Abstract: A diagnostic monitor checks the carbon dioxide (CO.sub.2) content of a gas exiting a patient during endotracheal or esophageal intubation. A plurality of composition portions substantially change color in response to exposure to the carbon dioxide. The composition portions change color in response to different times of exposure to carbon dioxide. A magnifying or condensing lens may be positioned on the monitor to enhance viewing of the color change. The monitor may advantageously be made as part of an intubation system through which the gases from a patient exit the patient. The differences in time of exposure needed to cause the color change may be accomplished by using semipermeable membranes having differing thicknesses, CO.sub.2 permeabilities, and/or surface areas with each membrane corresponding to a particular one of the composition portions.

Abstract: A self-contained jet pump type breathing apparatus is provided for introducing gases into the lungs of a patient having an inspiratory jet pump for sweeping gases toward the patient, an expiratory jet pump for sweeping exhaled gases away from the patient and an absorber for absorbing carbon dioxide from the exhaled gases which are again supplied to the respiratory jet pump. An anesthetic introduction conduit permits the flow of anesthetic gases into the breathing apparatus. In addition, a jet producer device, is also provided, which obtains fresh compressed gases from the absorber and compressor and supplies pulsating pressurized gases to the respiratory jet pumps.