Is Liquid Breathing In Our Near Future?

There's something serene and calming about watching a fish swim underwater. Whether you're enjoying "The Little Mermaid" or engrossed in a particularly thrilling sci-fi movie about delving into the depths of the ocean, maybe a small part of your mind has wondered — what if we, humans, were able to breathe water like fish do?

Turns out, you're not the only one with such a fascinating thought. The concept of liquid breathing has existed for some time — more specifically since the First World War, when saline solutions were applied to the lungs of dogs as a means of researching how to combat poison gas inhalation. Eventually, the interest shifted to focus on liquid breathing as a means to safely escape a submerged submarine. But, science soon found out that the lungs of mammals aren't built for extracting oxygen out of water instead of air. The air we breathe has about 20 times as much oxygen than what's available in water, for starters. Plus, liquid is thicker than air, which means it's a lot more challenging to flush it out of our bodies.  

But this didn't stop researchers from looking into how liquid ventilation could benefit man in the future — whether it's to travel into outer space more easily, dive underwater to depths hitherto unexplored by humans, or more importantly save lives in hospitals. In the 1960s, researchers experimented on mice and cats who were submerged under colorless, odorless, and non-toxic liquid called perfluorocarbons to see how they faired. 

What are perfluorocarbons and could they be the answer to liquid ventilation in the future?

The 1960s research moved to a liquid made with perfluorocarbons, or PFC, instead of water. Perfluorocarbons are molecules made using carbon and hydrogen where most of the hydrogens are replaced with fluorine. They are not harmful to your internal organs like the kidneys and liver. Perfluorocarbon liquids (PCFL) also contain a lot of space between molecules, which means they allow room for three times more oxygen as your blood and 40 times more oxygen as water. 

Initial studies saw potential but with partial liquid ventilation — inhaling perfluorocarbon liquid combined with air from a normal ventilator. The reason for partial liquid ventilation is that perfluorocarbons are still thicker than air and don't clear out carbon dioxide from your lungs as quickly as normal air does. However, partial liquid ventilation had apparently worked on people with lung injuries and premature babies with lungs that weren't able to do their jobs on their own. But total liquid ventilation — using only perfluorocarbon liquid — to help those with breathing difficulties is still a quest for our future scientists. 

"The technology of liquid pulmonary ventilation can be used to rescue spluttered people," shared a specialist in liquid ventilation from the Sherbrooke University in Canada, Philippe Micheau (via TASS). While the invention of perfluorocarbons has definitely made strides in the concept of liquid breathing, it's hard to say if complete liquid breathing is something we'll see in the near future. Science has to still solve the puzzle of viscosity — the opposition the natural human anatomy poses to inhaling and exhaling liquid as effortlessly as air.