Adenosine vs. Cardizem in tachy med/surg pt.

I have a question. I have one year of experience in med/surg( woo hoo!) and the other PM I had a pt. who was s/p MI from the night before who became tachycardic. He was maintaining a HR anywhere from 130's to 150's and c/o palpitations. Now this pt. is a hot mess to begin with...trach, PEG tube, all sorts of nasties in his sputum and now he's had an MI during this hospitalization for other issues. The pt. had become tachy the night before and Adenosine was pushed by the house supervisor with ICU nurses present and of course the pt. attached to the code cart. I paged the MD and he ordered the same thing again. So we pushed the Adenosine and his rhythm immediately changed to SR, no pause whatsoever. First off, it is my belief that this pt. should have been in the ICU but apparently the MDs ratianale is that he wanted to tx the MI medically with Plavix and ASA. But he was continually having these tachy episodes. But that's another topic. My question is: why Adenosine? I've had tachy pts. before and I was ordered to push cardizem and that brought them back to SR. So, is there something I'm missing here? Why would the MD choose a drug that we are not allowed to push on the M/S floor and have to pull resources from the ICU to administer?
My understanding is that tachy arrhythmias stress the cardiac muscle badly, aggravate tissue damage, and are a predictor of bad outcomes. In the ER we routinely give 3 doses of Cardizem (beta blocker) IV prophylactically to avoid tachy stuff. The treatment of your patient baffles me. Maybe a cardiac nurse will jump in with an answer, or is there something missing from your description that precludes use of beta blockers. Interesting question, thanks for asking.

Adenosine is a medical cardioversion, it reboots the heart, and is usually used to treat SVT. Cardizem (diltiazem) is a calcium channel blocker and is not technically and anti-arrhythmic like adenosine is. It's not uncommon to see both calcium channel blockers and beta blockers appear to convert a patient out of A-fib or A-flutter when given as a bolus IVP, but many cardiologists will tell you it doesn't happen. Adenosine given IVP outside of the ICU should be given with the STAT RN present if you have one, and/or the MD present, and with the patient hooked up to the code card, it also requires some experience to push since the injection and the flush have to happen very fast due to the short half life. By M/S floor, do mean the pt wasn't even on telemetry? You'd think if he required two pushes of adenosine in a couple of days that he would have earned a telemetry bed, although not an ICU bed at least where I work.

It's hard to understand without seeing the pt's strip prior to the adenosine -- what's the baseline rhythm? Do they have afib, or a block going on? I've seen a doc jump straight to adenosine when the patient can't take the sustained BP drop that can happen if you need several doses of cardizem or a cardizem drip to do the job -- if your patient's septic, the BP is probably either in the toilet or headed that way. Adenosine is in, does the job, and dissipates in 10 seconds. Cardizem can hang around, and around, and around...and if your patient's getting dig or other cardiac meds like beta blockers, it can actually prolong the effects of the dig. So, you snap your patient out of the tachycardia, only to have them bottom out their pressure or drop their HR the other direction. Cardizem can also cause some interesting effects in someone on diflucan, so depending on the patient's other comorbidities, it may be safer to go straight to adenosine, as strange as that sounds.I'd be campaigning to get my patient to a cath lab, ASAP. Or made a DNR/DNI/comfort care only....

Quote from dthfytrMy understanding is that tachy arrhythmias stress the cardiac muscle badly, aggravate tissue damage, and are a predictor of bad outcomes. In the ER we routinely give 3 doses of Cardizem (beta blocker) IV prophylactically to avoid tachy stuff. The treatment of your patient baffles me. Maybe a cardiac nurse will jump in with an answer, or is there something missing from your description that precludes use of beta blockers. Interesting question, thanks for asking.

