Wendy Teoh at The Big Sick 2019. Full talk w video and notes at https://scanfoam.org/

1. The Un-Named
Lecture
Dr Wendy TeohDr Wendy Teoh
MBBS, FANZCA,FAMS
Private Anaesthesia Practice, Singapore
Airway Lead, Singapore Society of Anaesthesiologists, Airway Special Interest Group,.

5. Thank you for inviting me back!
teohwendy@yahoo.com
Singapore

14. What do
pussies, blow jobs and airways
have in common?

16. Uterine artery blood flow
Pre-pregnancy 10-15ml/min
Term pregnancy 700-800ml/min
Uterine artery blood flow
Pre-pregnancy 10-15ml/min
Term pregnancy 700-800ml/min

17. Greetings!Greetings!
KK Women’s & Children’s Hospital, Singapore
Worked here 2000- 2014

18. Tsunamis….

19. Earthquakes…

20. K Tan, S Chern. Progress in Obstetrics from 19-21st centuries. Perspectives from KK Hospital Singapore-
The Former World’s Largest Maternity Hospital. The Internet Journal of Gynecology & Obstetrics. 2002 Vol2 No2.

21. “Birthquake”
39,835 babies delivered in 1966
• 1975 Guiness Book of World
Records
"The largest maternity hospital in
the world is the KK Government
Maternity Hospital in Singapore.
“birthquake” of 39,835 babies
(more than 109 per day) in
1966."

23. Once upon a time…
• World’s largest obstetric hospital
1966-1976
• 1975 Guiness Book of World
Records
• But….Dwindling birth rates
15000-> 12000+ deliveries/ yr
Still tertiary referral centre for
Obstetrics + Gynaecology
• Expansion of women anaesthesia
services
at KK Hospital
• Breast, Plastic & Recon
• Ortho, ENT, Colorectal
• Acute & Chronic Pain
12,000 deliveries annually
30% nation’s babies

24. Private Hospitals –
70% deliveries in Singapore
• Mt Elizabeth Orchard Hospital
• Mt Elizabeth Novena Hospital
• Gleneagles Hospital
• Mt Alvernia Hospital
• Raffles Hospital
• Parkway East Hospital
• Thomson Medical Centre – 10k deliveries annually

25. KK Hospital
12000+ deliveries annually, 30% cesarean rate
• 8 yr audit, 28 237 CS
• our GA rate 11% (vs. UK <6% vs. USA <1%)
• average 368 per year = 1 a day!
• ample training opportunity in obstetric intubation & familiarity
with GA
• 1: 220 difficult intubation, 1:513 failed intubation
(0.5% difficult, 0.2% failed)
Teoh WH, et al. Incidence of difficult & failed intubations during obstetric general anaesthesia in a tertiary referral
centre.
British Journal of Anaesthesia 2012; 108 (suppl 2): ii212

26. Ministry of Health 2004 audit

28. GA/ RSI with cricoid pressure by skilled assistant.
First intubation attempt- is your best chance.
• Preparation for optimal laryngoscopy*
• Working suction
• Position: Head ramped/ sniffing air position.
• PreOxygenate 100% O2 (till end tidal O2 >0.9).
• ETT 7.0 ready with stylet in-situ (gum elastic bougie on standby).
• Short-handled Macintosh laryngoscope (C-MAC- Karl Storz
Videolaryngoscope).
• Specialist anaesthetist/ experienced senior in attendance.
• Adequate dose relaxant: Succinylcholine 1.5-2mg/kg.
• Cricoid pressure should be released if thought to be impairing view
of vocal cords, or impeding bag mask ventilation, or with LMA
insertion.
KKH Guideline for Managing the Obstetric Airway Under General Anaesthesia
April 2013

29. Videolaryngoscopy
Videolaryngoscopy
--Different strokes for different folks
Different strokes for different folks --

30. Disclosures
• equipment and logistics support for research
and education and to conduct airway workshops
in the ASEAN and Asia-Pacific region from
• Verathon, Karl Storz, Aircraft Medical,IDS
Medical, Ambu, Intersurgical, Pentax, Airtraq,
King Systems, LMA Pacmed, Teleflex, Smiths
Medical, VBM, Laerdal, Cook, I:E Medics, GE,
Sonosite, Bluestone.

