ASA Guideline Review

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JOSEPH C. GABEL PROFESSOR & CHAIR ∣ DEPT. OF ANESTHESIOLOGY THE UNIVERSITY OF TEXAS MEDICAL SCHOOL AT HOUSTON

MEDICAL DIRECTOR ∣ PERIOPERATIVE SERVICES MEMORIAL HERMANN HOSPITAL, HOUSTON, TX

CARIN A. HAGBERG, MD

ASA Guideline Review Management of the Difficult Airway

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EQUIPMENT Aircraft Medical

Ambu A/S Clarus Medical

Cook Cookgas

Intersurgical Karl Storz Endoscopy

King Systems LMA North America

Mercury Medical Verathon

RESEARCH GRANTS Karl Storz Endoscopy

King Systems Ambu

SPEAKERS’ BUREAU LMA North America

Ambu A/S Cook

UNPAID CONSULTANT Ambu

Lecture Objectives

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‣ Review specifics of revised ASA DA guidelines

‣ Review basics of a preoperative airway exam

‣ Discuss appropriate options for CVCI situation

‣ Discuss appropriate options for extubation of the difficult airway

‣ Communication of DA to future caregivers

The clinical situation in which a conventionally trained

anesthesiologist experiences difficulty with FMV of the upper

airway, tracheal intubation, or both.

Represents a complex interaction between patient

factors, the clinical setting, and the skills of the practitioner.

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Difficult Airway

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APSF Survey Results Identify Safety Issues Priority

Difficult Airway Management

Cost-Saving: Production Pressure

Anesthesia Delivery: Remote Sites

Anesthesia Delivery: Office-Based

Neurologic Deficit Due to Anes Touch

Coronary Heart Disease (pts)

Occupational Stress

Fatigue

Medication Errors

Cost-Saving Time for Pre-Op Eval 52

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Airway - Still #1

Stoelting, RK: APSF Newsletter 1999; 14:6

Practice Guidelines Management of the Difficult Airway

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‣ Systematically developed recommendations that assist the practitioner in making decisions

‣ Purpose to facilitate management of the DA & reduce the likelihood of adverse outcomes

‣ Not intended as standards of care or absolute requirements

‣ Revised & updated the 1993 and 2003 publication of ASA’s guidelines for management of the DA

Anesthesiology 2003 98:1269-77

An updated report by the ASA task force

Airway history should be conducted on all patients, if

feasible.

Intent is to detect medical, surgical, & anesthetic factors that

may indicate DA.

Examine previous MR, if available in a timely manner.

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Patient History

ESSENTIAL ROUTINE PREOPERATIVE AIRWAY EVALUATION

1) Length of upper incisors!

2) Involuntary: maxillary teeth anterior to mandibular teeth!

3) Voluntary: protrusion of mandibular teeth anterior to maxillary teeth - lip bite test !

4) Interincisor distance <4 cm!

5) Oropharyngeal class (MP 3 or 4)!

6) Narrowness of palate!

7) Mandibular space compliance

8) Mandibular space length!9) Length of neck!10) Head/Neck ROM!11) Thickness of neck

TMD <6 cm

SMD <12

? >40 cm

!Anesthesiology 2013; 118:251-70

Identify patients w/ individual predictors

Determine any combinations of predictors that may lead to difficulty

Perform additional testing & obtain preop consultation

Review w/ expert(s) to formulate plan for airway management

Ability to better acurately predict should reduce number of adverse outcomes & improve safety of airway management

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Does the airway exam predict difficult intubation?

In Fleisher L (ed). Evidence-Based Practice of Anesthesiology. W.B. Saunders, 2004; 34-46

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Neck Circumference

Brodsky JB, Lemmens HJM, Brock-Utne JG, Vierra M, Saidman LI; Morbid Obesity & Tracheal Intubation. Anesth Analg; 2002; 94:732-6.

