chbare Posted July 11, 2011 Posted July 11, 2011 Unfortunately, antidysrhythmic medications have significant pro-arrhythmic effects, so "calming" the heart is probably not the best analogy. However, if you are well versed in their mechanisms of action, I would not make a big deal of it. However, some people take these sayings literally. A real common one around here is that "lidocaine numbs the heart." Unfortunately, I feel this shows a fundamental lack of knowledge regarding the mechanism of action of these medications when we distill things down to catch all statements. The evidence is rather telling in that I gather both agents are equally ineffective at having a functional member of society walk out of the hospital. Therefore, it's a crap shoot IMHO. My bias being that I really do not focus on medications that much in an arrest unless there are clear indications such as a drug overdose or electrolyte imbalance that would potentially benefit from certain treatment modalities. Anecdotally, my experiences with both agents are equivalent. Take care, chbare. 1
tniuqs Posted July 14, 2011 Posted July 14, 2011 So this contradicts you saying lidocaine has been taken out entirely. FireEMT2009 I should have been more clear, in Alberta Canada the Alberta Health Services as removed Lydocaine has from protocols using Canadian Prehospital Evidence Based Protocols, some privately run operations still retain Lydocaine in their protocols. Here is a link to a multitude of experts opinions and Canadian Prehospital Evidence Based Protocols. http://emergency.medicine.dal.ca/ehsprotocols/protocols/toc.cfm
DwayneEMTP Posted July 15, 2011 Posted July 15, 2011 One interesting point, or at least it seems to to me as I've not looked it up in several years and can't remember how valid it is... Only twice I used Amiodarone, even after we began carrying it I used Lidocaine only because I was more comfortable with it. But the first time I used it the ER doc lectured me, kindly, saying that it was the lesser choice because it crossed all of the cardiac drug classes and made in hospital management more difficult unless it was continued as opposed to switching to other more appropriate choices that had been queered by it's use. I have no idea of the validity of this argument, though the next time I used it I delivered my patient to the same doc and got the same lecture. The few times I've needed to choose since I've used Lidocaine based on that. Simple and foolish I know..but there you have it... Dwayne 1
medicgirl05 Posted July 15, 2011 Posted July 15, 2011 Ms. Medicgirl, I am very surprised and interested in the fact that you only have lidocaine available for the ventricular arrhythmias. I would like to hear your opinion on lidocaine. How do you like using it? Do you have complaints or precautions that I should use if I decide to use it? We have both drugs in our drug box available for us to use, so its a medic's preference on which one they use. Thanks in advance. FireEMT2009 I can count on one hand the number of times I have used Lido. Mostly just for V-fib and we don't often see that particular rhythm. Out of the times that I have used it, along with the other conversion steps, I have had the one save. I think it is strange that we dont carry Amiodarone but I don't really get an opinion on that. :-) I work at a transfer service and they carry amiodarone, though I haven't had the chance to use it.
Siffaliss Posted July 16, 2011 Posted July 16, 2011 (edited) Unfortunately I don't recall word for word what my formularies say, so here are a few of the basic actions and contraindications for each drug. Other precautions are considered, however I have laundry to do and am running out of time for play stuff. Perhaps this will help ... Amiodarone pharmacodynamics - prolongs the action potential and refractory period (repolarization inhibition) - with prolonged therapy, the effective refractory period increases in atria, ventricles, AV node, His-Perkinje system, and by pass tracts and conduction slows in the atria, AV node, His-Perkinje system, and ventricles; as well SA node automaticity decreases - inhibits adrenergic stimulation and decreases peripheral vascular resistance (PVR) - some vasodilation Amiodarone contraindications - AV block, pre-existing 2nd or 3rd degree block (without artificial pacemaker) - bradycardia resulting is syncope – amiodarone reduces sinus node automaticity and may cause atropine resistant sinus bradycardia - sinus node impairment - sensitivity to amiodarone or iodine (contains iodine) - cardiogenic shock - thyroid disease Lidocaine pharmacodynamics - one of the oldest antiarrhythmics - suppresses automaticity and shortens the effective refractory period and action potential of the His-Purkinje fibers and suppresses spontaneous ventricular depolarization during diastole - unlike quinidine and procainamide, lidocaine doesn’t significantly alter hemodynamics when given in usual doses - seems to act preferentially on diseased or ischemic myocardial tissue; exerting its effects on the conduction system, it inhibits reentry mechanisms and halts ventricular arrhythmias Lidocaine contraindications - ventricular escape rhythms, idioventricular rhythms - severe degrees of SA, AV, or intraventricular block - hypersensitivity to amide-type local anesthetics - Stokes-adams syndrome (resultant cerebral ischemia from infranodal block due to disease in the bundle of His, causes dizziness and fainting) Current ACLS guidelines still state that either Lidocaine or Amiodarone can be used in a VF or pulseless VT code. I dunno what the new ones will look like when they're squeaked out later this year for drugs specifically in algorithms. Considering some of the contraindications for each drug and that you've of course gotten a full history (or as much of one as you can from frantic families and other sorts), AND are thinking about H's and T's, you might lean specifically towards one drug or the other. Remember that if you end up needing an infusion of an anti-arrhythmic to sustain ROSC, you would need to infuse Lidocaine if you pushed it, so on and so forth ... This is basic pharmacology knowledge we'd learned by the second year of my program, so ACLS was a breeze. Each code is different in one way or another, so I wouldn't say that it's always better to use one over the other. Getting ROSC is not really a save if they can't walk out of the hospital being able to lead a relatively normal life afterwards, it's just prolonging the inevitable. I've been in the field for 5 years now so I'm still green on a crapload of stuff of course. Of the several dozen codes I've been on during my EMS time so far, I've had 2 actual saves. LOTS of ROSC but nothing viable after transfer of care at hospital. One save was due to good family CPR and a shockable rhythm when we got there. We only had the tourniquet on for the IV, intubation kit was being set up and pt was being bagged with an OPA at that time. No drugs given here. The second was because we were right beside our pt when she collapsed. Ripped off the shirt, slappedy slap the pads on, oh look, v-fib ... she went from a GCS=3 to a GCS=15 within minutes, and is still around today. We had Lidocaine removed from our drug kits and replaced with Amiodarone, however it's not to be used for codes. Only as an infusion for those appropriate wide/regular/stable problems people have sometimes ... Edited July 16, 2011 by Siffaliss
FireEMT2009 Posted July 16, 2011 Author Posted July 16, 2011 I should have been more clear, in Alberta Canada the Alberta Health Services as removed Lydocaine has from protocols using Canadian Prehospital Evidence Based Protocols, some privately run operations still retain Lydocaine in their protocols. Here is a link to a multitude of experts opinions and Canadian Prehospital Evidence Based Protocols. http://emergency.med...otocols/toc.cfm Mr. Tniuqs, I didn't mean to insult you or offend you if i did. I was just trying to support my point.
tniuqs Posted July 16, 2011 Posted July 16, 2011 Mr. Tniuqs, I didn't mean to insult you or offend you if i did. I was just trying to support my point. No worries I wasn't clear ... and I personally wonder if elimination of Lydocaine based on current research warrants removal from AHS EMS protocols, it does limit options . ps Besides its really hard to offend a Turnip .
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