A nasal cannula comprising: a body portion, having a first end and a second end, the first and second ends being spaced apart from one another by the body portion； a body fluid inlet port formed at the first end, and a body fluid outlet port formed at the second end； and a first nasal inlet port and a first nasal output port each extending from the body portion of the cannula, the first nasal inlet port being in fluid communication with the body fluid outlet port, and the first nasal outlet port being in fluid communication with the body fluid inlet port, wherein the nasal cannula comprises first and second end caps at the first and second ends respectively, which first and second end caps are attachable to the body portion, and wherein the body fluid inlet port is formed in the first end cap, and the body fluid outlet port is formed in the second end cap.
