PSU Airway Management Excellent CenterAirway Assessment and Difficult Airway

ManagementNalinee Kovitwanawong, MD.Department of Anesthesiology

Faculty of MedicinePrince of Songkla University

Scope of Problem

Approximate 20-25 million patients per year in the US are

intubated for surgical procedures

1-3% incidence of unanticipated difficult airway

UK : approximate 3 million patients per year for GA.

Almost half : tracheal intubation

2.2% was expected difficult airway

International : HUGE problem

First phase of NAP4. BJA2011; 106(2):266-71

A Closed Claims Analysis 1961-1996

- Airway injury during GA is a significant source of morbidity

for patient and liability for anesthesiologist

- 4,460 claims : 6% were airway injury claims

39% of airway injury claims associated with

difficult intubation

- No different in ASA status, proportion of obese patients

- 8% result in death

Anesthesiology 1999; 91: 1703-11

National Health Service Litigation Authority data in UK 1995-2007

claims related to airway management :

5th Most common reason for anesthesia related litigation

BJA 2011; 106(2): 266-71

ASA Closed Claims 1976-2007

no. of claims

Permanent br. damage 867

Airway injury 581

Difficult intubation 466

Spinal cord injury 417

Medication Errors 283

Central venous cath injury 183

Best Practice & Research Clinical Anaesthesiology 2011; 25: 263-76

ASA Closed Claims 1976-2007

Esophageal intubation has nearly disappeared

Inadequate O2 or ventilation has declined in OR not out OR

setting

Difficult intubation remains a concern 27% of adverse

respiratory events

Pulmonary aspiration 3rd most common respiratory event

Best Practice & Research Clinical Anaesthesiology 2011; 25: 263-76

PSU Data : AirwayTechniques

Teachniques 2012 2013 2014 2015Endotracheal/tracheostomy 9,111 9,980 8,433 9,824

Awake intubation blind nasal 7 9 6 0

Awake intubation by oral 17 28 49 42

Awake intubation by fiberoptic 39 59 61 71

I gel insertion 533 218 153 42

Laryngeal mask anesthesia 1,794 1,465 1,503 1,527

Laryngeal tube 12 0 10 0Glidescope Technique 306 275 266 537

Difficult Airway

American Society of Anaesthesiologists Task Force definitions

The difficult airway is “the clinical situation in which a conventionally trained Anesthesiologist experiences difficulty with facemask ventilation, difficulty in supraglottic device ventilation, difficulty in tracheal intubation or all three”

o difficulty with facemask ventilation is the inability of an unassisted anesthesiologist a) to maintain oxygen saturation, measured by pulse oximetry 92%.b) to prevent or reverse signs of inadequate ventilation during positive-pressure mask ventilation under general anesthesia.

o Difficulty in SGA ventilation : poor device placement or inability to adequately ventilate with device successfully placed.

o Difficult laryngoscopy occurs when it is not possible to visualize any portion of the vocal cords with conventional laryngoscopy after 2 attempts. This typically corresponds to a Cormack and Lehane Grade IV laryngoscopy view

o Difficult endotracheal intubation occurs when “proper insertion of the tracheal tube with conventional laryngoscopy requires more than 2 attempts”

o Difficult surgical airway : may be cause by anatomical abnormality.

PSU Data : Difficult Airway

AirwayFrequency

2013 2014 2015

1. Suspected difficult airway 434 544 474

2. Anticipated difficult airway 30 46 22

3. Unanticipated difficult airway 0 0 0

4. Failed intubate 0 1 1

Incidence

• incidence of difficult airways is poorly defined, and varies according to the setting

• incidence of failed intubation (Cook and MacDougall-Davis, 2012)

• ~ 1 in 1–2000 in the elective setting

• ~ 1 in 300 during rapid sequence intubation in the obstetric setting

• ~ 1 in 50–100 in the emergency department (ED), intensive care unit (ICU), and pre-hospital settings

Difficult airway management

• Team and equipments preparation

• Airway assessment

• Call for help

• Oxygenation

• Aware airway trauma

• Aware cannot intubate/cannot ventilate

• Plan for extubation

• Follow up

Prediction of difficult airway

Unrecognized

difficult airway

25-30 %

Hypoxia

Dead

Adenoid

Polyp

Tumor

maxillar

Tongue

Mandible

Tonsil

Buccal mucosa

Cervical

spine

Larynx

Subglottic

Thyroid

Trachea

Esophagus

Airway assessment

• History

• physical examination

• Investigation

: chest x- ray

: computed tomography (CT)

