Difficult Airway Management
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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
Current Concepts
Sir Robert Reynolds Macintosh
3 ingredients of a good anesthetic...
GOOD AIRWAY
GOOD AIRWAY
GOOD AIRWAY
Perhaps the most
fundamental principle in all
of anesthesiology
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Scope of the Problem
Local: 25k GA’s performed
- 250-75 possible unanticipated DA/DIs per yr
National: 46k ASA members
- 46k DIs per yr
- Doesn’t consider other clinical settings/nonmember care providers
International: HUGE problemIn patients undergoing GA, 1-3% incidence of
unanticipated DA
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Prospective Study All major airway events
over a 1yr period Anesthesia, ICU, ED
Important insights regarding airway management
complications
Elective ASA I-II, <60 Obese ENT Obstructive lesions
Case Types
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Deficiencies in airway assessment Underutilization of awake intubation Inappropriate use of SGA Poor planing
Outcomes
Most frequent cause of anesthesia-related mortality 56% SGA complications
Aspiration
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Extrinsic Factors: Clinician
features commonly included judgement & training
personal + institutional preparedness
Intrinsic Factors: Patient
features contributed to >75% anesthetic events
Increasing use of capnography is
the single change with the greatest
potential to prevent deaths
INTEGRATION
Mallampati score Neck circumference Thyromental distance
Neck ROM
Critical in deciding best approach
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Prediction of Difficult Tracheal Intubation Time for a Paradigm Change
Langeron O, MD, PhD, Cuvillon P, MD, Ibanez-Esteve C, MD, Lenfant F, MD, PhD, Riou B, MD, PhD, LeManach Y, MD, PhD Anesthesiology 2012; 117:1123-33
Gray Zone
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Important to assess risk of DI beyond a dichotomous approach
Patients should be identified as low, intermediate, & high risk
Implement an airway management strategy accordingly
Difficult Airway
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Endoscopy
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Ultrasoundi-CAT™
Award-Winning Cone Beam 3D Imaging System
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Anticipated Difficult Airway
ASA Awake intubation: non-invasive (e.g. fiberoptics) vs. invasive access (e.g. cricothyroidotomy)
Canada No recommendations
France Awake technique (fiberoptic intubation, transtracheal oxygenation, retrograde intubation or tracheostomy)
UK (DAS) No recommendations
Italy (SIAARTI)
Awake intubation in severe cases (expert decision): fiberoptic or retrograde intubation; general anaesthesia in borderline cases
Germany (DGAI)
Maintenance of spontaneous breathing, awake technique: (fiberoptic intubation, LMA, tracheostomy)
Heidegger T, Gerig HJ. Best Pract Res Clin Anaesthesiol 2005; 19:661-741
Indications for Awake Intubation
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‣ Previous DI ‣ Anticipated DA𝘈
- Prominent protruding teeth - Small mouth opening - Narrow mandible - Micrognathia - Macroglossia - Short muscular neck - Very long neck - Limited neck ROM - Congenital airway anomalies - Obesity - Pathology involving airway - Malignancy involving airway - Upper airway obstruction
Benumof JL: Airway Management Principles & Practice. 1996; 9:161
Indications for Awake Intubation
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‣ Trauma: - Face - Upper airway - Cervical spine
‣ Anticipated difficult BMV
‣ Severe risk of aspiration
‣ Respiratory failure
‣ Severe hemodynamic instability
Benumof JL: Airway Management Principles & Practice. 1996; 9:161
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Marco Brunori
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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.
Anesthesiology 2013 118:251-70.
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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
53,04 BMV attempts (2004-08)
77 Impossible BMV (0.15%) Inability to exchange air during BMV attempts, despite multiple providers, airway adjustments, or NMB
Independent Predictors M: mask seal O: mouth opening (III or IV) A: adult male N: neck radiation S: history of snoring
>3 risk factors markedly increase risk for IMV
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Prediction & Outcomes: Impossible Mask Ventilation Review of 50,000 Anesthetics
Sachin K, MD, MBA et al. Anesthesiology 2009; 110
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Impossible Mask Ventilation
Difficult Intubation
4x
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Simpler method for CPR??
ABC
!
CAB
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Cardiac-only resuscitation & minimizing delays or interruptions in chest compressions increase survival
Exception: infants/children where cardiorespiratory arrest is usually secondary to hypoxia
Endotracheal intubation remains the gold standard for securing the airway
Against the routine use of cricoid pressure as part of airway management
Continous waveform capnography for confirmation of ETT placement
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Recommendations for Continuous Capnography
‣All patients undergoing advanced life support
‣Undergoing or recovering from moderate or deep sedation
‣ In all anesthetized patients, regardless of the airway device used
‣All patients whose trachea is intubated, regardless of patient location
http://www.aagbi.org/sites/default/files May, 2011
Failed laryngoscopy: 0.04-0.07%
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Marco Brunori
Difficult laryngoscopy: 1.5-13%
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Marco Brunori
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
In current anesthetic practice, there are a myriad of devices & techniques to ensure
that the airway is patent.
