Enterally-administered TPN?

Sour Lemon · Sep 13, 2017

I know the invariably-fatal consequences of administering enteral feed IV, but need advice about any potential ill-effects if TPN were given via a PEG/PEJ. Clearly it's not optimal, but is it harmful? Asking for a colleague whose colleague's patient received about 6/24 worth when an inexperienced new nurse somehow (yeah, I have no idea either) connected the line to an enteral port.

Well, if you're going to reverse IV and PEG, that's probably the direction you want to reverse. My first thought was that it's probably not harmful, at all ...but then I wondered why the patient was getting TPN to start out with. That probably makes a difference.

talaxandra · Sep 13, 2017

I get the impression they were transitioning from TPN to EN, and the enteral access was new, but it's all third-hand so anything could be the case.

Sour Lemon · Sep 13, 2017

I get the impression they were transitioning from TPN to EN, and the enteral access was new, but it's all third-hand so anything could be the case.

That's probably a best case scenario, again ...no major, recent surgery is good.

mrsboots87 · Sep 13, 2017

Probably the most expensive bag of "tube feed" that nurse will ever hang. Haha

iluvivt, BSN, RN · Sep 13, 2017

It would have been devastating if it was the other way around and enteral formula had been administerered via a central line. In fact, a patient died in Oakland during a nurses strike when a strike replacement nurse did just that. The gut can handle all kinds of things and the patient will probably do fine with some monitoring.

KatieMI, BSN, MSN, RN · Sep 13, 2017

We had a few patients who were fed with TPN mix through j tubes for weeks. These guys had short bowel syndrome and pancreatic exocrine insufficiency, among very many other problems.

Apparently, TPN costs a whole lot but still less than some special nutrition mixes developed for such patients and, at least in one case, Medicaid took his sweet time to approve "special nutrition needs". The patient had to be fed somehow in the meanwhile, so he was getting TPN as a "bridge". Only one difference was that the lipids were run round the clock. It was not ideal way, probably, but it worked fine.

blondy2061h, MSN, RN · Sep 13, 2017

Interesting question. I've never considered this. I wonder what the absorption is like, since tpn is basically the pure nutrients to be delivered directly to the blood stream, not broken down by enzymes and digestion.

KatieMI, BSN, MSN, RN · Sep 15, 2017

Interesting question. I've never considered this. I wonder what the absorption is like, since tpn is basically the pure nutrients to be delivered directly to the blood stream, not broken down by enzymes and digestion.

Absorbtion in this case depends mostly on condition and area of preserved small bowel. Condition of pancreas matters very little (as complex carbs, fats and proteins do not need to be digested). If pancreatic function is preserved, it decreases some after a while but still continues (contrary to popular thinking, it is also very much needed for supporting the enteral function per se, as mucosal lining continues to be regenerated - that's why even people on 100% TPN still habe BMs from time to time).

As food is usually flows in constantly, motility disorders of biliary tree with stones formation can happen.

Glucose level is more predictable than on IV TPN because the complex mechanisms of insulin release like incretin secretion are not bypassed. 30 min break from pump doesn't need to be covered with D10.

Level of satiety comes very sharp and quickly (because of quicker absorbtion of aminoacids) in case of bolus feedings.

Fat-soluble vitamins, B12 and some microelements (iron, zink, selenium, copper) still can need to be substituted parenterally, as they are poorly absorbed at the best of circumstances. Drinking vitamin/elements mixes for TPN doesn't help, as every of them has its own mechanism of absorbtion, sometimes only in one region of bowel, and with only so many molecules being able to absorbed at a time. Nutritional monitoring for such patients is actually more complicated than TPN protocols, but preservation of gut function is too much of a benefit.

I have to go on Vivonex from time to time, which is "elemental" nutrition for adults. The mix is not very far away from TPN by contents, and it looks quite funny when you see this small can, drink it and in 10 min feel like you ate a lumberjack dinner plus some helpings. But in couple of hours I feel hungry again unless I had something else with it. I also spoke with patients with PKU who live on aminoacid mixes for life and sometimes eat little else but pure sugar and starch - they didn't complain on hunger if well compensated.