Assessment Of The Assessment Of The Upper AirwayUpper Airway

NIK AHMAD SHAIFFUDIN BIN NIK HIMMD., MMed (Emerg.Med. USM), AMM

Hospital Sultanah Nur Zahirahdrnikahmad@gmail.com

Emergency Airway Skill Training IV Course 2013

Presentation OutlinePresentation Outline

1. Introduction2. Airway Revisited

– Adult vs Pediatric Airway3. Approach to upper airway assessment

– General…. – Recognizing difficult airway

4. Take Home Messages

DISCLAIMER:

Hold you horses!You ain’t getting a full license at the end of the course!

Most of us already know this much

After E.A.S.T. (hopefully)

On going learning and professional skills development

INTRODUCTION

• Airway assessment & management ….. The single most important skill for ECP

• “A” in the ABC of resuscitation…. Without a secure airway and adequate oxygenation the other resuscitative measures are doomed to failure

• With the exception of immediate defibrillation in cardiac arrest patient….. No single resuscitative maneuver takes priority over the airway assessment & management!!

Anatomical hollow canals that allow the passage of air into and outside the respiratory systemDivided into upper and lower airways; the arbitrary border is the glottis

• Upper airway has muscular, bony and cartilaginous part• Lower airways is almost all smooth muscle

Lower

Upper

Understanding The Airways

AIRWAY REVISITED

Upper AirwayFunctional anatomy is important to expert airway management…A clear understanding will…

o Guide the choice of intubationo Enhanced the best approacho Basis for avoiding complications o …..… early detection

Understanding The Airways

Lower AirwayMiddle Airway

Important distances in adult:

Incisor teeth to vocal cords 15 cmIncisor teeth to carina 20 cmExternal nares to carina 30 cm

*+/- 1 to 2 cm

Adults VS Pediatric Airway :Adults VS Pediatric Airway :Anatomy & PhysiologyAnatomy & Physiology

The Pediatric Airway:The Pediatric Airway:““They’re not just little adults!”They’re not just little adults!”

Anatomical Differences….

PHYSIOLOGICAL DIFFERENCES

Infant

1. Fewer alveoli2. Increase oxygen consumption3. Rate dependant4. Diaphragmatic dependant5. High airway resistance6. Infant is more vulnerable to respiratory

muscle fatigue

Anatomical Differences…cont

Physiology• Kids desaturate fast!

Ron Walls, MD “Manual of Emergency Airway Management”

APPROACH TO UPPER AIRWAY ASSESSMENT

1. Look for potential or compromised airway

2. Need for basic airway adjuncts3. Suitability for NIV4. Candidacy for definitive airway

or IPPV5. Emergency surgical airway6. Clues to diagnosis or etiology

and its subsequent management

Purpose Of Airway Assessment….

How do you know if the airway is patent…… How do you know if the airway is patent…… When to secure it?When to secure it?

Is your patient is going to be difficult for Is your patient is going to be difficult for definitive airway…?definitive airway…?

…… and does it really matter?

In emergency setting….

Approach To Emergency Upper Airway Assessment…. General

1. SPEECHSpeak to your patient !!!Patency & AdequacyWhat is your name ? Or Boleh saya bantu ?Response provides information both airway and neurological

status!!….. Suggestive the airway is patent and adequate for the time

being!!!!

Approach To Emergency Upper Airway Assessment…. General

2. LOOK…..Consciousness - full, alternating, reducedRespiratory effort - normal, increased or reducedDo they just look difficult?

•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) •Distance ( Sternomental > 12 cm, Thyroidmental > 7 cm…)

Oxygenation - Respiratory rate and SPO2 read togetherCapnograph…. 3. LISTEN…Phonation, snore, stridor, wheeze, gargles etc Try to get airway history…… if possible !!!