: magnetic resonance imaging (MRI)

History taking

• Snoring, OSA, difficult intubation

• Chart

• Congenital anormaly

• Nose, mouth, neck pathologies

• Previous surgery

• Airway disease

Congenital anormaly andAirway disease

Down’s syndrome

Pierre Robin syndrome

Cystic hygroma Lymphangioma

Supraglottitis, croup,

epiglottitis

Retropharyngeal abscess

Ludwig’s angina

Papillomatosis

CA tongue, CA larynx

Tumor of oral cavity

Thyroid gland disease

Head, facial, cervical spine injury

Laryngeal trauma

Acute burn

Burn scar

Rheumatoid arthritis

Temporomandibular joint

ankylosis

C-spine immobility

Diabetic mellitus

Stiff joint syndrome at cervical joint

or TM jointSalzarulo HH,1986, Warner ME,1998

McAnulty GR, et al.2000

Ankylosing spondylitis

Morbid obesity

edentulous

Airway Assessment

6-D Method of Airway Assessment

6-D Method of Airway Assessment

Proc(Bayl Univ Med Cent).2005 Jul 18(3): 220-227.

6-D Method of Airway Assessment

Accuracy of Risk Factors in Predicting Difficulty with Tracheal Intubation

Bedside predictors of difficult tracheal intubation are imperfect !!

NAP4 study : major complications related to airway management

Led to death

Brain damage

Need for emergency surgical airway

Unanticipated ICU admission

Prolongation of ICU stay

T.M.Cook et al.BJA 2011; 106(5): 617-42

Recommendation

• Strong recommendation for : most patients

should receive the intervention

• Weak recommendation for : most patients

would want the suggested course of action,

but some would not

• Strong recommendation against : most

patients should not receive the intervention

• Weak recommendation against : most

patients would not want the suggested

course of action, but some would

Level of evidence

Level of evidence A (High) : systematic

reviews of RCTs

Level of evidence B (Moderate) : RCTs

with limitations, observational studies

with sig therapeutic effect

Level of evidence C (Low) : RCTs with sig

limitations, observational studies, case

series, expert opinion

Management of the difficult and failed airway in the

unconscious/induced patient (RSI)

https://www.das.uk.com/guidelines/das_intubation_guidelines

Positioning during intubation

Positioning during intubation

Difficult direct laryngoscope

Proper positioning of patient and

laryngoscope blade tip

External laryngeal pressure (strong

recommendation for, level B)

Blade change (little evidence) : specific

anatomy finding during initial DL

Tracheal tube introducer (strong

recommendation for, level B)

cricoid pressure (weak recommendation

against, level C)

Limit to tracheal intubation attempts

Patient morbidity increases with the

number of attempts

aspiration

hypoxemia

hypotension

trauma

etc.

Three failed attempts : indication to

declare “failed intubation”

VDO Laryngoscope

Difficult VDO laryngoscope

3 independent tasks

Namely

Laryngeal exposure

Delivery of ETT to laryngeal inlet

Non-channeled blades

Preload stylet with a curvature matching

Channeled blades

Suction prior to insertion

SAD

Difficult face mask ventilation

Placement of appropriately size

oro/nasopharyngeal airway

Two-handed mask hold

Exaggerated head extension

(strong recommendation for, level C)

Release of cricoid pressure (weak

recommendation for, level C)

After corrective maneuvers : SAD, ETT

Tracheal intubation confirmation

Capnographic confirmation (strong

recommendation for, level B)

ongoing continuous wave form

capnographic monitoring during the

duration of intubation (strong

recommendation for, level C)

continuous wave form capnographic

monitoring has also been recommended in

deep sedation patient

Documentation

Appropriate documentation should be

completed following every airway intervention

(strong recommendation for, level C)

Medical record

Informing the patient

Patient’s surgeon

Letter to primary care provider

Bracelets

local or national database

Education in difficult airway management

Technical skills : specific medical knowledge

: procedural ability required for

managing the airway

Non-technical skill : leadership, teamwork,

situational awareness, task management and

decision making

There is no “magic number” for competence,

weaken with time

International WS for Airway Management 2012

S

A

M

2

0

1

2

Top 6 oral presentation

R

C

A

T

2

0

1

3

Top 5 oral presentation

D

A

S

2

0

1

3

Thank You