Don't mix cardiac drugs?

[DwayneEMTP]

Ok, my first jump into ALS territory in an attempt to cement my status as the world dumbest medic student...

On the NR dynamic cardiology I was stopped for mixing drugs. My teacher claims I was told a million times not to do that, but I must have been asleep for those million seconds, because I don't remember it.

I had a normal sinus rhythm with a PVC (single ectopic beat) occurring irregularly approximately every 4-6 seconds. I was taught that this should be suppressed chemically, even in an asymptomatic patient, so that it doesn't degrade to Vtach or Vfib. I gave 0.5 mg/kg lido with no change in rhythm and then another bolus of 0.5 mg/kg lido, which again had no effect. Then I said, “I'm going to consider amiodarone”, at which point the proctor stopped me. He said “you might have failed for two reasons (They aren't supposed to tell you if you passed or not). First, you never, ever change drugs on the same rhythm. Second, you should have started a lidocaine drip at this point.”

So my questions are these. Why would I hang a bag of the same drug that has already shown to be ineffective on this rhythm?

Why wouldn't I change to another drug that, arguably, has the same or higher probability of correcting this rhythm when the two are not contraindicated for each other? (that I can find)

Note: we were taught lido first simply based on the fact that most systems (at least in this area) don't carry enough amiodarone to hang a drip if it should prove successful, as well as the shorter halflife of lido allows the hospital more options if needed. (If I remember correctly, which is doubtful).

Ok...to the 1.5 people foolish enough to actually believe I could become a decent medic, I apologize if this question embarrasses you...but there you have it.

Thanks for your thoughts all...

Dwayne

[BushyFromOz]

okay....ill have a totally uninformed opinion on this and say what you were doing was different from the sheet of paper with the boxes on it he was marking you by?

[AZCEP]

Ok, my first jump into ALS territory in an attempt to cement my status as the world dumbest medic student...

You were smart enough to ask the question, so your status is in serious doubt.

I had a normal sinus rhythm with a PVC (single ectopic beat) occurring irregularly approximately every 4-6 seconds. I was taught that this should be suppressed chemically, even in an asymptomatic patient, so that it doesn't degrade to Vtach or Vfib. I gave 0.5 mg/kg lido with no change in rhythm and then another bolus of 0.5 mg/kg lido, which again had no effect. Then I said, “I'm going to consider amiodarone”, at which point the proctor stopped me. He said “you might have failed for two reasons (They aren't supposed to tell you if you passed or not). First, you never, ever change drugs on the same rhythm. Second, you should have started a lidocaine drip at this point.”

A couple of issues here.

First, the presence of asymptomatic ventricular ectopy does not absolutely have to be treated. Even with the amount that you are seeing. Chances are it is being caused by something, and you should try to locate that cause.

Second, I'm not sure where you got the initial dosing from. Most reference sources use the initial dose of lidocaine at 1-1.5 mg/kg. The follow-up doses are then half of the initial. Even with your dose of 0.5 mg/kg, you would still be several doses from the maximum of 3 mg/kg prior to starting a drip.

Your move to "consider" Amiodarone isn't altogether wrong, it just isn't what NREMT wants to hear. You are correct to start thinking of using something else, but you should be sure that the dysrhythmia needs correcting.

So my questions are these. Why would I hang a bag of the same drug that has already shown to be ineffective on this rhythm?

You wouldn't. After you find out that the full dose of Lidocaine--3 mg/kg--isn't working, you should consider an alternative. You might not need to use it, but it should be considered.

Why wouldn't I change to another drug that, arguably, has the same or higher probability of correcting this rhythm when the two are not contraindicated for each other? (that I can find)

They aren't contraindicated, but they CAN increase the risk of AV blocks or refractory bradycardias when used together.

Note: we were taught lido first simply based on the fact that most systems (at least in this area) don't carry enough amiodarone to hang a drip if it should prove successful, as well as the shorter halflife of lido allows the hospital more options if needed. (If I remember correctly, which is doubtful).

The nice thing about Amiodarone is it's ability to manage tachydysrythmias regardless of origin. It also has a 20-25 minute half-life. This allows you to use it without needing to hang a drip if you don't carry enough, which you are correct, most don't. Lidocaine doesn't allow for more options. It is the drug that most are the most comfortable/complacent with. It's easier for people too recall how to use, because it's been around for so long.

Ok...to the 1.5 people foolish enough to actually believe I could become a decent medic, I apologize if this question embarrasses you...but there you have it.

+5 for asking a question that more should be willing to ask. Maybe if you hadn't been snoozing through class, you could have asked it before your NREMT test, but I can't blame you for that. With the quality of instruction in some programs, a good sleep is the best thing you can accomplish. :roll:

[DwayneEMTP]

[Just Plain Ruff]

Dang D, you have the mind of a good medic there. You have learned way more than you think you have. the ability to question something that never really comes to mind to most medic students is exceptional.

