Talk:Liquid breathing

message: This should really be cleaned up and moved to Liquid breathing. Although this article uses the terms "liquid breathing" and "fluid breathing" to mean the same thing, it in fact is referring to the breathing of a liquid. Since all breathing is breathing of a fluid, the improper use of that term should be removed. If nobody else does this first, I'll get around to it eventually. Merenta 20:34, 10 November 2004 (UTC)
replies: text: So what happened?, the Liquid breathing just redirects to this page. I agree that "fluid breathing" is a misnomer, as air is fluid--JinFX HuangDi 1968 06:12, 18 February 2005 (UTC)
replies: text:  Argh! Air... is... a... fluid... 24.218.139.205 05:53, 24 June 2005 (UTC)

text: * Support, for the reasons suggested above.  Alai 23:47, 27 August 2005 (UTC)

text: * Support. You're absolutely right, of course, Merenta. — Knowledge Seeker দ 00:34, 1 September 2005 (UTC)
thread_title:  Move to [[Liquid breathing]] ? 

message: It is interesting to see an article that is pretty factually accurate, but really misses the point in almost all the critical areas. I hate editing Wikipedia pieces (but don't mind writing the first one). If anyone is interested in "fixing" this piece, let me know - meanwhile here are some corrections and comments: 
First, there is one critical missed point that renders much of the discussion and speculation about diving and space-flight applications moot. The major problem with TLV isn't simply the density of PFCs, but rather the fundamental physics of fluid flow. While different PFCs have differing viscosities, on average PFC is 80 times more viscous than air. Whether it is a mouse, a dog, or cat, if you look at the literature you will notice that 5-7 breaths a minute is the maximum achieveable (Shaffer T H, Forman DL, et al. Physiological effects of ventilation with liquid fluorocarbon at controlled temperatures. Undersea Biomed Res. 1984 Sep;11(3):287-98.). You cannot do more than 5-7 breaths a minute because the liquid is too viscous compared to air. Now, it would be possible to avoid the limitation on BPMs with PFCs in an animal thats use a flow-through system for respiration, such as fish, or birds. But not in most vertebrates. 
In 1976, Miyamoto and Mikami (Maximum capacity of ventilation and efficiency of gas exchange during liquid breathing in guinea pigs. Jpn J Physiol. 1976;26(6):603-18.) calculated that the resting man normally produces 192 mL/min of CO2 (S.T.P.). This level of CO2 production would require TLV (PFC) ventilation volumes of about 4 L/min (or about 70 mL/kg/min). Although this is ~70% of the normal gas ventilatory flow for a resting adult, it is near the upper limit of flows that can be accomplished at normal pressures in TLV (Kylstra, 1974). The higher peak and mean ventilating pressures necessary to move the amount of liquid required for CO2 exchange in TLV would expose the lungs to an increased risk of barotrauma (pressure injury) and volu-trauma (over-distention injury). 
During higher than normal CO2 production rates, such as physical exertion or illness, TLV would clearly not be adequate for CO2 removal. Some examples of high CO2 (hypercapnic) states are, 1) increased metabolic states (e.g. cancer, infection, burns), 2) states of physiologic stress (e.g. hyperthermia, agitation), 3) post-ischemic conditions where substantial metabolic debt has been incurred, and 4) physical exertion (such as swimming and diving). Under all these conditions the need to rapidly unload CO22 and deliver large amounts of O2 is essential. Such hypercapnic/hypercarbic states are also frequently present in shock due to sepsis or trauma, and thought to be due to both an increased production of CO2, and decreased elimination of CO2 due to low blood flow or pulmonary edema. 
In anesthetized, paralyzed, normothermic dogs, TLV is capable of maintaining steady-state gas exchange with adequate O2 delivery and CO2 removal. However, TLV is not cannot deliver steady-state CO2 removal under basal metabolic conditions in smaller animals with higher specific metabolic rates, such as guinea pigs. As Matthews and co-workers document (Matthews WH, Balzer RH, et al. Steady-state gas exchange in normothermic, anesthetized, liquid-ventilated dogs. Undersea Biomed Res. 1978 Dec;5(4):341-54), the parameters for maintaining normocapnia in anesthetized beagles are narrow, even under basal normothermic metabolic conditions. In this study, as TLV rates were increased from 2.8 to 5.6 liquid breaths per minute, and alveolar ventilation was increased from 574 to 600 mL/min/animal (an increase of 4%), the pa CO2 continued to increase until dangerous hypercapnia occurred. The authors suggested that this increase was due to a 2% drop in liquid-alveolar ventilation, however using their own formulas and data, it easy to show by calculation that the dogs receiving higher ventilation rates actually have higher rates of alveolar ventilation (dVa/dt). These results would seem paradoxical until consideration is given to the inverse relationship of pa CO2 to alveolar ventilation, a relationship which holds only under equilibrium conditions. From a practical standpoint, this means TLV cannot be used in situations where humans or other mammals exert themselves. Under conditions of stress or exertion, respiratory rate increases dramatically. If a person or animal is running, or even engaging in normal activities, metabolic demands and CO2 generation will increase beyond the capability of TLV to provide adequate gas exchange.
