it's 3:00 a.m. and your patient needs an awake intubation what's your plan to anesti the airway there are a lot of choices out there but if you need the job done well and rapidly you need to consider nerve blocks of the airway and in this video we'll take you through a simple step-by-step method to get complete Airway anesthesia in less than 5 [Music] minutes it's super satisfying to pass the tube into the trachea with a patient wide awake and completely numb and at the end end of this video we'll show you an example of just that but I've seen my share of awake Airways that were a painful struggle with gagging coughing and multiple failed attempts why is it so hard sometimes well for starters the airway is richly inovated and inherently hard to anesthetize you also need to block at least six nerves to get complete Airway anesthesia which can be technically challenging and finally putting local anesthetics directly on the airway mucosa sounds good but it's often flawed in practice especially when the patient has secretions that block the absorption the airway is interated by three principal nerves the aptly named glossop farang nerve inates the tongue or glossus and the fenal walls it also takes care of the posterior third of the tongue the vallecula and the anterior surface of the epiglottis this is the nerve responsible for the gag reflex which can make or break your awake intubation remember this yeah that's our friend glosser andal the superior lingal nerve is a branch of the Vagas and inates the inlet to the larynx which includes the posterior surface of the epig glotus the area epiglottic Folds and the upper surface of the cords themselves the nerve runs along the thyrohyoid membrane and then divides the internal Branch punctures the membrane to inovate the airway while the external Branch continues on as a motor Branch to the cryo thyroid muscle and then we have the recurrent lenial nerve another vagus branch that inates the airway at and below the cords the pallet is inovated by the maxillary branch of the trigeminal but it's not all that clinically relevant for our purposes note that the cords themselves are coiner by both the superior and recurrent lenial nerves okay that's the Anatomy now how do we block it if we took a poll we'd probably find dozens of technique combinations do we use an atomizer or should I make the patient gargle with viscous lidocaine I find a lot of trainees get confused with a surplus of choices now what if I told you there was one way that was reliable safe and super slick that you could use in 96% of awake Airways and I know some might stop me here and say well why not just crank up some Remy and Dex and mazam and give just a little bit of propop fall and we can overcome those PES Airway reflexes well sedation can be a useful adjunct but there are two drawbacks first patient cooperation is critical for these procedures and more importantly if you over sedate you turn a potentially bad Airway into an emergent and actual bad Airway the secret to awake intubation is complete Airway anesthesia let the local anesthetic do the work so back to our three sets of nerves for each of these I'm going to suggest a plan a block that gets the job done for you when it counts to to do all three you'll need the following a 22 gauge spinal needle four 3M syringes 1 10 mil syringe 25 or 23 gauge needles 20 Ms of 2% Lane a tongue depressor a syringe for skin local and prep gauze and gloves we'll do the glosser and gal nerve first the glossop and gal okay I'm just going to call it the GP nerve from now on gives three main branches but importantly runs submucosal by the tonsil pillars we're going to take 3 MLS of 2% Lane and administer that submucosal using a 22 gauge spinal needle to get there you need to retract the tongue to the side this can be done with a tongue depressor or you can use a lingos scope with a Mac 3 blade which has the added advantage of shining a light right on the target as you retract the tongue you'll see the anterior and posterior tonsler pillars with a Palatine tonsil in between anatomically the ideal place to inject the local is the coddle aspect of the posterior tonsil pillar where it meets the floor of the mouth simply because that's where it's closest to the GP nerve but studies and clinical experience have shown that putting the at the base of the anterior pillar is just as effective in most patients and doesn't require as much mouth opening okay let's see this done get a view of the anterior tonsil pillar Advance the needle through the mucosa about 1 cm aspirate and inject all three Mills that's it then come out and do the other side pretty pretty quick pretty easy and pretty well tolerated now let's test this GP block mhm yep just what I thought if you aspirate blood you're probably too far lateral and in fact might be in the kateed don't inject unless you want to make your Airway really exciting pull back and aim more medial if you aspirate air you've gone through and through and are now in the ferin behind the tongue withdraw and don't be quite so aggressive Zoro next we'll move on to the superior lenial nerve block we're we're going to use a linear ultrasound probe to image the thyrohyoid membrane between the hyoid bone and the thyroid cartilage place the probe in the sagittal orientation just off the midline here we see the bright hyoid bone and the thyroid cartilage and can appreciate the membrane stretching between them the tissue just deep to that is the preepiglottic space you can't see the nerve in most cases but if you put the laline atic just deep to the membrane you'll block it here we see the needle inserted out of plane from the medial side we'll often use small puffs of saline or Lo to locate our needle tip once your tip is through the membrane you'll usually feel a pop aspirate and inject your 3 Ms of local you'll see the