Respiratory face mask and breathing circuit assembly

A breathing circuit apparatus for use with an anesthesia mask, wherein said anesthesia mask is sized and configured to overlie at least the nose and mouth of a patient, and wherein said mask has a resilient sealing cushion for engaging the face of said patient and preventing leakage of gas from said mask, said breathing circuit comprising:

• a first flexible tube for connection between said mask and a supply of fresh gas,
• a second flexible tube for connection between said mask and a source of scavenging vacuum,
• a flexible reservoir bag interposed between said second flexible tube and said source of scavenging vacuum,
• a one-way valve interposed between said flexible bag and said second flexible tube, and
• a vacuum modulator interposed between said flexible reservoir bag and said source of scavenging vacuum for reducing the magnitude of the vacuum provided by said scavenging vacuum source sufficiently to avoid collapse of said flexible reservoir bag by said provided vacuum.

The method of administering sedation anesthesia to a patient comprising the following steps:

• a. providing a respiratory face mask having a donut-shaped peripheral sealing cushion;
• b. fitting said face mask to the face of a patient such that said face mask sealing cushion extends underneath the patient's chin and engages the nose portion and mouth portion of the patient's face;
• c. providing a breathing circuit including means for automatically preventing re-breathing of exhaled gas by said patient;
• d. attaching said breathing circuit to said face mask;
• and
• e. applying at least one anesthesia gas to said patient via said fitted face mask through said breathing circuit.