Abstract: A compact respirator system for use either connected to stationary outlets for breathing gas or connected as a portable unit to a tube of breathing gas. A breathing bladder and a valve block form a unit that may be disposed either with the breathing bladder in a pressure chamber for conventional respiratory operation or with the breathing bladder removed from the pressure chamber for manual actuation. A pulse transmitter actuates a pressure pulse generator for providing the pressure chamber with intermittent pulses for compressing and expanding, respectively, the breathing bladder for said conventional respiratory operation. An automatic valve keeps open a pilot pressure channel to an expiratory valve forming a portion of a pilot valve, which latter also includes a patient-triggered valve for initiating rapid breathing assistance if the patient shows signs of beginning to breathe spontaneously.