1. What equipment should be in your Difficult Airway Cart ?
Margaret Healy
CNM 2 Anaesthesia
University College Hospital
Galway
Difficult airways are an inevitable part of the delivery of anaesthesia in both the Operating Theatre, the ICU and the emergency department. Difficulties both anticipated and surprising can make endotracheal intubation challenging and, sometimes, nearly impossible. Failure to achieve or restore a patent airway can lead, in a matter of minutes, to hypoxic neurological injury and death . As with many conditions, the keys to success in a moment of crisis are forethought and preparation. To achieve this we all need to be familiar with the Difficult Airway Society guidelines and with the devices available in the Difficult Airway Cart. Having a dedicated Diff Airway Cart takes a lot of the drama out of this emergency scenario

2. What is a “Difficult Airway”?
The difficult airway is defined as the clinical situation in which a conventionally trained anaesthetist experiences difficulty with mask ventilation, difficulty with tracheal intubation, or both
We have discussed difficult airways in detail this morning and I will briefly remind you of how we define a diff airway

3. The Difficult Airway Society has developed guidelines in the management of difficult airways. These are available to download and it is recommended that you laminate it and attach to cart. DAS are aware that their guidelines need to be updated as more elaborate devices have come on stream.

4. Difficult Airway Society recommendations
Practitioners should be competent in a number of core airway skills.
Work in an appropriate environment (trained assistance, with access to a range of airway devices and techniques, appropriate monitoring during surgery and facilities for the appropriate level of post op care)
That equipment is stocked in dedicated trolleys. These should be regularly checked and stocked. The exact number and location of each trolley should be determined locally
All anaesthetists and anaesthetic assistants should be familiar with the contents and location of the trolley
Training should be provided in the use of equipment selected by each department
There should be a Consultant Airway Coordinator in each department, a training room and dedicated lists for airway training
Just going through the DAS recommendations a few points were very pertinent

5. CORE SKILLS LMA for ventilation
FOI through LMA, Aintree or other airway
ILMA
Indirect laryngoscopes Glidescope, Airtraq etc
Emergency cricothyrotomy
Every anaesthetist and assistant should be very familiar with these core skills to deal with a difficult airway scenario

6. Difficult Airway Trolley
A shelf and 5 Drawers that follow sequence of Difficult Airway Algorithm
Mobile
Robust
Clearly labelled
Easily cleaned
Attach DAS algorithms
Restocking list
An adequately stocked Difficult Airway Cart, that can be quickly wheeled in is an absolute must!
The dedicated trolley must be mobile, robust ,contain everything you may need to manage various difficult airway situations and it must be capable of facilitating fibreoptic bronchoscopy. Also, don’t forget it needs to pass the standards of Infection Control Manager!!

7. Recommended equipment for management of unanticipated difficult intubation
DAS guidelines algorithm flowcharts
Equipment list for restocking
At least one alternative blade(e.g. straight, McCoy)
Intubating LMA (Size 3,4,5 with dedicated tubes and pushers)
Flexible fibreoptic laryngoscope (with portable/battery light source)
Aintree Intubation Catheter
Proseal LMA / Supreme LMA
Cricothyroid cannulae with High pressure jet ventilation system (Manujet) OR
Large bore cricothyroid cannulae (e.g. Cuffed Melker) OR
Surgical Cricothyroidotomy kit

8. Miller Blades (Straight)
The Miller blades are commonly used for infants. It is easier to visualize the glottis using these blades than the Macintosh blade in infants, due to the larger size of the epiglottis relative to that of the glottis.
DAS recommend at least 1 alternative blade should be available

9. Levering Laryngoscope (McCoy)
Hinged tip which facilitates elevation of the epiglottis
Less force required to intubate
Improves view at laryngoscopy
Useful in patients wearing cervical hard collars
Inexpensive
Steep learning curve
I think we are all familiar with the McCoy blade which was invented by Dr Eamon McCoy, which is a very useful device that has got many out of trouble on many an occasion!
The 'McCoy-style' blade is based on the standard Macintosh blade. It has a hinged tip that is operated by a lever mechanism on the back of the handle. It allows elevation of the epiglottis while reducing the amount of force required. This blade has been shown to improve the view at laryngoscopy in difficult intubations and in patients wearing cervical hard collars / limited neck movement.

