Direct Laryngoscopy May Be Dead - Just Not to Me

The Gist:  Video laryngoscopy (VL) augments patient safety and is a great tool for endotracheal intubation (ETI) but trainees should likely be comfortable with both DL and VL.  There's a solid argument for Emergency Physicians to maintain DL skills while using the capabilities proffered by VL in situations to improve training and patient safety.  (As a medical student, I recognize I have minimal experience and probably should not have an opinion on this issue but, like most things, I do).  For expert airway tips and tricks, visit Life in the Fast Lane's Own the Airway.

A couple of months back, I heard something frightening in the midst of shoulder presses at the gym - that direct laryngoscopy is dying.  On the superb Prehospital and Retrieval Medicine (PHARM) podcast, interviewee Dr. DuCanto discussed the importance of fiberoptic laryngoscopy during difficult airways.  Days later, I shuddered again, when I found that Dr. Ron Walls proclaimed DL "dead" via Twitter.  This discussion struck entirely too close to home.  

In preparation for intubation, many attendings, upon seeing my eager, young face, steer the Glidescope in my direction.  I discovered a little bit of confidence is a dangerous thing when the airway is involved; thus, I love having this tool powered up and ready.  It's perfect for airways during chest compressions/resuscitation and many difficult airways.  Like the faithful bougie, I like to have a fiberoptic device at the bedside during an ETI.  However, it seems that many physicians think one should learn to intubate solely with video laryngoscopy but in my limited experience, I have run into occasional problems where I converted from VL to DL with immediate success.  Of note, however, I wasn't taught any specific set of skills for VL.

Video laryngoscopy is superb in many ways.

• It allows more than one person to visualize the airway well.  
• This is especially valuable in training situations, allowing the trainer to give real time feedback to the trainee.  Additionally, this adds some theoretical patient protection (Although, in the age of apneic oxygenation, it probably routinely adds more trainee protection, "No, sir, that would be the gooose, try again.")  
• Safer for some difficult airways. Again, VL allows more than one individual the opportunity to visualize the airway which, in my experience (dangerous words!),  can be helpful for team problem solving.   
• Airway outsourcing (see EMCrit Wee:  I've always wanted a henchman/woman).  I think that most good Emergency Physicians have at least a third, if not fourth, hand tucked away somewhere.  Either that or they've mastered the art of preparation and adaptation for various procedures.  The following tasks can be outsourced, allowing the operator to keep their hands free/clutching the tube/bougie.   
• I have a clear disdain for cricoid pressure as it has destroyed more views of the cords than it's created for me; however, laryngeal manipulation using the VL is an excellent idea, if needed.
• Suction. Again, an assistant can direct the Yankauer to the necessary regions without getting in the way (too much, theoretically).  
• Prepass bougie/ETT.
• A combination VL/DL exists in the C-Mac device, which allows an intubator to use a VL view or DL view.  While I have no first hand experience with this device, studies such as this one in Anesthesia & Analgesia, look promising.  This study in BMC Anesthesiology demonstrates that the VL view resulted in faster visualization but actually required a greater number of attempts at ETI for success (perhaps due to operator familiarity/lack of training). 

So, why am I somewhat reticent?

• Different skill set than DL, at least to do VL correctly.  Drs. Weingart and DuCanto on EMCrit Episode 73 highlight some necessary differences to properly perform VL. 
• The individual performing ETI should focus their gaze as such:  Mouth -> Screen -> Mouth -> Screen. 
• Hold the ETT further back and rotate 15 degrees, using a rotatory motion of the thumb and forefinger
• Sometimes the VL screen gets obscured by blood, secretions, or fog.  Most airways in EM are less pristine than the ones I initially trained on in the OR.  In these cases, DL may allow for quicker ETI.  
• Passing the tube is somteimes more difficult with the Glidescope as there seems to be less space in the mouth.  Sometimes good technique can overcome this, but some studies demonstrate the ETI time isn't consistently lower in the VL group (the time to good view may be quicker, but not to cord placement).  The literature pretty consistently shows that one can achieve a technically good view in less time with VL but the time to ETI is not consistently better across studies (1,2).  
• For example, this trial showed an average time to ETI of 22.5 sec (18-29.5) with DL compared with 33 sec (27.5-35.5) with VL (Glidescope), which was statistically significant.  This may be in part due to operator familiarity, favoring DL, but I think this point is still valid.
• A meta-analysis in the Canadian Journal of Anesthesia demonstrated a statistically significant difference, favoring VL, in achieving a good view of the cords; however, there was no statistically significant difference in time to ETI between DL and VL. 
• VL is a technology/electricity dependent process.   I grew up in an area of the US where natural disasters may leave a community without electricity for a month and leave buildings/one's house in ruins.  I've spent a fair amount of time in South Asia where these situations are more like a way of life.  Many areas of the world are resource limited and may have frequent power outages and limited funds for this equipment.  
• Dr. Minh Le Cong of the superb PHARM podcast is working to mitigate these issues with the "Search for the Sub $100 Videolaryngoscope" and possibilities of using an iPhone/iPad for VL....check it out!   

(Cox's Bazaar, Bangladesh, 2010)

Take home?

Best said by Dr. Seth Trueger @MDaware on Twitter:  "VL/DL = belt + suspenders. and real time training. and supervisor midaz"  

References:

(1)NIFOROPOULOU P,

PANTAZOPOULOS

I, 

DEMESTIHA

T, 

KOUDOUNA

 E, 

XANTHOS T. 

