Without evidence of benefit, an intervention should not be presumed to be beneficial or safe.

- Rogue Medic

V Tach Storm – Part I


In the comments to Is Amiodarone the Best Drug for Stable Ventricular Tachycardia is the following from Doc Cottle of Mill Hill Ave Command.

I just gave procainamide in the ER a few weeks ago, partly because it seemed like the best drug for the odd situation, but also just to get people back into the habit of using it. When a trauma/CC surgeon heard I was giving it, he said “You’re not old enough to give procainamide!”

Unfortunately, I would not be on the receiving end of that comment, for age or procainamide. My adult wide complex tachycardia protocol does not include procainamide. My pediatric wide complex tachycardia protocol does include procainamide. Go figure.

It would be nice to have an antiarrhythmic that is significantly more effective than placebo. I do not think that we have good evidence that amiodarone, or lidocaine, is really any better than placebo. Less than 30% effective at terminating stable monomorphic V Tach (VT or Ventricular Tachycardia) does not exactly suggest effective. Causing hypotension, bradycardia, torsades, and other arrhythmias does not exactly suggest safe.

Well, stick around long enough, and the passe becomes hip again.

Calcium chloride, too.

By the way, you might appreciate Rob Orman’s podcast ERCAST, where he talks about treating refractory VT. (http://blog.ercast.org/2010/12/v-tach-storm/)

V Tach Storm is an important podcast, but I have a few problems with what is covered.

The topic is –

 

What do we do when we run out of algorithm?

 

I don’t think that should be the question. I think that we have become too protocol driven, but that is part of what Dr. Orman describes.

The question is Why is the patient experiencing this arrhythmia?

We can get rid of arrhythmias without addressing the underlying cause. With some treatments, we exacerbate the underlying cause.

What was done for/to the patient?

PS – The age is cut off at the beginning of the podcast. The patient is 75 years old. EMS initially gave lidocaine, then shocked him without any sedation, even though he had stable vital signs and should have been given sedation. Even if the patient hypotension, ketamine would have been a good sedative, but few of us in EMS have ketamine.

 

Shocked four times without sedation.

 

Ouch!

 

Then, amiodarone was given, even though amiodarone is not a drug that consistently produces good outcomes. For a baseball player, a batting average of .290 is not bad. For a drug, .290 is only good if there are no better alternatives and the drug is safe.

Studies show that amiodarone is only 29% effective at terminating V Tach,[1] only 25% effective at terminating V Tach, [2], and only 15% effective at terminating V Tach within 20 minutes, but if we don’t mind waiting an hour it can be as much as 29% effective.[3]

If we are not trying to convert the rhythm promptly, should we even consider V Tach an emergency? If lights and sirens only make a difference of a minute, or two, V Tach is obviously not a lights and sirens emergency. Maybe we need a treatment that works.

At least amiodarone doesn’t cause arrhythmias. Right?

Intravenous amiodarone did not prevent induction of sustained ventricular tachycardia in any of five patients inducible at baseline. Of six patients with non-sustained ventricular tachycardia, five had sustained ventricular tachycardia or fibrillation induced after amiodarone infusion.[4]

Of 6 patients with non-sustained V Tach, 5 of them developed sustained V Tach or developed V Fib (Ventricular Fibrillation). In what way does amiodarone seem like a good idea?

Is amiodarone safe?

As long as we don’t mind causing hypotension, causing bradycardia, converting non-sustained V Tach to sustained V Tach, causing torsades, and causing V Fib. We wouldn’t hold those really bad things against amiodarone.

Continued in Part II.

Footnotes:

[1] Amiodarone is poorly effective for the acute termination of ventricular tachycardia.
Marill KA, deSouza IS, Nishijima DK, Stair TO, Setnik GS, Ruskin JN.
Ann Emerg Med. 2006 Mar;47(3):217-24. Epub 2005 Nov 21.
PMID: 16492484 [PubMed – indexed for MEDLINE]

[2] Amiodarone or procainamide for the termination of sustained stable ventricular tachycardia: an historical multicenter comparison.
Marill KA, deSouza IS, Nishijima DK, Senecal EL, Setnik GS, Stair TO, Ruskin JN, Ellinor PT.
Acad Emerg Med. 2010 Mar;17(3):297-306.
PMID: 20370763 [PubMed – indexed for MEDLINE]

Free Full Text from Academic Emergency Medicine.

[3] Intravenous amiodarone for the pharmacological termination of haemodynamically-tolerated sustained ventricular tachycardia: is bolus dose amiodarone an appropriate first-line treatment?
Tomlinson DR, Cherian P, Betts TR, Bashir Y.
Emerg Med J. 2008 Jan;25(1):15-8.
PMID: 18156531 [PubMed – indexed for MEDLINE]

[4] Effects of intravenous amiodarone on ventricular refractoriness, intraventricular conduction, and ventricular tachycardia induction.
Kułakowski P, Karczmarewicz S, Karpiński G, Soszyńska M, Ceremuzyński L.
Europace. 2000 Jul;2(3):207-15.
PMID: 11227590 [PubMed – indexed for MEDLINE]

Free Full Text PDF + HTML from Europace

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