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1988-1998 Decade of SGA
Anesth Analg 2010;110:Cover
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2001-2011 Decade of Video Laryngoscopy
Anesth Analg 2010;110:Cover
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Original Research Telemedicine & Telepresence for Prehospital & Remote Hospital Tracheal Intubation Using a GlideScope™ Videolaryngoscope: A Model for Tele-Intubation
Sakles JC, MD, FACEP, Mosler J, MD, Hadeed G, MPH, Hudson M, MD, Valenzuela T, MD, Latifi R, MD, FACSTelemedicine & e-Health, April 2011
Intubation bot lets doctors safely shove tubes down unconscious human throats By Michael Gorman, Apr 16th 2011http://www.engadget.com/2011/04/16/intubation-bot-lets-doctors-safely-shove-tubes-down-unconscious/
!!!
Dr. Thomas M. Hemmerling from McGill University
Health Centre has created the world’s first intubation
robot, called the Kepler Intubation System (KIS), a robotic arm with a video
laryngoscope that’s controlled via a joystick.
!!
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Shikani Optical Stylet
Levitan FPS
Scope
Foley Airway Styler
Air-Vu
Pocket Scope
Video Airway System
FIBEROPTIC LIGHTED STYLETS
SHIKANI FAMILY
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Bonfils Intubation Fiberscope™ ‣ Rigid FOB stylet
‣ Fixed shape w/ 400 curve
‣ Movable eye-piece, adapter
‣ Battery or FOB light source
‣ Portable, rugged
‣ Retromolar or transmolar route - w/ and w/out laryngoscopy
‣ Adult & pedi sizes
Sensa Scope®
- Rigid S-shaped endoscope - Stererable tip
- Built-in camera & LED light source - Connects to a video monitor to all full screen image - Miniaturized CMOS chip allows for high image quality
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Hybrid Scopes
Video Rifl Scope™ - Rigid video styler
- Articulating tip 1350 - Powered solely by lithium CR-123 batteries - LCD screen that rotates 1800 - Miniaturized CMOS chip allows for high image quality
Olympus MAF™
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Battery-driven fiber videoscope incorporating video camera, light source, & recording unit
Still images & movies can be recorded to a memory chip
Camera body can rotate either side by 900
LCD panel can tilt 0-1200
2.6 mm working chanel
AMBU® aSCOPE™
Sterile & single-use flexible fiberoptic scope
- 5.3 mm (>6.0 ETT) - 63 cm length
New camera technology
Lightweight, ergonomic handle
Reusable screen, Ambu aScope™ monitor
Always available, no cleaning & repairs, no cross contamination
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aSCOPE™
Flex Intubation Video Endoscope
CMOS distal chip
5.5 mm (w) x 65 cm (l) (6.5 mm ETT)
2.3 mm working channel
Deflection 1400 Integrated LED light source
“Satin Sheath” requires no lubrication
Highly portable w/ battery & AC
Video & still images Compatible w/ C-MAC monitor &
C-HUB
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5 Scope Nasal Intubation
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Difficult Mask Ventilation Can’t Intubate, Can’t Ventilate
ASALMA, help, transtracheal catheterization, surgical cricothyroidotomy Anesthesiology
2003; 98:1261-68
Canada1 intubation attempt, LMA, Combitube, awakening, transtracheal airway Can J Anaesth
1998; 45:757-76
FranceLMA, transtracheal catheterization, surgical cricothyroidotomy Ann Fr Réanim
1996; 15:207-14
UK (DAS)Help, LMA, transtracheal catheterization, surgical cricothyroidotomy Anaesthesia
2004; 59:675-94
Italy (SIAARTI)
Oxygenation; LMA or Combitube; transtracheal catheterization or surgical cricothyroidotomy Minerva Anestesiol
1998; 64:361-73
Germany (DGAI)
Oxygenation; LMA or Combitube; transtracheal catheterization or surgical cricothyroidotomy Anaesth Intensiv
2004; 5:302-6
Heidegger T, Switz , Vergleich - unerwartet schwieriger Atemweg
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AHA Guidelines
!
!
