1 The Difficult Airway: What to do when @*% hits the fan!! Adam Davidson Grand Rounds March 19 th, 2009

The Difficult Airway: What to do when @*%% hits the fan!!

Adam Davidson

Grand Rounds

March 19th, 2009

2

The Reality

3-5% of academic ED intubations involve more than 3 attempts and of those, 80% are intubated with standard laryngoscopy1

Success rates approaching 99% with RSI and direct laryngoscopy1

7 out of 6000 cases were intubated with alternative methods to direct laryngoscopy in a 20 center study2

1. Levitan R. Myths and Realities: The “Difficult Airway” and Alternative Airways in the Emergency Setting. Acad EM, 2001; 8:8, 829

2. Walls RM, et al. 6,294 emergency department intubations: second report of the ongoing National Emergency Airway Registry (NEAR) II study. Ann Emerg Med. 2000; 36(4, part 2)

3

EM physicians are airway experts and direct laryngoscopy is very reliable…But what if things aren’t as straight forward??

4

Direct Laryngoscopy

There are multiple variations and adjuncts to help with direct laryngoscopy

These include the Macintosh blade, the Miller blade, the McCoy blade, and the bougie

These have been around longer and most people are familiar with their use

This talk will focus on alternatives to direct laryngoscopy further down the difficult airway algorithms

5

Objectives

Review the anticipated and unanticipated difficult airway algorithms

Present alternatives to direct laryngoscopy Review manual in-line stabilization Review case scenarios and present options

for managing airway difficulties Glidescope Demo (Maybe)

6

July 1st 2008, Level 1 Trauma: EMS unable to intubate!

7

July 30th, 2008 - EMS Patch: Can’t intubate and can’t ventilate!

8

The Anticipated Difficult Airway

Walls, R. Manual of Emergency Airway Management. 2nd Ed, 2004

Difficult Bag-Mask (MOANS)

Mask Seal (beard, nose, etc)

Obese/Obstruction

Age >55

No teeth

Stiff (asthma, COPD)

Difficult Intubation (LEMON)

Look externally-gestalt

Evaluate 3-3-2

Mallampati

Obstruction- stridor, drooling

Neck Mobility

9

The Unanticipated or Failed Airway

Walls, R. Manual of Emergency Airway Management. 2nd Ed, 2004

10

Glidescope

11

Video Laryngoscopy (Glidescope)

Similar shape to laryngoscope blade Exagerated curve designed to wrap around tongue,

not displace into submental space Does not require anterior lift/pressure to bring glottis

into view Accompanying rigid stylet increases ETT

manouverability Camera protected in housing with anti-fog heating Overall glidescope success rates: 99.96%3

3 Cooper RM, et al. Early clinical experience with a new videolaryngoscope in 728 patients. Can J Anesth. 2005; 52: 191-8.

12

Summarizing the Data

“Can we recommend any of these devices? Most data contains flaws, most data comes from normal patients who are rarely difficult to intubate and much of the data is heterogeneous. Accepting these limitations, the devices with robust data that performed best were the Bonfils and Ctrach in normal patients, and the Bonfils, CTrach and Glidescope in ‘difficult’ patients. Before drawing conclusions on device performance from the ‘difficult’ patient groups it is important to note the small numbers of patients studied, for each device. There is very limited and inadequate comparative data between devices and compared to the standard Macintosh laryngoscope.”

13

Glidescope vs DL with neck imobility Ankylosing Spondylitis: 60% had C+L grade 3

or 4 airways, improved to 1 or 2 in 85%4

Another study of AS patients showed 93% of patients had C+L grade improved by 1 or more5

Manual In-Line Stabilization (MILS): Glidescope: 50% Grade 1, 50% grade 2

DL: 65% Grade 2, 35% Grade 3 (without BURP)6

4 Lai HY, et al. The use of the Glidescope for tracheal intubation in patients with ankylosing spondylitis. B J Anesth. 2006; 97:3, 419.5 Argo F, et al. Tracheal intubation using a Macintosh laryngoscope or a Glidescope in 15 patients with cervical spine immobilization. B J Anesth. 2001; 93: 705.6 Huang WT, et al. Clinical comparisons between GlideScope video laryngoscope and Trachlight in simulated cervical spine instability. J Clin Anesth. 2007; 19(2):110-4

