IV infusions

You can set up an experiment to see what happens. Get 2 bags of fluid yellow and blue food colouring, and set it all up as you would administer it to a pt. If you see green anywhere you shouldn't then your colleagues are correct.

i don't see how's that bolusing. if one is on a pump and the other drip is free flowing, there won't be enough drip in the tubing that is on a pump to be bolused anyways.

Ideally you should have it on another line, but since you have only 1 line, run the versed on a pump along with the bolus; start another line, then switch it to the new line. We joke about "everything is compatible in the world of anesthesia" because the open hearts come back with everything infusing into 1 port (pressors, antibiotics, blood, insulin, etc)! I guess they figure as long as it doesn't clog your line, it's ok temporarily. Just fix it later.

The best practice is to to have a dedicated lumen of line for your drips but that is not always possible so if you have to do the next best thing until the situation changes. If you had one good PIV in place just simply add a double extension set directly to the cannula. then put your bolus onto to one and your Versed onto the other. It does require you to peel off the dressing, have a primed dual extension set ready and then redress the site. If you have a T ext set on the PIV or use the intima or nexiva there is a Y right at the site

Another option is to set up the the bolus line as your primary and then then set up the drip as a primary that is infused at the closest Y site below the port with both on pumps. The Versed drip will still only deliver the amount of drug that you have set your volumetric pump to deliver.

As far as depending upon a precipitate to clue you into the fact that you have an incompatibility unfortunately that is only one of the potential incompatibility problems which would be a physical incompatibility. You can also have chemical and therapeutic so do not rely only on a physical and visible reaction.

If there is any time where only the medication is running, then at that point there is only medication in the line (say, going at, for sake of illustration, 4cc/hr, and the tubing holds about 8cc so the tubing is 100% medication and 0% bolus fluid). Let's pretend it's blue, so you can see it well. It's blue all the way down to the vein.

Then, upstream, the bolus pump kicks in at 150cc/hr, and in an instant two hour's worth of medication essentially gets pushed (or more, depending on how much of that tube was full of blue before). This could be an exceptionally bad idea for many meds given as maintenance drips, like hemodynamic meds, sedation, or electrolyte replacement.

After that push, of course the medication is being flushed in at its set rate along with the bolus. Since it's along for the ride with the bolus fluid, the concentration the medication is quite low, although the absolute amount of it going into the patient is accurate, 4cc/hr. Your tubing is now very pale blue, right? That 4cc little bit of blue diluted by the bigger amount hourly of bolus, but at least it is received at a constant rate.

Now, however, the bolus is shut off. The tubing is still mostly bolus fluid, with a little bit of medication in it, the palest of blues. However, now it's only running at 4cc/hr, the rate of the medication drip up above, and there isn't much medication in those initial cc of fluid in the tube-- it's mostly bolus fluid, so for some longish period of time the patient is not getting his maintenance dose of medication, in this example, about two hours. Also not a good idea for any med meant to be given at a constant rate.

Not until the blue has had a chance to come down and fill the tube all the way to the vein is the patient getting his regularly-scheduled dose of blue stuff.

This is why you need a double-lumen line. The blue stuff is in one and is never pushed, flushed, or drawn from, to maintain a steady administration rate. The boluses run through the other lumen (or another line entirely), being locked or TKO in between boluses.

Hope that helps you visualize why you never run boluses on top of med drips.

As others have pointed out, you need to consider the volume of fluid between where fluids enter the line and the patient. A varying rate in the fluids a gtt mixes with can cause unintentional boluses as well as periods without the medication. If you're titrating frequently, even a constant rate in the mainline with too much volume between the gtt connection and the patient can cause delays in when your titrated rates actually reach the patient.

That being said, when done correctly there's nothing wrong with running variable rate mainline and gtts. The issue isn't whether what's reaching the patient will change ever so slightly, because it always will, it's a matter of what's clinically significant.

I never like to Y-in gtts on the mainline itself, even the lowest port. I prefer micro bore splitters, these have a volume of <.1 ccs>

If you're using an angiocath, your first one can go directly to the hub. Even when you're using a Nexiva catheter, which will have the largest volume between the gtt connection and the patient, the volume is still on 0.4cc. So, if you're running a fentanyl gtt at 10mcg/ml and the mainline complete stops allowing the catheter volume to fill with fentanyl and the restarts, you're only bolusing with 4mcg, which isn't clinically significant. With each gtt consider the length of time the med remains active as well as the volume of lumen between it and the patient, as well as in terms of time to patient, and it's very much possible to do this effectively and safely.

Think about it this way: If you're peeing into a river, you're still just peeing... you don't "feel" the rate of the river...

Pump A is controlling the bolus through the primary line while pump B is controlling the drip through the secondary line.

I hate these threads, they only put doubt in my head.

Doubt why? There is no doubt that there is a best practice way to do this! It does require an understanding of physics,pharmacology and nursing. I do not like to guess or take chances when I am infusing anything I would prefer what evidence suggests is the best way to do it. I realize that in nursing/medicice that sometimes you have to make things work until you can do it the best way. We had to give levophed peripherally until we could get there to place the PICC the other night plus countless other examples that I can give.