A Windows(r)-based program for order entry and total parenteral nutrition (TPN) calculation. Abacus was designed by health-system pharmacists to ensure safety and reduce the opportunity for user errors in the prescribing, calculating and mixing of parenteral nutrition solutions. Abacus may be used to implement physician TPN order entry, with orders held for final checking by pharmacists. It calculates and balances physician prescriptions and allows warning limits to be set according to customer protocols. The program can be customized to match individual facilities' forms and procedures. According to the ASHP (see 1 below), approximately 65% of US hospitals use automated compounders for mixing parenteral nutrition solutions each day. These hospitals are the target customers for Abacus, which replaces Baxa Corporation's TPN-PC(tm) and TPN-PC Plus(tm) Software for order entry and calculation. Abacus is available as a stand-alone calculation tool (Abacus CE), in a single-user edition (Abacus SE) and a multi-user edition (Abacus ME). The program complements the Baxa line of automated compounders - the Exacta-Mix(tm) 2400, the MicroMacro(tm) 12 and 23, and the Exacta-Mix 600.