Liquid Breathing – It’s Not As Easy as It Looks

Who can forget James Cameron’s movie The Abyss!

If I need to remind you, Cameron is the creator of Avatar.

The Abyss was an imaginative movie of the 1980s, where the plot concerned commercial divers who had been hired by the Navy to assist with the salvage of a nuclear submarine. It involved very deep diving, and special technology that actually has some basis in fact.

By far the most memorable part of the movie involves a diving helmet filled with a liquid that the diver, with some trepidation, breathed.

Below is a clip from the movie that demonstrated, quite dramatically, and with a live animal, the concept of liquid breathing.



It’s not a trick – it really works, on small rodents.

In the 1960s and 70s the Office of Navy Research funded basic research at Duke University on liquid breathing, with Dr. Johannes A. Kylstra as the lead scientist on the project. After proving the technique worked on rodents and dogs, it progressed to the point of having a commercial diver, Frank Falejczyk, become the first person to breathe oxygenated liquid.

First, Frank inhaled well-oxygenated saline on an operating table. Unfortunately, extraction of the liquid from his lung did not work as planned. He developed pneumonia as a result of the exposure. But eventually, the researchers found that oxygenated perfluorocarbons could be tolerated by the lung, and could, at least in animals, allow the extraction of dissolved oxygen for a period of time without ill effects.

Eventually, Falejczyk made a presentation on his trials to an audience that happened to include James Cameron.  Apparently, Cameron was impressed.

So, can man breathe liquid and not drown? At least one retired physician says yes. Arnold Lande, a retired American heart and lung surgeon, has patented a scuba suit that would, he suggests, allow a human to breathe oxygenated liquid.

Now, making such a device work is in fact a tall order. Although Kylstra’s animal experiments showed that rodents and even dogs could be ventilated for up to an hour, the limiting factor seemed to be the accumulation of carbon dioxide in the body. The perfluorocarbons gave up their stored oxygen readily, but did not adequately eliminate carbon dioxide.

That is a major problem.

In the 1980s an Israeli colleague and I conducted biomedical research on potential Navy applications of high frequency ventilation (HFV), an unusual method of mechanical ventilation that now has many clinical applications. It soon occurred to me that appropriate frequencies applied to the mouth or chest wall could greatly accelerate the diffusion of carbon dioxide in liquid, just as it did in air. However, I never proposed studying liquid ventilation, and if I had, the proposal would likely have been rejected almost immediately on the basis of Frank Falejczyk’s bad outcome.

Dr. Lande has proposed solving the carbon dioxide retention problem by tieing artificial gills straight into the human circulatory system. There are obvious safety concerns with such a plan, but if those concerns could be engineered out, there is still the problem of creating working gills with enough throughput to eliminate CO2 from a working diver.

I once witnessed a demonstration of an artificial gill, conducted in front of several well-educated Navy diving physicians and scientists. After descending about three feet down into a pool, the “inventor” lay motionless for 30 seconds, then bounded up out of the water, breathlessly saying, “Basically, it works.”

His panted words were not convincing.

Based on fairly recent history, and the fact that for deep diving, not one lung but both lungs would have to be completely filled with perfluorocarbon or similar liquid, it seems that a practical and safe liquid breathing system will be a huge engineering challenge. I can envision ways that it could be done, but at what cost, and for what purpose?

I am mindful, being an aviator, that such questions were not allowed to stymie Wilbur and Orville Wright. However, these days, human experimentation involving the complete filling of human lungs would face a formidable hurdle, called the Human Use Committee.  In the U.S. at least, a repeat of Kylstra’s experiments is very unlikely to be approved by Research Ethics committees.

But could it happen in other countries with lessor human research safeguards?

Time will tell.

The Puerto Rico Trench and Denizens of the Deep

(Public domain - from U.S. Geological Survey)
Puerto Rico Trench. (Click once or twice for full image) U.S. Geological Survey

The Puerto Rico Trench is the deepest part of the Atlantic Ocean, and is only surpassed in its depth by the Marianas Trench in the Pacific Ocean. It is 500 miles long, and at its deepest plummets 28,232 feet down.

After receiving my doctorate with a special interest in deep-sea physiology, I was invited on board the oceanographic Research Vessel (RV) Gilliss for an expedition to the Puerto Rico Trench. I was accompanied on that research cruise by Dr. Robert Y. George, a deep-sea biological oceanographer from Florida State University.

I had been studying the effect of very high pressure on invertebrate hearts. As luck would have it, the largest population of deep-sea creatures indigenous to the deepest places in the ocean are invertebrates (animals lacking  vertebrae, backbones.) But on the way down to the deepest reaches of the trench, you encounter some very strange creatures indeed, such as the Humpback Angler Fish.

Click for a larger image







These bizarre and frightening looking fish inhabit the abyssal pelagic zone (or the Abyss) between 13,000 and 20,000 feet. But below the water containing these abyssal fish lies the zone of the deep trenches, the hadalpelagic zone between 20,000 and 36,000 feet, the deepest point in any ocean.

“Denizens of the Deep” are known in merfolk tradition as the beasts that swallow up the sun at the end of the day, which is somewhat ironic since sunlight never reaches down to the abyssal and hadal zones. Whatever light is there, is produced by bioluminescence. Down there, light means either a meal, or a trap. And since meals are uncommon in the sparsely populated ocean depths, predators seem designed to ensure they miss no opportunities to feed. Their jaws, fangs, and other anatomical structures seem especially designed to snag a hapless passer-by, and provide no chance of escape for those caught.  Fortunately for us, animals adapted to the high pressure, low oxygen environment of the deep ocean cannot survive in shallow waters.

But imagine for a moment that something perturbed that natural order. Time has separated us from man-eating dinosaurs, but the only thing separating us from deep-sea monsters, ferocious predators that make piranhas look playful, is something as simple as pressure and oxygen.  Could things change?

Well, not to scare you, but until 1983 or so, the Puerto Rico Trench was a huge pharmaceutical dumping ground. Massive quantities of steroids and antibiotics, and chemicals capable of causing genetic mutations, came to rest on the sea floor, or were dispersed in the waters above and around the trench.

Read more about that here:

You don’t need to take just one person’s word for it. Professor R.Y. George himself commented on the issue in his resumé.

July 5 – July 30, 1977. Revisited Puerto Rico Trench (now Pharmaceutical Dump Site) aboard R/V GILLISS of the University of Miami to study Barophylic (pressure-loving)bacteria (Dr. Jody Demming’s Ph. D. work from Dr. Rita Colwell’s Lab. in the University of Maryland), and to study meiofauna, macrofauna and megafauna (in collaboration with Dr. Robert Higgins of the Smithsonian Institution).

Frankly, if I was visiting Puerto Rico, and signed up for a deep-sea fishing trip, I’d ask the boat captain just how deep we’d be fishing. I really wouldn’t want to bring up a Humpback Angler Fish large enough to eat the boat. After all, Angler Fish are fishermen too.

For a NOAA sponsored animated tour of the Trench, play the following high resolution video.