14

Cormack + Lehane Grades

15

Other difficult airways

Anesthesia staff/residents performing elective nasotracheal intubation: C+L G1- 94% vs 66%, with time of 23.3sec vs 43 sec and less sore throat7

2 studies on obese patients w /BMI>408,9

Device used was Airtrach videolaryngoscope 318 pts: Time: 29s vs 109s, Grades: 100/6/0/0

vs 54/36/16/0. More desats + blind attempts 108 pts: Time: 24 sec vs 56 sec, 1 vs 9 desats

below 92%7 Jones PM, et al. A comparison of Glidescope videolaryngoscopy to direct laryngoscopy for nasotracheal intubation. Anesth and Analg. 2008; 107:1, 144.8 Dhonneur G, et al. Video-assisted versus conventional tracheal intubation in morbidly obese patients. Obes Surg. 2008; Sept.9 Ndoko SK, et al. Tracheal intubation of morbidly obese patients: a randomized trial comparing performance of Macintosh and Airtraq laryngoscopes. B J Anaes. 2008; 100:2, 263.

16

C-Spine Movement

Healthy pt’s, C-spine motion from occiput to C5 measured with fluoro during intubation

No difference b/w GS and DL28

Anther compared GS, Trachlight and DL10

Movement measured with fluoro at 4 sites:occiput/C1, C1/C2, C2-C5, C5-T1

TL (%decr): 49, 72, 64, 41 (Mean 57%) GS (%decr): 0, 0, 50%, 0 Possible benefit @ C2-C5??28 Robitaille A, et al. Cervical spine motion during tracheal intubation with manual in-line stabilization: direct laryngoscopy versus Glidescope videolaryngoscopy. Anesth Analg. 2008; 106:3, 935

10 Turkstra TP, et al. Cervical spine motion: a fluoroscopic comparison during tracheal intubation with lighted stylet, Glidescope, and Macintosh laryngoscope. Anesth Analg. 2005; 101, 910-5..

17

Hemodynamics

Glidescope shown to have no advantage or disadvantage hemodynamically compared to direct laryngoscopy

No significant difference in MAP or HR6

6 Huang WT, et al. Clinical comparisons between GlideScope video laryngoscope and Trachlight in simulated cervical spine instability. J Clin Anesth. 2007; 19(2):110-4

18

Glidescope Problems

CJA study, 14 pt’s failed despite Gr1 view3

Unable to maneuver ETT into glottis Thought to be overcome with 90 degree stylet Poor visualization with blood/secretions

(better than flex scope) Needs to be sterilized b/w uses or require

disposable handles ($$$) Shown to take longer with increased apnea

and no difference in success for easy airways12

3 Cooper RM, et al. Early clinical experience with a new videolaryngoscope in 728 patients. Can J Anesth. 2005; 52

12 Lim TJ, et al. Evaluation of ease of intubation with the Glidescope or Macintosh laryngoscope by anaesthetists in simulated easy and difficult laryngoscopy. Anaesth. 2005; 60, 180. : 191-8.

19

Glidescope Conclusions

Will improve glottic view and success with most difficult airways

Useful teaching tool and easier for novices Can be used as an adjunct with other

devices: Trachlight, Bronchoscope Doesn’t appear to convey any C-spine or

hemodynamic advantages Still not first-line for anticipated easy airways

20

Other Fiberoptic Laryngoscopes

Airtrach

Bonfils

C-Trach

McGrath

21

Trachlight Flexible stylet with bright LED @ end Blind intubation technique Re-usable

22

Trachlight vs DL

Similar success rates with C+L Grades 1+213

Improved success, faster and decreased trauma with Grades 3+413

Decreased C-Spine motion compared to DL and Glidescope10

One study has shown smaller rise in HR and MAP compared to DL6

4 other studies show no difference in hemodynamics13-16

13 Davis L, et al. Lighted stylet tracheal intubation: A review. Anesth Analg. 2000; 90, 745.

14 Knight RG, et al. Arterial blood pressure and heart rate response to lighted stylet or direct laryngoscopy for endotracheal intubation. Anesthesiology. 1988; 69: 269.

