On December 19th, 1799 George Washington died without an airway. Rumors and speculations started just minutes after his death regarding the cause, possible treatments, and the rapid progression of what some have assumed to be either epiglottitis or a peritonsillar abscess. Regardless of the cause, a man left this world without an airway. What I find interesting is that one of the physicians that were overseeing his care considered performing a surgical airway. This was quickly shot down by his accompanying colleagues as an extreme measure. Now fast forward 219 years to the present day. The occurrence of someone being declared dead without an airway is still occurring! This article addresses some of the factors that might play into challenging airway access during cardiac arrest.
Instantaneous Rigor
It was Labor Day weekend when the pager went off for a middle aged female who collapsed.We were lead upstairs to the bathroom where we found our patient sitting on the toilet PNB. The patient’s husband informed us that she had collapsed just moments ago. CPR was initiated and patient was found to be in asystole. A few minutes into the arrest the Fire Department arrived and assisted by performing chest compressions. My partner was at the head and attempted to drop in an oral airway when he noticed the patient had a clenched jaw. I remember asking me with his eyes “what we should do to obtain an airway?” Now at this moment a few things went through my head, 1. Is this rigor? 2. Is a surgical airway warranted? 3. What if I pushed a paralytic?
BVM was attempted with a nasal airway with extreme difficulty and the decision to perform a surgical airway was executed. The finger, scalpel, bougie technique was utilized and the patient had an airway and was being ventilated in under a minute. We noted an ETC02 waveform with a value in the 40’s. The patient remained in asystole despite continued resuscitation, and the ETC02 slowly diminished into nothing. I finished this call and immediately called a very close friend of mine who is an anesthesiologist. Our conversation ended with him telling me some words that reconfirmed my actions “You’re not dead until you have an airway."
Now almost a year later, I reflect on that call and have talked to several well respected physicians about the options that are available in a patient with acute intra-arrest trismus. The concept of utilizing paralytics in a patient with hypotension and shock is known to require higher doses, what kind of dose would be required for a patient in arrest?
This phenomenon I encountered is commonly referred to as “Instantaneous Rigor” (1). There is scarce literature on the topic, but there are enough documented cases that I think it begets attention. One Wiki article explains the perceived science behind it as, "the ATP is required to reuptake calcium into the sarcomere's sarcoplasmic reticulum(SR). During cardiac arrest there is limited ATP available, previously released calcium ions cannot return to the SR. The remaining leftover calcium ions eventually find their way to a binding site on the thin filament's regulatory protein. Since the myosin head is already ready to bind, no additional ATP expenditure is required and the sarcomere contracts."
Intra-Arrest Paralytics
The concept of giving paralytics during arrest is controversial and without overarching evidence. We can read cases where patients wake up during mechanical CPR and become combative. This is usually handled with a sedative and paralytic agent. There are some anecdotal experiences that state that sedatives alone were not enough to keep the patient from grabbing at things while compressions were in progress. So what kind of dosing should we consider if we need to deliver a paralytic during cardiac arrest?
When we give a paralytic to a patient who is in shock we are encouraged to increase the dose. Several sources recommend a dosing range of 1.6 to 2 mg/kg of IBW (2). Good chest compressions are obviously a central part of assuring this drug is disseminated throughout the circulatory system. You can expect prolonged onset times, and delayed visible effects of NMBA action. So does it make sense to try this?
Surgical Airway
In the heat of the moment the surgical airway was the route that I decided to take, and now that I have had time to sit and reflect on this case, I believe it is the route I would take in the future. The Pa02 within the blood is adequate for the first few minutes of arrest. By the time we arrive and do several cycles of CPR we are running on little to no oxygen availability for the cells. We can expect even lower reserves of oxygen if the arrest was respiratory in nature. Restoring a partial pressure of oxygen high enough to influence binding of hemoglobin on our expected right shift during arrest is extremely pertinent.
The Logistics of an Intra-Arrest Cric
Performing a surgical airway during external chest compressions requires just some slight modifications. The key is to position yourself in a way that does not disturb chest compressions. This can be done by placing the operator on the opposite side of the provider performing chest compressions. If possible the scalpel should be held in the provider’s dominant hand. The laryngeal handshake coined by Rich Levitan can aid in maintaining a sturdy platform while chest compressions being performed. Hyperextension of the neck allows better palpation of the cricothyroid membrane. It also allows more real-estate for hand placement of the operator performing Front Of Neck Access (FONA).
Is a Surgical Airway 100% Necessary?
Dr. Josh Farkas did a blog back in January of 2015 titled “The Respiratory Death Algorithm” (3). In this article he expresses a very important thought process when it comes to the question of whether a cric was 100% necessary. In the latter part of this blog he states; “Perhaps Scott Weingart’s cricothyrotomy was not 100% necessary (the only way to prove this with 100% certainty would be not to do the cricothyrotomy with a subsequent bad outcome). Maybe it was only 95% or 90% necessary. What if perhaps this was a “false-cric”? Well, in that case we should embrace it and accept it in the same way that we accept negative appendectomies, normal cardiac catheterizations, and failed extubations. The misconception that every cricothyrotomy is 100% necessary is dangerous, and runs contrary to basic airway management principles.”
Is There A Role For Supraglottic Airways?
Speaking with my friend Dr. Jose Torres & Dr. Jim DuCanto who have both experienced this presentation, I do believe there is a role for a supraglottic airway (SGA). If oral opening is large enough to slide a deflated LMA through, there is promise for adequate ventilation. As Dr. Ducanto stated to me in a text “Deflated LMA’s are like cockroaches, they will fit in very small places.”
How Far Is ‘Far Enough?’
If you cannot open the mouth wide enough to get a hyper-angulated channeled blade into the mouth, or an oral airway, the mouth is not open far enough to realistically work with. The head-tilt-chin-lift maneuver cannot be relied on alone without an oral airway in place, the two are most effective when used together. You may consider using an nasopharyngeal airway (NPA) plus a head-tilt-chin-lift, jaw thrust, or a combination of those to assist with bagging the patient until your surgical airway supplies are ready. A normal oral opening ranges from 40-60mm (Approximately 2-3 fingers width). An opening of 35mm or less is considered to be restricted and can be difficult to perform airway interventions. One way to simulate this is to use a band or ratchet straps to reduce the oral opening on an airway mannequin. This can help build up confidence and heuristics that aid in troubleshooting this presentation in the field.
In my anecdotal experience, I believe that there is little role for intra-arrest paralytics in the setting of decreased jaw compliance. The method that gets the oxygen into the plasma the quickest is the best method. For me, that is the surgical airway. Regardless of the method you decide to use, remember its not 1799 anymore. No one dies without an airway.
References:
1.Instantaneous Rigor: Am J Emerg Med. 2012 Jul;30(6):1014.e1-2. doi: 10.1016/j.ajem.2011.04.004. Epub 2011 Jun 14
2. Anesth Analg. 2000 Jan;90(1):175-9.
3. https://emcrit.org/pulmcrit/the-respiratory-death-airway-algorithm/
* Intra-arrest Surgical Airway Illustration by Joel Porter.