SURGICAL
AIRWAY
SUCCEED
FAIL
CONFIRM
ANESTHESIA
WITH MASK
VENTILATION
AWAKEN
SURGICAL
AIRWAY
EXTUBATE
OVER JET
STYLET
REGIONAL
ANESTHESIA
CANCEL
CASE
REGROUP
Intubation choices include use of different
laryngoscope blades, LMA as an intubation
conduit (with or without fiberoptic guidance),
fiberoptic intubation, intubating stylet or tube
changer, light wand, retrograde intubation,
and blind oral or nasal intubation.
*
*
*
AWAKEN
63. LMA in the Difficult Airway AlgorithmLMA in the Difficult Airway Algorithm
66. ASA Difficult Airway AlgorithmASA Difficult Airway Algorithm
Take-Home MessagesTake-Home Messages
If suspicious of trouble –If suspicious of trouble – secure the airway awakesecure the airway awake
If you get into trouble –If you get into trouble – awaken the patientawaken the patient
Have a plan B and C immediately available or inHave a plan B and C immediately available or in
place –place – think aheadthink ahead
Intubation choices –Intubation choices – do what you do bestdo what you do best