Mild hyperbaric therapy is a safe, effective means for treating and assisting the treatment of many conditions when applied properly. In addition to the therapeutic side of mild hyperbaric, it also is widely promoted and utilized as a preventative therapy, recuperative therapy, and restorative therapy. Whatever your reasons for seeking out mild hyperbaric, there are a few things that everyone should understand regarding safety and contraindications.
Potential Risks Associated with Mild Hyperbaric Therapy:
Please note that it is important to not simply read the headers for each risk, but to read the entire section. This is very important because your level of education as a patron of mild hyperbaric therapy not only helps to greatly reduce these few potential risks, but in addition your education helps to dispel the myths and misconceptions which are likely to be brought to your attention during your first few weeks of undergoing therapy. Remember, your friends and relatives love you… but they most likely are not experts in the field of hyperbaric medicine. It is now your responsibility to educate them!
There is no other single potential risk that gets the amount of press as that of FIRE! However, the reality is that not only has the occurrence been almost absent in our country. In fact, until recent… very recent… there had not been a single hyperbaric fire in the United States and you can actually count the total number of incidences worldwide on two hands. The reason for such a low incidence is due simply to the fact that it is completely avoidable if one practices some simple precautions. Fire is not spontaneous! It requires three things:
- Flammable material (this could be anything from dry wood to gasoline to denim jeans)
- Oxygen (greater than 12%, normal breathing air is 21%; sufficient amount)
- Ignition source (something has to start the fire).
Remove any of the three and you don’t have fire; it is literally impossible! Obviously it is not practical to remove the oxygen and it should be noted that oxygen is not flammable it merely increases the burn rate and lowers the threshold for something to catch fire. Removing flammable material also isn’t completely practical, sure we can wear clothing that is less conducive to creating sparks and not enter the chamber with newspapers which use alcohol based inks in their production; but guess what? You are flammable! If you weren’t, then fire wouldn’t be an issue in the first place. But you are, and things like your hair are very flammable! So does this mean that everyone going into a hyperbaric chamber should shave their head? Absolutely not! But maybe we should think twice about smoking in the chamber. Well, maybe we should just think twice about smoking! Basically the point I am trying to drive home is that the single best way to prevent fire from occurring inside a hyperbaric chamber is to not bring in objects that produce sparks (lighters, wind-up toy cars, electronics, etc.). Now, it is important to understand two significant differences between mild hyperbaric and hyperbaric as done in a clinical setting such as would be used in treating the bends or acute carbon monoxide poisoning. Those two differences are oxygen concentration and pressure. Clinical hyperbaric chambers are often filled will 100% oxygen and operated at pressures 4-6 times that of mild hyperbaric chambers
. These two factors greatly increase the burn rate and greatly reduce the amount of energy to get something burning. On the contrary, in the mild hyperbaric environment the oxygen concentration rarely raises above 30% (even when someone is breathing “100%” oxygen through a mask). At this time I believe it should be noted that no fire has ever been reported inside a portable hyperbaric chamber to the date of this publishing, and that everyday thousands and thousands of individuals climb inside portable hyperbaric chambers set for 1.3 ATA w/ 10 LPM of additional oxygen feeding into the chamber, further… the majority of these individuals are bringing any number of electrical devices into the chamber from cell phones to laptops. Why no fire you ask? Well, because you have little more risk of catching on fire in the mild hyperbaric chamber environment than you do sitting on your couch. Now, on the contrary… thousands and thousands of people get into hyperbaric chambers at hospitals and wound healing centers around the country and world every day; and not a single one of them is allowed to take in any electronic equipment, wind-up toy car, or any device that could possibly lead to a spark! Because in that environment… a single spark can lead to a disastrous situation extremely quick. In conclusion, the risk of fire is exacerbated in a high oxygen high pressure environment; however, without a source to ignite some flammable material… fire is not only rare but impossible. In the mild hyperbaric chamber environment an individual is at almost no more risk of being in a dangerous fire situation than would they be sitting on a couch. Last, although electronics are widely used in the mild hyperbaric environment with a flawless safety record many people may urge you to not use such devices out of what would appear to be unwarranted safety concerns.
