Italian to English Medical Medical (general) treatment orders

This is from a pre-printed nursing progress note form. On one side of the form, there is an area to write notes regarding procedures/vital signs/tests done in the morning, afternoon and evening. On the other side of the sheet are pre-printed items that deal with diet, mobilization, medication, and tests to be done.

This item is first in a line that looks like this:

[ ] HGT per ___3____ [ ] TMT [ ] PA ogni ___________

I think HGT is HemoGluco Test (see http://www.proz.com/kudoz/3174883)

I think TMT is Treadmill Test

PA is pressione arteriale/blood pressure

The next line, just to be complete, says: CPAP ______ Reservoir ______ Venturi _______ . Other items say Fermo a letto / Gambe giù dal letto / Mobilizzato, and other items talk about diet: Digiuno / Libera / Per diabetici. There is a box or line next to each item which can be checked ['ticked' for the UK folks] or where something may be written in.

In my document, the '3' is handwritten on the line following HGT.

I'm not sure how to translate the 'per' here, because I don't understand what the "HGT per 3" order is asking the nurse to do. (Is it to perform the test every 3 hours? But that would be the word "ogni" as used with the PA.)

What does this "HGT per 3" mean, and how would we say it in English?

Thanks again for your help.