100 Patients - BMI >40 kg/m2 - Elective surgery

PreOperative Measurements - TMD, SMD - Height, Weight - Neck circumference

Aim to identify factors that complicate DL & intubation

Intubation Difficulties Neither absolute obesity nor BMI

Large neck circumference & high Mallampati scores

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Anesthesiology 2013 118:251-70.

Other options include (not limited to): surgery utilizing face mask or SGA anesthesia (LMA, ILMA, laryngeal tube), local anesthesia infiltration or regional nerve blockade. Pursuit of these options usually implies that mask ventilation will not be problematic. Therefore, these options may be of limited value if this step in the algorithm has been reached via the Emergency Pathway.

Invasive airway access includes surgical or percutaneous airway, jet ventilation, & retrograde intubation.

Alternative DI approaches include (not limited to): video-assisted laryngoscopy, alternative laryngoscope blades, SGA (LMA, ILMA) as an intubation conduit (w/ or w/out fiberoptic guidance), fiberoptic intubation, intubating stylet or tube changer, light wand, retrograde intubation, and blind oral or nasal intubation.

Consider re-preparation of the patient for awake intubation or canceling surgery.

Emergency non-invasive airway ventilation consists of a SGA.

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Face Mask Ventilation Not Adequate

Consider/Attempt SGA

SGA AdequateSGA NOT Adequate

Emergency, Non-Invasive Airway Ventilation


EMERGENCY AIRWAY PATHWAY

Call for Help

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Langeron O, MD, PhD, Masso E, MD, Huraux C, MD, Guggiari M, Bianchi A, MD, Coriat, MD, Riou B, MD, PhD Anesthesiology 2009; 92:1229-36

Prediction of Difficult Mask Ventilation ‣ Prospective study

- 1,502 pts - French university hospital

‣ DMV: inability to maintain O2 sat >92% or prevent/reverse signs of inadequate ventilation during PPMV under GA

‣ Incidence 5%

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Difficult Mask Ventilation Pre-Operative Risk Factors

M: mask seal

O: BMI >26 kg/m2

A: Age >55 yrs

N: Lack of teeth

S: History of snoring

>2 risk factors markedly increases risk

Langeron O, MD et al. Anesthesiology 2000; 92:1229-36

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Techniques for Difficult Intubation

‣ Esophageal tracheal combitube

‣ Intratracheal jet stylet

‣ Invasive airway access

‣ Laryngeal mask airway

‣ Oral & nasopharyngeal airways

‣ Rigid ventilating bronchoscope

‣ Transtracheal jet ventilation

‣ Two-person mask ventilation

2 person effort

Large oropharyngeal and/or nasopharyngeal airways

Triple Airway Maneuver

- T: tilt head - A: advance mandible - M: mouth open

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Optimal Attempt at BMV

Actively pursue opportunites to deliver supplemental oxygen

throughout the process of difficult airway management.

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Anesthesiology 2003; 98:1269-77

Alveolar Oxygen Delivery

It is not possible to visualize any portion

of the VC after multiple attempts at

conventional laryngoscopy

!

Incidence 1.5-3%

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Difficult Laryngoscopy

Predicts easy intubation in 95% of cases

!

!

!

<3% need any intubation adjuncts

Likely to require gum

elastic bougie, but no other

adjuncts

easy

COOK MODIFICATION CORMACK-LEHANE CLASSIFICATION

Cook TM; Anesthesia 2000; 55:274-9

grade 1

grade 2a

Associated w/ difficult intubation in 75% of

cases !

Specialist intubation techniques are likely required

restricted difficult

grade 2b

grade 3a

grade 3b

grade 4

R.A.M.P.

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Nissen IPAD

Troop Elevation Pillow

Helps maximize upper airway patency

Improves ventilation mechanics

Lengthens apneic time period to critical hypoxia in massive obesity

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Difficult Tracheal Intubation

Tracheal intubation requires multiple attempts, in the presence or absence of

tracheal pathology

!

