A gas blender with auxiliary mixed gas outlet for mixing a primary gas, generally air, and a secondary gas, generally oxygen, to obtain a mixed gas having several controlled characteristics. The gas blender may be incorporated into a Continuous Positive Airway Pressure (CPAP) device. The gas blender controls the mixing to produce the mixed gas having a predetermined mixture setpoint, generally an oxygen percentage, and a predetermined control setpoint, generally a pressure setpoint or flow rate setpoint. The gas blender provides an auxiliary mixed gas source for use by an auxiliary piece of equipment such as a nebulizer or resuscitation bag. The gas blender includes a primary gas inlet passageway, a secondary gas inlet passageway, a gas mixing apparatus, a mixed gas distribution passageway with an auxiliary mixed gas outlet, a gas sensor, a delivery sensor, a mixed gas delivery control valve, a mixed gas controlled passageway, and a controller.