<unk>  is a form of respiration in which a normally air-breathing organism breathes an oxygen-rich<unk>  (such as a perfluorocarbon), rather than breathing air. By selecting a<unk>  that is capable of holding large amounts of oxygen and CO2, gas exchange can occur. This requires certain physical properties such as respiratory gas solubility, density, viscosity, vapor pressure, and lipid solubility which some perfluorochemicals (PFCs) have. Thus, it is critical to choose the appropriate PFC for a specific biomedical application, such as<unk>  ventilation, drug delivery or blood substitutes. The physical properties of PFC<unk> s vary substantially; however, the one common property is their high solubility for respiratory gases. In fact, these<unk> s carry more oxygen and carbon dioxide than blood. In theory,<unk>  could assist in the treatment of patients with severe pulmonary or cardiac trauma, especially in pediatric cases.<unk>  has also been proposed for use in deep diving and space travel. Despite some recent advances in<unk>  ventilation, a standard mode of application has not yet been established.
Liquid breathing
Mouth breathing
Kussmaul breathing
Alaryngeal speech
Shallow breathing
Voice change
Night Sweats
Pursed-lip breathing