October 15, 2012

Is Roc vs Sux Moot?

I'm a big fan of rocuronium for RSI. The argument is succinctly -- and arguably definitively -- made by Reuben Strayer in 8 minutes.

One of the cornerstones of the argument is the landmark paper by the Benumof Brothers*: patients will invariably desaturate before the sux wears off.

The ubiquitous "time to hemoglobin desaturation curve" that is shown in every airway talk, chapter, paper, etc:
Benumof JL, Dagg R, Benumof R. Critical hemoglobin desaturation will occur before return to an unparalyzed state following 1 mg/kg intravenous succinylcholine. Anesthesiology. 1997 Oct;87(4):979-82. 
...not only comes from this paper, but was specifically made to demonstrate that the patient will desaturate before the sux wears off.

But wait a minute. This is from 1997. This was before NODESAT -- the use of nasal cannula during laryngoscopy to maintain oxygen saturation.

Does nasal oxygenation during laryngoscopy bring succinylcholine's shorter duration of action back into the question?

My thoughts are below this other mandatory airway management picture:


My answer is no: roc still beats sux.

  • Sux risks hyperkalemia, i.e. succinylkalemia
  • When the sux wears off, the patient won't be breathing calmly & cleanly. They will be fighting like heck because people are stabbing them in the back of the throat
  • The patient who can't get intubated in 8 minutes still needs to be intubated (there is no "cancel case" in the ED) -- and more paralyis is helpful for bagging, placing an LMA, cric, etc
  • Intubating conditions are as rapid and as good with roc
  • Sux may lead to faster desaturation, because even with NODESAT...
  • NODESAT is amazing but not 100% perfect:
This is just an anecdote** of course, but I had a patient who was preoxygenated perfectly with 100% oxygen via NIV with PEEP using DSI, and even with the nasal cannula at 15 L/min during laryngoscopy, desaturated within 15 seconds.

So I still think roc wins. But of course, I was trained by big fans of roc.



*There are 2 Benumof authors on the paper -- Jonathan and Reuben. I don't know for certain but I like to think they are brothers, and I think they should play the Brugada Brothers in a game of basketball.

**Level of Evidence: A for Anecdote

4 comments:

  1. good thought seth - NCO2 clearly prolongs apnea time, though by how much is quite variable. I still hold that planning on on sux wearing off to get you out of can't intubate can't ventilate leads to bad decisions, and that the longer duration of roc is an advantage.

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  2. If part of your intubating plan is to wait for the patient to wake up if you can't get the tube, you should just be calling anesthesia to tube the patient.

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  3. Agree 100% with your commentary.

    I wonder if that woman realizes what a huge role she's played in airway management by consenting to those two images. They're everywhere.

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  4. This comment is from Anand Senthi:

    I do think the NODESAT approach alters the argument between Sux and Roc as you point out Seth. I'm surprised more people are not discussing this.
    Also I think the argument that in emergent airways waiting till the patient starts breathing doesn't solve your problem because you still need to intubate the patient is very simplistic and fails to reflect reality. Many of our airways in ED are urgent but not emergent - eg for airway protection. If the patient starts breathing and you are oxygenating you are in the Vortex green zone and you have time to mobilise your resources. That may include (obtaining senior airway support (eg anaesethetics or an on call ED physician) who may have access to better intubating tools for difficult airways. Or you may choose to throw an LMA Supreme down under sedation without paralysis + NGT and be happy with the reasonably good airway protection in a patient you can oxygenate and ventilate. In the prehospital or smaller ED this might be adequate until you transfer the patient to a place where intubation can occur more safely.
    Also while many patients are easier to ventilate with paralysis on board some are the opposite so sux wearing off in a timely manner may still be useful.
    Not saying I'm advocating sux over roc - just think the argument is more complex and roc is not the hands down winner many passionate Roc disciples are making out.

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