10. Supraglottic Devices
Supraglottic devices are the suitable alternative to endotracheal intubation, Useful when endotracheal intubation has failed
Suitable for use by those with limited experience with endotracheal intubation
Should be immediately available for every difficult airway situation
Various types available
Endotracheal intubation is cited as the optimum technique for airway management, but when this is not possible …………..

11. Fastrach (Intubating LMA)
Advanced version of the standard LMA, which allows a specifically designed ETT to be passed blindly into the trachea
Useful in “can’t intubate, can’t ventilate” scenarios
Allows fast insertion into correct position without moving patients head or neck
Can be used alone or as a guide to intubation
Facilitates ventilation between ILMA insertion and ETT insertion
Available in 3 sizes, 3, 4 & 5 with dedicated ETTs available in 6 / 6.5 / 7 / 7.5 & 8mm
This is an advanced version of the standard LMA, greatly reduces the need for manipulation of the head and neck, making the device more useful for patients in whom cervical spine injury is suspected .

12. LMA Pro-Seal
Not necessarily a Difficult Airway Device, but is useful in situation where patient has not been fasting
May be useful in failed obstetric intubation
This has an extra tube which provides excess access to stomach contents
Protects against aspiration by providing an escape for unexpected regurgitation
Drain tube prevents against gastric insufflation

13. LMA Supreme™
Quite new to the market, combines all the best features of all previous LMA except you can’t intubate through it
The SLMA is easily and rapidly inserted, providing a reliable airway and a good airway seal
Rates of failure, manipulations required and complications are very low.
Can be used when tracheal intubation fails in non-fasted patients
Can be used in CPR
Useful in “failed intubation” and the “can’t intubate-can’t ventilate” situation

14. Fibreoptic Bronchoscope

15. Fiberoptic Intubation (FBI)
The use of a flexible bronchoscope to intubate
The endotracheal tube is passed directly over the bronchoscope into the trachea
Uses: - Patients with difficult airways
- Pre-operative assessment
- Extubation assessment
Advantages:
This technique allows direct visualization of the airway
Direct confirmation of ETT placement
Can be done awake
Disadvantages:
Expensive, difficult, requires care and skill
View may be hampered by blood or secretions
Requires detailed decontamination / traceability

16. Berman Airway
Berman, an American anaesthetist , designed airways to aid blind intubation
Useful to aid oral fibreoptic intubation
Also useful as a bite block

17. Aintree Intubation Catheter
Hollow bougie which fits over a standard intubating fibrescope
Aids intubation through a dedicated airway such as a laryngeal mask
Place LMA, load Aintree onto fibrescope, pass fibrescope to the carina and slide off the aintree. Remove the fibrescope and LMA and intubate over the Aintree
Possible to ventilate via this catheter if necessary, throughout the intubation procedure

18. Surgical Techniques
A cricothyrotomy is only indicated when all other devices and techniques have failed or are not available
Final step for CICV in all airway algorithms
Quicker than a tracheotomy
Life saving
Convert to definitive airway asap
Must be provided on all carts
CICV --- CANT INTUBATE / CANT VENTILATE
Quicker because the larynx is more superficial than the trachea and more easily accessible. Less complicated
Life saving especially in patients who have massive oropharyngeal swelling caused by tumour or insect bite, profuse bleeding after facial/ neck trauma /POST OPERATIVELY, or airway obstruction caused by a foreign body.

19. Surgical Airway Technique
3 different techniques
Needle Cricothyrotomy +TTJV
(Manujet)
Large Cannulae Cricothyrotomy (Melker / Quicktrach)
Surgical Cricothyrotomy
There are several surgical approaches to airway establishment, which should be considered in this order 1. Needle Cricothyrotomy also know as Transtracheal Jet Ventilation 2. Large cannulae crocothyrotomy

20. 1.Needle Cricothyrotomy (Manujet III with Jet Ventilation Catheter)
Useful for elective or emergency TTJV
Perc puncture of cricothyroid ligament
It consists of an injector with pressure gauge and adjustable driving pressure (0-4 BAR)
Catheters available in 3 sizes Adult 13g, Child 14g and Baby 16g
In the “cant intubate, can’t ventilate” scenario a means to deliver oxygen must be available if hypoxaemia or other adverse outcomes are to be avoided. This can be accomplished quickly and easily with the Jet ventilation system. This technique is used to provide oxygenation using high pressure delivery systems. A large bore IV catheter is inserted through the cricothyroid membrane. The lungs are ventilated using a high pressure oxygen source and a regulating valve to control oxygen flow through oxygen tubing attached to the IV catheter.