The statement, “As in Kylstra's studies, Clark had problems due to the size of the animals' airways. The tiny size limited the amount of liquid that could get into the lungs. For that and other reasons, carbon dioxide tended to build up in the system and could not be removed fast enough," is incorrect. The “small size" of mouse airways is irrelevant to liquid distribution and to limitations on liquid breath rate. The small airways in a mouse are the same size as the small airways in a human or an elephant. PFCs have incredible spreading co-efficients and extraordinarily low surface tensions. They will get into almost any space, or through almost any hole. Indeed, they are used for leak-detection. The real limiting factor is that alveoli in both mice and men are scaled pretty much the same because of the physics of gas exchange. The same is true of capillaries in all mammals because of the physics of mass exchange and diffusion (Dawson, T. H. (1991). Engineering Design of the Cardiovascular System of Mammals. Prentice Hall Biophysics and Bioengineering Series (ed. A. Noordergraaf). Englewood Cliffs, NJ: Prentice Hall).
A capillary in a mouse is the same size as that in an elephant. Consequently, blood pressure, mean arterial pressure, and capillary opening pressure, are about the same for all mammals (giraffe's have their own issues). Resting blood pressure in a mouse and a man is virtually the same (Gregg, D. E., Eckstein, R. W. and Fineberg, M. H. (1937). Pressure pulses and blood pressure values in unanesthetized dogs, Am. J. Physiol. 118,399-410, and Woodbury, R. A. and Hamilton, W. F. (1937). Blood pressure studies in small animals. Am. J. Physiol. 119,663 -674.).
Lungs were injured by many PFCs used in early liquid ventilation studies, because the vapor pressure was too high, and PFC that gets trapped in alveoli, or gets into the lung parenchyma, turns into gas. This PFC gas is not eliminated rapidly enough to avoid serious injury. If you inject 1 ml of FC-75 (vapor pressure of 30 torr at STP) into a mouse's peritoneum, the mouse inflates to about the size of a golf ball over a time course of several hours. A few days to a week later, the animal dies from starvation because its abdominal viscera are compressed (there is no fat on the animal at necropsy, and its organs are shrunken from starvation). Perflubron (perfluorooctylbromide) is the only molecularly consistent PFC. All others contain different chain lengths of the constituent perflurochemical. For example, the 3M Fluorinert compounds which were often used for early liquid ventilation experiments such as FC-75 (perfluoro(butyltetrahydrofuran), as previously noted, has a vapor pressure of 30 torr at STP and FC-77 (perfluorooctane) has a vapor pressure of 85 torr. Thus, the vapor pressure for a given PFC is the average of the molecular species present. As a consequence, even a little high vapor pressure PFC will cause lung injury. By contrast, the vapor pressure for perflubron which is the only PFC so far approved for clinical trials, is 11 torr and that is the “true” vapor pressure of perflubron since all molecules are of the same chain length.
These claims are largely incorrect and unsubstantiated:
"Profound expertise is mandatory to perform and maintain filling of the lung with perfluorocarbon to functional residual capacity (FRC). Disruption of PLV immediately deteriorates gas exchange. Incomplete filling of the lung has been shown to be less effective than filling the lung to functional residual capacity volume. Severe adverse events affecting gas exchange and pulmonary circulation limit the use of PLV."
First it is easy to maintain filling to FRC, and Alliance Pharmaceuticals had developed systems to measure the amount of PFC vaporized in real time, as well as to condense vaporized perflubron, measure it, and collect it for return the patient.
I don't know what "disruption" of PLV means, but PLV is only initiated in the first place because gas exchange is inadequate! Of course, if you stop adding perflubron, gas exchange will deteriorate -- it will go back to about what it was before -- unless the injury has improved or resolved. It is not easy to disrupt PLV because once the liquid is in the lungs it is in there until it vaporizes. The only way to get it out would be turn the patient upside down and attempt to drain it of out of him -- and even then you will still end up with pretty near FRC in the lungs. I know this because we tried to recover as much PFC from our experimental animals as possible in order to save money as all the PFCs are very expensive. The statement "Severe adverse events affecting gas exchange and pulmonary circulation limit the use of PLV," is totally unsupported and incorrect. There are no adverse hemodynamic effects, and the worst that can be said of PLV in clinical trials is that did little better, and maybe a bit worse, than gas ventilated patients AFTER the new lung protective ventilation strategies were adopted. Nobody ever tried PLV with the lower tidal volumes and lung protective ventilation strategies because Alliance ran out of money. Nor were there any clinical studies with high frequency oscillation ventilation (where PLV absolutely shines and all the issues of baro and volutrauma from liquid moving more slowly as the lungs are inflated and deflated go away). The tragedy of therapeutic PLV for respiratory distress syndrome is that the clinical trials were so badly designed and Alliance’s handling of the technology was even more poorly managed (Reiss SG. Understanding the fundamentals of perfluorocarbons and perfluorocarbon emulsions relevant to in vivo oxygen delivery. Artif Cells Blood Substit Immobil Biotechnol. 2005;33(1):47-63).
