What rate should I infuse at?

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Here is a scenario question..

I have a two way y- connector. One port is running a medication at 4 ml/h. The other port is running a driving fluid at 11 Ml/h. These are the only two things running through my line. This is just a scenario, so don't need to ask why I'm running a driver etc etc.

I have an order to stop running the mediation, but there is medication remaining in the connector (where the two ports join) just proximal to the line... Therefore I need to run a flush to safely infuse the rest of this medication.

what rate do I run it at? Do I run it at 4ml/h? Or do I run it at 15 ml/h?

i guess my question is... When the two connectors join, what rate is the combined fluids running at? :)

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Specializes in MICU.

I think you should infuse it at the prescribed rate

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what rate do I run it at? Do I run it at 4ml/h? Or do I run it at 15 ml/h?

i guess my question is... When the two connectors join, what rate is the combined fluids running at?

What do you think you should do?

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Well, I would run it at a rate of 11ml/h. Because we titrate to effect, and the medication would have been diluted at the connected site and running at the higher rate into the patient.

i don't think that running 4ml/h in one port and 11ml/h in the other port equals a total of 15ml/h.

Do you agree? Or is there something I'm missing.

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i don't think that running 4ml/h in one port and 11ml/h in the other port equals a total of 15ml/h.

Why not?

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Specializes in Med/Surg, Academics.

You have multiple dose-and rate related questions here, in my opinion.

The pt is receiving a total of 15mls per hour: 4 mls of med and 11 mls of IVF. No matter how fast your IVF is going, the pt is still receiving 4mls of med and hour because that is controlled by the med pump.

Only if you change the rate of IVF while the med is being infused will the patient receive the med faster or slower, but that's only for the volume of med already in the line. It will still be a total volume of 4 mls per hour, but with the small amount already in the line received at a faster or slower rate. That could make a big difference for the patient with such small amounts necessary for med effect.

That said, you flush the line at 11mls per hour after disconnecting the med line. Anything faster or slower changes the rate (but not the hourly volume) at which the patient receives the med left in the line.

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Thank you very much for directly answering my question. :)

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Specializes in Critical Care.

To finish the infusion at the prescribed rate, you would actually need to increase the "driver" fluid to 15 ml/hr after the medication drip at 4ml/hr is stopped. I don't think there's any reason to do that, personally I would let it finish at the slower rate, that's one of the purposes of the driver/carrier fluid is to clear the line when the infusion is done. You do need to consider why it's being stopped however, if you're stopping a nipride gtt because their pressure is 60/40, then you don't want the remainder in the line infusing at all.

The rate however of the driver/carrier fluid would need to go up to 15/ml hour to push in the medication remaining in the line at the same dose the patient was receiving prior to stopping the medication infusion. Think of it this way; let's say the medication is 1mg/ml (the exact concentration makes no difference for this example), once the medication combines with the carrier fluid while both are running, you now have a concentration of 4mg/15ml running at 15ml/hr (4mg/hr). Once you stop the medication infusion, the concentration in the line ahead of the medication port is still 4mg/15ml, but it is now being pushed into the patient at only 11ml/hr, which means the patient would be receiving 2.9 mg/hr instead of 4 mg/hr.

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Specializes in Med/Surg, Academics.

Good lord, I'm an idiot! Muno's right.

Here's a question concerning med in the line, especially central lines. (I don't work ICU....thankfully, apparently. :unsure: )

What do y'all do with med in the lines when, as in your example with Nipride, you want it stopped NOW.

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Specializes in Med/Surg, Academics.

On the bright side, I give wrong answers with such confidence and style.

*bows*

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Specializes in Critical Care.
On the bright side, I give wrong answers with such confidence and style.

*bows*

I'd be willing to bet a large percentage would give the same answer you did as on 'off-the-cuff' answer, it's an easy one to rationalize incorrectly. The main thing is that it's probably not actually significant either way, so basically both answer have the same effect.

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Specializes in Critical Care.
Good lord, I'm an idiot! Muno's right.

Here's a question concerning med in the line, especially central lines. (I don't work ICU....thankfully, apparently. :unsure: )

What do y'all do with med in the lines when, as in your example with Nipride, you want it stopped NOW.

In the nipride example I'd stop the drip and aspirate the lumen it's in until I hit blood, I'd then wait to flush the blood until I had a blood pressure that would allow for whatever small amount of nipride was still in their to be tolerated. It get's trickier when your medications for undoing what the nipride did are in the same lumen as the nipride. For instance open heart's typically come back with various drips hanging and all hooked up to the med-port on the PA catheter; NTG, nipride, nicardipine, dopamine, levo, vaso, might all be going through the same port, so to give your dopamine/vaso/levo (prior to more volume) to correct the hypotension you're likely going to still push through some nipride with it initially

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