Even less warranted of a concern than fire is an explosion. Does this mean that it is absolutely not possible? Of course not, but the stage that must be set is so rare that to this date I only know of a single instance in history in which this has happened. First things first, how does an explosion happen? An explosion is the result of rapid expansion resulting in an acute pressure increase in which the container (hyperbaric chamber in this case) cannot withstand. If the pressure increase is not accelerated nor dramatic enough, then the increasing pressure will eventually stress the weakest component; resulting in pressure leakage and eventually pressure equilibrium.
Now, it should be noted that the only way such a rapid increase in pressure could ever occur would be the expansive force generated by the intense heat in a catastrophic fire, and even then; it is still unlikely for a “burst apart at the seams” explosion to occur. In conclusion, all be it rare; an explosion is possible. However, utilizing the safe clinical practices to prevent fires from ever occurring in deep pressure chambers and the lack of enriched oxygen utilized in mild hyperbaric chambers makes the possibility of a hyperbaric chamber exploding about equal to the chances of winning six Olympic gold medals in swimming; possible, but not likely to happen again for a very long time… if ever!
At mild pressures below 1.5 ATA, oxygen toxicity is virtually unheard of. However, at pressures greater than 2 ATA with 100% oxygen this is a real documented risk. Understanding the risks has resulted in standard clinical operating procedures which have greatly lessened the occurrence and have provided for the emergency procedures to protect the patient from further injury. Although the debate is still open on the exact cause and effect, the most favored explanation is the exhaustion of the body’s natural oxygen radical detoxification mechanisms including superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase plus certain enzyme compounds. It has been proposed in both the clinical and mild hypebaric therapy arenas that anti-oxidant supplements (Vitamin E, Vitamin C, Selenium, etc.) should be taken while undergoing hyperbaric; however there has been no demonstrated effect of lowering the incidence of oxygen toxicity through this practice. Of course, antioxidant supplementation can’t hurt; and for this reason many physicians still prescribe anti-oxidant supplements in hopes that they still provide some level of additional protection. Further, many physicians working with neurological conditions at treatment pressure ranging from 1.25-1.5 ATA recommend taking a 3-4 week break after as little as a month of continuous treatment. This practice is unsubstantiated from an oxygen toxicity point of concern and may actually be counterproductive to the overall objective of the treatment.
Seizure is the most common effect associated with oxygen toxicity, and once again is virtually unheard of at pressures below 2.0 ATA. The seizure itself is harmless (considered a non-medical emergency), the problem and risks related to seizures are more associated with physical injury that could happen while having the seizure as the body loses motor control. Of course, standard procedure for a seizure is to let it happen and move anything that could injure the individual out of the way.
Myopia, another symptom of oxygen toxicity, characterized by nearsightedness, is a refractive defect of the eye. It is believed that this is lenticular in action, meaning that the pressures exerted on the eyeball and cornea result in slight modification of the shape of the structures. Generally within six weeks of discontinuing therapy vision returns to normal. Note, this occurrence is unheard of below 2.0 ATA and is evident in some 20-40% of those who undergo daily 90-120 minute treatment at pressures above 2.0 ATA.
Cataracts is another eye issue that from time to time a potential patient may have concerns about. Once again, this is a condition that is shown to only be aggravated by deep pressures of 2.0 ATA and greater. Further, cataracts are typically only seen in patients who are exposed to these pressures and who have undergone 150-850 daily treatments (well beyond conventional treatment and only seen historically in foreign experimental research. The author knows of no reported cases of cataracts development at pressures of 1.5 ATA and below regardless of the number of treatments.
Risk factors contributing to oxygen toxicity include adrenocortical hormones, CO2 inhalation, dextoamphetamine, epinephrine, hyperthermia, insulin, norepinephrine, paraquat, hyperthyroidism, vitamin E deficiency, alcohol, recreational drugs, and any other compound that would either speed up metabolism or compromise the body’s natural oxygen radical detoxification pathways. Please note that not a single one of these risk factors is considered an absolute contraindication for hyperbaric, even in the deep pressure clinical setting. However, the combination of multiple risk factors is something that should be considered in any setting.