These incorrect statements should be supported by peer-reviewed references, or deleted. 
Finally, the really important thing about Gas Liquid Ventilation (GLV) cooling or warming, and the major innovation, is that it uncouples heat exchange from gas exchange. Inducing hypothermia using TLV is problematic because PFC viscosity (pressure/flow) also places a limit on the rate at which heat can be extracted from an animal or patient using TLV. In addition to the CO2 diffusion limitation, there is indirect evidence suggesting that thermal equilibrium is not reached between blood and liquid in small airways at high TLV "alveolar ventilation" rates. Thus, there appears to be a heat-diffusion limitation to TLV that is analogous to the CO2 diffusion limitation. 
This phenomenon may explain why Shaffer's TLV cat studies failed to achieve concurrent increases in the rates of animal core cooling, when significantly greater PFC temperature gradients were used (Shaffer T H, Forman DL, et al. Physiological effects of ventilation with liquid fluorocarbon at controlled temperatures. Undersea Biomed Res. 1984 Sep;11(3):287-98). Shaffer found that decreasing PFC infusion temperature from approximately 20.degrees C to about 10 degrees C (from  ∆T =15.degrees C to ∆T =24.degrees C), resulted in cooling rates increasing from 0.13.degrees C/min (7.8 degrees C/hr) to 0.15.degrees C/min (9.0degrees C/hr) a change of only 15%. This 15% increase occurred despite an increase of ∆T equal to 60%. These results suggest a sharp decline in the efficiency of heat extraction with increased ∆T at higher TLV ventilation rates (in this experiment, rate was increased from 4.5 to 5.3 liquid breaths/min). 
In Shaffer's study, the authors calculate from PFC inspiration and expiration temperature differences, a 96% increase in heat extraction per kg from their animals at the 10degrees C PFC infusion temperature versus that calculated at 20degrees C. However, the fact is that this increase in heat extraction does not show up in the rate of body core cooling (15%), to which it should be proportional. This indicates that Shaffer's calculations of heat removal performed on the basis of integrated measurements of expired fluid temperatures must have been in error. As further evidence of this error, calculations of expected cooling rates of animals used in this study (using a reasonable 0.8 cal/g/degrees C, or kcal/kg/.degrees C average specific heat capacity for the body), indicate that up to half of the heat extraction calculated by PFC temperature differences in this experiment are unaccounted for even at the fastest cooling rates. For example, an animal with an average 0.8 kcal/kg/.degrees C specific heat capacity, cooling at the reported rate of 9.0.degree. C/hr, could theoretically give up heat at a rate no faster than (0.8 kcal/kg/C)(4184 J/kcal)(9 C/hr)=30,124 J/kg/hr. However, Shaffer's experiment reports on the basis of temperature readings of PFC infused and expired, the extraction of 65,637 J/kg/hr. It is likely that the difficult integration of [expired fluid temperature] versus (fluid volume) curve for this experiment was in error by a factor of 2.0. For examples of experiments in which integrated cooling rates calculated from PFC temperature differences match actual animal body cooling, see: Harris SB, Darwin MG, et al. Rapid (0.5 degrees C/min) minimally invasive induction of hypothermia using cold perfluorochemical lung lavage in dogs. Resuscitation. 2001 Aug;50(2):189-204. The authors found that at rapid (machine-controlled) liquid infusion and removal rates, and peak fluid temperatures do not accurately reflect volume-averaged fluid temperatures, or fluid heats. 
In TLV too few breaths and too little turbulence probably results in a lot of the liquid at the terminal end of the airways remaining there from one breath to the next. Heat exchange is very poor. In conclusion it is not possible to meet the gas exchange demands of a critically ill patient with TLV, nor is it possible to meet the gas exchange demands of humans under real-world conditions making TLV with currently available PFCs impossible for applications such deep sea diving or space travel. PLV remains a promising modality for the treatment of respiratory distress and for the induction of hyper- or hypothermia (Wauer RR, Gama de Abreu M. 4th European symposium on perfluorocarbon application. Eur J Med Res. 2006 Mar 16;11 Suppl 1:1-12).
Unmentioned in the Wikipedia article are potent anti-inflammatory and immune modulating properties of most PFCs, properties which undoubtedly contribute the salutary effects of PLV in the setting of lung injury (Haeberle HA, et al. Perflubron reduces lung inflammation in respiratory syncytial virus infection by inhibiting chemokine expression and nuclear factor-kappa B activation. Am J Respir Crit Care Med. 2002 May 15;165(10):1433-8, Forman MB, et al. Pharmacologic perturbation of neutrophils by Fluosol results in a sustained reduction in infarct size in the canine model of reperfusion. J Am Coll Cardiol. 1992 Jan;19(1):205-16 and Jiang L, et al. Effect of different ventilation modes with FC-77 on pulmonary inflammatory reaction in piglets after cardiopulmonary bypass. Pediatr Pulmonol. 2007 Feb;42(2):150).
--Necrobiologist 11:04, 3 February 2007 (UTC)
thread_title:  Comments and Suggestions For Revision 

