I’d like to congratulate you for such initiative which I hope to see one day as a standard practice in my home country. However, I agree that some work and budget constraints put a limit to such practice for which I hope that the coming lines would provide a suitable and reasonable alternative for the time being.
Your choice for the items to be prepared is a wise one especially with TPN which is a medium risk preparation. Considering USP 797 and JCI 6th Edition standards:-
Low risk preparations include immediate use CSP with 1 hour beyond use date. This includes IV mixing with simple manipulations of adding a solution to vial which constitutes the majority of mixing practices. Such practice can be performed on site using aseptic technique.
Based on the logistics of service available for you I’d like to recommend the following:-
1- Developing an IV manual listing the standard dilutions that should be used to be familiar among the prescribing physician, pharmacy and nursing staff.
2- Priority for preparation in the pharmacy during the working hours to be for medium and high risk preparations as well as supplying the daily doses of all IV preparations.
3- Perform a hospital wide in-service training for the nurses regarding:-
A) Levels of risks associated with CSPs and those allowed to be prepared on site.
B) Proper use of ASEPTIC TECHNIQUE for preparing low risk CSPs on site in a dedicated area to do so.
C) Stress on the use of standard dilutions recommended by pharmacy so that the practice would be unified.
4- Use of premixes for medication with long refrigerator BUDs can save you a lot of effort, time and risk. This can be instituted for many commonly used antibiotics.
5- Proper recycling of the unused preparations.
In other words, that’s to utilize nursing staff to work with the same pharmacy standards so that it would be easy for you when you transfer to a full pharmacy lead IV service.
On the other side, you have to perform continuous quality checks that includes, but not limited to:-
1- IV order load outside the working hours.
2- Items that are commonly ordered out of working hours to be prepared as premixes, as possible.
3- Monitor any reported infections due to failure to follow standard aseptic technique.
4- Monitor the compliance with standard aseptic technique by nursing staff.
5- Reported error rate associated with preparation outside the pharmacy.
6- Wastage due to discontinued orders.
You can combine the above data in a way that will give you an insight about the efficiency of the service and a measure to convince your management about the importance of utilizing a 24 hrs service if it appeared to be more cost efficient.