A real risk regardless of the pressure you are working with; however, not life threatening and typically quite temporary as the tympanic membrane repairs quite rapidly even in the event of a rupture. Just as the incision to place “tubes” in a myringotomy will heal upon removal of the tubes, so shall a ruptured membrane in the majority of cases. Does this mean don’t worry about managing pressure in the middle ear? Absolutely not! As prevention of the risk is all too simple, and undo harm because of negligence and/or lack of education is completely unacceptable. Nobody should have to walk around for a few days to a couple of weeks with an inflamed middle ear and muffled hearing as a result. Be sure to read, “managing pressure in the middle ear
” before undergoing your first treatment and/or administering your first treatment. These simple procedures and recommendations are the cornerstone of good practice regardless of the pressure you will be going to.
One misconception that needs to be greatly debunked is that of the idea that otic barotraumas could not occur in mild hyperbarics and only at deeper pressures above 1.5 ATA. On the contrary, it is actually more likely as the greatest change in volume as a result of pressure increase occurs within the first 10 feet (1.3 ATA). In fact, after 2.0 ATA the rate of change becomes so manageable that beyond this pressure problems rarely occur. So, once again… regardless of the treatment pressure, otic barotraumas is a real concern; not life threatening but worth taking the time to learn how to prevent and manage.
A risk that really isn’t a risk at all. Unlike oxygen of which the body utilizes, nitrogen is considered an inert gas, one capable of building up to the point of intoxication; similar to that of being intoxicated from alcohol. Nitrogen narcosis is really a concern for aquatic divers spending longer durations at deeper depths breathing normal air or even an altered mixture of oxygen and nitrogen. For divers, it is a triple edged sword. They can’t just breathe 100% oxygen the entire time while at great depths as this could result in an oxygen seizure (quite dangerous by the way when you are 100 feet underwater), They can’t spend unlimited amounts of time breathing normal air as this would result in potential narcosis (also quite dangerous when at significant depths underwater). Last, we have helium, an inert gas that is not narcotic and can be mixed safely with oxygen for divers to breath for unlimited amounts of times; the problem with helium is not only is it extremely expensive but it greatly robs the body of precious heat as it passes through (an incredible issue when diving at depth, since water gets colder the deeper you go). So, for divers there are a number of variables to consider when choosing a breathing mixture, but in the mild hyperbaric community this absolutely is not an issue. In clinical hyperbarics the patient is always breathing pure oxygen except during the standard air breaks in which the patient breaths ambient air for five minutes every 20-30 minutes. These short durations of ambient air are not enough to create nitrogen narcosis and are designed to prevent oxygen toxicity which is the real concern for deep pressure hyperbaric clinicians and patients. In the mild hyperbaric therapy arena, it is absolutely not an issue; this can be seen in the U.S. Navy dive tables which show dives to depths of 20 feet (1.6 ATA) have what is referred to as a No-Stop Limit, meaning that a diver can stay at these depths for unlimited amounts of time breathing ambient air with no concerns of nitrogen narcosis or the Bends for that matter. So, if a patient is being treated at 1.6 ATA or below regardless of the gas mixture, (room air or 100% oxygen) nitrogen narcosis should not be an issue. In conclusion, as stated above… nitrogen narcosis is a risk that really isn’t a risk at all (at least in hyperbarics, not so true for divers); but every once in a while, somebody wants to bring it up… and understanding why it is of no concern is as important as knowing that it isn’t!
The Bends (Decompression Sickness):
If you understood the above paragraph concerning nitrogen narcosis, then understanding why the Bends is a non-issue is quite simple. The Bends occurs when excessive dissolved nitrogen forms bubbles in the tissues and blood stream upon to rapid of decompression. These bubbles can accumulate in the joints, lungs, heart, and of most concern… the brain. Both recreational divers and commercial divers need to be aware of the Bends if they will either be diving for prolonged periods of time or be diving to depths greater than 20 feet. The deeper the depth, the less time a diver can spend without needing to take breaks during their ascent to the surface. For example: At 70 feet (a little over 3 ATA), divers should not spend more than 60 minutes unless they are prepared to take extra step during their ascent to prevent the Bends from occurring. At a depth of 100 feet (4 ATA), a diver only has 25 minutes. And at depths below 150 feet (almost 6 ATA), a diver has only 5 minutes before excessive nitrogen levels prevents a rapid ascent to the surface.