 Video-laryngoscopes in the adult airway management: a topical review of the literature Acta Anaesthesiologica Scandinavica Volume 54, Issue 9, pages 1050–1061, October 2010 

(2)Jungbauer A, 

Schumann M, 

Brunkhorst V, 

Börgers A, 

Groeben H.

Expected difficult tracheal intubation: a prospective comparison of direct laryngoscopy and video laryngoscopy in 200 patients.  Br. J. Anaesth. (2009) 102 (4):546-550

Note:  I use Glidescope interchangeably with VL at times when talking about personal experience since it's the VL method I have the most experience with.  

The Tomahawk View - A Lifesaver in an Awake Intubation

The Gist:  Always have an airway plan and a back-up airway plan.   In emergency medicine and critical care, where the fields are vast and situations acute, reading may help one have a broader range of differentials and skills readily accessible when needed.

One afternoon at Janus General, the sound of noisy breathing permeated the air, emanating from a man grasping a nebulizer.  He was clearly working to breathe and refused to recline.  The patient was transferred from an outside hospital with no history, aside from a CT scan of the chest demonstrating a mediastinal mass with mass effect on the trachea.  Noting the patient's work of breathing, single word answers, and stridor, it was clear he needed airway support.  The entire ordeal that transpired was fascinating and thought provoking - one of those experiences that will implant a medical student with awe, fear, and love of the airway.       

What we did:

Phenylephrine to bilateral nostrils

Benzocaine spray to bilateral nostrils

Viscus lidocaine applied to curettes to bilateral nostrils

Nasal trumpet to right nostril

Aerosolized 4% lidocaine to nostrils and mouth (repeatedly)

Transferred to OR with the surgeon and chest tray nearby
Midazolam 2 mg IV

6.0 ETT to right nostril with suctioning through left nostril

Fiberoptic scope through ETT -> unable to navigate tube through cords due to mobility

Glycopyrrolate 0.2 mg IV

Lots of suction via left nostril

Glidescope inserted into mouth in the "tomahawk" fashion

Fiberoptic scope through ETT used as a navigable bougie

ETT visualized through cords

Propofol IV

(Rocuronium, Isofluorane, and surgery then commenced)

What could have been done differently?  Each medical experience gives us the opportunity to use the retrospectoscope and learn from our endeavors.

• Improved local anesthetic of the posterior palate.  
• Method
• Dry the mouth with an anti-sialogogue (IV) and by patting the mouth dry with 4"x4" gauze prior to applicaiton of local anesthestic
• Gargle 2% viscus lidocaine for a good coating. 
• Increased aerosolized 4% lidocaine in the oropharynx.  
• Ensure the flow rate is 5L/min to obtain adequate particle size (if the flow is much higher than 5L/min the particles will be so small that they will travel further into the small airways of the lungs...which is useless for intubation). (1)
• Goal: reduced gagging, which was especially evident we utilized the glidescope in the mouth.  
• Give glycopyrrolate IV earlier
• Goal: Reduce airway secretions through anti-muscarinic effects. It takes 10-15 minutes to see the anti-sialogogue benefit so we really should have given this at the beginning of the sequence with the phenylephrine.  In the ED, it's unlikely that one has 10-15 minutes for this to work so give glycopyrrolate early.
• Earlier utilization fiberoptic laryngoscopy (glidescope or equivalent) 
• The management of this patient's airway turned a quick corner as soon as the fiberoptic laryngoscope was used in the "tomahawk" fashion.  It took mere seconds to position the ETT after obtaining a view of the cords using this method. 
• Improved sedation/pain control
• This patient first received midazolam in the OR, during the actual intubation.  One would only need to glance at the patient briefly to note the feeling of utter terror on his face and earlier analgesia or sedation may have made the intubation a little easier.  The group was clearly concerned about preserving the airway reflexes, but I think we could have achieved this. After listening to Dr. Scott Weingart discuss, "Awake Intubation," I think we could have expedited the process if we had given the patient a small dose of fentanyl and then sedated him with ketofol (50/50 ketamine/propofol mix) or dexmedetomidine (1).  As a result, the patient would have preserved airway reflexes and would probably have tolerated the glidescope in his mouth a little better.   
• Taken control of the airway earlier. 

So, why does reading help?

• Before the anesthesiologist reached for the glidescope, I asked the nurse anesthetist whether or not the anesthesiologist could use the glidescope via a tomahawk approach to improve visualization of the cords.  One of the anesthesiologists asked, moments later, for the glidescope and used the "tomahawk" view.  I had just read a journal article on this technique and, given this patient and the ergonomics of the situation, it seemed intuitive.  Reading the article allowed me to understand and anticipate what was going on around me.
• The March 2012 edition of the Annals of Emergency Medicine featured a small study comprised of healthy volunteers in which vocal cord visualization was achieved through both nasal fiberoptic and glidescope modalities in similar amounts of time. This study, however, evaluated the view of the cords, not the actual passage of the ETT through the cords (2).  
• Improved ability to anticipate the next step in management, gather supplies, and ask questions that may impact care.  As a medical student, I've learned that one of the most tactful ways to suggest something in patient care exists in asking a question, at an appropriate time, naturally. For example, when asked "In what kind of cases would you use glycopyrrolate or atropine as an anti-sialogogue?"  The attending then asked the CRNA to give 0.2 mg of glycopyrrolate.   

References:

1.  Weingart, S.  "Awake Intubation.  http://emcrit.org/procedures/awake-intubation/  Accessed on 31 March 2012.  

2.  GlideScope Versus Flexible Fiber Optic for Awake Upright Laryngoscopy Ann Emerg Med. 2012 Mar;59(3):159-64