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

1.About Air/Gas Embolism

A gas embolism, or air embolism, is a condition wherein gas or air bubbles enter the
bloodstream and cause an obstruction in circulation. These bubbles can consist of air or other gases, such as nitrogen, carbon dioxide, and nitrous oxide used for medical
procedures. A gas embolism, if not treated, can result in severe illness or even death.

There are two types of gas embolism – arterial gas embolism (AGE) and venous gas embolism (VGE).

AGE occurs when gas enters veins via the lungs, or enters arteries, which take blood to the heart. AGE often occurs in divers, who breathe compressed air underwater. During ascent to the surface of the water, if they do not fully exhale, their lungs expand and overinflate, forcing gas bubbles into the bloodstream. AGE also can occur during catheterization, radiology procedures and open-heart surgery, when air is allowed to enter into the blood. Approximately 4% of AGE sufferers die immediately from heart attack or breathing problems, and 5% die from other AGE-related complications.

VGE happens when gas enters the veins (vessels taking blood away from the heart) and
generally occurs as a result of surgery or other invasive medical procedures. VGE can occur during lung, brain, heart and other surgeries, with the greatest risk of VGE occurring during brain surgery. VGE also can be a result of non-surgical medical procedures, such as catheterization and the use of breathing machines. VGE can be easily
diagnosed during surgical or invasive procedures by monitoring end-tidal carbon dioxide levels and using real-time, sensitive monitoring. One such way of monitoring is Doppler ultrasonography, which is generally used during brain surgery, and transesophageal echocardiography, to detect air levels in the heart or veins.

Some symptoms of gas embolism include a loss of consciousness, headache, dizziness, nausea, vomiting, confusion, weakness, paralysis of limbs, disorientation, difficulty concentrating, vertigo, shortness of breath, blindness, convulsions, weakness on one side of the body and heart attack. Coma may occur in some patients. Delayed recovery from anesthesia may also be evidence of a gas embolism.

Gas embolism is an emergency situation, with the outcome depending on how quickly
oxygen is provided. Studies have shown that one of the quickest and most effective ways to administer oxygen is via a hyperbaric chamber.

References:
Boussuges A, Molenat F, Carturan D, Gerbeaux P, Sainty JM. Venous gas embolism: detection with pulsed Doppler guided by two-dimensional echocardiography. Acta Anaesthesiol Scand. 1999;43(3):328-32.

Downlaod Guide

Hart GB. Treatment of decompression illness and air embolism with hyperbaric oxygen. Aerosp Med.1974;45(10):1190-93.

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

Muth CM, Shank ES. Gas embolism. N Engl J Med. 2000;342(7):476–82.

Neuman TS, Thom SR. Physiology and medicine of hyberbaric oxygen therapy. Philadelphia, PA: Saunders Elsevier Inc.; 2008.

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

van Hulst RA, Klein J, Lachmann B. Gas embolism: pathophysiology and treatment. Clin Physiol Funct Imaging. 2003;23(5):237-46.

2.Common Treatments

Immediate treatment with increased atmospheric pressure is the best way to ensure a full recovery from a gas embolism. The traditional treatment for a gas embolism involves first taking steps to prevent more gas bubbles from entering the patient. Next, the patient receives high concentrations of oxygen to reduce the size of the gas bubbles, and an outlet is provided for the gas bubbles to exit the body if the bubbles are not completely eliminated by the oxygen.

Studies have shown that aggressive CPR is effective at reducing a gas embolism and preventing further complications. In addition, cardiac massage has also been shown to be effective for treating a gas embolism. For VGE, it is possible to remove the air using a
central venous catheter or a pulmonary arterial catheter. Placing the patient flat on his/her back or in a head-down position may also be used to help healing. Although conventional treatments, such as these, have been proven to be effective at treating gas embolism, hyperbaric chamber therapy has been shown to be the most effective way of significantly reducing gas embolism and increasing blood oxygen levels.

Hyperbaric chamber therapy provides the 100% oxygen saturation needed. Plus studies show that an increase in ambient pressure through hyperbaric chamber therapy reduces gas bubbles and delivers oxygen to the bloodstream to treat gas emboli.

While hyperbaric chamber therapy is not the first step in treating VGE, it is definitely the first line of treatment for AGE.