message: I have added a paragraph about the impossibility of using liquid breathing to withstand high G-forces. Source: http://yarchive.net/med/liquid_breathe.html 17:47, 2 March 2006 User:71.247.67.39
Also, the trials by Alliance produced little results. I added the following sentence:
Unfortunately, results of the clinical trials were disappointing and Alliance is no longer pursuing partial liquid ventilation application.
-neolex
20:02, 2 March 2006 User:71.247.67.39
: For the record, the space application is possible, just not with fluorocarbons.  See the discussion in "Removed from Article" below. Cryobiologist 20:39, 17 January 2007 (UTC)
thread_title:  Space application not possible 

message: The section on using this in space travel is based around a very common misconception. It contains this sentence, which seems to sum up the misconception:
"A person immersed in liquid of the same density as tissue has acceleration forces distributed around the body, rather than applied at a single point such as a seat or harness straps. This principle is used in the Libelle G-suit, which allows aircraft pilots to remain conscious and functioning at more than 10 G acceleration by surrounding them with water in a rigid suit."
The problem here is that a G-suit works because it applies unequal pressure to a pilots body; it squeezes the legs and lower abdomen (but not upper body) so that blood can't pool in the lower body during high-g maneuvers. If the suit applied the same pressure evenly across the pilots body, it would be useless. The particular flight suit linked to in the article is simply a regular flight suit that has a system to automatically change the pressure being applies across different parts of the pilot's body, allowing it to provide optimal support during different types of maneuvers - but it still works on the principle of applying unequal pressure to prevent blood from pooling in different parts of the body.
Being immersed in a fluid would not magically protect you from acceleration forces. For example, if a person were standing immersed in a tank of fluid and the entire tank began accelerating upward, the person’s blood would still pool in his lower body and eventually cause a blackout. His lower body would get slightly larger as it fills with blood and his upper body would get slightly smaller as the blood drains out. Since the fluid is applying pressure evenly across his entire body surface, it wouldn't do him any good.
20:39, 14 February 2007 User:128.227.142.57
: The space section is correct, and is supported by an authoritative secondary source (Textbook of Medical Physiology).  The reason fluid immersion prevents blood pooling is because hydrostatic pressure is NOT the same at all points on the body when g forces are applied.  At one gee, water pressure increases by 0.5 psi per foot of depth.  At 10 gees, water pressure increases by 5 psi per foot of depth.  Under water, at 10 gees, a seated pilot's legs will experience an external pressure of 15 psi relative to the head, which exactly counterbalances internal pressures that would otherwise distend the legs and cause blood pooling.  Think of a bag of water immersed in a tank of water.  There's no force to change the shape of the bag regardless of gees.
: The Libelle G-suit, by the way, is a purely passive device.  The only "automatic" change in pressure applied to different parts of the pilot's body is due to the water bladders which experience passive hydrodrastic pressure gradients by the mechanism described above.  Please see the review article Current Concepts in Acceleration Physiology Cryobiologist 23:33, 14 February 2007 (UTC)
thread_title:  Space section is all wrong 

message: I remember an episode of Captain Simian and the Space Monkeys in which they crashed onto a water-planet, and were concerned with drowning until they realized they could breathe the "water" and called it "wet air."  05:48, 19 February 2007 User:75.72.21.221
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
 