Adenosine is an endogenous nucleoside (remember ATP and the Krebs cycle from A&P?). that's why it has such a short half-life, our bodies burn up trillions of molecules every second in order to produce energy. I agree with dthfytr, the treatment is a little baffling. In my experience, we usually only give adenosine to slow a rate down enough to acquire a good 12 lead tracing, in order to distinguish between re-entrant tachycardia and other forms of SVT. Remember anything fast that's not v-tach is technically an SVT, very blanket term. when someone's rate is >160 with a narrow complex, it's often hard to tell sinus vs atrial.Ca++ channel and beta-blockers are what we usually use to suppress a tachyarrhythmia. Of course like other posters have said, you have a potential undesired effect of hypotension. It's tough without seeing a 12 lead, but you had a patient with symptomatic tachycardia and adenosine is endorsed in ACLS algorithim. I don't think a patient should have to be in a "critical care" area to receive adenosine, but the pauses can be dramatic at times. If the rhythm was sinus in nature, there wouldn't be a need to chemically cardiovert the patient. You would be trying to identify an underlying cause (pain, fever, anemia, etc) and correct that. Adenosine would be of little use in sinus tach.Hope this helps some.

Adenosine is contraindicated for WPW (Wolf-Parkinson-White) syndrome which is noted by the "J" slope on the R wave in a tachycardia >150. Cardiazem is the next drug of choice. I'm assuming the MD had an EKG to look at before.I do agree that the patient should have been transferred to an ICU for closer monitoring.

Thanks for correcting me on the Cardizem. Fear not, I,m not practicing now.

My guess is that the SVT involved an accessory pathway, in which case an AV nodal blocking agent like Cardizem would be contraindicated. Adenosine interrupts accessory pathways, plus its half life is around ten seconds, so it would be the appropriate choice. Sounds like this patient might need an ablation, but is too medically fragile at this point to undergo the procedure.

I'm throwing this out there, also, but at our facility adenosine is actually not able to be pushed sans MD present at bedside (and in ICU, and with the patient attached to the crash cart). This being said, I might have missed it but the original poster didn't say anything re: what the rhythm actually was (afib, or SVT). Most of the time when we get orders for a tachy rhythm like this we will try either cardizem, lopressor, or give a loading dose (or a few) of digoxin. This is, of course, after fluid balance and rhythm is identified. Keep in mind that . I've also seen IV verapamil and amiodarone gtts, but those are more rare. Verapamil actually worked well for a patient that had been in an accelerated ventricular rhythm (and asymptomatic) for a while with no response to other meds. Also, amiodarone has a ridiculous half-life of 58 days (range is 25-100 days).

Quote from resumecprAdenosine is contraindicated for WPW (Wolf-Parkinson-White) syndrome which is noted by the "J" slope on the R wave in a tachycardia >150. Cardiazem is the next drug of choice. I'm assuming the MD had an EKG to look at before.I do agree that the patient should have been transferred to an ICU for closer monitoring.

Adenosine is used to see the underlying rhythm. To slow the heart rate down to see exactly what is going with the heart. I think this drug was great drug of choice. Any floor that has Telemetry would have a good choice.

Forgive me if I sound like an idiot. I just woke up. Anyway, of course the pt. was on tele. My floor is a catch all. It's a small hospital and we are the neuro unit, renal unit, step down unit and cardiac unit, etc. This was not A-fib or A-flutter. The tele tech was just calling it a Sinus tach which is what it looked like to me on the monitor. The pt.'s other VSS. I agree this pt. should be a DNR if they're not going to be in the ICU. But as you can see the pt. has a trach and a PEG and family has not made the pt. a DNR which leads me to believe they're reluctant to. But the pt is A+O x 2 at least. The house supervisor is a part of the RRT and is required to have critical care experience so she and an ICU nurse were present and pushed the adenosine. Charge nurse was also present as I had never done this before and I was just there to get primary fluids started and to prepare 20 ml NS for the house sup. and to learn of course. Thanks for all the replies. Some of them are going over my head right now...possibly because I just woke up or because I'm not a specifically cardiac nurse...