ERC/ITLS Guidelines
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EZ Tube
LTS-D
i-Gel
LMA Supreme
Air-Q
Newer Generation SLA’s
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Gastro-LT™
Designed for obtaining & maintaining airway patency during procedures in which gastric access is desired
Deep sedation or general anesthesia
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Baska Mask
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Single-use, silicone cuffless device
Built-in bite block
Anterior strap to aid placement
Two drain tubes (active suction, drainage)
TulipSingle-use, PVC
Similar to COPA
Depth markings for depth insertion
Green (small) Orange (medium) Red (large)
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Considerations Using SGA as Conduit for Intubation
‣ Type of device - Simple SGA vs Intubating SGA
‣ Difficult airway scenario - Predicted vs Unpredicted - Elective vs Emergent
‣ Technique - Awake vs Asleep - Blind +/- Bougie - FOB +/- Aintree exchange catheter
‣ Exchange or leave in place
‣ Equipment cost & availability
‣ Polyethylene, 1cm markings
‣ 19 Fr, 56 cm, straight distal tip
‣ Hollow, allows FOB passage (4mm scope; distal 3mm free)
‣ 3 distal ports & luer-lock connector for jet ventilation
‣ Used for exchange of SGAs
‣ Limitations of LMA - Length, narrowness, aperture bars
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Aintree Airway Exchange Catheter
POCKET Bougie™
‣ 14 Fr (4.7 mm) solid intubation guide
‣ Balanced rigidity, flexibility, & memory w/ no metal core
‣ Double-sided depth markings
‣ Tactiglide technology
‣ Designed to fit into a pocket
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Difficult Airway Society Pediatric Difficult Airway Guidelines
‣ Target audience is non-specialists - Wish to learn or maintain pediatric
airway skills - Rehearse unexpected difficult
airway scenarios - Teach good practice
‣ Developed 3 separate algorithms, 1-8 yo - DMV after routine induction - Unanticipated DTI as above - CICV after paralysis
‣ Grade I evidence minimal
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Failure to manage the airway continues to be among the leading anesthesia-related causes of
adverse outcomes in obstetrics
“Often we speak of the safety of modern anesthesiology; it is safe because of the
committment to learn from previous errors,
to discover new techniques &
equipment, and to perform at the
highest possible level each and every day”
ASA DA 1993
ASA DA
2003
Miller Blade 1941
Macintosh Blade 1943
Gum Elastic Bougie 1949
Lighted Stylet 1958
Retrograde Intubation 1960
First SGA 1981
FOB Intubation 1972
Bullard 1989
TTJV 1971
Cricothyrotomy comeback
1976
Bonfils 1983
UpsherScope 1996
Shikani 1996
Glidescope 2003
McGrath 2005
WuScope 1994
DCI Video 2002
Sensascope 2007
�54History of Airway Techniques
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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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Site Inferior CTM
Methods Needle
Percutaneous Surgical
Equipment Scalpel Tube Finger
curved blunt dilator
tracheal hook
trousseau tracheal dilator
Cricothyrotomy Final CVCI Option
Cricothyrotomy may be necessary to secure
the airway !
<50% of anesthesiologists felt
competent to perform
Difficult Airway Management: Practice Patterns Among Anesthesiologists Practicing in the United States Have We Made Any Progress?
Ezri T, MD, Szmuk P, MD, Warters RD, MD, Katz J, MD, Hagberg C, MD
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‣ Needle cric rescue technique of choice
!‣ Often unsuccessful
- Barotrauma - BD - Death
!‣ Practitioner must be experienced.
Institute early!!
Trauma
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‣ Bag-mask ventilation during RSI
‣ Cricoid pressure
‣Manual in-line immobilization
‣ ASA Difficult Airway Guidelines
‣ Role of anesthesiologist
Final CVCI option in airway algorithms
Methods include needle, percutaneous, and surgical
Perform in inferior portion CTM
Universal cricothyrotomy catheter set
Studies are lacking Movement of the neck during cric
Ease of cric with MILS
Neurological deterioration after cric
Curved blunt dilator
Tracheal hook
Trousseau tracheal dilator
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Summary‣ Algorithms only serve as guidelines
‣ Be cognizant of predictors of the DA
‣ Equipment must be available
‣ Acquire & maintain advanced airway management skills
‣ Do what works best for you
‣ You CAN make a difference!!
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Aphorisms
Practice is the best of all instructors.
The better you are, the luckier you become.
We live a life of choice, not chance.
ASA NEWSLETTER Abouleish EI. Moments With The Pen. <www.momentswiththepen.com>
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BVM Ventilation Prior to Intubation
Difficult to achieve adequate preoxygenation
High risk of arterial desaturation
Pre-existing conditions - Obesity - Lung injury - Altered LOC - Combativeness
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Cricoid Pressure
Removed as a Level I recommendation
May worsen laryngoscopic view
Impair bag-valve mask (BVM/ventilation)
Not reduce incidence of aspiration
Recommendation: Apply throughout induction and intubation attempts if
necessary, alter/remove to ease intubation or SGA insertion.
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Cervical Spine Manual In-Line Stabilization (MILS)
Inferior view/longer time or failure to secure airway
Recommended by ATLS guidelines
No outcome data demonstrating inferior
Benefits should be balanced against potential for hypoxic
damage
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Video Laryngoscopy
Does VL reduce cervical motion compared to DL in
patients w/ known or suspected CSI?
!
Is there improved intubation success rate in the trauma
patient?
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!‣ Common problems
- Hemodynamic instability - Time pressure - Lack of patient cooperation - Risk of aspiration - Need for cervical spine protection - Facial injuries - Limited options (can’t wake up/
cancel case) !!
Airway Management Controversies Trauma Care
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Good decisions
come from experience
Unfortunatelyexperience often comes
from bad decisions