15 Friedman PG, et al. A comparison of light wand and suspension laryngoscopic intubation techniques in outpatients. Anesth Analg. 1997; 85: 578.

16 Hirabayashi Y, et al. Effects of lightwand (Trachlight) compared with direct laryngoscopy on circulatory responses to tracheal intubation. B J Anaes. 1998; 81: 253.

23

Potential Advantages

Micro/retrognathia: Treacher-Collins, Pierre Robin, etc

Neck immobility: C-spine Blood/Secretions (alone/with DL/Glidescope) Traditional markers of difficult intubation don’t

appear to affect success with Trachlight Lack of mandibular protrusion, Mallampati,

C+L grade, short hyomental distance 13,17


17 Agro F, et al. Lightwand intubation using the Trachlight: a brief review of current knowledge. Can J Anesth. 2001; February: 592.

24

Disadvantages

Those with <6 attempts with both Trachlight and DL showed 67% success rate and averaged 22 sec longer with Trachlight compared with DL (94% success)18

Suggest benefits only to those with practice and regular use

Limited with grossly obese habitus and brightly lit rooms

Contraindicated with oropharyngeal tumours, infections, trauma, or presence of FB17


18 Soh CR, et al. Tracheal intubation by novice staff: the direct vision laryngoscope or the lighted stylet (Trachlight)? Emerg Med J. 2002; 19: 292.

25

Intubating LMA’s

26

Pro-Seal LMA Shown to have better seal than classic LMA11

Allows passage of OG tube to allow stomach decompression

Larger size makes it more difficult to place than classic LMA11

99% success with 2114 pt’s when a bougie is placed through OG opening and into esophagus to guide proper placement20

Excellent when “all else fails”

11 Brimacombe J, et al. A multicenter study comparing the Proseal and Classic laryngeal mask airway in anesthetized, non-paralyzed patients. Anesthesiology. 2002;96: 289.

20 Goldmann K, et al. Use of Proseal laryngeal mask airway in 2114 adult patients: a prospective study. Amb Anesthesiology. 2008; 107:6, 1856.

27

Intubating LMA’s (Classic + Fasttrach) Rescue device for failed airway

Useful adjunct for fiberoptic intubation Definitive airway can be placed blind or with

fiberoptic guidance Multiple options to place ETT: blind, fiberoptic

assist, fiberoptic placement of bougie or tube exchanger, Trachlight assist26

Can be done with patient awake21,22

21 Muraika L, et al. Fiberoptic tracheal intubatin through a laryngeal mask airway in a child with Treacher-Collins syndrome. Anesth Analg. 2003;97: 1298.

22 Asai T, et al. Awake tracheal intubation through the laryngeal mask in neonates with upper airway obstruction. Ped Anesth. 2008; 18: 77.

26 Barnett R, et al. Augmented fiberoptic intubation. Crit Care Clinics. 2000; 16:3, 453.

28

Classic LMA

Common adult sizes: 3, 4, 5 Need to have bars removed in order to pass

ETT (newer versions) #3: 6-0 tube, #4: 6.5 tube, #5: 7-0 tube19

19 http://www.geocities.com/HotSprings/Villa/2613/textpicjip.html (Aids to fiberoptic intubation) Dr. Srinivasan, Kuwait.

29

I-LMA (Fastrach)

Accomodates up to size 8-0 ETT19

Metal handle for maneuverability Comes with flexible, cuffed ETT and

stabilizing rod

19 http://www.geocities.com/HotSprings/Villa/2613/textpicjip.html (Aids to fiberoptic intubation) Dr. Srinivasan, Kuwait.

