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Ten years ago, I emailed a prominent lung specialist with my suggestion for a treatment for Tuberculosis. His lack of response led me to believe that the idea had no merit whatsoever – but I had no idea what the failings might be. I still don’t and I’m hoping someone will enlighten me as to why this is not worth exploring.

The idea is based upon the fact that Mycobacterium Tuberculosis is aerobic – in fact Wikipedia states it “requires high levels of oxygen”. I’d heard that the TB “Sanatoriums” used to practice the treatment of breaking ribs on one side to collapse that lung and “rest” it. It seemed to me that this resting was actually starving the bacterium of Oxygen and killing the infestation.

My suggestion is that we take advantage of having two lungs by inserting a pair of breathing tubes into the respiratory tract and into the head of the two bronchi: it may be necessary to use ultrasound or other imaging to accurately position the tubes.

We feed pure Nitrogen into one tube, and 40/60 Oxygen/Nitrogen into the other – double Oxygen concentration. The patient therefore receives all their Oxygen requirements through one lung. After some period of time, when we judge that the bacteria in the “starved” lung are all dead, we switch the supplies to the 2 tubes and treat the other lung.

Can anyone see why this idea is so flawed?

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    $\begingroup$ The proposal is very flawed as pointed out by WYSIWYG, but I generally would like to see more questions like this. $\endgroup$ – James Jul 7 '15 at 10:29
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    $\begingroup$ also in tubeculosis, the mycobacteria go into tubecules and can remain in a dormant state for prolonged periods of time. Its unlikely this will kill those protected and dormant bugs. $\endgroup$ – shigeta Jul 8 '15 at 0:51
  • $\begingroup$ Your main flaw is forgetting that HUMAN cells require oxygen. See xkcd.com/1217 for details. $\endgroup$ – IMil Jul 8 '15 at 7:47
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  • High oxygen concentration can be deleterious; it can induce oxidative damage.
  • The systemic blood circulation would supply oxygen to the "oxygen-deprived" lung.
  • Moreover, Mycobacteria can survive in anaerobic conditions.

And what if both lungs are infected? There are many flaws in the proposed therapy.

Adding this point from one of the comments below:

There are several cases of extrapulmonary tuberculosis and in these cases treating just the lung would not make sense.

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  • $\begingroup$ That link is interesting - so possibly they can survive indefinitely without Oxygen - that might explain his attitude. I don't think the oxidative damage side of it appears to be a major factor given that it will only be in one lung for a limited time period...? I deal with treating both lungs in the text of the question. Yes, the derived lung would be supplied with Oxygen via the circulation - but I assume the bacteria receive their oxygen from the air in the lung - not via the blood supply...? $\endgroup$ – Lefty Jul 7 '15 at 9:58
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    $\begingroup$ @Lefty "I assume the bacteria receive their oxygen from the air in the lung - not via the blood supply" : not true. In fact Mycobacteria reside inside the lysosomes of macrophages and there are several examples of extrapulmonary tuberculosis. $\endgroup$ – WYSIWYG Jul 7 '15 at 10:05
  • $\begingroup$ just one more question then sorry. Do you think the whole rib-cracking thing was ineffective then - given that "resting" the lung wouldn't have any effect on the colonies present in the lung? $\endgroup$ – Lefty Jul 7 '15 at 10:15
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    $\begingroup$ ncbi.nlm.nih.gov/pmc/articles/PMC1079536 This is the reference I found today but I've read it 2 or 3 times before. $\endgroup$ – Lefty Jul 7 '15 at 10:18
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    $\begingroup$ As we know, this is not effective, but if it were, we could simply treat one lung at a time. The general understanding of this principal is important. $\endgroup$ – Joshua Jul 7 '15 at 15:21
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The accepted answer is correct but I would like to point out a misunderstanding that has to underly the idea that this would work:

In reality lungs aren't a magical one-way gate for the various gases. Lungs do not extract oxygen from the air, they permit oxygen exchange between the air and the blood. Since the air normally has a higher oxygen level than the blood the result is a net transfer of oxygen to the blood--something we see as extracting the oxygen from the air.

However, in an anoxic environment you'll get the reverse--oxygen will move from the blood (admittedly, not too much of it as this is blood that has already passed through the body) into the air.

This is also why too much carbon dioxide is lethal--the lungs likewise have no magic ability to expel it. It just normally moves from the higher concentration (the blood) to the lower concentration (the air in the lungs.) Too much and you can't get rid of it, or in extreme cases even get more of it.

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  • $\begingroup$ Thanks! I see what you mean now. But it was mentioned in @WYSIWYG's answer earlier, so I thought yours would add something. $\endgroup$ – AliceD Jul 8 '15 at 1:02
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    $\begingroup$ @Christiaan I'm explaining why WYSIWYG's answer happens. $\endgroup$ – Loren Pechtel Jul 8 '15 at 1:13
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What a great question! I'm sorry to add another blow to your theory... but... Even if oxygen depletion would be effective, treating the lungs alone is not good enough. True enough, Mycobacterium tuberculosis bacteria usually attack the lungs, but TB bacteria can also attack other parts of the body such as the kidney, spine, and brain (Fig. 1). If not treated properly, TB disease can be fatal. Because the TB bacterium has the potential to infect various parts of the body, a systemic treatment is necessary and long-term antibiotics are therefore the first-line treatment (Source: Center for Disease Control and Prevention).

In fact, there is tuberculosis of the lungs, tuberculous meningitis (infection of the brain membranes), skeletal TB, genitourinary TB and gastrointestinal TB (Source: Medscape).

TB
Fig. 1. Signs and symptoms of TB infection in various parts of the body. Source: Infection Landscapes.

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The most evident problem I can see for this TB treatment is that mycobacteria can survive without oxygen. Latent TB (a person is infected but doesn't have active TB) is one of the major problem in the treatment of TB and one-third of the world's population has latent TB! (http://www.who.int/mediacentre/factsheets/fs104/en/). A new TB treatment can only be effective if it targets both active and dormant bacteria.

Of course other aspects need to take into account. Over 95% of TB deaths occur in low- and middle-income countries with reduced access to medications and hospitals. A new treatment needs to have an affordable price, be simple and fast (http://aac.asm.org/content/53/3/849.full). These are other limitations of to the suggested treatment.

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  • $\begingroup$ Well, the fact is, it would never work, I understand that now, but irritating reality aside, I would have thought it would be massively cheaper than antibiotics and hospitalisation wouldn't it? I can see that imaging would add a lot to the cost but I'm not certain it would be necessary. $\endgroup$ – Lefty Jul 7 '15 at 23:01
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    $\begingroup$ @Lefty good heavens, of course not! Even if your theory worked, it also implies extensive hospitalization. More, in fact, than antibiotic treatment. The patients would need to be hospitalized for the full duration of the treatment, the concentrations of the various gases constantly monitored, doctors and nurses hovering for days etc. $\endgroup$ – terdon Jul 8 '15 at 12:55
  • $\begingroup$ @terdon Surely that all depends on exactly how long it would take to kill the bacteria? If they could survive 3 minutes - like humans - then the entire procedure could be over in 10 minutes. Given they can survive indefinitely then yes, I accept that an infinite amount of time in hospital might be quite expensive. $\endgroup$ – Lefty Jul 8 '15 at 13:13

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