Predictors: Medical History

• Joint disease • Acromegaly

• Thyroid or major neck surgeries

• Tumors, known abnormal structures

• Genetic anomalies• Epiglottitis

• Previous problems in surgery

• Diabetes• Pregnancy• Obesity

Ron Walls, MD, “Manual of Emergency Airway Management”

Difficult Airways… Look For Predictors & Risks

– Believe the history of previous difficult airway management…..– All airway management techniques fail and this is often

unanticipated !!!!– Never fail to prepare for failure– Even a thorough advance evaluation will help you identify difficult

airways only about 50% of the time ACEP

Ron Walls, MD, “Manual of Emergency Airway Management”

M. Rosen & I.P.Latto 1984 , British Journal Of Anesthesia

Difficult Airway ….. Risk Assessment

• Assessing & Identifying a potentially difficult airway is essential to preparing and developing a strategy for successful ETI and also preparing an alternate plan in the event of a failed ETI.

Ron Walls, MD, “Manual of Emergency Airway Management”

Recognizing Difficult Recognizing Difficult AirwayAirway

3. Difficult Extraglottic Device (EGD)

Four Dimensions of Airway Difficulties

4. Difficult to perform cricothyrotomy

2. Difficult to ventilate with a BVM

1. Difficult laryngoscopy & intubation

Ron Walls, MD, “Manual of Emergency Airway Management”

Dr. Binnions Lemon Law: An easy way to remember multiple test

• Look externally.• Evaluate the 3-3-2 rule.• Mallampati.• Obstruction?• Neck mobility• Scene & Situation

Rosen's Emergency Medicine: Concepts and Clinical Practice, 6th ed., Copyright © 2006 Mosby, Inc

…………Quick AssessmentQuick AssessmentSubjective clinical judgment can be highly specific (>90%), but severely insensitive Subjective clinical judgment can be highly specific (>90%), but severely insensitive

(<20%) and so must be augmented by other evaluations(<20%) and so must be augmented by other evaluations

1. Difficult Laryngoscopy & Intubation

LOOK Externally

• Facial or neck trauma• Large incisors/ broken teeth• Beards or facial hair• Protruding tongue• Short, fat neck• Morbidly obese• Dysmorphism

LEMONS

EVALUATE 3-3-2

• Will patients mouth open wide enough to accommodate 3 fingers?

• Will 3 fingers fit between the mentum and hyoid bone?

• Will 2 fingers fit between the hyoid and thyroid notch?– If not, expect a difficult

intubation

LEMONS

Incisors distance ( Mouth opening) Distance -3 fingers? LEM

ONS

Hyoid-mentum ( Length of mandible) Distance -3 fingers?

LEMONS

Hyoid to the thyroid notch Distance- 2 fingers ?

• Patients who have a longer Hyoid to thyroid distance, greater then 2 finger widths, tend to be more difficult to intubate.

• A more caudal hyoid bone thus indicates a relatively caudal larynx.

Upper & Lower Face• Size upper face = lower face …..

• Lower face > upper face then you should anticipate some degree of difficulty lining up the structures.

LEMONS

LEMONS

INTUBATION FAILUREINTUBATION FAILURE HIGHLOW

Mallampati Score ???LEMONS

Obstruction• Laryngoscopy or intubation may be

more difficult in the presence of an obstruction– Anatomy– Trauma– Foreign body obstruction– Edema (burns)

LEMONS

Obstructions

Grade 1: Full aperture visibleGrade 2: Lower part of cords visibleGrade 3: Only epiglottis visibleGrade 4: Epiglottis not visible

LEMONS

Laryngoscopic View Grades

Cormack & Lehane Grading

Grade I = Grade I = success & ease success & ease of intubationof intubation

<1<1%%

<5%<5%

10-30%10-30%

% listed = % listed = incidenceincidence

LEMONS

Neck Mobility

• Ideally the neck should be able to extend back approximately 35°

• Problems:– Cervical Spine Immobilization– Ankylosing Spondylitis– Rheumatoid Arthritis– Halo fixation

LEMONS

Scene and Situation (SEE)

• Scene safety• Environment

– Do you have a reasonable chance to get the tube?– Space, positioning, access

• Egress– Will you be able to ventilate during egress?– A respiratory rate of 4 is better than a rate of 0!– Enough meds for a long extrication?

