Editing Trimix (breathing gas) (section)

==Advantages of keeping some nitrogen in the mix==
Retaining nitrogen in trimix can contribute to the prevention of [[High Pressure Nervous Syndrome]], a problem that can occur when breathing [[heliox]] at depths beyond about {{convert|130|m|ft}}.<ref name="Brubakk" /><ref name="Hunger 1974" /><ref name="Bennett et al 1982" /><ref name="Campbell" /> Nitrogen is also much less expensive than helium.