For addition to the Fiction section:
There is a children's series called "Dark Life" by Kat Falls (ages 8-12). The characters inhale a liquid substance called Liquigen that allows them to breathe underwater without additional breathing apparatuses.
Falls, K. (2010). Dark life. New York: Scholastic Press.
When fifteen-year-old Ty, who has always lived on the ocean floor, joins Topside girl Gemma in the frontier's underworld to seek and stop outlaws who threaten his home, they learn that the government may pose an even greater threat. (WorldCat)
Falls, K. (2011). Rip tide. New York: Scholastic Press.
Ty discovers an entire township chained to a sunken submarine, its inhabitants condemned to an icy underwater grave. It's only the first clue to a mystery that has claimed hundreds of lives and stands to claim two more -- - lives very precious to Ty and his Topsider ally, Gemma. (WorldCat)
66.65.47.62 (talk) 22:58, 2 November 2013 (UTC)
thread_title:  Fiction 

message: I have reverted the recent edit that said reducing the physical stress of G forces requires "filling all normally air-filled body cavities with liquid." This is not necessary for the mere reduction of the stress of G forces. As the article explains, simple water immersion does reduce the stress of G forces, allowing tolerance up to 15 or 20 Gs. It is the near-elimination (as opposed to reduction) of the stress of G forces that requires both water immersion and filling of the major air-filled cavities with a similar liquid, which is where the role of liquid breathing comes in. Cryobiologist 17:18, 18 March 2007 (UTC)
replies: text: Although this comment is extremely dated, it should be noted that bones also contain air filled cavities that cannot have fluid replace the air by the nature of their nature. One would have to find a fluid that preferentially replaces air, fails to displace oxygen, be of a similar density and mass of water *and* be delivered by the blood stream within the individual's lifetime. That'd qualify as unobtainium.Wzrd1 (talk) 07:57, 20 August 2015 (UTC)
thread_title:  Filling all air-filled cavities 

message: Would it be possible to get the same benefits of a liquid breathing apparatus by simply filling the lungs with saline or whatever, and then pumping oxygenated blood directly into the user from some outside source?  Thanks!  --TotoBaggins 15:44, 2 August 2007 (UTC)
replies: text: You mean as regards acceleration, diving, and so on? The answer is yes. The technology is called ECMO, and I suspect, due to the CO2 problem, some form of ECMO will replace or augment lung ventilation, if liquid-filled lungs are ever used to allow humans direct access to the deep oceans (abysal plain). SBHarris 17:43, 2 August 2007 (UTC)
replies: text:  Thanks for the response.  This approach seems a lot more feasible than pumping liquid through the lungs, etc.  It occurred to me after reading about athletes using their own fresh & oxygenated blood in blood doping.  --TotoBaggins 18:05, 2 August 2007 (UTC)
thread_title:  Different method 

message: The link in the acknowledgement seems to be broken on my end. Could somebody verify this and repair or delete the input. Carnelain 21:52, 16 August 2007 (UTC)
thread_title:  Broken Link 

message: There seems to be a bit of a disconnect or of missing information, especially between the lede and the first sections. While "perfluorocarbon" is linked, and a more detailed discussion should be at the linked article, it really needs some more expansion here before the methods of application are detailed. The article needs to be able to stand on its own, at the moment, this doesn't seem to be quite given to me as a non-expert. Ingolfson 09:37, 8 September 2007 (UTC)
thread_title:  Context / gaps 

message: A new editor who states he is a developer of TLV has made some good-faith edits about TLV and how workable it is, compared with standard gas ventilation. Here's one: "the necessity for the liquid filled tube system that contains pumps and heater and membrane oxygenator to deliver and remove tidal volume aliquots of conditioned perfluorocarbon to the lungs is a great disadvantage.very similar to the control of respiratory parameters during assisted gas ventilation." In fact, I do not believe this, as a membrane oxygenator is lot harder to manage than a simple gas blender. So these kinds of things need a cite (such as the idea that tidal volumes are easier to control with liquid than gas, with new technology), and I'll explain need for such citations on the new user's talk page. SBHarris 21:30, 26 January 2008 (UTC)
thread_title:  Needs cite 

