History

In the 17th century bridge construction demanded workers dive to great underwater depths with the introduction of caissons (a chamber, usually of steel but sometimes of wood or reinforced concrete, used in the construction of foundations or piers in or near a body of water).  The air in the chamber is kept under pressure great enough to prevent the entrance of water, while shafts through the bulkhead permit the passage of workers, equipment, and excavated material between the bottom and the surface.  Workers frequently suffered from caisson’s disease (the “bends”) and were treated in metallic vessels large enough to hold people and strong enough to hold air under pressure.  These vessels, combined with newly-developed air compressors, resulted in the enabled treatment of patients with hyperbaric air decompression.  This represented the first reports of decompression sickness; the caisson workers assumed a bent posture (the “bends”) to help relieve the pain caused by nucleation of accrued nitrogen in their joints as they emerged from depths of up to 70 feet.

Conventional western medicine uses HBOT to treat the following:

Uncontrolled Decompression during Diving: results in one of two types of decompression sickness (DCS).

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DCS I involves only the extremities (arms/legs) and the joints
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DCS II involves the central nervous system (brain/spinal cord)

Treatment involves recompressing the patient in 100% oxygen, followed by controlled decompression using data developed by the U.S. Navy.

Carbon Monoxide Poisoning: This colorless, odorless gas passes readily through alveoli (lung tissue air sacs) into the blood where it binds tightly to oxygen-carrying proteins in the blood (hemoglobin).  Carbon monoxide also locks up the energy factory machinery (cytochrome system) inside each cell’s mitochondria.  This prevents our bodies from being able to use oxygen.  The use of HBOT to treat carbon monoxide poisoning is controversial.  It is used to prevent/treat the development of neurologic injury in patients with severe exposure to this deadly gas.  Usually, patients undergo one or two 90-minute treatments at 2-3 atmospheres (2-3 times the atmospheric pressure at sea level).

Difficult Wounds: Chronic, non-healing wounds are found in a variety of clinical patients.  Recent data has supported the use of HBOT in the treatment of non-healing wounds caused by irradiation.  There is less data to support the use of HBOT in other clinical settings.  However, HBOT is often recommended in patients with difficult clinical problems.  For example, diabetes mellitus and vascular disease are notorious for late complications of non-healing wounds.  Amputation of an infected lower leg is the end result in many unfortunate cases.  These patients have been shown, recently, to benefit from HBOT.  One study showed decreased major amputation rate in diabetic patients who underwent HBOT (30 daily 90-minute treatments at 2-3 atmospheres).

Soft Tissue Infections: with anaerobic bacteria had a lower mortality rate in patients who underwent hyperbaric oxygen therapy, according to one study.  Another study showed HBOT to have no benefit in these infections.  According to one author (Sheridan), HBOT seems a reasonable adjunct to surgery, if it can be safely administered without delaying standard treatment (surgery and antibiotics).  Treatment would consist of 90-minute treatments at 2-3 atmospheres once or twice daily.

The following link will take you to a full-text review article on HBOT in the New England Journal of Medicine:

http://content.nejm.org/cgi/content/full/334/25/1642?ijkey=jUKDuJvHX0/.2

Alternative Medicine

Stroke:  Although HBOT is used conventionally in the United States, its use is reportedly higher in other countries. Stroke patients in Germany may undergo this form of treatment according to David Hughes, D.Sc. of the Hyperbaric Oxygen Institute.  Hughes states that HBOT has decreased the aftercare costs for stroke patients in Germany by as much as 71%.  As recent as 1995, one French study (Nighoghossian) showed that HBOT may be helpful in the treatment of ischemic stroke. But more recent investigations (Rusyniak et al) have shown that HBOT “does not appear to be beneficial and may be harmful in patients with acute ischemic stroke”.