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

Moon R. Air or Gas Embolis. Hyperbaric Oxygen Committee Report. 2003;5-10.

Muth CM, Shank ES. Gas embolism. N Engl J Med. 2000;342(7):476–82.

Neuman TS, Thom SR. Physiology and medicine of hyberbaric oxygen therapy. Philadelphia, PA: Saunders Elsevier Inc.; 2008.

Orebaugh SL. Venous air embolism: clinical and experimental considerations. Crit Care
Med. 1992;20(8):1169-77.

3.Hyperbaric Therapy

In hyperbaric chamber therapy, patients are enclosed in a pressurized hyperbaric chamber, exposing them to an oxygen-only environment. In comparison, air in the atmosphere has an oxygen saturation of about 21%. The high oxygen levels and pressure in a hyperbaric chamber quickly raises the oxygen level in a patient’s blood.

Hyperbaric chamber therapy is used widely for the treatment of a number of medical disorders in many hospitals, clinics and doctors’ offices. Hyperbaric chamber therapy can be beneficial for a variety of conditions, and has especially been proven to be effective at
treating air or gas embolism.

Recently, studies have shown that hyperbaric oxygen therapy is effective as an immediate treatment for patients suffering from gas emboli, since it significantly reduces the size of gas bubbles and increases blood oxygen levels. The primary reason for the usefulness of hyperbaric chambers as a treatment option for gas embolism is derived from its ability to diffuse oxygen into the gas emboli and then transfer nitrogen from the bubble into the blood. Increased oxygen can promote recompression of the circulatory system, thereby reducing injury from a decrease in blood supply, and improving oxygen levels.

Studies have shown that high levels of oxygen not only reduces gas bubbles and
improves oxygen levels in patients with gas emboli, but it also restores blood flow and oxygenation.

The first line of treatment for AGE is generally hyperbaric chamber therapy. Hyperbaric chamber therapy has also been proven to be effective in preventing cerebral edema and reducing the adherence of white blood cells on damaged tissue. Although other treatments for gas embolism have been proven to be effective, such as infusion therapy, anticoagulant therapy, lidocaine therapy, and corticosteroid therapy, hyperbaric oxygen therapy is the first treatment choice.

References:
Camporesi EM, Mascia MF, Thom SR. Physiological principles of hyperbaric oxygenation. In: Handbook on Hyperbaric Medicine. NY: Springer-Verlag; 1996:35-58.

Clarke D. Hyperbaric oxygen therapy. American Journal of Emergency Medicine. Jul 1993; 11(4):436-7.

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.

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

Muth CM, Shank ES. Gas embolism. N Engl J Med. 2000;342(7):476–82.

4.Patient Results

Health care professionals frequently report success after using hyperbaric chamber treatments for their patients who suffer from a gas embolism during invasive procedures, and when treating divers. Approximately 70% of patients will heal from gas embolism once given treatment.

Studies have shown a 90% increased rate of success if hyperbaric oxygen therapy is administered within 1 hour of the formation of a gas embolism. If treatment is delayed more than 6 hours, the rate of success diminishes to 75%, with rate of success continuing to decline with each passing hour. Although every situation and every patient is different, there are very few patients, approximately 10% to 20%, who do not recover. Studies indicate that prognosis is reduced significantly during brain or heart surgery, due to the fact that diagnosis of gas embolism cannot be made until after the procedure is completed.

Reports indicate that the use of hyperbaric chamber therapy is the most beneficial line of treatment for gas embolism and must be the first line of treatment. Not all scientific studies are conclusive due to a number of factors. So far there have not been many randomized, well-controlled studies on the effect of hyperbaric chamber therapy on gas embolism. However, a large number of case reviews indicate poor outcomes without immediate recompression treatment. Therefore many health care professionals recommend this as the first line of therapy.

References:
Muth CM, Shank ES. Gas embolism. N Engl J Med. 2000;342(7):476–82.

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

5.Safety Information

Like all medical treatments, hyperbaric chamber therapy can have side effects that may not be seen with the first few treatments, but may develop after time. The side effects are variable and do not occur in all individuals. It has been reported that side effects are more
common with an extended duration of treatment. Hyperbaric chamber therapy treatment lasting more than 90 minutes is more likely to cause side effects. Furthermore, certain
patients may have predisposing factors that may make them more prone to developing the side effects associated with hyperbaric chamber treatment.

