Abstract: A hose assembly for a breathing system has a corrugated flexible breathing hose with a first adaptor at one (machine) end of the hose for connection to an anesthesia machine remote from the subject patient using the hose for breathing. The adaptor has a cylindrical wall with a sampling port projecting laterally from the wall. A second adaptor is at the opposite (patient) end of the hose for connection to a breathing mask or endotracheal tube. A gas sample tube inside the hose has a sample entrance end projecting from the patient end adaptor a specified amount, extends through the entire length of the hose to the sampling port where it can communicate with a luer-lock connector and external sampling line to a gas sample monitor or, in another embodiment, the tube itself extends to the monitor.