30

Youtube Video: Awake I-LMA

http://www.youtube.com/watch?v=KAskavry0jw

31

Intubating LMA’s Success rates of 100% for fiberoptic and

lightwand assisted intubations19,23

2 small studies showed blind ETT passage with I-LMA ~95%24,25

For those with predicted short course of intubation: LMA can be left in place

Prolonged LMA placement can lead to tissue ischemia, prevent NG/OG placement as well as access to possible bleeding tissue etc26

LMA will eventually need to be removed for most ER patients

24 Combes X, et al. Intubating laryngeal mask airway in morbidly obese and lean patients. Anesthesiology. 2005; 102: 1106.

25 Frappier J, et al. Airway management using the intubating laryngeal mask airway for the morbidly obese patient. Anesth Analg. 2003; 96: 1510.

32

Intubating LMA’s and Bronchoscope Fiberoptic ETT placement can be difficult or

impossible in certain situations Retro/micrognathia: posterior tongue and

anterior larynx can create angles too steep to maneuver scope26

Blood/secretions: unable to visualize larynx Fiberoptic takes time to set up. LMA allows

ventilation while preparing ETT placement


33

Retro/micrognathia

Pierre Robin

Treacher Collins

34

Intubating LMA’s and Difficult Airways Case reports: 4 patients with Treacher-

Collins and 2 with Pierre Robin Failed awake fiberoptic intubation 100% successful with first attempt at ETT

placement through I-LMA21,22

Obese pt’s (avg BMI 42 vs 23 control) Blind passage of ETT: 96% obese vs 94%24

Another study of pt’s with average BMI 45 96.3% success rate at blind ETT passage25





35

Issues/Problems w/ ILMA’s

Sellick’s increases difficulty of passing ETT23

Only small ETT’s able to pass through classic LMA’s (not ideal for long intubations)

Removing the LMA once ETT placed!! This is not a simple procedure and there is a

high risk of accidental extubation

23 Reardon R, et al. The intubating laryngeal mask airway: suggestions for use in the emergency department. Acad Emerg Med. 2001; 8:8, 833.

36

Removing the LMA Needs to be planned-out and should be done

with help of an assistant Several options for LMA removal Fasttrach comes with stabilizing rod that is

designed to hold ETT in place while LMA is withdrawn (not ventilating during procedure)

Other reports of coupling 2 ETT’s together to continue ventilation while ETT is withdrawn 21,27

Once distal part of ETT visible, have assistant hold with McGill forceps


27 Weiss M, et al. Continuous ventilation technique for laryngeal mask airway removal after fiberoptic intubation in children. Ped Anesth. 2004;14: 936.

37

Intubating LMA’s-Conclusions Rescue device for failed airways while

retaining the option for definitive airway placement

Facilitating fiberoptic intubation in difficult patients

LMA should be removed for most ER cases and this is a technical and risky process

ET tubes that fit with the Pro-Seal and Classic LMA’s are too small for prolonged intubations

38

Manual In-Line Stabilization (MILS)

39

40

MILS

Adopted in 1980’s after stabilization during transport improved spinal outcomes29

Since it’s advent there have been 10 cases of 2o injury associated with airway management29

These cases reviewed in Br J Anesthesiology in 2000 and found 1 possibly due to DL and intubation

This case had a neck hematoma, prolonged hypoxia and required an emergent cric.

29 Manoach S, et al. Manual in-line stabilization for acute airway management of suspected cervical spine injury: historical review and current questions. Annals Emerg Med. 2007;50:3, 236.

41

Does MILS work?

2 cadaveric studies of C-spine motion with total of 9 patients29

Data using MILS in live patients comes from 5 case series’ of 275 injured patients.

In this series, 120 patients had unstable but salvageable injuries. No secondary injury observed.

Were these results because of MILS or in spite of??

42

Is MILS a bad thing?

MILS worsens C+L view, increases chance of failed intubation29,30

Jaw thrust has shown to cause more segmental motion than DL29

Jaw thrust is ubiquitous in suspected C-spine injuries and no reports of 2o injury exist29

4 cadaveric studies and 1 on healthy volunteers found no difference or worsening of cervical motion with MILS.29 Why??

