An impeller for pumping fluid that comprises discharge flow paths that allow high pressure liquid to be used to flush out low pressure gas that can accumulate within the internal structure of the impeller. The impeller comprises transition regions, vanes, and at least one discharge flow path. The vanes are rotational about a central axis. The transition regions and the plurality of vanes have a high pressure flow path and a low pressure flow path. The at least one discharge flow path is in fluid communication with a section of the low pressure flow path of at least one of the transition region(s) and the vane(s).