Peripheral Vascular Disease and Chronic Wounds:  Hughes also claims that HBOT is used in France for peripheral vascular disease (PVD); which can be caused by atherosclerosis, arteriosclerosis, and diabetes, and others.  PVD oftentimes results in poor wound-healing and chronic ulcers (most often on/around the foot and ankle).  HBOT is not part of routine, conventional wound care for diabetic foot ulcers. It may, however, be considered for some patients. The American Diabetes Association recognizes HBOT as a potential adjunctive therapy for complex limb-threatening diabetic foot wounds unsuitable for revascularization procedures.

Multiple Sclerosis:  Dr. Hughes also states that HBOT is used in Great Britain to treat Multiple Sclerosis (MS).  Based on an unpublished article from 1993 by D. Perrin, Hughes cites that more than 25,000 MS patients have benefited from HBOT.  But, according to Kleijnen, patients who have chronic progressive or chronic stable multiple sclerosis showed no consistent positive effects to HBOT (results based on Expanded Disability Status Score [EDSS] and the Functional Status Score).  An earlier study by Kindwall (1991) treated patients in accordance with protocols that reported to produce a benefit in multiple sclerosis. Investigators were unable to substantiate any useful long-term effect of hyperbaric oxygen therapy.

Others:  Dr. Hughes also states that in Russia HBOT is used for detoxification of drug and alcohol overdose, and that citizens in Japan are never more than 30 minutes away from a hyperbaric chamber.

There are many proposed uses for HBOT in human disease.  Listed below are links to several other websites.

Links

http://www.cerebralpalsy.ws/hyperbaric_oxygen_therapy.htm

http://drcranton.com/hbo.htm

http://www.cincinnatihyperbarics.com/

http://www.netnet.net/mums/HBO.htm

http://www.hbot4u.com/

Complications of HBOT

In the elective setting, when patients are properly prepared and monitored, serious treatment-related complications are extremely rare. However, particularly in the emergent setting, it is important to have an understanding of potential complications so they can be avoided.  Complications may occur during compression, during treatment, or during decompression.

Complications during compression: are related to Boyle’s Law, which states that the volume of a gas in a closed space will decrease as pressure increases.  Closed spaces in which this may be significant are air-filled spaces beneath dental fillings, the middle ear, and sinuses.

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Middle Ear:  To facilitate clearance of the eustachian tube, alert patients are instructed to swallow during compression.   In the non-alert patient and those who are on a breathing machine (intubated),  it is necessary to perform a myringotomy before compression to ensure that there is no injury to the tympanic membrane (ear drum).  A single small incision in the lower front quadrant of the tympanic membrane immediately before compression.
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Sinuses:   more difficult to alleviate, although topical decongestants may be of value.
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Anxiety:  may also be a problem during compression when patients are first placed into the chamber; some patients require anxiolytics to facilitate treatment.

Potential complications during treatment: include seizures and those related to compromised patient access in monoplace chambers. Seizures, thought to be secondary to oxygen toxicity, have been reported to occur in as many as 10% of patients undergoing hyperbaric oxygen treatment for 90 minutes at 3 atmospheres. However, the incidence of seizures has been dramatically reduced with the routine use of “air breaks.” This is a maneuver in which the patient breathes compressed room air for 10 of every 30 minutes.

Complications that occur during decompression: are possibly the most serious potential complications. Gas trapped in air spaces that do not communicate with the chamber will expand rapidly.

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A pneumothorax (collection of air between the lung and chest wall) will become much larger.  Patients who have had recent attempts at upper body central venous catheters must be evaluated for occult pneumothorax. If necessary, chest tubes should be placed prophylactically and can be attached to a Heimlich valve during treatment.
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If the sinuses or middle ears have become obstructed, pain may ensue. Awake patients need to be appropriately coached to clear their sinuses and middle ears.
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If patients have significant air trapping or bronchospasm, localized air trapping may result in serious pulmonary barotrauma if decompression rates are too rapid; patients who are wheezing or have severe bronchospasm should not be treated.