30 Santoni BG, et al. Manual in-line stabilization increases pressures applied by the laryngoscope blade during direct laryngoscopy and endotracheal intubation. Anesthesiology. 2009; 110: 24.

43

Each patient underwent standard DL and then laryngoscopy with MILS

Pressure averaged 2x greater with MILS Previous study done by same group showed

pressure transmitted to cranio-cervical motion 66% of patients with MILS had worse C+L

views

44

MILS Conclusions

Annals review states more research needed to come to a firm conclusion

Anesthesiology 2009 editorial by Annals authors, states lack of 2o injury in-spite, not because of MILS31

Stabilization in transport and caution during intubation likely all that’s required to prevent 2o injury

Is MILS worth a potential failed intubation??31 Manoach S, et al. Laryngoscopy force, visualization, and intubation failure in acute trauma. Anesthesiology. 2009; 110: 6-7.

45

Case 1

46

Awake Intubation OK if you have time OK if no C-spine concerns Obese pt’s can desat even with sedation for

awake intubationGlidescope can be used to help position bronchoscope tip32

Glidescope can be used to move tongue and visualize landmarks for patients with large tongue, retrognathia33

Glidescope shown to be tolerated and successful for awake intubations34

32 Xue FS, et al. Glidescope-assisted awake fiberoptic intubation: initial experience with 13 patients. Anesthesiology. 2006;61: 1007

33 Vitin AA, et al. A difficult case with Glidescope-assisted fiberoptic intubation. J Clin Anesth. 2007; 564.

34 Doyle DJ. Awake intubation using the Glidescope videolaryngoscope: initial experience in 4 cases. Can J Anesthesia. 2004; 55:5, 520.

47

Case 1: RSI

Easiest and most important maneuver to maximize success????

POSITION!!!

48

Troop Pillow

Available in the OR’s of all 3 hospitals.

Or could just use lot’s of blankets!!

49

Case 1: Rescue or Adjunct

Glidescope works well Intubating LMA shown to be highly

successful with obese patients Allows ventilation while definitive airway

placed Trachlight not a good option in obese

patients

50

Case 2

51

Retro/Micrognathia Direct laryngoscopy difficult because no place

to displace tongue Fiberoptic intubation difficult because of

posterior tongue and anterior larynx33

Glidescope doesn’t require displacement of tongue

Options: Glidescope, Glidescope combination with bronchoscope or lighted stylet35****

Intubating LMA as a rescue device or to facilitate fiberoptic intubation


35 Leissner KB, et al. Intubation with simultaneous use of the Glidescope and the Trachlight. J Anesth. 2008; 22: 328.

52

Case 3: Bleeding

53

Case 3:

Suction, suction, suction Yonkers are your friend Direct Laryngoscopy: push on chest and aim

for bubble Trachlight: excellent light transmission

through blood/secretions17,35

Can use in combo with DL, Glidescope35

Intubating LMA with trachlight for rescue



54

Thank You!!

55

References1. Levitan R. Myths and Realities: The “Difficult Airway” and

Alternative Airways in the Emergency Setting. Acad EM, 2001; 8:8, 829

2. Walls RM, et al. 6,294 emergency department intubations: second report of the ongoing National Emergency Airway Registry (NEAR) II study. Ann Emerg Med. 2000; 36(4, part 2)

3. Cooper RM, et al. Early clinical experience with a new videolaryngoscope in 728 patients. Can J Anesth. 2005; 52: 191-8.

4. Lai HY, et al. The use of the Glidescope for tracheal intubation in patients with ankylosing spondylitis. B J Anesth. 2006; 97:3, 419.

5. Argo F, et al. Tracheal intubation using a Macintosh laryngoscope or a Glidescope in 15 patients with cervical spine immobilization. B J Anesth. 2001; 93: 705.

