Most important thing to know when using TPN?

I've seen a case of subcutaneous inflitration of the TPN solution due to the development of phlebitis or a clot in the subclavian vein the triple lumen catheter was in. This was in a patient who had a long-dwelling triple lumen catheter. It happened while I was working on an IV Team. Our first clue was that we had continual seepage of TPN solution from the central line insertion site. After countless dressing changes we really starting trying to figure out what the heck was going on. The whole left side of the patient's shoulder, arm and chest gradually started swelling. A couple of us finally took the upper part of his gown down and stood at the foot of the bed where we could see both sides of his body very clearly. The resulting edema was pitting, we discovered. The line had to be pulled and venogram was ordered. We ended up having to do peripheral TPN with 10% dextrose solutions. It is not something that one thinks of happening, but the subclavian vein can develop the same problems of phlebitis as in a peripheral vein.

Back to peripheral TPN. We had a patient on peripheral TPN who's IV kept going bad. After our IV Team changed it 4 times in a 24 hour period someone took a good look at what was hanging on the IV pole. It was TPN meant for a central line! This patient was getting 40% dextrose peripherally! No wonder his IV's were going bad! The pharmacy had failed to change the IV orders (the patient had had a central line pulled) and the nurse who hung the bag on the peripheral line didn't even bother to read the label of what she was hanging, or didn't know that you can't hang anything greater than 10% dextrose on a peripheral line. The IV Team nurses screwed up too because we should have been looking at the label on the bag of fluids.

I've seen nurses who try to place "catch up" when a patients TPN solutions are shut off for numerous antibiotic infusions. They'll figure that the patient is losing anywhere from 4 to 12 hours of TPN infusion because of having to stop to give them IV antibiotic piggybacks so they re-calculated the TPN flow rate to "make up" or "catch up" on what they were thinking the patient missed. Can't do that. It throws the patient's metabolism and electrolytes way off kilter. The flow rates of TPN solutions are calculated by the doctors so as not to shock the person's system with high concentration of electrolytes in it. Running TPN faster than what the doctor has ordered will cause a shock in the patient's electrolyte metabolism.

A good question to ask is what do you do if your TPN bag runs dry and you don't have the next bag. What do you hang to keep the line open? We always hung 10% Dextrose. Also, did you look at the side effects of Liposyn or Intralipid if it is run too rapidly? Sometimes Liposyn is run by itself, other times it is mixed into a TPN solution. Also, it is a big deal to change the IV tubings on these TPN lines every 24 hours and the dressing changes on the catheter site at least every 72 hours using sterile technique. Our IV team was a real stickler on these two things.

Just a funny little tidbit that only nurses who work around this stuff all the time would know. . .the TPN solution is very good for plants. We would have nurses watching out of the corner of their eye for the bag of TPN coming down so they could grab the solution that was left to take home to their plants. TPN solution bags have to be changed every 24 hours whether the solution in them is all used up or not for infection control reasons.