Liquid breathing

Liquid breathing is when an organism that usually breathes air breathes a special liquid rich in oxygen. This liquid can exchange carbon dioxide ($\mathrm{C}\mathrm{O}{\phantom{A}}_2$) and oxygen, like perfluorocarbon ($\mathrm{P}\mathrm{F}\mathrm{C}$).

It should possess some properties like dissolving of gases in it, appropriate viscosity and stability. Correct selection of PFC is highly important based on medical application, whether respiration or drug delivery or blood substitution is required. PFC liquids can carry more oxygen and more $\mathrm{C}\mathrm{O}{\phantom{A}}_2$ as compared to blood.

Liquid breathing could save the life of a person who has sustained serious injury to their lungs or heart. Liquid breathing has also been proposed for use in deep diving It could also be used for deep-sea diving and space travel. But there is no standard way to use it yet.