Prehospital and Retrieval Medicine – Fiberoptics on a Budget
Fibreoptic guided intubation via a laryngeal airway on a budget
– a resilient advanced technique for the emergency provider facing a potentially difficult airway
The following description is of an advanced airway technique that is readily taught and learnt by those already skilled in direct laryngoscopy and rapid sequence intubation , using affordable equipment combining two technologies : a reuseable semi-rigid fibreoptic stylet and a disposable intubating laryngeal airway. The technique offers the advantages of a staged approach to managing the potentially difficult airway or even a failed intubation scenario. The first stage, that of insertion of the laryngeal airway, establishes primary safety for the technique by enabling rapid oxygenation and ventilation. The second stage, that of fibreoptic guided stylet assisted intubation via the laryngeal airway maintains the principle of safety, by using the airway as a protected conduit for the stylet and tracheal tube and visual confirmation of correct tube placement. The stylet is simpler to learn and operate than a flexible fibreoptic or CMOS camera tip based scope.
The equipment required (the complete setup costs less than $2500 AU initially)
1. Clarus Levitan FPS semi rigid optical stylet, approximate cost $2100 AU
-sterilisable using STARRAD technique or standard endoscope cleaning protocols
-requires light source ( not included), usually a spare laryngoscope handle with light bulb
2. Mercury Medical Air-Q intubating laryngeal airway, approximate cost $12 AU ea
-disposable, in sizes 1.5 to 4.5
-newer Air-Q intubating laryngeal airway with oesophageal blocker tip , allowing occlusion and drainage of oesophagus. Approx cost $22 AU ea
3. Endotracheal tube
preferably a Fastrach intubating laryngeal mask tracheal tube, approximate cost $70 ea, disposable
-Fastrach ILMA tracheal tubes specially designed to not kink when passed at acute angle using wire reinforcement. Very flexible ETT, not stiff at all, so requires a stylet or an airway conduit to enable intubation.
– atraumatic silicone soft tip
Image of Levitan FPS stylet mounted on a standard laryngoscope with light bulb and a disposable 7.0 ETT specially designed for the Fastrach ILMA ( note white soft silicone tip and wire reinforced shaft)
Image of 4.5 Air-Q intubating laryngeal airway inserted into a TruCorps airway mannikin
Image of assembled stylet with loaded ETT. Note ETT proximal connector has been removed to make ETT correct length for loading onto stylet. The stylet needs to be bent into a S shaped curve as pictured. This is quite safe to do without damaging the device.
Image of tip of Levitan FPS stylet just emerging from tip of ETT. Note the wire reinforcing of the specially designed ETT
Image of insertion of stylet with loaded ETT into the Air-Q. The use of a water based lubricant is optional to apply on outside surface of ETT. Using the 7.0 special ETT shown there was no need for lubrication for insertion and removal of stylet or Air-Q in this mannikin setup.
Image of completed insertion of device. Note a short length of exposed ETT is required to enable reinsertion of proximal ETT connector and attachment to a bag-valve manual resuscitator or ventilator circuit. Once the ETT tip is visually confirmed to have passed the vocal cords, the stylet is removed carefully with one hand gripping the ETT proximal end to securely hold it in place. The ETT proximal connector can now be reattached and end tidal capnography be used to reconfirm tracheal position. At this stage after successful tracheal intubation via the Air-Q, my advice is to leave all airway devices in situ and avoid attempts to remove the laryngeal airway over the ETT, in the emergency airway scenario. The only advantage this might offer is to allow placement of a gastric drainage catheter. With the newer Air-Q airway which has an inflatable oesophageal blocker balloon tip, gastric drainage port and channel, there is simply no need to remove the airway once intubation as occurred. With the first generation Air-Q if you really must place a gastric drain then you can deflate the Air-Q bowl and withdraw the device out of the mouth to a small degree, all with leaving the ETT still in place. This should allow you to insert an orogastric drain and then still leave the Air-Q in place. For transport of the patient, one should secure the device with at least two ties. One tie should secure the proximal end of the ETT to the proximal shaft of the Air-Q, so the two devices are fixed as one to prevent dislodgement of the ETT within the Air-Q. The second tie should secure the Air-Q to the patient’s head by placing a knot around the shaft of the Air Q as close to the patient’s lips as possible then looping the tie around the patient’s neck in the standard manner of securing LMAs or ETTs. Whilst this sounds like a complicated process and one might regard removing the Air-Q and leaving the ETT alone in situ as being simpler to manage, having secured two devices in situ, is in fact an even more resilient technique. For example if the ETT becomes dislodged, it can be quickly removed by cutting one tie and rescue oxygenation can occur via the Air-Q still in situ, secured by its second tie. It remains as the same conduit in the same place for a repeat successful intubation using the stylet to redetermine the position of the laryngeal inlet again.
Image taken through the eye piece of the Levitan FPS stylet. Actual quality of fibreoptic visualisation is better but the image correctly shows the narrow field of view via the stylet.
This image demonstrates a simulated blind intubation via the Air-Q without using the stylet. Note the flat angle of the ETT as it exits the bowl of the Air-Q. This will likely lead to failure to correctly approach the laryngeal inlet, which will be sitting superior to the bowl of the Air-Q
This image demonstrates the benefit of using the stylet shaped into a S curve. The exiting angle of the ETT is now more acute and aimed in a superior direction to the bowl. This replicates the designed angle of the Fastrach ILMA that allows for a more than 95% blind successful intubation attempt within 2 tries. The advantage using the Levitan FPS stylet is that the intubation attempt is fibreoptic visually guided, emulating the benefit of flexible fibreoptic endoscope guided intubation.
This image demonstrates the limitations of using the Levitan FPS optical stylet in other laryngeal airway devices such as this Fastrach ILMA. The acute angle of the bend of the shaft of the Fastrach prevents passage of the stylet adequately.
The same situation can be seen with the LMA Supreme.
How this technique adapts to the novel concept of the Rapid Sequence Airway:
The described technique of inserting a laryngeal airway primarily then a fibreoptic guided stylet assisted tracheal intubation fits perfectly into the concept of a Rapid sequence airway, in which standard RSI drugs are used to place a supraglottic airway device, as the first stage. Then when critical hypoxia is corrected using the supraglottic device, a more controlled tracheal intubation is performed as a second stage. Usually this would mean removing the laryngeal airway device and performing traditional laryngoscopy or newer video laryngoscopy for the intubation. With the Air-Q/ Levitan FPS combination, there no longer needs to be the step in removing the supraglottic device to perform the intubation.
I have described a novel technique that addresses most of the major issues in the predicted and unpredicted difficult airway. I did not conceive this technique and I stand on the shoulder of giants in emergency airway management. Using a blended airway approach that combines technologies and concepts, the end result is a technique that is resilient, simple to learn and teach and affordable to most emergency services and even individual providers. The ability to stage your airway intervention yet remain grounded in the safety principle of primary oxygenation at all times, is analogous to the strategy to conquer Mount Everest. One does not simply do this in one single attempt as hypoxic physiology remains a lethal complication at all times, as is the case in emergency airway management! Laying siege to the mountain and making the ascent in planned stages has always been the time tested strategy that is not only most successful but carries the least risk of death. So when you predict the airway is going to be difficult and become your own personal Mt Everest, remember this technique and hopefully you would have prepared yourself and the correct gear to make the outcome safe and successful!