Hyperbaric Chambers: Ventilators, Hyperbaric Oxygen Chambers & Medical Gas Mixer

1.About Carbon Monoxide Poisoning

Carbon monoxide poisoning accounts for more than 400 unintentional deaths each year, more than
4,000 hospitalizations, and more than 20,000 emergency room visits, making it the main cause of accidental deaths by poisoning in the United States and Europe. Sadly, carbon monoxide poisoning caused by inhaling car fumes also accounts for more than 2,000 suicide deaths each year.

Carbon monoxide is an odorless, colorless, and tasteless gas, which can be inhaled just regular air
without being noticed. Hence it is known as the “great imitator”. It is released by vehicle combustion fumes, stoves, lanterns, gas ranges, heating systems, kerosene space heaters, faulty gas appliances, small gasoline engines, and burning wood and charcoal. Carbon monoxide poisoning can affect people, as well as family pets. Exposure to carbon monoxide in small or enclosed spaces can increase the chance of poisoning.

When carbon monoxide is breathed in it attaches itself to red blood cells, and therefore replaces the
oxygen in the bloodstream with carbon monoxide. This blocks oxygen from reaching vital parts of the body and kills cells.

Symptoms of carbon monoxide poisoning include headache, weakness, dizziness, confusion, chest pain,
nausea and vomiting. Carbon monoxide poisoning also can cause drowsiness, which may prolong diagnosis. The severity of the symptoms depends on amount of exposure and concentration of gas.Because symptoms of carbon monoxide poisoning are similar to flu-like symptoms and other illnesses, it is difficult to diagnose and may go undetected.People exposed to carbon monoxide while sleeping or intoxicated may die before even recognizing the symptoms. Exposure to high concentrations of carbon
monoxide poisoning can result in loss of consciousness or death. Long-term symptoms of carbon monoxide exposure, such as disorientation or memory loss, can show-up 2 to 40 days after exposure.Recent studies show that carbon monoxide exposure also has negative side effects on the immune
system and metabolism.

Carbon monoxide poisoning can be avoided simply by education and awareness. While 93% of homes
have smoke alarms, only 15% have carbon monoxide alarms. Investing in a carbon monoxide alarm,having frequent home inspections of appliances and regular service and maintenance on appliances prone to emit levels of carbon monoxide will protect your home from carbon monoxide poisoning. In addition, proper ventilation of all gas and fuel appliances, fireplaces, and chimneys will prevent carbon monoxide poisoning.

To treat carbon monoxide poisoning, high doses of oxygen must be administered immediately. Studies
have shown that therapy with a hyperbaric chamber—a high oxygen environment—is a good treatment for moderate-to-severe carbon monoxide poisoning.

References:
Barret L, Danel V, Faure J. Carbon monoxide poisoning, a diagnosis frequently overlooked. J Toxicol Clin
Toxicol. 1985;23(4-6):309-13.

Downlaod Guide

Department of Health and Human Services, Agency for Toxic Substances & Disease Registry. Toxicological Profile for Carbon Monoxide. http://www.atsdr.cdc.gov/toxprofiles/tp201.html. Updated October 26, 2009. Accessed July 30, 2010.

Grace TW, Platt FW. Subacute carbon monoxide poisoning. Another great imitator. JAMA. 1981;246(15):1698-700.

Mathieu, D. Carbon monoxide poisoning. In : Mathieu D, Mathieu-Nolf M, Linke JC, Favory R, Wattel F, eds. Handbook on Hyperbaric Medicine. Dordrecht, Netherlands: Springer; 2006.

Neuman TS, Thom SR. Carbon monoxide pathophysiology and treatment. In: Thom SR, ed. Physiology and Medicine of Hyberbaric Oxygen Therapy. Philadelphia, PA: Saunders Elsevier Inc.; 2008.

Norkool DM, Kirkpatrick JN. Treatment of acute carbon monoxide poisoning with hyperbaric oxygen: A review of 115 cases. Ann Emergency Med. 1985;14(12):1168-1171.

Omaye ST. Metabolic modulation of carbon monoxide toxicity. Toxicology. 2002;180(2):139-50.

Thom SR, Bhopale VM, Fisher D, Zhang J, Gimotty P. Delayed neuropathology after carbon monoxide poisoning is immunemediated. PNAS. 2004;101(37):13660-65.

