TPN HELP!!! (please)

I'm not sure I understand the question. TPN is composed of carbs, proteins, lipids, and lytes. It's formulated to meet the individual patient's nutritional requirement. Here's a PDF I found on parenteral nutrition--may help.

http://web2.umkc.edu/medpharm/nutrition/tpn.pdf

I'm not exactly positive about this, but I believe that they are hung separately because the TPN must run through a specific filter and if the lipids go through this same filter, it can cause the filter to become clogged. However, at my facility our TPN and lipids are separate but going through the same filter.. maybe we have a large enough filter to handle the lipids?? Again, not positive.. but this is a starting point you can go from... Hope you find your answer!

So, quickly, a history of what has brought this topic about-

I'm in clinicals, and I made the egregious misake of asking my instructor this question:

"WHY DO THEY HANG LIPIDS SEPARATELY FROM ELECTROLYTES IN TPN??"

I was told to look it up, found no satisfactory answer and had nothing to present in post-conference. Due to that bit of insubordination (???), I now have a 2 page paper due TOMORROW, and have yet to nail a black and white answer. I will truly appreciate any help I can get. I am terrified that I will not have this done.... Please share any and all information that you guys have.

My guess is your instructor did not know, and hence had you do the research. I know they used to hang seperately but now I almost always see them hung in 1 bag. However, in the past it might have been to either more accurately measure how much lipids you are getting or to monitor for adverse reaction to the lipids.

I found this website:

http://www.merck.com/mmpe/sec01/ch003/ch003c.html

which includes a section:

Adverse reactions to lipid emulsions (eg, dyspnea, cutaneous allergic reactions, nausea, headache, back pain, sweating, dizziness) are uncommon but may occur early, particularly if lipids are given at > 1.0 kcal/ kg/h. Temporary hyperlipidemia may occur, particularly in patients with kidney or liver failure; treatment is usually not required. Delayed adverse reactions to lipid emulsions include hepatomegaly, mild elevation of liver enzymes, splenomegaly, thrombocytopenia, leukopenia, and, especially in premature infants with respiratory distress syndrome, pulmonary function abnormalities. Temporarily or permanently slowing or stopping lipid emulsion infusion may prevent or minimize these adverse reactions.

So when one of those reactions do occur - it can be harder to stop a combined bag that you need for other nutrition than to stop an individual lipid container.

You might also check out:

http://www.ceufast.com/courses/viewcourse.asp?id=180

Not sure how you will get two pages out of that - but good luck.

Hope this helps

Pat

At my last hospital, the pharmacy prepared TPN with lipids/electrolytes/drugs/additives in the solution. At my current hospital, lipids are hung separately in its own bag. I'm assuming this is the practice where this student is having clinicals, and he/she is asking why lipids are separated in their own bag.

My answer would be "because pharmacy made it this way." LOL

Seriously, though, I'd talk to the hospital pharmacist and ask them for the rationale and any resources that may point to why that would be best practice versus including lipids and electrolytes in one solution. Both preparations exist in real life practice!

I'm not exactly positive about this, but I believe that they are hung separately because the TPN must run through a specific filter and if the lipids go through this same filter, it can cause the filter to become clogged. However, at my facility our TPN and lipids are separate but going through the same filter.. maybe we have a large enough filter to handle the lipids?? Again, not positive.. but this is a starting point you can go from... Hope you find your answer!

I don't think that is correct. When I hung TPN preparations that included lipids in the solution, we used an in-line filter and they made their merry way to the patient.

I don't think that is correct. When I hung TPN preparations that included lipids in the solution, we used an in-line filter and they made their merry way to the patient.

Could be a bigger filter. The 2nd source I quoted before said for TPN alone it is a 0.2 micron filter, whereas if you filter both it is a 1.2 micron filter.

Pat

In my experience the Filter size does matter! So, it depends what your hospital buys. I have worked in hopitals where we run lipids and TPN throught the same filters and some that you have to run the lipids in after the filter (so you do not clogg the filter up). Another reason can be the type of tubing. Some tubing needs to be changed every 12 hours when running lipids, and TPN can run for 24 hours before the tubing needs to be changed. I have worked in places that mix the TPN and lipids in the same bag, I have not seen that in the last few hospitals..I think a lot of what we do is dictated by what the hospital has in stock. I agree with one of the previous posters, call the pharmacy and ask the pharmacist... they can tell you why they do it that way in that facility.

It's definately got to do with the filters required. Also, many years ago when I dealt with such things, it was also due to the rate of infusion being different. You may have 2 or 3 bags of TPN go in each day, but only one bottle of lipids. I agree that your instructor probably didn't know the answer too !

I always thought it was because the lipids required a special filter. BUT, I agree that if you call the hospital pharmacist and tell him you are a nursing student at the hospital. Ask why they do it? I'm sure he or she could help you and direct you to written info about it. Hope this helps. =)

You guys were AWESOME... however, since I'm not too familiar with this site yet, I'd like to thank everyone at once, having not figured out how to respond individually.

The pharmacist was indeed the best source of information, though she was busy and a bit brisk... she told me that the reason the lipids are separated is due to the fact that if a lipid emusion is present, it will obsure any presence of precipitation. Another interesting fact: it's not the same precipitation as outside!!! It refers (as I'm sure you ALL already know) to crystals being formed in the fluids. Wow. The more I learn, the more I realize I don't know ANYTHING!!

Amazing!

Thanks again for all your help- and whoever said that about making this a 2 page paper- NO JOKE!! A one sentence answer does not 2 pages make. Oh well- I'll do my best... lots of fluff.

THANK YOU THANK YOU THANK YOU!!! You guys are incredible, and I'll be back soon, I'm sure. XOXOX

It also has to do with the fact that some additives (ie electrolytes) are more stable in the dextrose solution than in lipids--so they'll keep longer, meaning less costs for the hospital.

And, who does the hospital get discounts from? Maybe the pharmacy that produces them separately, so they go with those.

Finally, in acute care, the electrolyte solutions may change daily based on labwork, while the amount of lipids infused is stable. If the hospital keeps the lipid solutions separate, then there are less total solutions they have to buy and store or prepare and store. In larger hospitals that go through a lot of TPN/PPN and lipids, this isn't a big deal. But in smaller hospitals, stocking every type of PPN/TPN with AND without lipids would be a prohibitive expense.

Also, not too long ago lipids used to be in a GLASS BOTTLE, bought "as is" by the hospital pharmacy and did not need to be altered in any way. TPN is a big BAG of dextrose that the pharmacy adds substances to. Our tubing is a Y set with a shared filter but the side that the Lipids are spiked has a vent for the glass bottle. Of course lipids are mostly in bags or plastic bottles now but still a reason that they were hung separately.

Another point to bring up is the fact that the dietitian and/or doctor makes changes to the rates of the lipids and TPN separately according to blood work and pt response. Having them separate allows you to adjust the rate of each.

These are more just "side" points to bring up. The posters above and the pharm. definitely got it right!

Good luck on the paper!