Hi Kim,
No experience with TPN, but E was inpatient when she had her NG-tube inserted, and the home health rep came to see us in the hospital on her last day, and then had supplies delivered to us in the hospital before we left. She said they couldn't always do it that way (I don't think they were allowed to deliver supplies until discharge orders were in), but it sure was nice to have everything we needed before going home. Another rep came to see us the day after discharge just to check on us, and answer any questions we had.
Our insurance provider contracts with Walgreens here in Portland for home health, and they have been fantastic to work with. Their dieticians worked with me several times (including over the weekend) to help find the right formula and feed rate for my daughter when she was have problems with nausea.