message: user:71.224.14.76 says he did the only human study, and cites T. H. Shaffer. That means he's actually claiming to be Shaffer, since to date Shaffer is the only person ever to try this on a human (the subject died shortly thereater, probably not as a result of the liquid ventilation). So don't WP:BITE the new user and let's see if he can learn to cite. If he IS Professor Thomas H. Shaffer, it would be an honor to see what he says, and to get his comments into Wiki-shape. That doesn't mean I think he's reversion-proof. But be VERY sure to WP:AGF with this guy, who may be the closest we've seen here to a living historical figure and authority as regards  the development of the subject at hand. SBHarris 02:14, 27 January 2008 (UTC)
replies: text: * I can't agree. The editor blatantly violated many rules of Wiki, after being warned many times. I don't see how we would have "egg on our faces", as you mentioned on my talk page; it is not my responsibility to assume that an unregistered user is in any sort of "higher" position than anyone else. He claims to be a developer? Fine, then it should be a simple matter for him to become a registered user, do a couple quick reads on the policies that we told him about, and do it correctly. I do typically assume good faith, a quick scroll through my contributions would verify that. However, I'm not going to give this IP address preferential treatment until he/she follows Wikipedia policies. I'm aware that there are some gray areas, but this certainly isn't one of them. See WP:COS. Tanthalas39 (talk) 16:30, 27 January 2008 (UTC)
replies: text:  You're doing fine. I've added a template to your TALK and USER pages with a pointer to the manual of style and other useful links. Please read them. I fixed up your references, and you might note how I did that. I've also got some comments on liquid ventilation which I left on your TALK page, but which could as easily go here. In fact, in future we should discuss your editing learning on your TALK page, and liquid ventilation questions HERE, rather than the other way around, if you see my point. But I'll put this here for now to preserve it as a record. SBHarris 22:01, 28 January 2008 (UTC)
thread_title:  New IP editor may be a known authority! 

message: Dr. Shaffer: I've fixed up the references you added: please see how it was done. I disagree with you that some aspects of total liquid ventilation are easier than gas: it most definitely IS harder to oxygenate and scrub fluorocarbon than it is to simply blend ingoing oxygen, and remove CO2 by simple ventilation and exhaust to the air (whereas liquid must be recycled as in a rebreather or anesthesia circuit). However, you may be right that control of volumes is inherently easier than with a gas. Could you explain why? SBHarris 21:57, 28 January 2008 (UTC)
replies: text: Thanks for the help with the references. Regarding TLV, for infants, we have gone back to the concept of ventilating with pre-oxygenated, warmed PFC which has plenty of oxygen(one-way system) and no carbon dioxide(Lancet, 1989).  To ventilate infants, it takes less than a liter of pre-oxygenated PFC to effectively recruit alveoli and stabilize the infant's under-inflated lungs during a transient period of TLV.  After returning to gas ventilation (some would call this PLV), our PFC sensors in the expired gas line indicate the amount of PFC which is required to maintain an effective PFC volume in the lung.  In the intensive care setting, determination of effective lung volume (FRC) is one of the most difficult variables to assess, but not for PFC in the lung. Also using TLV circuits for larger patients, using microprocessor controlled ventilators, we can carefully control tidal volume and FRC during each phase of ventilation as described in the Heckman et al. article. As compared to our early ventilators, we no longer use patient weight as a measure of PFC in the lungs, we have the membrane and PFC loss technology greatly improved. There is a significant amount of technology and TLV results published (PubMed), but it is difficult to get all of this information across at once.--Thshaffer (talk) 00:15, 29 January 2008 (UTC)
thread_title:  TLV vs. gas ventilation 

message: It seems that the Libelle G-suit hyperlink in the space travel section is broken. Vsst (talk) 18:58, 22 August 2008 (UTC)
thread_title:  Libelle G-suit 

message: This article, in the lead, says that liquid breathing is used for medical treatment. This assertion is unreferenced in the Medical Treatment section. From google searching, LiquiVent was a failure. Alliance is a penny stock. Looks like the best they have is Oxygent sp? which is in clinical trials in China. Clinical trials do not equal medical treatment, in my opinion. This has led me to totally dispute the neutrality of this page. -Shootbamboo (talk) 05:05, 27 December 2008 (UTC)
thread_title:  Dispute page 

message: This article would be better titled Liquid breathing research, IMHO. The current title implies too strongly the feasibility of total liquid ventilation, instead of characterizing it as an investigative field. -Shootbamboo (talk) 20:43, 1 January 2009 (UTC)
thread_title:  Title dispute 

message: I've tried to clean this page up as much as possible, but the technical parts really require someone with more knowledge of the subject. Hopefully, at the very least, the pov dispute's resolved. I think the article's pretty clear now that the technique remains unrealized. LSD (talk) 01:45, 15 January 2009 (UTC)
replies: text: In the absence of any disagreement, I've removed the POV tag. LSD (talk) 19:17, 3 February 2009 (UTC)