Keep up the good work. I have nothing more to add to this discussion as AZCEP is doing all that.

[Ridryder 911]

I agree Azcep, Dwayne I am not sure what protocols they are using. Since '84 the initial dosage of Lido has been 1-1.5 mg/kg and the underlying causes of the etiology first. In the past ten years the recognition of the toxic effects of Lidocaine has been addressed. Personally, I cannot remember, when I administered Lido for PVC's. The first medication, that should be addressed is oxygen, since it is usually hypoxia and ischemia that is the cause of most irritability. Most agree the rules of when to treat is more aggressive than in reality, unless it is considered to be cause and in the presence of an AMI. Remember, treat the patient NOT the monitor.

For as mixture of med.'s , it is recommended to stay with one drug (the old saying, bring the one home, you brought to the dance) . The NREMT representative should be familiar with Amiodarone and since AHA recommends either one, and since the NREMT utilizes AHA guidelines, it would be a mute point.

I am sure your instructors maybe well intended and since we are only seeing one viewpoint, it is difficult for even the best to teach in-depth in a short period of time. I would highly suggest reviewing AHA ACLS for more clarification, and view the video (even though corny at times). I also recommend obtaining the checklist from the NREMT web site.

Good luck and hang in there!

R/r 911

[AZCEP]

I had covered the H/Ts at this point, all negative. Are there causes outside of that that I should be aware of?

Unfortunately, the Hs and Ts memory aid is really on the most simplistic of reminders. Most commonly hypoxia will be the issue, but there are a lot more reasons for a dysrhythmia to show itself.

Again, I was taught (I hate to keep using that phrase, but their knowledge is all I have in my tool box right now) 1mg/kg if using defib, half that dose for attempting to suppress ventricular ectopics in asymptomatic patients. I looked it up online and found it both ways: 1-1.5mg/kg and then half of that for repeated doses or 0.5-0.75 mg/kg, both up to the max of 3mg/kg/pt. So is the 0.5-0.75 mg/kg an old algorithm maybe and my school just hadn't caught up yet?

You can use any dose in that range, but you shouldn't expect any great results until you get enough into the system to illicit a response. Half to three-quarters of a milligram/kg will give results, and is recommended for the elderly, hepatic failure, and signs of poor perfusion, but chances are it will take a few more doses to work for you.

So is it realistic then to continue to bolus, yet not expect conversion/suppression until I near the max dose? If not, how far is logical to go before considering it refractory?

Most will give two 1-1.5 mg/kg doses prior to changing regimens. Using the half-doses would allow you to use it a bit longer if you felt you needed to.

We were expected to be very aggressive with ventricular ectopics, based on the theory that they tend to degrade rapidly.

This doesn't happen nearly as often as people would have you believe. Consider the status of the patient in front of you, rather than an outdated nugget from an instructor.

I trust you to understand that I'm not arguing with you in any way, just attempting to trot out my line of thinking so I can adjust it where necessary. I'm not defending these decisions, I did the best I could with what I knew.

Argue away. If you only have one set of information to work from, you will tend to hold fast to it when there may be another way to do things. Willingness to accept a different viewpoint is a sign of a good critically thinking provider.

Every new provider, leaving class, feels the same way you do. More is learned in the first two weeks after class ends than in the entirety of the program you graduate from. Luckily, the resources to bolster your confidence are no more than a computer terminal away.

[CBEMT]

I had a normal sinus rhythm with a PVC (single ectopic beat) occurring irregularly approximately every 4-6 seconds. I was taught that this should be suppressed chemically, even in an asymptomatic patient, so that it doesn't degrade to Vtach or Vfib. I gave 0.5 mg/kg lido with no change in rhythm and then another bolus of 0.5 mg/kg lido, which again had no effect. Then I said, “I'm going to consider amiodarone”, at which point the proctor stopped me. He said “you might have failed for two reasons (They aren't supposed to tell you if you passed or not). First, you never, ever change drugs on the same rhythm. Second, you should have started a lidocaine drip at this point.”

This boggles my mind. Most people probably throw 4-6 a minute after their first cup of coffee. They're teaching you to hang lido drips for it?

[akflightmedic]

OK, since you have already been given great information and advice, I had nothing left to add, except......

You said " NORMAL sinus rhythm with PVCs"

I say....is it normal if there are PVCs???

Maybe it is just a Sinus rhthym with PVCs instead of a normal one....

I know, its all semantics but hey...

[backinboston]

Something I was taught in addition to the adage of "bring home the one, you brought to the dance" is the possible result of "torsade de pointes" as a result of mixing lido and amiodarone to treat a dysrhythmia.

However, if you reach a max on either, you can always call med control and see if there licence will hold up the risk/benefit