A patient support apparatus has a lower frame and an upper supported above the lower frame and movable relative to the lower frame. A plurality of casters are coupled to the lower frame. A wheel is movable relative to the lower frame between a lowered position engaging the floor and a raised position spaced from the floor. A drive assembly is coupled to the wheel and is operable to drive the wheel to propel the patient support apparatus along the floor. A foot pedal is coupled to the lower frame and is movable to raise and lower the wheel relative to the floor.