Winter PM, Miller JN. Carbon monoxide poisoning. JAMA. 1976;236(13):1502.

2.Common Treatments

Tests and exams can be conducted to diagnose carbon monoxide poisoning and to determine its effects.
An arterial blood gas and a complete blood count are the initial tests given. A breathing analysis also may be done with a handheld breath analyzer to determine the amount of carbon monoxide gas exhaled. If these tests are positive, more tests and questionnaires may be administered to determine the effects of the gas on cognitive abilities. Tests may also be done to check for heart and brain damage. As soon as carbon monoxide poisoning is suspected though, oxygen is administered before or during any further
testing.

Oxygen therapy is the primary treatment for carbon monoxide poisoning, and studies show that hyperbaric chamber therapy significantly reduces carbon monoxide levels and increases oxygen levels in a shorter time than traditional oxygen therapy administered through a face mask. Hyperbaric chamber therapy provides 100% oxygen saturation, thereby removing the carbon monoxide gas from the bloodstream faster. Studies show that an increase in pressure through hyperbaric chamber therapy will deliver oxygen to the bloodstream more effectively.

While hyperbaric chamber therapy was not traditionally the treatment of choice for carbon monoxide
poisoning, that is changing since it is best for quick relief from symptoms and immediate oxygenation.

References:
Hardy KR, Thom SR. Pathophysiology and Treatment of Carbon monoxide Poisoning. Clin Toxicol. 1994;32(6):613-29.

Mathieu, D. Carbon monoxide poisoning. In : Mathieu D, Mathieu-Nolf M, Linke JC, Favory R, Wattel F, eds. Handbook on Hyperbaric Medicine. Dordrecht, Netherlands: Springer; 2006.

Neubauer RA, Walker M. Hyberbaric Oxygen Therapy. New York, NY: Penguin Putnam, Inc.; 1998.

Neuman TS, Thom SR. Carbon monoxide pathophysiology and treatment. In: Thom SR, ed. Physiology and Medicine of Hyberbaric Oxygen Therapy. Philadelphia, PA: Saunders Elsevier Inc.; 2008.

Thom SR, Keim LW. Carbon monoxide poisoning: A review epidemiology, pathophysiology, clinical findings, and treatment options including hyperbaric oxygen therapy. Clin Toxicol. 1989;27(3):141-56.

Norkool DM, Kirkpatrick JN. Treatment of acute carbon monoxide poisoning with hyperbaric oxygen: A review of 115 cases. Ann Emergency Med. 1985;14(12):1168-1171.

Thom SR. Hyperbaric-Oxygen Therapy for Acute Carbon Monoxide Poisoning. N Engl J Med. 2002;347:1105-6.

3.Hyperbaric Therapy

During treatment in a hyperbaric chamber, patients are exposed to an oxygen-only environment inside a
closed pressurized hyperbaric chamber. The average healthy person only requires about 21% oxygen atmospheric levels, but to quickly reoxygenate the blood of a patient with carbon monoxide poisoning, 100% oxygen is required.

Today, hyperbaric oxygen chambers are used extensively for the treatment of several medical disorders
and can be found in many clinics, hospitals and doctors’ offices. One of the many uses of hyperbaric chamber therapy is treating poisoning caused by carbon monoxide.

Recent studies have been seen to show that hyperbaric oxygen therapy can be beneficial to provide
immediate symptom relief to patients suffering from carbon monoxide poisoning by significantly increasing levels of oxygen and removing carbon monoxide gas from the bloodstream. Its ability to effectively and quickly remove the poisonous gas from the hemoglobin in the blood is quickly making it the treatment of choice for carbon monoxide poisoning.

Studies have often shown not only do high levels of oxygen improve oxygen levels in patients with
carbon monoxide poisoning, but it also relieves symptoms and promotes a full recovery. During hyperbaric oxygen therapy, 100% oxygen is administered in high pressures to restore the blood’s oxygen-carrying capacity to normal by reducing levels of the carbon monoxide gas. Because hyperbaric oxygen therapy works faster than oxygen administered through a fitted facemask, this treatment is generally used in moderate to severe carbon monoxide cases when symptoms become more serious and may lead to death or brain or heart damage.

