Airway Assessment, Airway Assessment, Difficult Airway Difficult Airway &Management&Management

Anatomy of LarynxAnatomy of Larynx

Basic anatomic componentsBasic anatomic components

Cartilaginous skeletonCartilaginous skeleton Intrinsic & extrinsic musclesIntrinsic & extrinsic muscles Mucosal liningMucosal lining

Anatomy of LarynxAnatomy of Larynx

Muscles of the larynxMuscles of the larynx

Tenses the vocal cordTenses the vocal cord CricothyroidCricothyroid vocalisvocalis

Opens &closes the glottisOpens &closes the glottis Abductor-post cricoarytenoidAbductor-post cricoarytenoid Adductor-lat cricoarytenoid, thyroarytenoidAdductor-lat cricoarytenoid, thyroarytenoid

arytenoidarytenoid

Muscles of the larynx—contdMuscles of the larynx—contd

Closes the vestibule of the larynxCloses the vestibule of the larynx

AryepiglottisAryepiglottis ThyroepiglotticusThyroepiglotticus thyroarytenoidthyroarytenoid

Nerve supply of the larynxNerve supply of the larynx

Motor supplyMotor supply Recurrent laryngeal nerveRecurrent laryngeal nerve External laryngeal nerveExternal laryngeal nerve

Sensory supplySensory supply Recurrent laryngeal nerveRecurrent laryngeal nerve Internal laryngeal nerveInternal laryngeal nerve

IntroductionIntroduction

““Airway” refers to the upper airway consisting Airway” refers to the upper airway consisting of the of the

-nasal cavity-nasal cavity

-oral cavity-oral cavity

-pharynx-pharynx

-larynx-larynx

-trachea-trachea

-principal bronchi -principal bronchi

Adult &Pediatric Airway DifferenceAdult &Pediatric Airway Difference

Smaller infant larynxSmaller infant larynx Narrowest portion-cricoid cartilage, vocal Narrowest portion-cricoid cartilage, vocal

foldsfolds Location-C3-C5 child,C4-6 adultLocation-C3-C5 child,C4-6 adult Epiglottis-longer ,narrower ,stifferEpiglottis-longer ,narrower ,stiffer Aryepiglottic fold-closer to midline in infantAryepiglottic fold-closer to midline in infant Mucosa-fragileMucosa-fragile

Assessment of airwayAssessment of airway

HistoryHistory

ExaminationExamination

nares- patency ,septumnares- patency ,septum

teeth-prominent incisors, edentulousteeth-prominent incisors, edentulous

palate-high arched, long narrowpalate-high arched, long narrow

neck-short, thick,massesneck-short, thick,masses

Airway AssessmentAirway Assessment

Specific testsSpecific tests 1.Inter-incisor distance- it is the distance1.Inter-incisor distance- it is the distance between the upper and lower incisorsbetween the upper and lower incisors >4 cm(2 finger breadth)>4 cm(2 finger breadth)

2.Atlanto -occipital joint extension-assess 2.Atlanto -occipital joint extension-assess feasibility for sniffing positionfeasibility for sniffing position

2.A-O Extension-aligns oral, pharyngeal,2.A-O Extension-aligns oral, pharyngeal,

laryngeal axis in a straight linelaryngeal axis in a straight line

N angle of extension-35 degreeN angle of extension-35 degree

3.Mallampatti test-correlates tongue size3.Mallampatti test-correlates tongue size

to pharyngeal sizeto pharyngeal size

Class I-IVClass I-IV

Mallampati ClassificationMallampati Classification

Class I-soft palate, fauces, uvula,tonsillarClass I-soft palate, fauces, uvula,tonsillar

pillars visiblepillars visible

Class II-soft palate, fauces, uvula visibleClass II-soft palate, fauces, uvula visible

Class III-soft palate, base of uvula visibleClass III-soft palate, base of uvula visible