text: Deleted. LSD (talk) 19:19, 3 February 2009 (UTC)
thread_title:  Cleanup 

message: I'm tempted to delete the whole section, since it's bascially irrelevent to the article, but at the very least it needs to be trimmed up.LSD (talk) 02:00, 15 January 2009 (UTC)
replies: text: Deleted. LSD (talk) 19:19, 3 February 2009 (UTC)
thread_title:  Fiction section 

message: What the devil does that mean? And how is it problem, seeing as a well done review article is suitable for an encyclopedia (though it may have more citations than the average wikipedia article, for sure). However, as soon as I remove citations, I have no doubt somebody will stick up an "inadequate citations" tag. So just what is it that is wanted? SBHarris 20:41, 10 July 2009 (UTC)
replies: text: In general, I think the article has too many primary sources inserted by potentially conflicted editors that make it unlike an encyclopedia article. -Shootbamboo (talk) 00:24, 11 July 2009 (UTC)
thread_title:  Article "reads like a review??" 

message: Looking at the request for third-party reliable sources, I feel that this article now has plenty of them, so I've removed the  template.
I can't see how the  template is helpful here, so I've removed that.
I do see that some parts of the article may need further referencing, so I've added a  template.
I think it would be more helpful in improving the article if any specific requests for citation were flagged in-line using  and any specific problems with the style of the article were discussed here to allow contributors to meet concerns. Thanks --RexxS (talk) 18:03, 8 September 2009 (UTC)
thread_title:  Maintenance templates 

message: The article, in the section Examples in Fiction, lists breathable liquid as being used in the book THE LOST SYMBOL... TWICE. One should be deleted. If I did it myself, someone would have like sent me some message saying that my improvement was not constructive.  —Preceding unsigned comment added by 76.71.131.15 (talk) 23:58, 20 October 2009 (UTC)
replies: text: Shouldn't someone put a spoiler warning on it? Or at least truncate the message so it doesn't ruin the story for people who haven't read it?  (Minutes (talk) 23:22, 14 February 2010 (UTC)
replies: text: I request that the Dan Brown reference come with a plot spoiler warning before it. In one sentence the last few chapters of the book have lost three major climax points. Knowing that robert Langdon does not die, would completely ruin the book for someone who has not read it yet.
— ~~Minty~~ (talk) 09:47, 21 March 2010 (UTC)
thread_title:  Dan Brown 

message: In this video David Blaine claims to have "filled his sink with Perflubron" and tried to breathe it. I am skeptical of his story.  —Preceding unsigned comment added by 76.126.242.132 (talk) 01:15, 20 January 2010 (UTC)
thread_title:  David Blaine claims to have tried breathing with "Preflubron" 

message: I suppose someone should add this into the lead of the article.  I don't have a source, but a medical expert will tell you that breathing fluids isn't exactly good for your diaphragm.  It takes a lot more force to pull and push out a fluid than it does a gas.  That is why lungs don't work like gills...  Anyway, I think it's important enough for the lead, so yeah.  —Preceding unsigned comment added by 68.89.219.173 (talk) 22:32, 21 September 2010 (UTC)
thread_title:  diaphragm 

message: I have removed the following text added in this 2009 edit:
::On the other hand, although perfluorochemicals are denser than water, lung tissue floats within the PFC filled lungs, and if the lungs are not over-filled, there is no compromise in pulmonary or systemic blood flow.Davidson et al. Cardiopulmonary interaction during partial liquid ventilation in surfactant treated preterm lambs. Eur J. Pediatr. 157(2): 138-45, 1998. Therefore, if the astronaut is immersed in liquid and his lungs are filled with liquid PFC, he should not experience adverse effects, in spite of the almost twofold density difference.  Based on interviews with adult patients that experienced partial liquid ventilation, when they became conscious they were unaware that 20-30 ml/kg of PFC was in their lungs during recovery.
:As noted earlier, the density of the fluid is an issue for the extreme acceleration protection application.  A body floating in a heavy liquid will be squished against the "roof" of the tank as surely as the one in air will be squished against the "floor". The whole scheme depends on surrounding the body and filling its cavities with a liquid of the same average density of the body, and even then differing densities withing the body will still cause there to be an upper acceleration limit. -- ToE 10:54, 31 December 2011 (UTC)
thread_title:  Removed text -- density issues for use in space travel 