The first treatment choice for carbon monoxide poisoning is generally 100% oxygen therapy. A recent
study indicated that three hyperbaric treatments during a 24-hour time frame significantly reduced the risk of damage to cognitive abilities. Other studies have reported that hyperbaric chamber therapy reduces the half-life of carbon monoxide gas to 15 to 23 minutes as opposed to 30-90 minutes for traditional oxygen therapy. Treatment with hyperbaric oxygen therapy is case dependent; for patients exhibiting moderate to severe symptoms, such as loss of consciousness, confusion, or for pregnant women, treatment with this therapy is the first line of choice.

References:
Kao LW, Nanagas KA. Carbon monoxide poisoning. Med Clin N Am. 2005;89(6):1161-94.

Mathieu, D. Carbon monoxide poisoning. In : Mathieu D, Mathieu-Nolf M, Linke JC, Favory R, Wattel F, eds. Handbook on Hyperbaric Medicine. Dordrecht, Netherlands: Springer; 2006.

Neuman TS, Thom SR. Carbon monoxide pathophysiology and treatment. In: Thom SR, ed. Physiology and Medicine of Hyberbaric Oxygen Therapy. Philadelphia, PA: Saunders Elsevier Inc.; 2008.

Norkool DM, Kirkpatrick JN. Treatment of acute carbon monoxide poisoning with hyperbaric oxygen: A review of 115 cases. Ann Emergency Med. 1985;14(12):1168-1171.

Stoller KP. Hyperbaric oxygen and carbon monoxide poisoning: a critical review. Neurol Res. 2007;29(2):146-55.

Weaver LK, Hopkins RO, Chan KJ, et al. Hyperbaric oxygen for acute carbon monoxide poisoning. N Engl J Med.

4.Patient Results

Medical professionals report success after using oxygen therapy to treat carbon monoxide poisoning.
Studies have shown that if carbon monoxide attaches to 10% to 15% of hemoglobin, patients begin exhibiting feelings of dizziness and confusion; at 30% to 40%, patients start feeling drowsy and become lethargic; and at 60% to 70%, poison levels become fatal and may result in seizure, coma or death.

Despite every patient and every situation being different, about 30% of patients with carbon monoxide
poisoning do not fully recover. Past studies show that longer exposure to the gas may cause more damage to the heart and brain, leading to fatal outcomes.

Hyperbaric chamber therapy has been reported to be the most beneficial type of treatment for moderate
to severe cases of carbon monoxide poisoning if it is the first treatment in these patients. Scientific publications about the effectiveness of hyperbaric chamber therapy for carbon monoxide poisoning indicate that there is usually recovery from symptoms within a few days, but results are inconclusive as the statistics surrounding recovery from carbon monoxide poisoning are unclear. If treatment is administered in enough time, a full recovery, although slow, is possible. However, if patients receive no
treatment, carbon monoxide poisoning can often end in death or brain or heart damage. Many medical professionals recommend this as the therapy of choice.

References:
Kao LW, Nanagas KA. Carbon monoxide poisoning. Med Clin N Am. 2005;89(6):1161-94.

Mathieu, D. Carbon monoxide poisoning. In : Mathieu D, Mathieu-Nolf M, Linke JC, Favory R, Wattel F, eds. Handbook on Hyperbaric Medicine. Dordrecht, Netherlands: Springer; 2006.

Neuman TS, Thom SR. Carbon monoxide pathophysiology and treatment. In: Thom SR, ed. Physiology and Medicine of Hyberbaric Oxygen Therapy. Philadelphia, PA: Saunders Elsevier Inc.; 2008.

Norkool DM, Kirkpatrick JN. Treatment of acute carbon monoxide poisoning with hyperbaric oxygen: A review of 115 cases. Ann Emergency Med. 1985;14(12):1168-1171.

Raub JA, Methieu-Nolf M, Hampson NB, Thom SR. Carbon monoxide poisoning—a public health perspective. Toxicology. 2000;145(1):1-14.

Rosenthal LD. Carbon Monoxide Poisoning: Immediate diagnosis and treatment are crucial to avoid complications. Am J Nursing. 2006;106(3):40-6.

5.Safety Information

Recent studies have indicated that three hyperbaric treatments within 24 hours can relieve symptoms
from carbon monoxide exposure and effectively remove the gas from hemoglobin in the blood. However, hyperbaric chamber therapy can produce a number of variable side effects that may develop after extended duration of treatment. The side effects are rare and therefore do not occur in most patients.