On the other hand, in the hyperbaric arena depths greater than 3 ATA are virtually never used except to treat the Bends. Further, at pressures above 2.0 ATA; 100% oxygen is utilized making the Bends a complete non-issue. Last, as we discussed above in the previous section… any dive or hyperbaric chamber treatment less than 1.6 ATA is at a depth/pressure that the U.S. Navy has determined insufficient to cause the Bends regardless of the gas mixture.
In conclusion… mild hyperbaric oxygen therapy
is not without its risks. However, when we consider the risks and we consider proper protocols and procedures; the majority of these risks become non-issues. In addition, when we consider the treatment pressures of mild hyperbaric (1.5 ATA and below); we find that that the risks seem to just disappear. This is not a suggestion to ignore safe practices and good judgment; simply a statement to the understanding of the origins of the risks associated with hyperbaric. The clinical setting of deeper pressures and 100% oxygen delivery is a completely different animal when it comes to risks and the everyday facilitation. Beyond the laws of physics and the word “hyperbaric” in the name, clinical hyperbarics and mild hyperbaric have little in common; from the ideal candidate to their effectiveness in specific conditions, and most certainly… the risks involved.
Contraindications - Absolute and Relative:
As mentioned above… mild hyperbaric therapy can be safe and effective; but this does not mean that it does not come without at least some potential risk. In the following section we will discuss contraindications to hyperbaric therapy and how they apply to mild hyperbaric therapy. Keep in mind that often times contraindications are not as “black and white” as they are made out to be, and understanding the original intent can help break through these misconceptions. An example of this would be the fact exercise is contraindicated for someone with high blood pressure. Does this mean that someone with high blood pressure should not exercise? Most likely not! But it most definitely means that one should exercise caution when beginning a new program. Sure, there are instances where conditions are absolute contraindications… and in a short moment you will learn what that one absolute contraindication for hyperbaric and mild hyperbaric therapy is. However, more often than not contraindications are quite grey, and having an understanding of the scientific/medical intent behind them can be a source of comfort and confidence when undergoing new therapies such as mild hyperbaric. Once again, it is important that you read over each and every one… as you are now an ambassador for the hyperbaric community.
The one and only absolute contraindication. Absolute in the acute stage and very relative for up to six months post pneumothorax. Don’t know what a pneumothorax is? Well, don’t worry too much because it’s not exactly one of those things you just walk around with and don’t have a single symptom of (especially a serious one)! A pneumothorax is the collection of air or gas in the space around the lungs, resulting in sudden sharp chest pain which is aggravated through a deep breath or cough. It is also typical of shortness of breath, chest tightness, easy fatigue, a rapid heart rate, and a bluish tint to the skin. Pneumothoraces are often the result of some sort of chest trauma, excess pressure on the lungs, and lung diseases such and COPD and Asthma.
The problem associated with a pneumothorax is occurs during depressurization. As pressure decreases, volume increases; and as the volume increases, the symptoms associated with a pneumothorax would worsen… potentially to the point where they would pass out and require resuscitation. Of course the deeper the pressure the more problematic a pneumothorax would be; at 1.3 ATA it is not likely that the individual being treated having the pneumothorax would pass out unless the symptoms were extremely aggravated; and in either case you have no business treating the individual before they seek medical attention.
The chances of a spontaneous pneumothorax occurring while in the hyperbaric arena are extremely rare, however real! And for this reason every clinic should have a standard operating procedure to handle such an instance. The author has never met anyone either clinical or otherwise who has ever seen firsthand or had heard of this occurring. In fact, hours are spent on this single topic at training for Board Certification in Hyperbaric Medicine, and although they will admit that a spontaneous pneumothorax has yet to happen… you never can be too cautious. In conclusion regarding a pneumothorax, if you have any of the above symptoms related to a pneumothorax, especially if you have more than one… have a physician order a chest x-ray before proceeding any further with hyperbaric.
