Saturday, March 31, 2012

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

3 comments:

  1. EMCrit has suggested that it maybe better to get the patient somewhere between semifowlers and upright, then climb on a step and do "conventional" video laryngoscopy. That way, it's closer to what we do most of the time

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  2. Thanks for the tip..it definitely makes sense. There's no way we could have maneuvered this patient into that position without sedation (which the patient needed and which I would have handled very differently...I believe you might call this a ketamine deficient state).

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