Class IV-soft palate not visible Class IV-soft palate not visible

4.Mandibular Space4.Mandibular Space

i) Thyromental distance(Patil’s test) i) Thyromental distance(Patil’s test)

distance from mentum –thyroid notchdistance from mentum –thyroid notch

Normal>6 cmNormal>6 cm

ii)Sternomental distanceii)Sternomental distance

distance from mentum-suprasternal notchdistance from mentum-suprasternal notch

Normal>12 cmNormal>12 cm

iii)Mandibulohyoid distanceiii)Mandibulohyoid distance

distance from mentum-hyoiddistance from mentum-hyoid

Normal 4 cm(3 finger breath)Normal 4 cm(3 finger breath)

5.Mandibular translation5.Mandibular translation

ability to prognathability to prognath

Class A,B,CClass A,B,C

Wilson’s Scoring SystemWilson’s Scoring System

5 variables5 variables

head movementshead movements

neck& jaw movementsneck& jaw movements

weightweight

mandibular recessionmandibular recession

buck teethbuck teeth

LEMON AssessmentLEMON Assessment

L-look externally (trauma, beard, moustache)L-look externally (trauma, beard, moustache)

E-evaluate 3-3-2 ruleE-evaluate 3-3-2 rule

M-mallampati scoreM-mallampati score

O-obstruction (abscess, epiglottitis, trauma)O-obstruction (abscess, epiglottitis, trauma)

N-neck mobilityN-neck mobility

Benumof’s criteria for airway Benumof’s criteria for airway assessmentassessment

Interincisor distanceInterincisor distance Range of cervical motionRange of cervical motion Mandibular spaceMandibular space

Thyromental distanceThyromental distance Hyomental distanceHyomental distance

Mandibular translationMandibular translation

Contd…benumof’s criteriaContd…benumof’s criteria

Mallampati classificationMallampati classification Configuration of the palateConfiguration of the palate Thickness of the neckThickness of the neck Buck teethBuck teeth

Direct laryngoscopyDirect laryngoscopy Cormack& Lehane-Grade I-IVCormack& Lehane-Grade I-IV

Grade I-entire laryngeal aperture visibleGrade I-entire laryngeal aperture visible

Grade II-post commissure visibleGrade II-post commissure visible

Grade III-epiglottis visibleGrade III-epiglottis visible

Grade IV-soft palate visibleGrade IV-soft palate visible

Difficult AirwayDifficult Airway

ASA has defined it as a situation in which theASA has defined it as a situation in which the

“ “conventionally trained anesthetist hasconventionally trained anesthetist has

difficulty with mask ventilation or difficulty difficulty with mask ventilation or difficulty

with tracheal intubation or BOTH.” with tracheal intubation or BOTH.”

Difficult ventilationDifficult ventilation

inability of 1 anesthetist to maintain oxygeninability of 1 anesthetist to maintain oxygen

saturation >92%saturation >92%

significant gas leak around face masksignificant gas leak around face mask

use of FGF button >2use of FGF button >2

no chest movementno chest movement

2 handed mask ventilation needed2 handed mask ventilation needed

change of operator requiredchange of operator required

Difficult IntubationDifficult Intubation

unable to place an ETT with conventionalunable to place an ETT with conventional

laryngoscopy with >3 attemptslaryngoscopy with >3 attempts

takes >10 mins for intubation takes >10 mins for intubation

Difficult Airway-FactorsDifficult Airway-Factors

CongenitalCongenital

Pierre Robin Syndrome, Down’s SyndromePierre Robin Syndrome, Down’s Syndrome

Klippel Fiel syndromeKlippel Fiel syndrome AcquiredAcquired

Infections-croup, abscess, supraglottitisInfections-croup, abscess, supraglottitis

Arthritis-RA,ASArthritis-RA,AS

Tumors-lipoma, cystic hygroma, goitreTumors-lipoma, cystic hygroma, goitre

TraumaTrauma

ObesityObesity

BurnsBurns

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