A nasal cannula 2 comprises a body portion 4 with first second ends 6,8 spaced apart from each other, a body fluid inlet port 12 at the first end and a body fluid outlet port 14 at the second end, and a first nasal inlet port 16 and a first nasal outlet port 18 each extending from the body portion； the first nasal inlet port in fluid communication with the body fluid outlet port and the first nasal outlet port in fluid communication with the body fluid inlet port. In a first embodiment the nasal cannula also comprises first and second end caps 24,26 attachable to the body portion at the first and second ends respectively, the body fluid inlet port being formed in the first end cap, and the body fluid outlet port being formed in the second end cap. In a second embodiment the nasal cannula also comprises a plate (32, Fig 2) extending from a middle portion of the body.