31. Videolaryngoscopy :Videolaryngoscopy :
Different Strokes for Different FolksDifferent Strokes for Different Folks
Dr Wendy TeohDr Wendy Teoh
MBBS, FANZCA,FAMS
Private Anaesthesia Practice, Singapore
Airway Lead, Singapore Society of Anaesthesiologists, Airway Special Interest Group,.

32. alronald@tiscali.co.uk

33. Different Strokes (VL blades & techniques)…

34. …for Different Folks (people & patients)…

35. What do Blow Jobs &What do Blow Jobs &
Bleeding ParturientsBleeding Parturients
Have in Common?Have in Common?
Wendy Teoh

38. Visitor !Visitor !
KK Women’s & Children’s Hospital, Singapore

40. Teoh WH, Yeoh SB, Tan HK. Airway management of an expanding soft palate haematoma
in a parturient. Anaesthesia & Intensive Care 2013; 41(5): 680-1.

43.  An awake nasotracheal fibreoptic intubation was
chosen as the primary plan,
 with the back-up plans of C-MAC® videolaryngoscopy
and a surgical airway.
 The patient was given IV metoclopromide 10 mg and
glycopyrrolate 0.2 mg
 before transport to the operating room where a
reactive fetal heart trace was confirmed.
 She was spitting blood and increasingly anxious.
 A 15 degree left lateral tilt to prevent aortocaval
compression
 patient in the head-up position to minimise
aspiration, aid blood drainage from the mouth and
relieve airway obstruction.

44.  Ribbon gauze soaked with a nasal decongestant (Iliadin
0.05%, containing 0.5 mg oxymetazoline hydrochloride and
0.01% benzalkonium chloride as preservative per ml) was
placed in both nostrils after midazolam anxiolysis.
 The C-MAC videolaryngoscope and a wide-bore rigid
Yankauer sucker
 supplemental oxygen administered via a suction catheter
directed pharyngeally via the left nostril.
 A 6.5 mm tracheal tube (Portex®, Smiths Medical) was
soaked in warm water to enhance its malleability,
lubricated with aqueous gel and gently inserted into the
right nostril to ensure fit,
 before being mounted onto an 5.3 mm adult fibreoptic
scope (Olympus model BF Type P240).

45.  The patient was sedated with titrated boluses of
fentanyl and propofol intravenously
 and the fiberscope introduced through the right
nostril.
 The field of vision was initially obscured by
blood. Spontaneous respiration was maintained.
 After suctioning and further fibrescope
manipulation, the glottic opening was eventually
visualised and 2 ml lignocaine 2% was injected
through the working channel of the fibrescope
onto the vocal cords (spray-as-you-go
technique).
 The fibrescope was then advanced through the
vocal cords and the tube railroaded into the
trachea.

47.  The trachea was extubated and the patient
sent to the Women’s Intensive Care Unit for
observation, where she received IV
dexamethasone 4 mg every 8 hours until
discharge the next day on oral cephalexin.
 mimimal trauma can be attributed in part to
the increased vascularity of the upper airway
in pregnancy, which also made the nasal
approach for awake fibreoptic intubation all
the more problematic

48.  Our anaesthetic team have extensive institutional
experience in maternal tracheal intubations because of a
caesarean delivery rate of 11% under general anesthesia
[1].
 The incidence of failed tracheal intubations is low and
there is increasing use of videolaryngoscopy. Providers find
the C-MAC videolaryngoscope intuitive [2], as it follows
the shape of a standard Macintosh blade [3],
 but increases the intubator’s viewing angle from the usual
15 degrees to a widened 80 degrees, improving the
laryngoscopic view, especially of an anterior larynx.
 Teoh WH, Yeoh SB, Ithnin F, Sia AT. Incidence of difficult and failed intubations during
obstetric general anaesthesia in a tertiary referral centre. Br J Anaesth 2012;108(Suppl
2): ii212.
 Greenland KB, Segal R, Acott C, Edwards MJ, Teoh WH, Bradley WP. Observations on
the assessment and optimal use of videolaryngoscopes. Anaesth Intensive Care
2012;40:622-630.
 Teoh WH, Saxena S, Shah MK, Sia AT. Comparison of 3 videolaryngoscopes: the Pentax
AirwayScope, C-Mac, Glidescope versus the Macintosh laryngoscope for tracheal
intubation. Anaesthesia 2010;65:1126-1132.

