Ask Dr Nerenberg | Health and Fitness

tpn vs glucose iv for nutrition?

Pt quit eating 2 weeks ago and family was told he would be scheduled for a peg. meanwhile he is on an iv glucose infusion. Why wouldn’t they give pt a tpn to keep him strong for the peg procedure. (pt pulled out all ngt’s. ) Are they the md’s hoping he will die before the peg procedure? thus not telling the family about the tpn(total parenteral nutrition) I told them tonight and they will inquire tomorrow. I just want to make sure they are not lied to.

Usually the need for TPN is determined by a “nitrogen” balance equation based upon laborotory tests like BUN and creatinine. Nitrogen balance is an indication of whether muscles are being built or are breaking down. If a patient is in a positive or zero nitrogen balance, then they don’t need TPN. Patients can go several days without food and still maintain a positive, zero or a slightly negative nitrogen balance and do not require TPN which supplies amino acids in addition to dextrose. After several days, patients go into a negative nitrogen balance and start breaking down their own proteins such as plasma albumin and skeletal muscle to supply amino acids that may be needed for production of clotting factors and immunoglobulins. This is where TPN is beneficial because it supplies the needed amino acids. So, the body doesn’t need to use it’s own proteins as a source. The patient is probably starting to go into a negative nitrogen balance after 2 weeks and the physicians are placing the PEG tube to use for enteral feedings in place of the NG tube. The desire is to use enteral feedings if possible rather than TPN for a lot of reasons. The first reason is that there is less risk of infection. Also, most TPN’s are administered through central lines which have to be properly maintained. Another reason is that enteral feedings cost less. Enteral feedings maintain normal bowel function and bowel flora which can be messed up when the GI tract isn’t used for long periods of time. Another arguement against TPN which may not apply in this case is that TPN floods the kidneys with a lot of amino acids which have to go through an active transport re-absorption phase routinely performed by the kidneys. It puts some wear and tear on the kidneys from the extra workload and can worsted renal failure.

I think the family should ask as many questions as needed about the care until they understand the plan. They should ask for a conference with the physician and nurses taking care of the patient. Then they will know for sure what is going on.

In My Work ( Total parenteral nutrition‏ ).MTS