Incidence 1.2-3.8%

Oral Axis (OA), Paryngeal Axis (PA) & Laryngeal Axis (LA) must be aligned to facilitate viewing of glottis by DI

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Sniffing Position

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‣ Alternative laryngoscope blades

‣ Awake intubation

‣ Blind intubation (oral/nasal)

‣ Fiberoptic intubation

‣ Intubating stylet-tube changer

‣ Invasive airway access

‣ Light wand

‣ Retrograde intubation

‣ Video Laryngoscopy

Techniques for Difficult Intubation

x

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Consider the relative merits & feasibility of 3 basic management choices:

vsAwake Intubation

Non-Invasive Technique!Initial Intubation Approach

Spontaneous Ventilation!Preservation

Intubation Attempts After!GA Induction

Spontaneous Ventilation!Ablation

Invasive Technique!Initial Intubation Approachvs

vs

Video-Assisted Laryngoscopy!Initial Intubation Approach

Difficult Airway Algorithm


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Develop primary & alternative strategies

Difficult Airway Algorithm

Awake Intubation

Airway Secured Surgical Access

SUCCEED

Airway Approached Non-Surgical

FAIL

Cancel Case Consider feasibility of Other Options

Surgical Airway


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Intubation Attempts After GA

Initial Intubation Attempts

Consider/Attempt LMA

Adequate Inadequate

EMERGENCY PATHWAYNON-EMERGENCY PATHWAY

SUCCEED FAIL

Face Mask Ventilation Adequate

Face Mask Ventilation Inadequate


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Patient Anesthetized, Intubation Unsuccessful

Non-Emergency Pathway


Alternative Approaches to Intubation

FAIL After Multiple Attempts

Invasive Airway Access

Consider Feasibility of Other Options

Awaken Patient

SUCCEED

Mask Ventilation Adequate

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‣ Invasive airway access includes: - Surgical or percutaneous tracheostomy

or cricothyrotomy

‣ Other options include (not limited to): - Surgery utilizing face mask or LMA

anesthesia - LA infiltration - Regional nerve block

‣ Consider re-preparation of the patient for awake intubation or canceling surgery

Alternative Approaches to Intubation Fail After Multiple Attempts

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Difficult Airway Recognized

Surgery Can Be Done Under RA

surgery cannot be quickly terminated

good airway access patient agrees to

awake TI if RA fails

poor airway access

RA acceptable RA unacceptable

all patient positions access to airway not

important

surgery can be quickly terminated

RA acceptable

RA FAILS

cancel case awake TI redo RA

GA

RA FAILS

cooperative patient

noncooperative patient

awake TI

GA

ASA DA Algorithm

GA Plan B ready to go

!In Benumof JL(ed): Airway Management Principles & Practice. St.Louis, Mosby-Year Book,1996,150.

DA difficult airway RA regional anesthesia GA general anesthesia TI tracheal intubation

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Beware the inexperienced, ambitious clinician, who offers to help

!

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Emergency Pathway

Ventilation Inadequate Intubation Unsuccessful

Emergency, Non-Invasive Airway Ventilation


CALL FOR HELP

SUCCEED FAIL

Invasive Airway Access

(b)*

Consider Feasibility of Other Options (a)

Awaken Patient (d)

Emergency, Invasive Airway Access (b)*

ONE MORE INTUBATION

ATTEMPT

Options for emergency, non-invasive airway ventilation include (not limited to): rigid bronchoscope,

Combitube, TTJ, LMA ventilation

Both will likely work as ventilatory mechanisms

Both can be inserted blindly

Few complications w/their use

Combitube often unfamiliar & unavailable

Proseal & other SGA’s

Consideration of intubation conduit

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LMA & Combitube

NON-PATHOLOGICAL ‣ Natural Anatomy

- Tongue ‣ Supralaryngeal ventilatory mechanism

- LMA, etc - Other alternative SLA

PATHOLOGICAL ‣ Abnormal Anatomy

- Cancer - Hematoma - Abscess - Edema

‣ Subglottic ventilatory mechanism - Rigid bronch, TTJV - Surgical airway

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Airway Obstruction

Able to ventilate below obstruction

Inexperienced

Risk of trauma to posterior wall of

trachea

Often unavailable

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Rigid Bronchoscopy

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Comparison of Flexible Fiberscope & Rigid Bronchoscope

