On Breathing Liquid
Unbelievably, I saw the movie the Abyss for the first time last night. In this film, as the rest of you know, they breath liquid to keep their lungs from collapsing below 2 miles of ocean. I was aware of the concept, but unclear on it's validity and history, so of course, I found out.
It turns out the concept is mostly sound. The lungs can be filled with oxygen rich solutions and function relatively normally. The problem arises in the expulsion of excess carbon dioxide. This was initially circumvented by keeping the liquid at incredibly low temperatures. One subject mouse survived for over 20hours breathing liquid at 18 degrees celcius. This is a problem however because it would induce hypothermia in the animals, and would not serve as a functional application. Unfortunately almost all animals tested have suffered varying degrees of lung damage. There have been some advancements in the application in recent years.
from Wikipedia
During later years, the techniques of liquid breathing were constantly refined and improved. The survival rate of all the tested animals in recent years has been very high, thanks mainly to improvements in carbon dioxide elimination. Current liquids used can dissolve over 65 ml of oxygen and 228 ml of carbon dioxide per 100 ml perfluorocarbon. By the early 1990s this procedure was developed:
1. The animal was anesthetized with intravenous sodium thiopental.
2. The animal was put on its back. A tube was placed down its airway, ready for the liquid breathing medium.
3. A blood sample was taken. The temperature of the liquid was adjusted correspondingly. It was no longer necessary to make the animals hypothermic.
4. The perfluorocarbon was instilled into the animal's lungs through the tube.
5. A floor-mounted 3-litre reservoir was filled with the perfluorocarbon. The liquid was driven by a pump through a series of machines which warmed and oxygenated the liquid and took the carbon dioxide out of it. The liquid flowed through a tube into a 3-way pneumatic valve which directed flow to the animal. A computer controlled the respiration (18 ml of fluid per second), pumping the liquid into the animal's lungs, then back out again to the reservoir, at a rate of about 6 complete respirations per minute.
6. At the end of the test, the animal was tilted for about 15 seconds and the perfluorocarbon was allowed to drain from the lungs. This can be seen in the film The Abyss where Ensign Monk drained the liquid out of the rat's lungs: in the filming, the rat genuinely breathed liquid.
These tests of the early 90s were successful: dogs could be kept alive in the perfluorcarbon medium for about 2 hours; after removal the dogs were usually slightly hypoxic, but returned to normal after a few days. When the animals were necropsied, the typical findings were mild oedema and some hemorrhaging, clearly an improvement over the lung damage of earlier tests.
The application of liquid breathing in human medicine, deep sea diving, and space travel is still speculative, but perhaps some day we will all get the opportunity to breath liquid. The mouse at the top is alive by the way.
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Informative Outline Sample: LIQUID BREATHING
General Purpose: To inform.
Specific Purpose: To inform the audience of the history of “liquid breathing”.
Introduction
Attention-Getting Device
I would like to begin by viewing a clip of the 1989 movie The Abyss. [View clip of The Abyss.] It may be surprising to you, but according to the Internet Movie Database website (imdb.com), the rat you just saw in the movie actually did breath the liquid. What you saw was not a Hollywood special effect, but reality, and is an example of what is called, fittingly enough, liquid breathing.
Thesis Statement
Today, I am going to briefly review some major scientific milestones in the field liquid breathing.
Preview
First, I will briefly review important aspects breathing. Next, I will explain the early experiments that sparked the beginning of liquid breathing. And finally, I will discuss the recent applications of liquid breathing used today.
Body
I. Brief review of important aspects of breathing (Biology, 5th ed.).
A. Components that are important to breathing.
1. Gases (21% O2 and <1% CO2 in air)
2. Blood
3. Lungs (gas exchange occurs in air sacs called alveoli)
B. Inhalation.
1. O2-rich air is taken into the lungs or inhaled.
2. CO2-rich blood enters the lungs via arteries from the heart.
C. Exhalation.
1. CO2-rich air is removed from the lungs or exhaled.
2. O2-rich blood leaves the lungs through arteries to the body.
3. CO2 is poisonous at higher concentrations.
Transition: Having reviewed these important aspects of breathing, I will now talk about the early liquid breathing experiments.
II. Early liquid breathing experiments.
A. Dr. J. Kylstra performed the first major experiment (scienceweb.org and the Journal of the Australian Amateur Rebreather Group, Issue No. 2)
1. Dr. Kylstra was a physiologist at the State University of New York (SUNY) at Buffalo.
2. He performed his landmark experiment in 1962.
3. The experiment.
a. Dr. Kylstra wanted to observe whether the animals would be able to move saline in and out of their lung, while extracting oxygen from the fluid.
b. He utilized rats and mice.
c. He used saline solution saturated with oxygen at high pressures.
4. Results and conclusions.
a. The animals were able to resume normal air breathing after breathing liquid.
b. Carbon dioxide (CO2) was not removed fast enough, so it accumulated to near-toxic levels (acidosis).
Transition: As Dr. Kylstra preformed his experiment at high pressures, the next key event was to obtain liquid breathing living-condition pressure.
B. Dr. L. Clark and Dr. F. Gollin performed the next major experiment (Science, June 24, 1966).
1. They performed their experiments in 1966.
2. The major development that Dr. Clark and Dr. Gollin realized was that oxygen and carbon dioxide were very soluble in fluorocarbon liquid, such as freon.
3. Their experiments were performed at regular pressures, instead of the high pressures that Dr. Kylstra utilized.
4. The experiment was done at several temperatures.
5. Results and conclusions.
a. The animals remained alive for several weeks after breathing the fluid.
b. As in Dr. Kylstra’s experiment, carbon dioxide accumulation was still a problem.
Transition: Now that I have discussed two important early developments in the field of liquid breathing. I will turn the attention to the recent applications.
III. Alliance Pharmaceutical Corp. markets the first liquid breathing fluid as a drug (LiquiVent Product Fact Sheet, Alliance Pharmaceutical Corporation).
A. This company developed LiquiVent, a oxygen-carrrying perfluorocarbon (PFC) liquid called perflubron.
B. This drug is marketed as a treatment for lung disorders requiring air ventilation.
Transition: With the advent of a marketed liquid breathing fluid, research on humans has been started, mainly on premature infants that have under-developed lungs.
IV. Dr. C. Leach and her associates publish the first major human clinical study using LiquiVent, Alliance Pharmaceutical Corporation’s liquid breathing drug (New England Journal of Medicine, Sept. 12, 1996).
A. Utilized the partial liquid ventilation technique, which combines conventional gas ventilation and liquid breathing.
B. 10 infants received partial liquid ventilation for 24 to 76 hours.
C. Infants were weaned from partial liquid ventilation without complications.
D. There were no adverse events clearly attributable to partial liquid ventilation.
E. The journal article in the NEJM has been cited in at least 31 other journal articles, which indicates research into liquid breathing technology is active.
F. Note that partial liquid ventilation has also been done in adults as is evident from the article by Dr. C. Reickert in the journal Chest (the American College of Chest Physicians journal called Chest, 119 (2), 2001).
Conclusion
In Conclusion, liquid breathing is science fact, not science fiction. The early liquid breathing experiments were more involved complete submersion, similar to diving. From this beginning, though, medical uses of liquid breathing arose in the form of partial liquid ventilation. Now, from the medical uses, maybe the research will complete the circle and produce liquid breathing advancement for diving applications. Maybe, in the near future, we will be breathing liquid, as did the rat in The Abyss.
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