Transcutaneous Cardiac Pacing w/ Bradyarrhythmic

[thowle]

So I've got a question on Transcutaneous Cardiac Pacing for a patient with symptomatic bradycardia rythm.

So I'm probably wrong on this whole thought process so correct me if I am; but if you're going the non-invasive asynchronous pacing route on a PT, once you connect and verify connection of pads; you adjust mA in 20 mA increments? until you see capture -- which should be shown as the QRS complex being longer than others and the T wave being higher mV, right?

And this should let us know that we have capture -- so we can start decreasing our voltage @ the leads until we are around the lowest mA to hold capture.

Is that right, half right, totally wrong -- just trying to make sure I'm on the same page.

Thanks,
Trav

 

[boingo]

I don't think there is one "right" answer, personally, once I get capture, I stay there, however I do go up in 20 mA increments. Tom B will hopefully respond soon, he has some good info on TCP to share.

 

[artman17847]

I have done it the same way. Increase the voltage till I get capture and leave it there. Just make sure you are getting good pulses with the rhythm.

 

[marineman]

The only way I know is what I was taught and I was taught slightly differently but as far as I know if you get capture and good pulses and are using the lowest current possible to keep capture life is good.

We start out bumping up pretty quickly until roughly 50mA then go up in 10mA a little slower until we get capture. We then come back down in 5mA increments until we lose capture then bump up very slowly in 5mA increments until we regain capture then go 5mA above where we regained capture.

The reason we were taught for coming back down is that a lot of people end up going up too fast and are using more mA then are actually required so our first rush up is to get in the area then the second time is the fine tuning. I'm not 100% sure on why we go 5mA above where we regain capture so maybe someone can answer that otherwise I'll ask on tuesday when we go back to class.

 

[Ridryder911]

I usually start high at 60 and 60 and decrease. I have found patients usually require more than most initially think. As well not only verifying capture on the monitor but perfusion level. Remember, one may assume they have capture but really only have partial capture and muscular movement. Good assessment of the patients perfusion status needs to be evaluated.

I also believe in good sedation and providing analgesics. There is no reason to make the patient suffer during stimulation. Again, careful control to maintain hemodynamics along with sedation is crucial.

R/r 911

 

[TomB]

This is just my opinion, but I think you should dial up the current slowly. The faster you dial up the current, the more violent the skeletal muscle contractions. If you wait a few seconds between each increase, it's better tolerated by the patient. TCP is uncomfortable, but it's not unbearable, at least up to 120 mA. I think it's the psychological aspect that makes it seems much worse than it is (for both the patient and the caregiver).

It is not a simple matter to identify electrical capture on the monitor. See my recent article the problem of false capture to see what I'm talking about. For true electrical capture, you should have a wide QRS complex with a tall, broad T wave. Don't think in terms of a "tall" QRS complex, because false capture (Bob Page calls it echo distortion) get's taller as you dial up the current.

If you are skilled enough at ECG interpretation to see the trasition from false capture to true electrical capture, then I agree with going up and down the capture threshhold until you know the exact mA that you achieve and lose electrical capture. It's not the same number! You might capture at 120 mA and lose it at 90 mA. For this reason, I don't personally think it's necessary to pace at 125 mA for a patient who captures at 120 mA, but to each his own. I know it's the common practice (although I believe we're shocking a lot more patients than we're pacing in the prehospital setting).

I certainly don't disagree with sedation for TCP! It makes you and your patient a lot more comfortable. By the way, if anyone has any strips of TCP, please scan them and share! It doesn't matter to me if you achieved true electrical capture or not. Either way, I think they're interesting case studies.

 

[MOflightmedic]

Hi Tom,

I have a great TCP strip of an unstable post cardiac arrest STEMI Pt, with an underlying high degree HB, that I flew to the cath lab about 4 weeks ago. I will get it scanned and post it to this tread but it will be a few days before I can do so. I will say that the Pt wouldn't of made it to the cath lab without being paced. I know the Pt had a successful drug eludeing stent placed and has been discharged from the hospital.

 

[TomB]

That's awesome! Can't wait to see it.