Confusion With Pumps and Seeking an Easier Method

I am actually a new grad. I haven't had tons of experience in clinicals to program new meds into a pump...Anyway the problem may be with my math skills.

All other areas on the pump are pre-set in my facility. I haven't seen my preceptor program anything else into the pump except in the VTBI space.

My preceptor and I hung blood, and on the pump there are 4 areas to fill in.

I know one is VTBI. This represents the ml/hour, right? So let's say for an antibiotic, I wanted it to infuse in 30 minutes (given that is the Dr.'s order), and it's a 50 ml bag, I would plug in 100 ml, which I get.

For some reason, I want an easier way to figure this scenario out. So my preceptor and I hang blood, she wants to check on the patient 15 minutes later (makes sense) so she tells me to put 75 ml under VTBI, and that's it. I forget how many ml were in the bag of blood..maybe 250? Is there a formula to figure this out, preferably dimensional analysis? (If I want to check on my pt 15 minutes later, and the volume in the bag is 250, what am I plugging into VTBI on my pump?) I'll think this out on my own, but I want to post this before I start that..I am on a fast paced unit, so I would love a formula for this (which I have forgotten from school)

I have worked on a lot of my dose calculation skills, but this part of dose calculations is something that slightly confuses me.

12 Answers

First of all, are you dealing with an Alaris pump or a Baxter pump? If it's an Alaris pump, the easiest way to do this for blood is to program the rate and VTBI. In our facility we need to do VS before the blood administration, 15 minutes after the start of the blood, and again at the end of the infusion. So you can program your pump for a rate of 120mL/hr. and a VTBI of 30mL. This does 2 things: first, it starts the blood at a slow rate so that you can watch the patient and see if they have an adverse reaction to it; secondly, the pump will beep off at 15 minutes reminding you to do a set of VS. So long as the patient is tolerating the blood without any adverse reactions, now you can program the pump at a slightly higher rate along with the remaining volume to be infused. Blood usually contains anywhere from 200mL to 400mL of volume and sometimes the actual volume is on the blood tag. After the 15 min. VS and it is time to reprogram the pump for the remainder of the VTBI, I always short the VTBI by 25mL so that the tubing doesn't go dry. That way the pump will start beeping and I can go in and add some VTBI and then switch the line over for the NS flush. For example, if there was 300mL in the bag to start with then I would program the remainder of the bag at 100-150mL/hr and a VTBI of 225mL. You can run blood over a minimum of 1 hour and a maximum of 4 hours.

Specializes in Emergency Department.

VTBI = Volume to be infused.

Rate = ml/hr

If you have 100 ml in the bag and you want to infuse that 100 ml, you put 100 ml in the VTBI blank.

If you want that to go in over 30 minutes, you put a rate of 200 ml/hr because that will infuse 100 ml in 1/2 hours (30 minutes).

If you want it to go in over 2 hours, you would put in 50 ml/hr.

The volume that is to be infused does not change. The rate does and changing the rate changes the amount of time it takes to infuse that amount.

Specializes in Emergency Department.

What your preceptor may have done is program a small VTBI at a relatively slow rate so that the pump will automatically beep and stop at 15 minutes so that she has to go to the patient and pump to intervene and do her 15 minute check. If everything looks OK, then she might then program the pump for the rest of the remaining volume at a faster rate that will empty the bag within the allowed time.

It all depends on the rate at which you are running the fluid. In this scenario, you said that the approx volume TBI was 250ml. If you wanted that to run in over 1 hour your rate would be 250ml/hr. If you wanted to check on the patient in 15 min (1/4 hour) I think you could set up a cross multiplication problem like this: 250 ml / 1 hr x 1/4 hr. The 1's don't change and you divide 250/4 to get 75ml/15 min. Now your pump will alarm after 15 min (when 75ml's have been infused) and you can go get your vitals. Assuming all is okay, you can then program in the remaining VTBI as 175ml at a rate of 250ml/hr and then all of the fluid (blood in this case) would be delivered in that 1 hour time frame.

Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.
So VTBI only tells you how many ml are in the bag, the ml/hr is important because that's the order. VTBI is important b/c it tells the pump when the IV bag is empty.

So I guess what's important is knowing how many ml's are in the bag and what the ordered rate is.

What is the formula to figure out what my preceptor did?? In other words, is there a dimensional analysis method to figure out how many ml should i put in VTBI if i want to check on my patient in 15 minutes?

Don't make this more complicated than you have you. For the blood. I am sure she programmed VTBI for 75 so that you may return to take vitals and reset the pump.

Your facility probably has a set policy that states how many mls are in 1 unit of blood....usually 350mls.

