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Tuesday, August 24, 2010

Drug Shortages Affect Those Still in the Dark Ages – Lidocaine

ResearchBlogging.org

I have moved Rogue Medic to EMS Blogs. Also posted over at Rogue Medic and at Research Blogging.


Go check out the rest of what is available at EMS Blogs and at Research Blogging.



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In the current JEMS, there is an embarrassing article. Drug Shortage Possible in N.Y.

It seems that the drugs that people are worried about are lidocaine, furosemide, 50% dextrose, and epinephrine 1:10,000 preloaded syringes. Here, I will discuss lidocaine.

Lidocaine is not appropriate for EMS patients, because there are more appropriate drugs. Lidocaine is still used for cardiac arrest, even though there is absolutely no reason to believe that it does anything positive for the patient.

There is no evidence that any antiarrhythmic drug given routinely during human cardiac arrest increases survival to hospital discharge. Amiodarone, however, has been shown to increase short-term survival to hospital admission when compared with placebo or lidocaine.[1]


In other words, amiodarone doesn't work, but lidocaine is even worse.

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Lidocaine is also used for ventricular tachycardia with similar lack of effect.

Lidocaine terminated ventricular tachycardia in four of 31 patients, ajmaline in 19 of 30 patients (P<0.001).[2]

Lidocaine is no better than holding the patients hand or any other placebo. Spontaneous remission of ventricular tachycardia should occur in more than 4 out of 31 patients.


DC shock was used in 16 nonresponders (22.9%) to procainamide and 10 non-responders (50%) to lidocaine.[3]


Only 35% of patients improved after lidocaine. Maybe they improved because of lidocaine - maybe not. More important is that 50% of patients who received lidocaine ended up being cardioverted. Did they require cardioversion because of the lidocaine?

Would you recommend a drug that leads to half of patients being cardioverted?

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Footnotes:

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[1] Medications for Arrest Rhythms
2005 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care
Part 7.2: Management of Cardiac Arrest
Free Full Text

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[2] Electrophysiological and haemodynamic effects of lidocaine and ajmaline in the management of sustained ventricular tachycardia.
Manz M, Mletzko R, Jung W, Lüderitz B.
Eur Heart J. 1992 Aug;13(8):1123-8.
PMID: 1505562 [PubMed - indexed for MEDLINE]

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[3] Efficacy of procainamide and lidocaine in terminating sustained monomorphic ventricular tachycardia.
Komura S, Chinushi M, Furushima H, Hosaka Y, Izumi D, Iijima K, Watanabe H, Yagihara N, Aizawa Y.
Circ J. 2010;74(5):864-9. Epub 2010 Mar 26.
PMID: 20339190 [PubMed - indexed for MEDLINE]

Free Full Text PDF

Table 3 is from this paper. As you can see, lidocaine is a joke compared to procainamide.


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2 comments:

  1. In my system we had to call for Amio but had Lido on standing order.

    Guess which one got used more?

    Our next update will give us Amio on standing order, but I can't see much changing.

    ReplyDelete
  2. CBEMT,

    In my system we had to call for Amio but had Lido on standing order.

    Guess which one got used more?

    I would guess that amiodarone was used more often. The medical command only - forbidden fruit tease effect. If we have to call for it, it must be powerful!

    However, I expect that you are going to tell me that the medics followed the path of least resistance to lidocaine.

    Our next update will give us Amio on standing order, but I can't see much changing.

    That is my point. Antiarrhythmics do not change much. We spend a lot of time on antiarrhythmics, but their ability of an antiarrhythmic to make a significant difference in the prehospital setting is theoretical, based on ED/cardiology treatment, which is not based on much more than theory.

    Our patients might be much better off if we were to dose patients with a sedative. If the patient becomes unstable, cardiovert.

    While most sedatives do lower the blood pressure, antiarrhythmics have the same tendency.

    ReplyDelete