Any hyperbaric chamber treatment lasting longer than 90 minutes will have a higher chance of
producing adverse effects. Certain patients may have a higher risk of experiencing side effects from hyperbaric chamber treatment.

Below are all the reported side effects of hyperbaric chamber therapy for any uses, not just with carbon
monoxide poisoning.

Anxiety
Bronchitis
Claustrophobia
Dry cough
Fluid around lung(s)
Hallucinations
Hiccups
Loss of consciousness
Lung fibrosis
Mid-chest pain
Muscle twitches
Nausea

Oxygen toxicity
Pallor
Seizures
Shortness of breath
Sweating
Tinnitus
Uncomfortable pressure changes
Vertigo
Visual blurring
Vomiting

A few of these symptoms are common, while most are quite rare.

Pressure or “popping” in the ears, the same as that felt when airplanes are landing or
taking off, is the side effect most often felt due to hyperbaric chamber therapy. While some patients report that this treatment is not comfortable for them, it is definitely not painful. To ensure a relaxing treatment, before entering the chamber, patients can be taught techniques that will release the pressure from their ears.

Some of recommended techniques are:
Blowing the nose
Pinching of the nose and blowing out through the mouth
Moving the lower jaw
Yawning

In general, this pressure will be felt only for the first 5 minutes as pressure increases in the hyperbaric chamber.

Claustrophobia, the second most experienced side effect from hyperbaric chamber
therapy, may cause extreme anxiety in patients and must be taken seriously. To prevent severe anxiety, patients can be meditation and calming techniques prior to beginning
treatment. Patients presenting with a severe case of anxiety may be prescribed a sedative. To reduce the likelihood of severe anxiety, medical professionals should consider these ideas:

Using a model with the entertainment option, which can help keep the patient’s focus on something other than the enclosed environment.
Sedation can be an option for severe cases of claustrophobia. This will in no way affect the hyperbaric chamber results.
Allow patients to get acclimated to and comfortable with the chamber by gradually, over several sessions, increasing the amount of time for each treatment session in the hyperbaric chamber.
Relaxation techniques can be beneficial for patients. These methods can be taught prior to treatment.

A serious side effect, oxygen toxicity, can cause seizures. The good news is that these
should stop immediately after the patient is removed from the hyperbaric chamber. Vision changes can also occur, but will dissipate once treatment is finished.

Patients who should avoid hyperbaric chamber therapy include: patients who have severe
COPD, are prone to or have pneumothorax, asthma or emphysema; patients with PCP infections, recent upper respiratory tract infections, a history of seizures, or metabolic
acidosis; patients taking certain over-the-counter and prescription medications (steroids, bleomycin, doxorubicin, cis platinum and disulfiram); and patients who smoke or drink alcoholic beverages frequently.

References:
Clark J, Whelan H. Oxygen toxicity. In: Kindwall EP, Whelan HT, eds. Hyperbaric Medicine Practice. 2nd ed. Best Publishing Co; 1999:69-97.

Clark JM, Lambertsen CJ. Pulmonary oxygen toxicity: a review. Pharmacol Rev. Jun 1971; 23(2):37-133.

Davis JC, Dunn JM, Heimbach RD. Hyperbaric medicine: patient selection, treatment procedures, and side effects. In: Davis JC, Hunt TK, eds. Problem Wounds: The Role of Oxygen. NY. Elsevier Science Publishing Co; 1988:225-235.

Plafki C, Peters P, Almeling M, Welslau W, Busch R. Complications and side effects of hyperbaric oxygen therapy. Aviat Space Environ Med. 2000;71(2):119-24.

Yildiz S, Aktas S, Comsit M, et al. Seizure incidence in 80,000 patient treatments with hyperbaric oxygen. Aviat Space Environ Med. 2004;75:992.

6.Preparing Patients

Hyperbaric chamber therapy patients are asked to lie inside the hyperbaric chamber and
to continue to breathe normally. The patient will be exposed to an oxygen level of 100%, and atmospheric pressure experienced will be 2 to 3 times that of what is normal. This method of therapy exposes carboxyhemoglobin, a mix of carbon monoxide and hemoglobin in the blood, to high levels of oxygen, thereby replacing the carbon
monoxide with oxygen so the carbon monoxide gas can be exhaled. The increased atmospheric pressure in turn increases the normal level of dissolved gases in the patient’s
blood by approximately 2 to 3 times (increasing from 0.32% to 6.8%).

