Cardiac Stress Testing

We just started last week. So for the MD administers it, since it is new but the RN can administer the injection. Has to be fast IVP similar to adenosine for PSVT. We had 3 patients last week, and had to reverse 1 due to arrythmias. Supposidly lower occurance than with adenosine. Interestinly adenosine increases flow 4x, this new agen is ony 2x. So it can not be used for endothelial dysfunction eval, also may not have as much PPV as adenosine with ekg changes.

Jeremy

Lexiscan is a new one for me, never heard of it. At our practice we have a Cardiologist quickly available but the nurses run the tests and administer the meds, we have Card Techs who run the EKG' and prep the pt's etc. Seems to work efficiently. We are not radiology nurses so that is all we do all day. Can Lexiscan be used for patients with Asthma? What did you mean by "So it can not be used for endothelial dysfunction eval, also may not have as much PPV as adenosine with ekg changes." What is PPV I didn't understand that.
I am interested in hearing if centers are having their Dobutamine patients walk while it is infusing, sort of like how we have a walking Adenosine protocol where they walk at a slow flat pace during the infusion it seems to limit the episodes of brady. Walking the Dobutamine's might get their heart rates up faster, but I know lot's of patients don't feel well during the infusion. Anyone have a protocol they can share?

Jeremy, what did you mean by "Supposidly lower occurance than with adenosine. Interestinly adenosine increases flow 4x, this new agen is ony 2x. So it can not be used for endothelial dysfunction eval, also may not have as much PPV as adenosine with ekg changes." Can you just explain it better for me. Can this new Lexiscan be used with pt's with Asthma or caffeine?

asthma and caffine are still concerns like adenosine. With some PET studies you can evaluate endothelial dysfunction, all thoes protocols are based on the 4x vasodilitation of adenosine. This new agent does not have as much increase in vasodilitation as adenosine.

PPV is positive predictive value, so if the patient has st depression with this new drug how is that used, can we use this same as ekg changes with dobutamine or adenosine

In our Cardiology department we have nurses administer dobutamine and adenosine while there is a PA or cardiologist present. We are having an inservice on Lexiscan on 11/12 and then will start using it. I will have to write a policy on its administration. Does anyone have a policy written already.

My concerns still are those patients with COPD/asthma. Anyone have any bad experiences with those patients?

I recently started working at a cardiology practice in August. They had just started using Lexiscan & I love it. Pt's don't complain nearly as bad as they did with Adenosine. Mild SOB, some nausea. You can use on pt's with asthma-not if actively wheezing.
I am interested in your practice. You stated the nurses run the tests.Do you not have to have a PA or NP to monitor EKG? We do, but our administrator is interested in the nurses doing it. Do you know of a course to become certified?
Thanks!

We have been using Lexiscan, a second generation Adenosine medication, since November and are delighted with it and its ease of administration. We have just about done away with all Adenosine and Dobutamine infusions. There is that doctor or two who will insist on Dobutamine, but that is rare. We have never done a walking Dobutamine! I would question the safety of that. We have done walking Adenosine tests to lessen the side effects and to improve image quality. I had the privilige of going to a presentation by Dr. Maharian who did some of the trials and he stated that walking Lexiscans do promote better images. Our Astellas rep is wonderful and supportive; she has been there to hold our hand if we needed it, and is actually planning a follow up with us.

There are so many benefits to the Lexiscan and one being that if the patient is a stress DIMPS and cannot get his heart rate up and is ready to call it quits, he can be injected with Lexiscan then the isotope and the test will be a valid one.

There is a bit of a question about how fast to bolus the medication. PI says over 10 seconds, but we inject over 20-30 seconds to reduce any side effects. I have heard that it caused bowel incontinence and I did have one patient who complained about a sudden urge, but he made it to the bathroom with no problem or radioactive poop.

The greatest complaint we have had is headache and nausea. Aminophylline can be given to attentuate protracted sysmptoms, but we have our patients drink coffee or cola right after the test. One patient required Zofran for nausea.

I am not sure about the asthma question. I know that we have used it safely for COPD patients, but we have not faced the dilemma of actively wheezing asthmatic patients. I would certainly have the mid-level or cardiologist evaluate the patient.

As far as scope of practice goes, Nuclear Medicine techs can and in some doctors' offices administer the Adenosine, Dobutamine and Lexiscan, but nurses cannot inject an isotope. We will always have a PA or NP with us when we stress the patients, the MDs (aka cardiologists will sometimes leave and wander around running two or more tests) We do have some of the doctors stay with us in a patient who may be a higher risk to develop complications.

We all joke and say that we cannot imagine life before Lexiscan! (Adenosine and Persantine are so 20th Century!) If your stress lab is thinking about trying Lexiscan, I would urge you to contact Astellas and give it a try.

I have always worked where nurses are available during stress tests. The nurse always administered the dobutamine (which I hate) and no we did not walk our patients, we did have them move their extremities to assist with heartrate elevation. We did walk our adenosine patients (never walked a LBBB) flat on a treadmill or just in place. Now, my facility where I work we are using lexiscan and I love it (was using persantine up until 2 months ago!) 10 second IV push, flush then the radionuclide agent in 10 to 20 seconds. I see mostly complaints of upset stomach, headache, and shortness of breath. Smokers I see a cough almost everytime. Seems well tolerated by most patients including COPD. Have done a few asthma patient that are stable (not actively wheezing). I have used amino x 1 for ongoing chest discomfort with complete relief.
a good website to check out for information is http://lexiscan.com . I still have my patients hold caffeine products for 24 hours before the test and encourage caffeine after the test is completed.
As the nurse in my facility, I am ACLS & the nuc tech (23 years experience) is ACLS. The nuc tech gives the lexiscan and follows with the radioisotope. Dobutamine I administer via a pump. I have alot of confidence in the nuc med tech I work with (he is also the RSO). Hope this information helps. ps...we rarely ever use dobutamine anymore!!