Abstract: A method and apparatus are provided for ventilation of patients during general anesthesia. Breathing gas is supplied to the patient during anesthesia at a controlled volume above the functional residual capacity of the patient's lungs. The patient is allowed to spontaneously respire when the volume of breathing gas is above the functional residual capacity. The pressure of the breathing gas is periodically reduced to facilitate expulsion of carbon dioxide-containing gas from the patient. The system promotes alveolar ventilation, carbon dioxide excretion, oxygenation and respiratory monitoring in patients who receive general anesthesia.

Abstract: A novel respiratory method and apparatus permits ventilatory therapy in patients requiring respiratory assistance by establishing a substantially continuous positive airway pressure to enhance functional residual capacity, and a periodic release of the substantially continuous positive airway pressure reduces airway pressure at intervals to permit passive reduction in lung volume below functional residual capacity to thereby enhance alveolar ventilation and carbon dioxide excretion.