While the most common side effects of hyperbaric chamber therapy are uncomfortable pressure changes, claustrophobia and oxygen toxicity, other rare side effects have been reported. Listed below are some of the possible side effects of this therapy based on
previous reports.

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

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

Most of the symptoms listed are a result of oxygen toxicity, with some being more common, but most being quite rare.

The most common side effect of hyperbaric chamber therapy is pressure or “popping” in the ears, which is similar to the pressure felt when taking off or landing in an airplane. While it is sometimes uncomfortable, it is not usually painful. To ensure that treatment is
relaxing, prior to entering the chamber, patients should be shown techniques that will help alleviate the pressure. Some of recommended techniques are:

Adjusting or rolling the lower jaw
Blowing the nose
Pinching the nose and blowing out of the mouth
Yawning

This pressure generally will be felt for only the first 5 minutes of treatment as pressure
builds in the hyperbaric chamber.

The second most common side effect of hyperbaric chamber therapy is claustrophobia. Patients who suffer from anxiety due to claustrophobia should be taught how to meditate and calm themselves before beginning treatment. More severe cases of anxiety may
require medication, such as a sedative.

While claustrophobia is much less life threatening than a gas or air embolism, it must still be taken seriously. Consider the following recommendations to reduce likelihood of severe anxiety:

Purchase a hyperbaric chamber with an entertainment package, which can serve to divert the patient’s attention away from the enclosed environment, to something else.

Sedation can be used for severe cases of claustrophobia. It will not inhibit the hyperbaric chamber results.
If possible, let patients get acclimated and comfortable by gradually increasing time spent in the chamber.
Patients can benefit from a relaxation method such as meditation.

Oxygen toxicity, another common side effect, may lead to seizures. However, these seizures should stop immediately if treatment is ended. Changes in vision may also occur, but will also clear up once treatment is complete.

Patients who have or are prone to pneumothorax or have severe COPD, emphysema, or asthma should avoid hyperbaric chamber therapy, along with patients with PCP infections, a history of seizures, recent upper respiratory tract infections, or metabolic acidosis. Patients taking certain prescription and over-the-counter drugs, such as bleomycin, cis platinum, disulfiram, doxorubicin, and steroids, should also avoid this treatment, as well as patients who regularly use nicotine or alcohol.

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

Patients undergoing hyperbaric chamber therapy will lie inside the hyperbaric chamber and breathe normally. It is important that doctors ensure that their patients know what to expect, so they are not nervous or anxious.

In addition, there are several things that they cannot wear or bring into the hyperbaric chamber with them. Patients should not wear any beauty products, including:

Contact lenses
Wigs/toupees
Jewelry and watches
Hearing aids
Perfume/cologne
Finger and toenail polish
Hair spray and hair gel
Glasses

The temperature inside of the hyperbaric chamber will not vary from the temperature in the room. Therefore, room temperature must be kept at a comfortable level for patients.

References:
Neuman TS, Thom SR. Physiology and medicine of hyberbaric oxygen therapy. Philadelphia, PA: Saunders Elsevier Inc.; 2008.

Mathieu D. Handbook on hyperbaric medicine. Dordrecht, Netherlands: Springer; 2006.

7.Other Hyperbaric Uses

As early as the mid 1800’s, hyperbaric therapy was recognized to have a positive effect on a variety of ailments. Since that time, hyperbaric therapy has continued to be studied and recognized as a preferred treatment for a number of conditions. The military has used
hyperbaric chamber therapy to treat decompression sickness since the 1930’s. Since that time, it has been used to treat various conditions, including carbon monoxide poisoning, severe infections, diabetic foot ulcers, damage caused by radiation treatments, brain and nervous disorders and many more. Clearly then, hyperbaric oxygen chambers provide many benefits that can extend beyond the healing of a gas embolism. Below is a more detailed description of some other uses for hyperbaric chambers.