message: 71.104.179.19 did edits in the Partial liquid breathing section, later commenting that "The last paragraph of this section was redundant. I just repeated the information from the first paragraphs in the section. I left the references, which were helpful, but the repetitive information was not helpful". I reverted those edits because I perceived them to be partial section blanking, & suspected vandalism because of the combination of an IP address & because there was a blank reason for editing.
Subsequent to 71.104.179.19's reversion of my reversion, & this time leaving a reason for editing, I do think that this user has a point.  However, this leaves some things out of the article.
Outside of this section, Liquivent (see by l-dictionary.thefreedictionary.com/perflubron) is only mentioned in the references. Should it be referred to earlier in the article?
The following seems germane to the article but misplaced in the Partial liquid breathing section.
The liquid has some unique properties. It has a very low surface tension, similar to surfactant, a substance that is produced in your lungs and prevents the alveoli from collapsing and sticking together during exhalation. It also has a high density, oxygen readily diffuses through it, and it may have some anti-inflammatory properties.
The following seems germane to the Partial liquid ventilation section & is not discussed elsewhere.
The hope is that the liquid will help the transport of oxygen to parts of the lung that are flooded and filled with debris, help remove this debris and open up more alveoli improving lung function. The study of PLV involves comparison to protocolized ventilator strategy designed to minimize lung damage.The hope is that the liquid will help the transport of oxygen to parts of the lung that are flooded and filled with debris, help remove this debris and open up more alveoli improving lung function. The study of PLV involves comparison to protocolized ventilator strategy designed to minimize lung damage.
While I am not knowledgeable about Liquid breathing or Partial liquid ventilation, I am not totally disinterested, as my mother died of acute respiratory distress syndrome (ARDS) a couple of decades ago. Such a therapy may help, or eventually help, others with ARDS.
I hope I did not offend anyone with my reversion or inadvertantly set off an edit war.  Again, I reverted because I perceived:
*partial section blanking
*Lack of an edit summary
*Anonymous editing by an IP address, which can sometimes be a sign of vanadlism, but not inherently per se.
Peaceray (talk) 05:39, 6 July 2012 (UTC)
thread_title:  Removal of "redundant text" from the Partial liquid ventilation section 

message: *What does "protocolize" mean hereinabove?? Wiktionary says that "protocolize" = "notarize", and that "notarize" = (transitive) "to be witness of the authenticity of a document and its accompanying signatures in one's capacity as notary public", but that meaning does not fit here. Anthony Appleyard (talk) 07:56, 6 July 2012 (UTC)
replies: text: I think "protocolize" in this context has a medical treatment meaning. I work most Saturdays at a library that specializes in nursing, so I will check a medical dictionary while I am there. Peaceray (talk) 08:02, 6 July 2012 (UTC)
thread_title:  -ize suffix 

message: In medicine, to protocolize means to develop a precise & detailed plan or procedure for a therapeutic regimen or a biomedical research problem. Coincidentally, I happened to find a lot of links to ventilation treatment & research when searching for "protocolize".
====definitions====
*
*
====examples====
*
*
The root context appears to be proto- (first, primitive, original) + col (from kolla, glue) + -ize (to become or produce).
Peaceray (talk) 02:10, 8 July 2012 (UTC)
thread_title: ''protocolize'' seems to be standard medical jargon

message: *
*
The root context appears to be proto- (first, primitive, original) + col (from kolla, glue) + -ize (to become or produce).
Peaceray (talk) 02:10, 8 July 2012 (UTC)
thread_title: examples

message: couldn't this also be used for Firefighters with scorched lungs?  — Preceding unsigned comment added by 99.122.86.208 (talk) 18:37, 13 May 2014 (UTC)
replies: text: This is also a bit dated, but deserves an answer. *If* they can get the bloody thing to work without damaging already damaged tissues, deliver oxygen and remove carbon dioxide in a manner that the body requires. In short, it'll work once they get all of the major kinks worked out, some kinks being bent 180 degrees around, others more manageable. It's still a bit of a new technology, with few willing to risk expenses on a thus far lossy return.Wzrd1 (talk) 08:04, 20 August 2015 (UTC)
thread_title:  liquid breathing 

message: I'm not really certain this belongs here. This sounds more like someone drowning, than someone liquid breathing, given that the fluid had to be "kissed" out to save his life.64.180.221.163 (talk) 12:47, 3 March 2015 (UTC)
thread_title:  Anime (Aldnoah) example 

message: ...because the article doesn't seem to mention it. Wouldn't this be incredibly painful?
Can someone with some knowledge of this field address that?
*Septegram*Talk*Contributions* 22:11, 25 April 2016 (UTC)
thread_title:  I Have To Ask... 

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thread_title:  External links modified 

message: This article doesn't make it clear. Kortoso  (talk) 21:48, 15 December 2016 (UTC)
thread_title:  Theoretical or practical? 

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thread_title:  External links modified 

message: how do you breathe it in? Anytime I accidently inhale water, I cough and choke 2601:1C0:4D7F:D7A0:705F:C903:B0A7:4A8E (talk) 01:28, 10 July 2023 (UTC)
thread_title:  How?