The only contraindication which… if you have done your reading, is also a risk of hyperbaric. Of course otic barotraumas of any kind are contraindicated not just those that have been caused by previous treatment. This is obviously a relative contraindication as pneumothorax clearly stated it is the one and only absolute. So what does that mean, relative contraindication. Relative means that dependant on the severity and the treatment… further treatment may or may not be contraindicated. Generally, it is not an issue… and in the case of a rupture, getting to pressure becomes very easy. An ENT, (ear, nose, and throat doctor) typically won’t discontinue treatment nor delay the start of treatment due to the presence of otic barotrauma, but will simply provide the patient with guidelines on how to properly manage their risks and what to do in the presence of certain symptoms. Once again, be sure to read, “Managing Pressure Changes In The Middle Ear
” before undergoing your first treatment and/or administering your first treatment. These simple procedures and recommendations are the cornerstone of good practice regardless of the pressure you will be going to.
Sinus Colds and the Flu:
To the contrary, hyperbaric would be indicated at treating colds and the flu, as oxygen is deadly to all viruses and nearly every pathogenic microorganism (as they are anaerobic and cannot protect themselves from oxidation). So the problem isn’t that extra oxygen is going to help the virus and or bacteria replicate and spread, the problem is the sinus congestion and resulting inability to manage pressure in the inner ear; leading to potential otic barotraumas. Once again, have a read of “Managing Pressure Changes In The Middle Ear
” and you will be all set. In most cases, a nasal vasoconstrictor is all that is needed to get the patient through the treatment with no problem. Personal note from the author: Most proactive people start taking vitamin C and/or Echinacea at the first onset of a cold. The author likes to do those things too, but he also likes to do a couple days of mild hyperbaric and infrared sauna therapy. Let’s just say it stops with the sniffles!
Oxygen Seizure Risk Factors:
As discussed in Risks Associated with Hyperbaric Medicine, a fair amount of attention was spent discussing oxygen toxicity and the resulting oxygen seizure. The list of risk factors is repeated below as each of them is considered a relative contraindication to treatment: adrenocortical hormones, CO2 inhalation, dextoamphetamine, epinephrine, hyperthermia, insulin, norepinephrine, paraquat, hyperthyroidism, vitamin E deficiency, alcohol, recreational drugs, and any other compound that would either speed up metabolism or compromise the body’s natural oxygen radical detoxification pathways. Please note that not a single one of these risk factors is considered an absolute contraindication for hyperbaric, even in the deep pressure clinical setting. However, the combination of multiple oxygen seizure risk factors is something that should be considered in any setting. Please remember from the section on Oxygen Toxicity that the risk of seizure from oxygen toxicity is a risk related to pressures typically greater than 2.0 ATA and is unheard of below 1.5 ATA
Final Notes on Contraindications:
The only absolute contraindication is a pneumothorax. All relative contraindications should be considered on a case by case basis. When applied with thoughtful consideration to the patient and respect for the potential risks of the therapy, the few contraindications become less of a hindrance and more a set of guides to ensure the patients safety and comfort.
About the Author: Greg Harris is the founder of Hyperbaric Options LLC and has spoken publicly about health & wellness in various settings over the past eight years. Greg has a passion for human potential and is a firm believer that nearly all of the health problems we face today, from degenerative neurological conditions to the common cold, are preventable and reversible. As a health professional, Greg has a unique ability to connect the dots where others have left them scattered; it is this ability to integrate disciplines and think outside of the box that give his lectures and written materials a fresh point of view.
Disclaimer: The information and advice published or made available throughout this article is not intended to replace the services of a physician, nor does it constitute a doctor-patient relationship. Information contained within the following and/or preceding pages is provided for informational purposes only and is not a substitute for professional medical advice. The author encourages all readers to further research any topics of interest and reminds the reader that the comments and materials being presented do not necessarily constitute scientific fact and may contain opinions, theories, and third party views not widely accepted. You should not use the information contained in this published material for diagnosing or treating a medical or health condition. You should consult a physician in all matters relating to your health, and particularly in respect to any symptoms that may require diagnosis or medical attention. Any action on your part in response to the information provided throughout the material is at the reader's discretion. Readers should consult their own physicians concerning the information in this material. Hyperbaric Options LLC is not liable for any direct or indirect claim, loss or damage resulting from use of this material.