Abstract: An infusible replacement fluid does not require separate regulatory clearance and does not need to be prepared by a pharmacist. The fluid is made from constituent fluids that are cleared for infusion. Further, the fluids are available in standard volumes of such size that that the proper proportions may be provided by a convenient number and size of packages. In a preferred embodiment, the replacement fluid is provided to the patient by “hanging” five bags of fluid, one of half-normal saline (e.g., 1 liter bag), three of ringers solution (e.g., 3 liter bags), and one sodium lactate for injection (e.g., 1 liter bag). The resulting concentrations of solutes closely approximates an ideal solution. The above constituents may be purchased and stored in a convenient location and used as required without the need for a pharmacist to prepare the fluids.