References

Sheridan RL; Shank ES; Hyperbaric Oxygen Treatment: A Brief Overview of a Controversial Topic. The Journal of Trauma. 1999;47(2):426-35

Daniel E. Rusyniak, MD; Mark A. Kirk, MD; Jason D. May, MD; Louise W. Kao, MD; Edward J. Brizendine, MS; Julie L. Welch, MD; William H. Cordell, MD; Robert J. Alonso, MD; Hyperbaric Oxygen Therapy in Acute Ischemic Stroke: Results of the Hyperbaric Oxygen in Acute Ischemic Stroke Trial Pilot Study. Stroke. 2003;34:571.

N. Nighoghossian, MD; P. Trouillas, MD; P. Adeleine, MD; F. Salord, MD
Hyperbaric Oxygen in the Treatment of Acute Ischemic Stroke A Double-blind Pilot Study. Stroke. 1995;26:1369-1372.

Consensus Development Conference of Diabetic Foot Wound Care. Diabetes Care 1999; 22:1354-60

Hyperbaric oxygen for multiple sclerosis. Review of controlled trials. Kleijnen,-J; Knipschild,-P
Acta-Neurol-Scand. 1995 May; 91(5): 330-4

Treatment of multiple sclerosis with hyperbaric oxygen. Results of a national registry.
Kindwall,-E-P; McQuillen,-M-P; Khatri,-B-O; Gruchow,-H-W; Kindwall,-M-L
Arch-Neurol. 1991 Feb; 48(2): 195-9

HBOT is administered in two primary ways, using a monoplace chamber or a multiplace chamber. The monoplace chamber is the less-costly option for initial setup and operation but provides less opportunity for patient interaction while in the chamber. Multiplace chambers allow medical personnel to work in the chamber and care for acute patients to some extent. The entire multiplace chamber is pressurized, so medical personnel may require a controlled decompression, depending on how long they were exposed to the hyperbaric air environment.

The purpose of this report is to provide a guide to the strengths and limitations of the evidence about the use of HBOT to treat patients who have brain injury, cerebral palsy, and stroke. Brain injury can be caused by an external physical force (also known as traumatic brain injury, or TBI); rapid acceleration or deceleration of the head; bleeding within or around the brain; lack of sufficient oxygen to the brain; or toxic substances passing through the blood-brain barrier. Brain injury results in temporary or permanent impairment of cognitive, emotional, and/or physical functioning. Cerebral palsy refers to a motor deficit that usually manifests itself by 2 years of age and is secondary to an abnormality of at least the part of the brain that relates to motor function. Stroke refers to a sudden interruption of the blood supply to the brain, usually caused by a blocked artery or a ruptured blood vessel, leading to an interruption of homeostasis of cells, and symptoms such as loss of speech and loss of motor function.

While these conditions have different etiologies, prognostic factors, and outcomes, they also have important similarities. Each condition represents a broad spectrum, from barely perceptible or mild disabilities to devastating ones. All three are characterized by acute and chronic phases and by changes over time in the type and degree of disability. Another similarity is that the outcome of conventional treatment is often unsatisfactory. For brain injury in particular, there is a strong sense that conventional treatment has made little impact on outcomes.

Predicting the outcome of brain injury, cerebral palsy, and stroke is difficult. Prognostic instruments, such as the Glasgow Coma Scale (GCS) for brain injury, are not precise enough to reliably predict an individual patient’s mortality and long-term functional status. Various prognostic criteria for the cerebral palsy patient’s function have been developed over the years. For example, if a patient is not sitting independently when placed by age 2, then one can predict with approximately 95 percent confidence that he/she never will be able to walk. However, it is not possible to predict precisely when an individual patient is likely to acquire a particular ability, such as smiling, recognizing other individuals, or saying or understanding a new word.

Mortality and morbidity from a stroke are related to older age, history of myocardial infarction, cardiac arrhythmias, diabetes mellitus, and the number of stroke deficits. Functional recovery is dependent on numerous variables, including age, neurologic deficit, comorbidities, psychosocial factors, educational level, vocational status, and characteristics of the stroke survivor’s environment.

The report focuses on the quality and consistency of studies reporting clinical outcomes of the use of HBOT in humans who have brain injury, cerebral palsy, or stroke. This information can be used to help providers counsel patients who use this therapy and to identify future research needs.