Quad strength Levophed not working

How did you hook it up? Remember that since it runs at a slower rate it will take longer to get to the patient. For instance, if you've hooked up to a port that has has 3cc of volume between it and the patient and the quad strength is going a 12 ml/hour, it will take 15 minutes to get to the patient.

If you connect it to the same connection the standard concentration was hooked up to and immediately start running it at the quad strength rate, it's just going to infuse the standard concentration levo at one quarter the rate for a period of time.

Thank you for responding. We considered the differences in flow and that the quad will be pushing in the normal at 1/4 the rate if it goes through the same line. This is why we initially augmented the volume by y-ing in a NS bag into the line that contained the quad levo. This allowed the levo to move at the same speed as the normal concentration but without changing the mcg/min. After we eventually stopped the saline bag, the pressure dropped and stayed down until we resumed the normal strength and stopped the quad strength. I was wondering if this is a situation like you see with Adenocard? If Adenocard is not pushed rapidly (and flushed), it will loose most of its potency by the time it reaches the heart.

What's the half life, respectively?

If you've y'd the quad strength and NS together as a carrier fluid, when you stop the NS you've now got a diluted quad strength in the line downstream from where it's y'd in and that diluted quad strength (no longer quad strength) will be infusing at a quad strength (low) rate which would give you less effect.

As an example consider if you've got quad strength levo running at 5cc/hr and it's y'd into NS at 25cc/hr. Below the point where they are y'd you essentially now have standard strength levo, but as long as the NS rate remains constant the patient will still get the 5cc/hr of quad strength levo. If you were to stop the NS now you are pushing standard strength levo at a rate that's figured for quad strength until the undiluted quad strength reaches the patient, which could take a while.

That makes sense but after a period of time, shouldn't the quad work just as well as the single strength?

Since you're using the same dose, just different a different concentration, it should have the exact same effect.

Something to consider is how long it might take the undiluted quad strength to reach the patient in the above example where it was running with NS and then the NS was turned off. If the Levo was Y'd in at a point where there is 5cc of lumen volume between that point and the lumen tip, and if the Levo was running at 5ml/hr along with NS at 25ml/hr and then the NS was turned off, it would take a full hour before the patient was getting the proper dose of Levo again.

It's safe to assume this was a whole new IV setup primed with 16/250 also, right? Not just a bag switch?

Sorry I know that's silly but just had to ask...

Although as shocking at it seems, after I've started the higher concentration bag on new tubing, I've even had to consider whether pharmacy actually put levophed in the bag. In the past, I've remixed another bag myself and got a different result.

Yes...if the patient is that fragile it can take up to an hour for things to "normalize". I usually run the new higher concentrate at the old rate for a few mins...when I see the slight bump up will slowly decrease the levo down to the previous rate/min/pt weight.

I know this is silly are you sure it was the correct concentration?

Yep, me too. Continue the rate until the MAP starts to climb then dial it back. :)