A method for gas-supersaturating fluids, e.g., physiologic saline, includes providing a chamber having a first inlet to receive the fluid; a second inlet to receive a gas, e.g., oxygen, from a gas supply that maintains pressure within the chamber at a predetermined level, advantageously about 600 psi; and an outlet advantageously coupled to a capillary assembly. An atomizer nozzle coupled to the first inlet advantageously creates within the chamber fine droplets of fluid into which gas diffuses to create the gas-supersaturated fluid, which collects within the chamber below the atomizer nozzle for removal via the outlet.