It is important to reassure the patient that, although there may be slight discomfort, the
treatment will not be painful. Hyperbaric chamber therapy actually is extremely relaxing with many patients taking naps during treatment. Internal entertainment systems found in some machines may further enhance patients’ comfort and relaxation. Except for brief moments of interruption during periodic “air breaks,” the hyperbaric chamber is extremely peaceful and relaxing.

Patients should not be wearing any beauty products, including:
Jewelry and watches
Hearing aids
Wigs/toupees
Cologne/perfume
Nail polish
Hair gel or spray
Contact lenses
Glasses

The temperature in the hyperbaric chamber is consistent with that of the room, therefore room temperature must be maintained at a comfortable level.

7.Common Questions

What is hyperbaric chamber therapy?
Hyperbaric chamber therapy, or hyperbaric oxygen therapy, is a medical treatment wherein a patient breathes in 100% oxygen in a closed pressurized chamber. Hyperbaric chamber therapy is used to treat several medical conditions, including carbon monoxide poisoning.

Can hyperbaric chamber therapy be used to treat carbon monoxide poisoning?
Yes, although it is not always the first treatment used for carbon monoxide poisoning, a condition that occurs as a result of inhaling fatal amounts of carbon monoxide gas. Hyperbaric therapy is known to remove carbon monoxide gas by increasing partial pressure. This form of treatment increases oxygen levels, thereby removing gas from hemoglobin in the blood and restoring oxygen-carrying capacity to restore blood flow and oxygen levels.

How does hyperbaric oxygen therapy work?
The immediate direct physical effects of oxygen and other gases under pressure facilitates the action of hyperbaric oxygen. Increased oxygen restores blood flow and effectively reduces carbon monoxide levels faster than traditional oxygen therapy. This method is widely becoming a treatment of choice for quick relief from symptoms and immediate oxygenation. It is effective for several conditions, but has proven to be extremely effective in the treatment of carbon monoxide poisoning.

Are there any side effects?
There are variable side effects that come from hyperbaric chamber treatment. Generally, although the effects are not seen during the first few treatments, they can develop after extended duration of treatment. The side effects do not occur in all people. Side effects are more often seen with treatments that last more than 90 minutes.
Side effects are rare, only occurring in 1/10,000 individuals. The side effect that is most common is claustrophobia. In addition, the excess pressure inside the chamber can cause middle ear injury. Oxygen toxicity, a rare but serious side effect, may also occur.

Is this treatment painful?
No. This treatment is not painful, with patients reporting only minor discomfort in the ears and sinuses. This is similar to the feeling experienced during aircraft takeoff or landing. Patients can relieve pressure by yawning, blowing the nose, or other techniques. Brief moments of interruption during periodic “air breaks” are common, but overall, therapy is extremely peaceful and relaxing.

What health issues can benefit from hyperbaric chamber treatments?
Carbon monoxide poisoning can be treated by this therapy, but it is not the only condition that can benefit from hyperbaric chamber treatments. Hyperbaric chambers can be used to treat gas embolism, diabetic foot ulcers, decompression sickness, gas embolism, compartment syndrome, severe infections, chronic ulcers and thermal burns. Research is ongoing in the effort to discover more conditions that may benefit from the use of this promising therapy.

8.Other Hyperbaric Uses

Hyperbaric chamber treatment was first introduced into clinical settings around the
1880’s. Today, its application has extended to many more conditions than had been originally intended. Hyperbaric chamber therapy has been used since the 1930s by the
military to treat divers’ decompression sickness. After that time, it has also been used to treat various conditions, including carbon monoxide poisoning, severe infections, diabetic foot ulcers, thermal burns and many other problems. Clearly then, increased oxygen at pressure provides benefits that go far beyond the treatment of carbon monoxide poisoning.

1. Air or Gas Embolism
Embolisms, or bubbles of trapped gas in the body, can occur as a result of respirator over-expansions, chest injuries, or surgical procedures. A hyperbaric chamber will
significantly reduce the volume of trapped air by placing it under pressure and allowing it time to diffuse out of the space where it is trapped. The reduced size of the bubble relieves pain and swelling immediately.

2. Intracranial Abscess
In cases where surgery has not been recommended for this condition, hyperbaric therapy can reduce swelling and increase the ability of the body to fight bacteria.

