Rules of Four

cointosser13

cointosser13

Forum Crew Member
Messages
63
Reaction score
4
Points
8
I don't know why I don't understand the "rules of four", or more commonly known as the Lidocaine clock method. Can someone explain it to me? I looked up online but none of the examples make sense to me. I'm a new medic student, so this is all new to me. Just trying to understand.
 
cointosser13 said:
I don't know why I don't understand the "rules of four", or more commonly known as the Lidocaine clock method. Can someone explain it to me? I looked up online but none of the examples make sense to me. I'm a new medic student, so this is all new to me. Just trying to understand.
Click to expand...

I found this with a quick search - gives a basic explanation well enough:

http://www.swgeneral.com/assets/1/7/EMS_Calculating_Drip_Rates.pdf

But I have to be honest, deeply learning and understanding the math - concentrations, drip sets, etc - will serve you far better in the long run. Don't rely on tricks to get by. If that's what you use on a call for quick reference then that's fine, but be sure you have a solid understanding of the math. It will only take a bit of practice but will serve you in the long-run as your career progresses.

Oh, and don't give people lidocaine.
 
Merck said:
I found this with a quick search - gives a basic explanation well enough:

http://www.swgeneral.com/assets/1/7/EMS_Calculating_Drip_Rates.pdf

But I have to be honest, deeply learning and understanding the math - concentrations, drip sets, etc - will serve you far better in the long run. Don't rely on tricks to get by. If that's what you use on a call for quick reference then that's fine, but be sure you have a solid understanding of the math. It will only take a bit of practice but will serve you in the long-run as your career progresses.

Oh, and don't give people lidocaine.
Click to expand...

I agree with everything you said up until the last line.

Any particular reason as to why?
 
Robb said:
I agree with everything you said up until the last line.

Any particular reason as to why?
Click to expand...

"The overall benefits of lidocaine for the treatment arrhythmias in cardiac arrest has come under scrutiny. It has been shown to have no short term or long term efficacy in cardiac arrest."
http://acls-algorithms.com/acls-drugs/acls-and-lidocaine

It's still in our arrest protocol but only as a second line after amiodorone.
 
LACoGurneyjockey said:
"The overall benefits of lidocaine for the treatment arrhythmias in cardiac arrest has come under scrutiny. It has been shown to have no short term or long term efficacy in cardiac arrest."
http://acls-algorithms.com/acls-drugs/acls-and-lidocaine

It's still in our arrest protocol but only as a second line after amiodorone.
Click to expand...

Lidocaine has uses aside from cardiac arrest. It's actually an interesting, versatile drug.

Has any drug ever been shown beneficial in cardiac arrest?
 
The lidocaine comment was a little facetious. Yes, it has use but as was mentioned, 2nd line for the most part. That said, I have had good success with it.
 
Gotcha, might have read into that too much.

I'm trying to find a study I saw the other day that showed a benefit in prophylactic infusions with ROSC if no antidysrhythmics had been administered during the arrest.

Lido is second line for us behind amio but in almost every patient I've hung amio on for pulsatile VT has tanked out their BP which makes sense to a point.
 
chaz90 said:
Yeah, the jury is still very much out on that as well.
Click to expand...

If ever there were a case for a "it's not going to hurt, and it just may help" approach, this is it, IMO.

IV lido has several potential benefits when given prior to intubation, the blunting of ICP increase being only one. I know it has never been shown to improve outcomes in RSI, but there is some evidence that it has benefit in certain scenarios. Plus, there are so many potential confounders in any study that looks at RSI that drawing solid conclusions is difficult.

Considering how much of what we do that isn't well supported but we keep doing it because it seems to make sense, I'm sort of puzzled as to why this specific thing is so quickly abandoned and held up as an example of "non-evidence based practice".

I'm definitely not saying that it's wrong not to use it, just that this isn't one I would run from real quickly for lack of evidence.
 
Halothane said:
Lidocaine has uses aside from cardiac arrest. It's actually an interesting, versatile drug.

Has any drug ever been shown beneficial in cardiac arrest?
Click to expand...

So very true.. if we based only on effectiveness; there would not be any given.
Actually, Lido (one of the oldest common medication) has a lot benefits. In some studies in comparrision to Amio there is not much difference in outcome but definitely in costs...

True, not as used medication as it used to.. but let's not throw it out ...

R/r 911
 
Ridryder911 said:
So very true.. if we based only on effectiveness; there would not be any given.

Actually, Lido (one of the oldest common medication) has a lot benefits. In some studies in comparrision to Amio there is not much difference in outcome but definitely in costs...

True, not as used medication as it used to.. but let's not throw it out ...
Click to expand...

Merck said:
Yes, it has use but as was mentioned, 2nd line for the most part.
Click to expand...

LACoGurneyjockey said:
"The overall benefits of lidocaine for the treatment arrhythmias in cardiac arrest has come under scrutiny. It has been shown to have no short term or long term efficacy in cardiac arrest."

It's still in our arrest protocol but only as a second line after amiodorone.
Click to expand...

It is really unfair to compare antiarrhythmics head-to-head across all causes of WCT and SCA...and it has little to do with cost. They certainly have overlapping areas of concern, but their mechanisms are all different.

Saying lidocaine is ineffective and thus "second line" for WCT's or SCA would be like saying defibrillation is ineffective in cardiac arrest because it doesn't work with a non-shockable rhythm.

Lidocaine is best used in ischemic tissues, and it will be piss poor at terminating arrhythmias due to other substrates. Not ischemia related? Not Na-channel blocker related? Probably should pick another drug.

The old: "WCT = Amio/Procainamide then Lido," is poorly predictive of success because we're taking the Throw Spaghetti On Wall, See What Sticks approach to its treatment.

We must consider the likely underlying pathophysiology of the arrhythmia and the drug (or drugs) most likely to work for the cause. If we don't follow this model, we shouldn't be surprised when a drug doesn't work. (Nor should we blame the drug!)

Robb said:
almost every patient I've hung amio on for pulsatile VT has tanked out their BP
Click to expand...

The drug exerts class Ia, II, III, and IV antiarrhythmic effects. Combining the loss of inotropy and SVR from Ca-channel blockade with the loss in chronotropy from B-blockade maaaay have something to do with your hypotension post-amio ;-)

Also one of the excipients packaged with amiodarone (polysorbate 80) exhibits strong cardiodepressor effects (chiefly negative inotropy) possibly due to histamine release.
 
You must log in or register to reply here.
Back
Top