Accounting for drug volume in IV infusions

Esme12, ASN, BSN, RN · Jun 19, 2014

For school I am not sure how they teach it. IN nursing you remove the 20mls from the bag then add medication.

Guests · Jun 19, 2014

For school I am not sure how they teach it. IN nursing you remove the 20mls from the bag then add medication.

I'm no infusionist but in my world, I simply add the 20 mL to the 1,000 mL and then round 1,020 to 1,000 for the purposes of calculations... and run the entire bag.

We're talking about a volumetric difference of only 2%.

There are probably medications out there where a 2% difference is significant but I've yet to come across one that I'd mix in a 1L bag.

The only meds that I can think of that I mix in 1000 cc are the ingredients for banana bags (which we don't use at my present facility).

Esme12, ASN, BSN, RN · Jun 19, 2014

We would do it for Cardiac drips when we triple concentrated them. I did work at a facility that did this for EVERYTHING... :facepalm: .

Shayboo · Jun 20, 2014

For our exams, we use the amount on the package. Example: Add 1.7mL of sterile water for a final concentration of 250mg/ mL

So the amount would be 1mL=250mg. If the order was for 500mg-it would be 2mL.

Bedside_Life RN · Jun 27, 2014

I am imagining that there would be two completely opposite responses from nurses reading this post. Some will say it's a minimal amount; don't worry about it. On the other hand they may think...absolutely it matters!. This is because in the "real world" accuracy of IV intake volume is VERY patient specific. For a few prime examples, let me share some experiences where intake volume and even more importantly the variable of what you are infusing is of great importance. For medications that have to be reconstituted you will often find there is a volume on the label for the final solution. In that instance you should follow the given volume. For medications such as vancomycin, tobramycin, etc., that pharmacy often premixes you will see two sections on the label. One area of the label may read "100mL of NaCl" and underneath this will be a secondary label reading "Vancomycin 1250mg/12.5mL". When you get this premix from pharmacy you will usually see a rate of something like 133mL/hr for a total volume of 113mL. In this instance the additive is included, and needs to be infused for a total volume of 113mL. Something to take into consideration with this example and even more importantly with blood transfusions, is the amount left in the tubing after administration. There have been many times when I have found that the issue of "back priming" or inaccurate VTBI leaves medication or blood in the secondary line. It would be important to take into consideration how much fluid your line holds. If the amount is 10mL, and you have back primed, then add that to the VTBI amount. This would be the same for blood products. Nothing erks me more than walking into a patient room and there are still 20mL of blood in the bag and 20mL still in the line. Someone donated that blood and make sure the patient gets as much of it as possible.

Another way to look at the VTBI, even with reconstitutions, is the importance of "why" your patient is in the hospital. Are they here for ARF, fluid overload, HF, Urinary retention, BPH, etc.. All of these and many more require the nurse and supporting nursing staff to be diligent about documenting very strict I&O. In this instance a week of inaccuracy may result in misleading patient progress and the inappropriate D/C of your patient. We want them to be ready to go home (or wherever they come from) and small amounts like 5-10mL with reconstitutions or having to hold maintenance fluids for procedures/transport are important in patient care.

Something that we all may be guilty of is the amount of fluid we give with PO medication administration, or not giving/receiving the amount of fluids from suction, drains, and flushes from tube feedings. For example, it is often hard to decide how much flush you have used between medications for a PEG/J tube/ etc. For the most part, things like this, or even emesis, or numerous loose stools can be easily overlooked.

In the end, these things do matter, so stray on the side of caution, take into consideration your patients' diagnosis and problems list, and document/include ANY addition or loss of fluid no matter how small. If you add 2mL to a bag of fluid, add that amount to the total volume. If you back prime, add your tubing amount to the total volume. Remember you are becoming a professional clinician, and the responsibility and expected standards for Nurses are continuously growing.

So if you change or manipulate any concentration or amount of a solution or medication, you are saying to the BON, I the nurse have knowingly changed the original ordered amount, and this can have a direct effect on medication effectiveness, treatment goals and length of hospital stay or re-admission rates.

Hope this helps even a little for when you become a nurse and are potentially taking care of my family members, or are giving report to other nurses. Who knows, you may even be giving/taking report from a nursing instructor that you look up to. Become the type of nurse that is confident in these situations, but always remember your limits. In nursing, you will never be too intelligent to learn.

Okay, off the soap box. haha