Comments
how to represent IV administration with notmal saline, e.g., Penicillin G 100000 UNIT/ML Injectable Solution, 50 mL via IV infusion of normal saline.

See CDA Example task force http://wiki.hl7.org/index.php?title=CDA_Example_Task_Force#MEDICATIONS

https://github.com/jddamore/HL7-Task-Force-Examples/blob/master/MED_IV_Antibiotics.xml

Grahame's Comments
no opinion