3. Necrotizing Soft Tissue Infections
Patients with this condition can benefit greatly from increased antibiotic properties created as a result of increased oxygen concentration from hyperbaric therapy. This
therapy also provides a boost in the immune system and activates infection-fighting cells that are in the blood.

4. Refractory Osteomylitis
By increasing oxygen tensions within infected bone, hyperbaric treatment promotes the growth of collagen along with the development of new capillaries. The removal of dead
bone cells is heavily dependent upon oxygen; therefore, the hyperbaric oxygen chamber is an effective treatment for this condition.

5. Delayed Radiation Injury (Soft Tissue and Bony Necrosis)
Radiated tissue damage has been shown to significantly benefit from hyperbaric treatment. Vital to the improvement of this condition are increases in the development of
new blood vessels, along with the positive stimulation of the functioning of the immune system. In addition, increased blood circulation and faster production of skin cells are needed.

6. Compromised Skin Grafts and Flaps
The growth of new capillaries is extremely important when skin grafts or flaps have covered areas that have some sort of damage, and hyperbaric chamber treatments
promote this growth.

7. Thermal Burns
By acting to promote healing in various ways, hyperbaric chamber therapy can decrease overall mortality in the case of thermal burns. Increased oxygen at pressure can decrease inflammation and swelling, while at the same time increasing the healing of white blood cells. It also prevents infection from spreading and decreases fluids in the affected area.

References:
Escobar SJ, Slade JB Jr, Hunt TK, et al. Adjuvant hyperbaric oxygen therapy (HBO2) for treatment of necrotizing fasciitis reduces mortality and amputation rate. Undersea Hyperb Med. Nov-Dec 2005;32(6):437-43.

Feldmeier J. Hyperbaric Oxygen 2003: Indications and Results- The Hyperbaric Oxygen Therapy
Committee Report. Kensington, Maryland: Undersea and Hyperbaric Medical Society, Inc.; 2003.

Gimbell M, Hunt T. Wound healing and hyperbaric oxygen. In: Kindwall EP, Whelan HT, Eds. Hyperbaric Medicine Practice. 2nd ed. Best Publishing Co; 1999:169-204.

Hart GB, O”Reilly RR, Broussard ND, et al. Treatment of burns with hyperbaric oxygen. Surgical Gynecology and Obstetrics. Nov 1974; 139(5):693-6.

Heyneman CA, Lawless-Liday C. Using Hyperbaric Oxygen to Treat Diabetic Foot Ulcers: Safety and Effectiveness. Crit Care Nurse. 2002;22:52-60.

Hunt TK, Pai MP. The effect of varying ambient oxygen tensions on wound metabolism and collagen synthesis. Surg Gynecol Obstet. Oct 1972;135(4):561-7.

Kaye D. Effect of hyperbaric oxygen on Clostridia in vitro and in vivo. Proc Soc Exp Biol
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Lampl L, Frey G, Bock KH. Hyperbaric oxygen in intracranial abscesses – update of a series of 13 patients. Undersea Biomed Res (Suppl.). 1992;19:83.

Lind F. HBO therapy in burns and smoke inhalation injury. In: Handbook on Hyperbaric
Medicine. NY. Springer-Verlag; 1996:510-530.

Mirski MA, Lele AV, Fitzsimmons L, Toung TJ. Diagnosis and treatment of vascular air
embolism. Anesthesiology. Jan 2007;106(1):164-77.

Niezgoda JA, Cianci P, Folden BW, et al. The effect of hyperbaric oxygen therapy on a burn wound model in human volunteers. Plast Reconstr Surg. May 1997;99(6):1620-5.

Park MK, Myers RA, Marzella L. Oxygen tensions and infections: modulation of microbial growth, activity of antimicrobial agents, and immunologic responses. Clin Infect Dis. Mar 1992;14(3):720-40.

Riseman JA, Zamboni WA, Curtis A, et al. Hyperbaric oxygen therapy for necrotizing fasciitis reduces mortality and the need for debridements. Surgery. Nov 1990;108(5):847-50.

Tibbles PM, Edelsberg JS. Hyperbaric-Oxygen Therapy. N Engl J Med. 1996;334:1642-48.

Van Unnika. Inhibition of toxin Production in Clostridium Perfringens in Vitro by Hyperbaric Oxygen. Antonie Van Leeuwenhoek. 1965;31:181-6.