1. Diabetic Foot Ulcers
Diabetic foot ulcers affect 70% of patients with diabetes and are caused by diabetic neuropathy or peripheral vascular disease; both associated with poor blood circulation or restricted blood flow. Hyperbaric chambers increase oxygen, which encourages white blood cell activity, promotes capillary growth, and induces tissue development. High
levels of oxygen increases blood supply to the wound, thereby significantly reducing the chance of amputation.

2. Carbon monoxide poisoning
Carbon monoxide (CO), found in smoke, is a colorless, odorless and tasteless gas, and is attracted to hemoglobin in the blood. It is a common cause of poisoning deaths in the US. Because oxygen is rapidly displaced from the hemoglobin, less oxygen is available for the tissues. Symptoms of CO poisoning can be unclear. Individuals may present with a headache, memory loss, confusion, and abnormal heart rate and appear very pink. Today, hyperbaric treatment is the most effective treatment of CO poisoning. Hyperbaric oxygen accelerates the release and elimination of carbon monoxide from hemoglobin and oxygenates the tissues. Hyperbaric therapy also prevents the biochemical damage caused by lack of oxygen. Patients suspected of suffering from CO poisoning must immediately be referred for hyperbaric therapy.

3. Clostridal Myositis and Myonecrosis (Gas Gangrene)
To promote the healing of gangrene, it is important to increase antibiotic action, which is provided by hyperbaric chamber therapy. Studies have shown that increased oxygen concentrations at pressure decreases the production of the toxin that contributes to this condition.

4. Crush Injury and Compartment Syndrome (Traumatic Ischemia)
This syndrome is a result of an injury that prevents blood from flowing to an extremity or a portion of an extremity, thereby compromising blood vessels and/or skeletal tissue. With hyperbaric therapy, limbs may be saved from possible amputation. Hyperbaric therapy increases concentrations of oxygen reaching the damaged tissues and causes a reduction of swelling.

5. Decompression sickness
Hyperbaric therapy is widely used to treat decompression illness. Patients with this condition may present in a coma, with muscle pain, edema, abnormal heart rhythms, respiratory distress, and abdominal pain. Immediate transportation to the nearest hyperbaric therapy facility is suggested. No other treatments are recommended for
decompression illness. Reports indicate that the majority of patients with decompression illness can recover, even if they are in a coma, if they are decompressed immediately.

6. Exceptional Blood Loss (Anemia)
Increased pressure created by hyperbaric therapy sessions, significantly increases the amount of oxygen dissolved in the blood plasma. It has been proven that if blood is lost, the increased oxygen load in the remaining cells will be able to support metabolic functions until the blood is regenerated and/or restored.

References:
Bove A. Bove and Davis’ Diving Medicine. 4th ed. Elsevier Inc.; 2004.

Bove A. Bove and Davis’ Diving Medicine. 4th ed. Elsevier Inc.; 2004.

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.

Hart GB, Lennon PA, Strauss MB: Hyperbaric oxygen in exceptional acute blood-loss anemia. Journal of Hyperbaric Medicine. 1987;2(4):305-210.

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

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.

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.

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

Weaver LK, Ramona O, Hopkins K, et al. Hyperbaric Oxygen for Acute Carbon Monoxide Poisoning. NEngl J Med. 2002;347:1057-67.

8.Summary

In summary, air or gas embolism is a serious condition that, if not treated quickly, can be fatal. To avoid this outcome, patients need to be exposed to 100% oxygen as soon as possible after the air embolism occurs. Since hyperbaric oxygen chambers provide the quickest and most effective way to deliver pure oxygen to the body, they should be the first line of treatment for this condition.

Some common problems associated with the use of hyperbaric oxygen therapy are slight discomfort as a result of increased pressure inside the chamber and anxiety due to claustrophobia. Both of these symptoms can be significantly alleviated if the patient is properly
informed about and prepared for the therapy. In a low percentage of cases, oxygen toxicity has occurred, resulting in a number of different side effects, from mild to severe.

The positive effects of hyperbaric oxygen therapy outweigh the possible negative side effects.
Not only can hyperbaric chambers be used to treat air embolism, but many other conditions, such
as carbon monoxide poisoning and diabetic foot ulcers, just to name a couple.

Therefore, if your hospital or clinic does not currently have a hyperbaric oxygen chamber you
might want to look into purchasing one.