pre-epiglottic space fill up with local which guarantees a great block of the superior lenial nerve this technique is safe and there's not a lot of ways to go wrong the superior thyroid artery is always in the vicinity so just take care to identify and avoid it and aspirate prior to injection there's a landmark based technique where you palpate the greater Cora of the hyoid bone and then hit that bone with your needle I don't know about you but I'm not really stoked about my coroa palpation skills in a neck like this like pair vertebrals this is a high stakes real estate area you have the ability to make it an image guided block why wouldn't you after the first injection we'll do the other side and finally we get to the recurrent lenial nerve to cover the cords and the trachea the simplest way to approach this is via a trans tracheal technique a convenient location to access the proximal trachea is the CCO thyroid membrane between the thyroid and CID cartilages the technique involves advancing a needle through that membrane into the airway and injecting the local anesthetic this usually provokes coughing and that action distributes the local in the trachea and to the underside of the cords anesthetizing those structures some people like to use a small angath here we see a 22 gauge attached to a syringe partially filled with saline after identifying the cryo thyroid membrane and prepping the skin the operator advances the needle directly back with no Ang ation there's often a surprising amount of soft tissue to get through in some patients when you feel a give aspirate and the presence of air bubbles returning confirms the needle tip placement within the trachea excellent now stabilize the canula and withdraw the needle attach your syringe containing four MLS of 2% Lane aspirate one last time and inject fairly quickly we can see the jet of local splashing around inside the trachea the other technique is just to use a needle with no canula again inserting Direct ly backward the needle enters the airway with a small give the operator stabilizes aspirates air and then injects quickly I find this easier and faster than the canula method which involves an extra step and sometimes gets kinked some get worried about the sharp needle in the airway back Walling the trachea which is possible especially when the patient starts coughing however the trachea diameter is larger than we often think and with good stabilization you minimize that risk now how do we find the cryo thyroid brain you could palpate of course which might be easy but then again wait we have ultrasound right cool Airway pokus to the rescue place a linear Probe on the anterior neck below the atom zapple and Orient it in the sagittal plane you may need to be slightly off center to get the best image what you'll see is this these small dark ovals are the tracheal rings and look like pearls on a string the bright wavy line underneath is the airway mucosal interface of the anterior trachea scan cranially until you see a much larger Pearl that is oval and more superficial this is the CID cartilage then continue cranially to find the hyper aoic thyroid cartilage the cryo thyroid membrane stretches between these two cartilagenous structures note that the bright white line is not the membrane that's still the airway mucosal interface a handy method to mark this on the skin accurately is to take a blunt needle and slide it between the probe and the skin centering it over the membrane on the ultrasound screen then remove the probe and put a mark where the needle is it's helpful to anesthetize a skin first before starting you'll want to drop four MLS of Lane in a 10 mil syringe so there's plenty of room to aspirate the air back here it is one more time insert pop aspirate and inject at the end of the injection the patient starts to cough which is normal and desirable to spread the local and that takes care of all three sets of nerves tongue retraction during the glossop andal nerve block can sometimes provoke a gag in some sensitive patients when this happens I'll spray a small amount of additional lincaine directed toward the posterior tons pillar let it sit for a minute and then retry what about nasal fiberoptic intubations don't sweat it usually you can skip aesti in the nasal cavity and the NASA ferx remember patients get NG tubes all the time and they only gag when the tube hits the back of the tongue is this technique good for every awake Airway no of course not the glossop and geal block is difficult if mouth opening is limited and there may be infection or tumor that precludes putting a needle in the neck but I find for the majority this is my plan a lots of people use nebulizers gargling spray and prey or other topical methods but these all take Precious time that's fine if it's a difficult Airway for an elective operative case but not good if your patient has respiratory distress these methods are also frequently ineffective because of secretions blood or tumor preventing the local from getting to the right spot we have plenty of data showing that patients just do better with blocks than topicalization in contrast this technique is well tolerated and even in a wide awake patient with no skin local it's not uncomfortable it's also a safe dose of Lidocaine we continue to hear about cases of last during Airway topicalization some of them fatal when you're using four or 10% lidocaine things add up very fast in this very vascular tissue this technique uses 320 mg which unless you're under 60 kg is within the safe limit of 5 Megs per kig and maybe most importantly these are quick to do the whole set is done in less than 5 minutes and by done I mean ready to put a tube in a wake speaking of which let's see how our um patient did with these blocks and there's proof that these simple blocks are frequently all you need for super slick easy awake Airways