49.  ENT surgeon said “ risk of rupturing the
haematoma, leading to blood tracking into the
bronchial tree.”
 Its potential use was for a VAFI (video-assisted
fibreoptic intubation) procedure and we also had
otolaryngologists present to establish a surgical
airway if needed.

50.  Awake fibreoptic intubation is often regarded the
‘gold standard’ in an anticipated difficult airway
 but few obstetric anaesthetists perform it
regularly, making them less confident with this
skill.
 This case highlights the value of obstetric
anaesthetists maintaining competency in awake
fibreoptic intubation, if not clinically, then via
airway workshops and simulation training.

51. What do Blow Jobs &What do Blow Jobs &
Bleeding ParturientsBleeding Parturients
Have in Common?!!!!Have in Common?!!!!
Literature search….

53. Blow jobs: aetiology of
soft palate trauma

55. Not entirely an Airway Management
problem..Consent issues too!

56. Chicken bone…

57. Videolaryngoscopes vs. conventional laryngoscopes:
provide glottic visualization without the need to align the oral, pharyngeal and tracheal axes.

58. VL Advantages ‘can see around corner’
Line of sight
No longer
Blind
Lens /camera here
Look around the curvature
of the tongue & bypasses
the mechanical challenges
of creating a direct line of
sight. (usually 15° only)

59. Videolaryngoscopy : improved views
Camera located in the distal third of a standard Macintosh blade.
For C-MAC= 3.5cm from tip of blade
and a magnified image is displayed on a screen.
The user’s ‘eye’ has an extended viewing angle from the standard 15º to 80ºThe user’s ‘eye’ has an extended viewing angle from the standard 15º to 80º

60. Same principle- “look around the corner”
GLIDESCOPE:
Camera 5.5cm from blade tip
Pentax AirwayScope:
Camera 3cm from blade
tip
AP Advance
McGrath series 5
King Vision

61. ASA Difficult Airway Algorithm Guidelines 2013
Feb 2013
Anesthesiology
video-assisted laryngoscopyvideo-assisted laryngoscopy
as an initial approach toas an initial approach to
intubationintubation

62. Commonest Videolaryngoscopes:
Pentax AirwayScope®
(AWS®; Tokyo, Japan)
Glidescope®(Verathon, Bothell, WA, USA)
C-Mac® (Storz, Karl Storz, Tuttlingen,
Germany)
McGrath (McGrath Series 5,
Aircraft Medical, Edinburgh, UK)
Airtraq
A.P.Advance
VennerScope

64. • MACINTOSH -like VLMACINTOSH -like VL
• Insertion technique: floor of mouth,
- use like conventional Macintosh blade
- displace tongue anterolaterally and flatten submandibular
tissues
C-MAC 3,4 blades
McGrath MAC
3,4 blades
A.P Advance
3,4 blades
AIC July 2012

65. VL Blades with anterior angulation
- Need J shaped stylet
- insert midline
ANGULATEDANGULATED VL’sVL’s
McGrath Series 5Glidescope C-MAC D blade
AIC July 2012

66. - with in-built tube-guide
- no stylet needed
Airtraq
A.P.Advance -DABblade
Pentax AWS
LMA C-trach
King Vision
CHANNELED VL’sCHANNELED VL’s
AIC July 2012

67. The different VLscopes
in difficult airways…..

69. Simulated
small mouth
opening 23 mm
and
stiff neck with
cervical collar

70. Airway experts
Randomised
10 intubations
with each
device

71. Overall succes
(max 2 attempts)

72. First attempt sucess/
max 1minute
• C-MAC™D-blade 55%,
• GlideScope™ 43%,
• McGrath Mac™ 64%,
• Airtraq™ 65%,
• A.P. Advance DAB™ 9%,
• KingVision™ 48%

73. • The kind of problems:
• unchannelled devices
• tube advancement problems 76%
• viewing problems in 24%
• channelled devices
• tube advancement problems 45%
• and viewing problems 55%;

74. • Did not study difficult airways
caused by other factors, such as
obesity. ..and no pathology..
• Possible that the performance of
videolaryngoscopes varies depending
on the type of difficult airway so that
there might not be a single perfect
videolaryngoscope,
• but instead videolaryngoscopes that
are ideal for specific airway
situations

