Intended use - The GEM Premier 3500 sensor and reagent PAK (cartridge) is for use by healthcare professionals to rapidly analyze heparinized whole blood samples at point of healthcare delivery (near patient test) in a clinical setting and in a central laboratory. It provides quantitative measurements of pH, pCO2, pO2, Na+, K+, Ca++, glucose, lactate and hematocrit. These parameters along with derived parameters aid in the diagnosis of a patient’s acid/base status, oxygen delivery capacity, and electrolyte and metabolite balance.