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

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

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.

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

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

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!!

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

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

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.

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 …………..

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 .

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

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  

Fibreoptic Bronchoscope

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

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

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

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.

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

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.

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

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

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.

3.Surgical Cricothyrotomy Requirements: No 11 blade Size 6 Shiley tracheostomy ( OR small ETT size 5.0-6.0) 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

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

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

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

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,