21. 1.Transtracheal Jet Ventilation (TTJV)
Jet ventilation using either specialized ventilator or high pressure driven valve circuit via a catheter passed through the cricothyroid membrane
Similar technique to previous
Disadvantages
Requires high pressure gas source
May cause subcutaneous emphysema, pneumo- mediastinum, pneumothorax or other types of barotrauma
Uses:
Emergency ventilation in the can’t intubate can’t ventilate scenario

22. 2. Cricothyrotomy Catheter (Melker cuffed/ Quicktrach)
Syringe
18g Introducer Needles (5cm & 7cm)
Guidewire
Curved Dilator
Airway Catheter

23. 2. Large Cannulae Cricothyrotomy
Used for emergency airway access when conventional ETT intubation cannot be performed
Percutaneous entry ( Seldinger ) technique via cricothyroid membrane
Dilate the tract and tracheal entrance site to permit passage of the emergency airway
Cuffed catheter to protect and control airway
The indication for a surgical airway is inability to intubate the trachea in a patient who requires it and the techniques available are cricothyroidotomy or tracheostomy. Conventional wisdom states that tracheostomy is the more complex and time-consuming procedure, which should only be performed by a (experienced) surgeon.
There are several surgical approaches to airway establishment: cricothyrotomy, percutaneous transtracheal jet ventilation, and tracheostomy are those most often employed during resuscitation. Cricothyrotomy is the introduction of a cuffed tube via a surgical opening in the airway through the cricothyroid membrane. The surgical opening may be made sharply and directly using a scalpel and a tracheal dilator, or it may be made via serial dilations from a needle puncture and introduction of a guidewire using one of a variety of commercially available "cricotome" kits. There have been no clinical studies comparing the "surgical" and "cricotome" techniques, and the choice between these two options should be based on operator experience and preference. Regardless of this choice, successful cricothyrotomy requires familiarity with airway and neck anatomy and comfort with the equipment used.

24. 3.Surgical Cricothyrotomy
Requirements:
No 11 blade
Size 6 Shiley tracheostomy
( OR small ETT size )
Small artery forceps
While various ready to use sets are available commercially, they do not always fit the needs of the individual
These are the basic requirements

25. Technique: Head fully extended
longitudinal incision is made through the skin and subcutaneous fat over the thyroid and cricoid cartilages
Tissue bluntly dissected
Cricothyroid ligament is transversely incised
Tracheal tube inserted

26. Accessories
Fibreoptic Bronchoscopy accessories – suction adaptor, irrigation valve, camera head, light cable, Leak tester,
mouth guard,
Berman airway
Endoscopy masks
Airway anaesthesia – nebuliser, atomiser,
Xylocaine Spray , Xylocaine 4% topical,
Co-Phenylcaine
Battery Light Source

27. Documentation D.A.S. guidelines Set up instructions
Decontamination Instructions
Checking / Restocking List

28. Conclusion Lack of clear instructions Technology is changing quickly
Core skills are vital
Difficult Airway devices should be used in routine cases to ensure familiarity
?? Standard Difficult Airway Cart nationally
There is a lack of clear instructions of what should be on a Difficult Airway Cart. There should be a standard cart with the recommended devices, in every operating department, ICU and Emergency department. One difficulty is that technology is changing so quickly , it is difficult to keep up with it. These devices should be used in routine cases to ensure familiarity with the technique before it is attempted in an emergency situation. Indeed it is difficult to cover all scenarios and equipment in a day like today. We are trying to do so, on a small scale with our Difficult Airway workstations in the next session. If this proves successful, it may be worth doing on a larger scale in the future over 1 or 2 day training course. Indeed it may be worth looking at doing so, in association with the College of Anaesthetists and the Difficult Airway Society as this involves a real team effort. Perhaps nationally we should have a standard Difficult Airway Trolley,