FF RBIPreparation time Longer ShorterVisualization of tube passage No YesSuccess rate of intubation High HighMechanical strength Lower HigherEndoscopic orientation Poorer BetterIntegrated suction channel Yes NoRetromolar route No YesNasal route Yes NoMobile light source (battery, adapter)

Available AvailableLearning curve Flatter SteeperCosts (acquisition, repair) Higher Lower

!Rudolph C, et al; Minerva Anestesiol 2007; 73:567-74

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Retrograde Intubation

‣ Techniques: classic, silk, guide wire, & FOB

‣ Safe, effective, & fast when technique is familiar

‣Useful whenever anatomic limitations obscure glottic opening (pathology, CSI, upper airway trauma)

‣CAN VENTILATE situations

  Techniques include classic, silk, guide wire (≥ 70 cm), and FOB

  Safe, effective and fast when technique is familiar

  Useful whenever anatomic limitations obscure glottic opening (pathology, CSI, upper airway trauma)

  CAN VENTILATE situations

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Transtracheal Jet Ventilation

‣ May be performed via catheter (cric or AEC) or via bronchoscope (rigid or flexible)

‣ Techniques vary with type of procedure

‣ Vigilance is of the essence

‣ OPEN THE AIRWAY!!!

  May be performed via a catheter (cric or AEC) or via a bronchoscope (rigid or flexible)

  Technique varies with type

of procedure   Vigilance is of the essence   Enk oxygen flow modulator

  OPEN THE AIRWAY !!!!

 

May be perform

ed via a catheter (cric or A

EC

) or via a bronchoscope (rigid or flexible)

 

Technique varies with type

of procedure  

Vigilance is of the essence

 

Enk oxygen flow

modulator

 

OPEN

THE AIR

WAY !!!!

  May be performed via a catheter (cric or AEC) or via a bronchoscope (rigid or flexible)

  Technique varies with type

of procedure   Vigilance is of the essence   Enk oxygen flow modulator

  OPEN THE AIRWAY !!!!

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Transtracheal Jet Ventilation

‣ Often unavailable

‣ Used inappropriately

‣ Significant risk of barotrauma - Too large TV - Too short exhalation phase - Catheter dislodgement

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Site Inferior CTM

Methods Needle

Percutaneous Surgical

Equipment Scalpel Tube Finger

curved blunt dilator

tracheal hook

trousseau tracheal dilator

Cricothyrotomy Final CVCI Option

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Laryngeal/tracheal disruption

Upper airway abscess or obstruction

Combined mandibular

maxillary fractures

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Surgical Technique First Choice

Extubation & ASA Task Force Recommendations

Consider relative merits of awake vs. deep extubation

Evaluate factors that may interfere w/upper airway patency

Formulate a plan for immediate reintubation if the airway becomes compromised

Consider a jet stylet

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Anesthesiology 2003; 98:1269-77

Awake extubation

Anesthetized (deep) extubation

Extubating after positive “cuff leak test”

Extubating when expert help is available

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Standard Approaches

Setting & Circumstances

Surgical Procedure

Type of anesthetic

Cardiorespiratory stability

Underlying patient disease

Establishment of present airway

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Important Considerations

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Lorraine Foley, MD, Tufts Medical School

Anticipate the possibility of DA management by performance of a

thorough pre-op airway assessment

Secure the airway awake if difficulty is suspected

Have a back-up plan(s) if the initial plan to secure the airway fails

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ASA Difficult Airway Algorithm Take Home Messages

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Experience Matters.

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Summary

‣ Algorithms only serve as guidelines

‣ Become educated

‣ Equipment must be available

‣ Practice, practice, practice!!

‣ Do what works BEST for you

‣ You CAN make a difference!!

Health & Medicine

ASA Guideline Review