Abstract: A cartridge assembly is provided for analyzing characteristics of a sample fluid. The cartridge assembly comprises an assembly body having a passageway, a cavity and, interposed between the passageway and the cavity, a manifold containing a port that serves as a feedthrough between the cavity and the passageway. The passageway forms a flow path through which the sample is drawn. The cartridge assembly also comprises a sensor responsive to a characteristic of the sample fluid. The sensor is housed in the assembly body cavity and is in communication with the passageway by way of the port in the manifold. Optionally, the cartridge assembly includes a temperature monitoring means and a heating means in thermal communication with the passageway. In addition, a method is provided in which the cartridge assembly is used for analyzing a characteristic of a sample. A bedside system for monitoring characteristics of a physiologic fluid comprising the cartridge assembly is provided as well.