75. In special settings/
Patient categories

76. • Cervical spine protection
– Manual in-line stabilization facilitates safe
intubation, but makes direct laryngoscopy more
difficult
– Video-laryngoscopy may or may-not reduce
cervical spine motion compared with direct
laryngoscopy, but the improvement of the
laryngeal view seems to translate into higher
intubation success rates
– Flexible fiberoptic intubation results in least
cervical motion
TRAUMATRAUMA

77. Inclusion:
abscess of the deep facial or cervical spaces
Mouth opening 1.5 – 3.5 cm
Randomised: Glidescope or Macintosh DL
Dental/ facial abcess
VL faster & more successful
Glidescope success: 100 %

78. Macintosh VL vs. Angulated VL
= The more difficult airway predictors patients have, then
Angulated VL performs relatively better

79. • “In trauma patients: Use of GlideScope
Videolaryngoscope
– Is associated with longer intubation times than direct
laryngoscopy”
– In patients with severe head injury:
• Use of GlideScope is associated with
– Longer intubation time,
– sat<80%
– Higher mortality
Trauma patients, non-expert intubators

80. High altitude glacier

81. Sun reflecting
snow/ glare
• Hypothesis: Macintosh direct laryngoscope would perform less well
than videolaryngoscopes
• under difficult environmental conditions
• (high-altitude glacier, sun-reflecting snow).

82. 20 physicians
manikins with limited cervical extension mouth opening
5 conditions: 1) in hospitals (indoors),
2) indoors at a high altitude,
3) outdoors on a glacier in sunlight without sunglasses,
4) outdoors on a glacier with sunglasses,
5) outdoors on a glacier with the physician and manikin
covered with a blanket.
Jungfrau,
3450m

83. • The following devices were compared to the Macintosh
laryngoscope,
– McGrath
– Airtraq-SP
– GlideScope
– KingVision
– C-MAC-D-Blade
– AP Advance Difficult Airway Blade
– Bonfils.
• Main outcome :first-attempt intubation success
• Secondary outcomes: intubation time, visibility on the
screen, and view of the glottis.

84. Results
• Best intubation success rates
» observed indoors, and
» on the glacier under a blanket.
• The Macintosh performed better than the videolaryngoscopes
under bright sunlight.
• We observed significant differences in the performance of devices
with built-in screens under varying conditions.
• Wearing sunglasses improved performance with some but not all
devices.
• Intubation times differed significantly between devices, regardless
of the environmental condition (P<0.01).
• Screen visibility differed significantly between conditions and
devices.

85. CONCLUSIONS- bright sunlight
• Successful intubation with videolaryngoscopes is less
likely under bright sunlight conditions.
• The Macintosh laryngoscope performs better than
videolaryngoscopes.

86. Covering the heads of both the physician and the patient with a
dark blanket sufficiently overcomes the detrimental effects of
sunlight during intubation.

87. In Summary:
Different Strokes for Different Folks
Which videolaryngoscope suits my patient?

88. Conclusions, special patient
categories:
• Trauma to the cervical spine:
– Video-laryngoscope or flexible optical laryngoscope
• ICU:
– First attempt: Macintosh-shaped videolaryngoscope
– Backup (or if there are predictors of difficult direct
laryngoscopy): Angulated video laryngoscope
• Emergency Department:
– First attempt: Macintosh-shaped video laryngoscope
– Backup: Angulated video laryngoscope
• Dental abscess with reduced mouth opening:
– If severe, or in doubt: Awake
– Otherwise angulated video-laryngoscope

89. Predictors of failure: altered neck anatomy, surgical scar, radiation changes, mass,
severe micrognathia (reduced thyromental distance, reduced cervical neck
movement), mouth opening <2.5cm

90. Predictors of failure: altered neck anatomy, surgical scar, radiation changes, mass,
severe micrognathia (reduced thyromental distance, reduced cervical neck
movement), mouth opening <2.5cm

91. Flexible Fiberoptic Intubation

92. What do
pussies, blow jobs and airways
have in common?

93. Come to the Bar
tonight!
Airway workshop
International Premier of the
Bleeding AirwayBleeding Airway