LEMONS

2. Difficult to Bag & Mask Ventilation (MOANS)

• Mask Seal• Obesity or Obstruction• Age > 55• No Teeth• Stiff

“The clinical situation where using 100% oxygen and bag/valve/mask ventilation, an unassisted anesthesiologist is unable to maintain oxygen saturation greater than 90% in a

person who was capable of doing so before intervention”

Practice Guidelines for Management of the Difficult Airway.ASA Taskforce. Anesthesiology 2003; 98:1269-1277

Estimated that up to 28% of all anaesthetic related deaths are secondary to the inability to mask ventilate or intubate.

Mask Seal

• Oddly Shaped Face• Bushy Beard• Blood/Vomit• Facial Trauma• Small Hands• Wrong Mask Size

MOANS

Obesity or Obstruction

• Obesity– Increased supraglottic airway resistance– Billowing cheeks– Difficult mask seal– Abdominal contents inhibit movement of

the diaphragm– Quicker desaturation– Heavy chest

MOANS

Obesity or Obstruction

• 3rd Trimester Pregnancy– Increased Mallampati Score– Gravid uterus inhibits movement of the diaphragm– Quick desaturation– Increased body mass

MOANS

Obesity or Obstruction

• Obstructions– Foreign Body– Angioedema– Abscesses– Epiglottitis– Cancer– Traumatic Disruption/Hematoma/Burns

MOANS

Age > 55

• Associated with BVM difficulty, possibly due to loss of tone in the upper airway

MOANS

No Teeth

• Face tends to “cave in”• Consider leaving dentures in for BVM and remove

for intubation

MOANS

Stiff

• Refers to Poor Compliance– Reactive Airway Disease– COPD– Pulmonary Edema/Advance Pneumonia– History of Snoring/Sleep Apnea

• Also predicts a higher Mallampati score

MOANS

Difficult EGD RODS

R - Restricted mouth openingO - Obstruction : Obstruction at the level of larynx or

below EGD will not pass this obstructionD - Disrupted or distorted airway : Fail to “seat &

seal”S - Stiff lungs or cervical spine: Ventilation difficult

due to airway resistance, poor lungs compliance and difficult insertion due to limited neck

movements.

Difficult Cricothyrotomy

• No absolute contraindications to performing emergency cricothyrotomy…

• Time is “SHORT” when cricothyrotomy is indicated!!

SHORT

S - SurgeryH - HematomaO - ObesityR - Radiation T - Tumor

Difficult Cricothyrotomy

• The evidence is clear that….. When emergency surgical airway is required, it is not the procedures that kills the patients, but delaying or not doing it causes harm !!

• Do what you can do BUT do not do what you cannot do. Ask for help !!!.... Airway management should suit the patient NOT the Dr, Nurse or Paramedics !!

Dr Cook & Dr MacDouglass-Davis , British Journal of Anesthesia

“BURP” – a.k.a.“External Laryngeal Manipulation”

• Backward, Upward, Rightward Pressure: manipulation of the trachea

• 90% of the time the best view will be obtained by pressing over the thyroid cartilage

Differs from the Sellick Differs from the Sellick ManeuverManeuver

TAKE HOME MESSAGES

1. Upper airway assessment is a critical part of the RSI process …. Assess every airway for difficulty !!!

2. Believe the history of difficult airway management3. Assess for the unexpected !!!. Hypoxia is the killer…

avoid it.

TAKE HOME MESSAGES4. If your assessment suggest risk for difficult airway

and are frantically looking for a difficult airway equipment/ device you ought to be looking (or calling) for your consultant quickly too.

5. ETCO2 post-intubation was mandatory since 10 years ago! Please use.

6. Arterial blood gas values are rarely helpful in the emergence decision to intubate and may be misleading …..

7. If assessment anticipated deterioration & compromised airway of the critically ill or injured ……intubate early before it occurs!!

8. It is better to err by identifying an airway as potentially difficult, only to subsequently find it is not….. than the other way around !!!

9. While this criteria helps identify difficult airways, it does not guarantee an easy intubation — Be Prepared !!!!

TAKE HOME MESSAGES

“ Good Judgment may come from experience but experience comes from bad judgment “..…

Mark Twain

Any questions?

Its spot the difficult airway patient time!

Look at you partner now. Difficult?

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TQ…TQ…