You know that your blood (non emergent) must be infused in no more that 4 hours.

To me it sounds like your preceptor set the pump to infuse the unit. But set the volume to be infused at 75 so the pump would call you back for a set of vitals then reset the pump for the rest of the infusion by resetting volume to be infused without the exact numbers it is impossible for me to say exactly what she did....ask her.

Depends on the type of pump but both types I've worked with have a rate field, VTBI, and time field. There is a fourth but it just tells you the total amount infused and the only option there is to clear the amount to zero. The other 3 fields are programmable. Is it possible that she programmed the rate at 75mL/hr and set a time limit of 15mins (that's the rate I typically run blood at for the first 15mins- IV gauge barring I speed clear the NS in the tubing at a rate of 200 until the blood fills the entire length of my primary tubing until my first tinge of pink enters the extension set connected to the IV catheter in my patient and then I bump the pump down to 75/hr and start my 15 minute countdown. After that is up and they have no s/s if a reaction I speed the pump up to 125 or more depending on patient condition/history.) Or the other option is that if she's been hanging blood long enough that at a rate of 75mL/hr 18 mLs would infuse over about 15 minutes (75/4=18.75) and that would just be a number she memorized.

Specializes in Family Nurse Practitioner.

My first thought was that she was running the blood slow for the beginning of the transfusion and wanted to know when the first 15 minutes were up. Check your policy. At my hospital there is no ordered rate for blood transfusions. Nurses titrate based on patient's history and how they are tolerating the infusion (vital signs and lung sounds). My current hospital uses the alaris pumps. I set up tubing and saline bag and run at 20ml/hr. I select RBC as drug/IV fluid type. When the blood comes, I change the VTBI (volume to be infused) to the volume on the blood bag. Then I change the rate to 999 ml/hr until the saline in the tubing goes into the patient and the blood starts to flow. I keep my finger near the pause/stop button until I see pink tinged fluid next to the IV. I change the rate back to 20, and then I hit start and time the start of the transfusion from this time. I only run the blood at 20ml/hr for the first 15 minutes and stay in the room with the patient (hospital policy). Some RNs will start running it at 50. After 15 minutes I do my vitals and increase the rate to anywhere from 70 to 150 ml/hr. 100 ml/hr is typical.

VTBI = Volume to be infused.

Rate = ml/hr

If you have 100 ml in the bag and you want to infuse that 100 ml, you put 100 ml in the VTBI blank.

If you want that to go in over 30 minutes, you put a rate of 200 ml/hr because that will infuse 100 ml in 1/2 hours (30 minutes).

If you want it to go in over 2 hours, you would put in 50 ml/hr.

The volume that is to be infused does not change. The rate does and changing the rate changes the amount of time it takes to infuse that amount.

So you're saying that VTBI is only the amount?

Ok, so like you said, if i wanted 100 ml to go over 2 hours, I would put in 50 ml/hr...in VTBI? or in the rate? I'm assuming rate. This I understand,...kind of. What i'm confused about is why my preceptor put in 75 ml in the VTBI, I'm pretty sure it was in the VTBI slot. and this was blood. If I remember correctly, it was ilke a 250 ml bag (of blood). She wanted to set the pump up so that the pump would go off after 15 minutes...If i'm not remembering this accurately, can you tell me how she would do this on the pump? Change the settings so that the pump can beep at 15 minutes? When i say "so the pump will go off" or "beep", I meant that my preceptor wanted to do her v/s and assessment after 15 minutes (I'm sure you all can understand why).

Do you know what I'm asking? Please LMK.

I didn't mention that the preceptor didn't bring the kardex to the room, something I always did in school. Soo, the missing ingredient is the ordered flow rate. I just kinda followed her into the room, and she was like "you wanna hang some blood?" after I had just left my assigned patient's room.

So VTBI only tells you how many ml are in the bag, the ml/hr is important because that's the order. VTBI is important b/c it tells the pump when the IV bag is empty.

So I guess what's important is knowing how many ml's are in the bag and what the ordered rate is.

What is the formula to figure out what my preceptor did?? In other words, is there a dimensional analysis method to figure out how many ml should i put in VTBI if i want to check on my patient in 15 minutes?

I knew the girl (patient) needed blood. I failed to look at the order, since I was just following my preceptor (this patient was too critical and anxious for me to have any part of her care, I assume). So there was some information missing. I got too ahead of myself, but I guess that's what I'm missing, the rate and ml in each unit. And yes, I know why she put in such a small volume, I know vitals are needed 15 minutes later.

Specializes in Critical Care, ED, Cath lab, CTPAC,Trauma.

Right....but usually PRBC unit is 350mls. It is to infuse over no longer that 4 hours.

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