6. Huang WT, et al. Clinical comparisons between GlideScope video laryngoscope and Trachlight in simulated cervical spine instability. J Clin Anesth. 2007; 19(2):110-4

7. Jones PM, et al. A comparison of Glidescope videolaryngoscopy to direct laryngoscopy for nasotracheal intubation. Anesth and Analg. 2008; 107:1, 144.

8. Dhonneur G, et al. Video-assisted versus conventional tracheal intubation in morbidly obese patients. Obes Surg. 2008; Sept.

9. Ndoko SK, et al. Tracheal intubation of morbidly obese patients: a randomized trial comparing performance of Macintosh and Airtraq laryngoscopes. B J Anaes. 2008; 100:2, 263.

10. Turkstra TP, et al. Cervical spine motion: a fluoroscopic comparison during tracheal intubation with lighted stylet, Glidescope, and Macintosh laryngoscope. Anesth Analg. 2005; 101, 910-5.

11 Brimacombe J, et al. A multicenter study comparing the Proseal and Classic laryngeal mask airway in anesthetized, non-paralyzed patients. Anesthesiology. 2002;96: 289.

12 Lim TJ, et al. Evaluation of ease of intubation with the Glidescope or Macintosh laryngoscope by anaesthetists in simulated easy and difficult laryngoscopy. Anaesth. 2005; 60, 180.


14 Knight RG, et al. Arterial blood pressure and heart rate response to lighted stylet or direct laryngoscopy for endotracheal intubation. Anesthesiology. 1988; 69: 269.

15 Friedman PG, et al. A comparison of light wand and suspension laryngoscopic intubation techniques in outpatients. Anesth Analg. 1997; 85: 578.

16 Hirabayashi Y, et al. Effects of lightwand (Trachlight) compared with direct laryngoscopy on circulatory responses to tracheal intubation. B J Anaes. 1998; 81: 253.


18 Soh CR, et al. Tracheal intubation by novice staff: the direct vision laryngoscope or the lighted stylet (Trachlight)? Emerg Med J. 2002; 19: 292.

19http://www.geocities.com/HotSprings/Villa/2613/textpicjip.html (Aids to fiberoptic intubation) Dr. Srinivasan, Kuwait.

20 Goldmann K, et al. Use of Proseal laryngeal mask airway in 2114 adult patients: a prospective study. Amb Anesthesiology. 2008; 107:6, 1856.

56

References21 Muraika L, et al. Fiberoptic tracheal intubatin through a

laryngeal mask airway in a child with Treacher-Collins syndrome. Anesth Analg. 2003;97: 1298.


23 Reardon R, et al. The intubating laryngeal mask airway: suggestions for use in the emergency department. Acad Emerg Med. 2001; 8:8, 833.




27 Weiss M, et al. Continuous ventilation technique for laryngeal mask airway removal after fiberoptic intubation in children. Ped Anesth. 2004;14: 936.

28 Robitaille A, et al. Cervical spine motion during tracheal intubation with manual in-line stabilization: direct laryngoscopy versus Glidescope videolaryngoscopy. Anesth Analg. 2008; 106:3, 935.

29 Manoach S, et al. Manual in-line stabilization for acute airway management of suspected cervical spine injury: historical review and current questions. Annals Emerg Med. 2007;50:3, 236.

30 Santoni BG, et al. Manual in-line stabilization increases pressures applied by the laryngoscope blade during direct laryngoscopy and endotracheal intubation. Anesthesiology. 2009; 110: 24.

31 Manoach S, et al. Laryngoscopy force, visualization, and intubation failure in acute trauma. Anesthesiology. 2009; 110: 6-7.

32 Xue FS, et al. Glidescope-assisted awake fiberoptic intubation: initial experience with 13 patients. Anesthesiology. 2006;61: 1007


34 Doyle DJ. Awake intubation using the Glidescope videolaryngoscope: initial experience in 4 cases. Can J Anesthesia. 2004; 55:5, 520.


Documents

1 The Difficult Airway: What to do when @*% hits the fan!! Adam Davidson Grand Rounds March 19 th, 2009