Frequently asked questions about hyperbaric oxygen therapy

What is hyperbaric oxygen therapy?

The Undersea and Hyperbaric Medical Society (UHMS) defines hyperbaric oxygen therapy (HBOT) as a medical treatment in which the patient is entirely enclosed in a chamber and breathes oxygen while the chamber pressure is increased to a pressure greater than one atmosphere.

According to the UHMS, breathing 100% oxygen at one atmosphere of pressure or exposing isolated parts of the body to 100% oxygen does not constitute hyperbaric oxygen therapy; the patient must receive the oxygen by inhalation within a pressurized chamber.

Are there different types of chambers?

There are basically 2 types of chambers, monoplace and multiplace. The main differences are chamber size, number of occupants, and how the oxygen is delivered.

  • Monoplace chambers are single-person chambers pressurized with 100% oxygen from which the patient breathes directly.
  • Multiplace chambers are designed to hold two or more persons. Multiplace chambers are pressurized with compressed air while patients breathe 100% oxygen through a mask, hood or endotrachial tube.

Why does St. Luke's have 2 large chambers?

The largest chamber is used 3 times each day for treating patients who have chronic conditions such as non-healing wounds, bone infections and tissue damaged by radiation.

The smaller multiplace chamber is setup as an intensive care unit and remains on standby for emergency, post-operative or critical care patients.

The monoplace chambers located at Aurora BayCare Medical Center in Green Bay, Aurora Medical Center in Kenosha, Aurora West Allis Medical Center and Aurora Medical Center Hartford treat wound healing and other non-emergency patients.

Is HBOT safe?

HBOT treatment is prescribed by a physician and performed under medical supervision. Although there are minor risks, like all medical treatments, overall hyperbaric oxygen therapy is extremely safe.

What does HBOT feel like?

At the start of the treatment, some patients experience a sensation similar to that felt while flying and/or landing in an airplane. As pressure builds, it is common to feel pressure in the ears. At the end of the treatment, as the pressure is released, the ears "pop" automatically. Most patients rest comfortably throughout treatment. Many read, sleep or listen to music. Because the temperature increases during pressurization, HBOT chambers are equipped with air conditioning to ensure patient comfort.

How long does a hyperbaric oxygen treatment last?

Most treatments, including those for wound healing, last about 2 hours. Treatments for acute indications, such as carbon monoxide poisoning, may last as long as 4 hours, and under rare circumstances, some diving injuries may require treatment even longer than 8 hours.

How much pressure will be used for HBOT treatment?

Treatments for most chronic conditions, including wound healing, are usually at 2.4 Atmospheres Absolute Pressure (ATA). Most emergencies are treated with greater pressures, but usually at 3 ATA or less. Treatment for cerebral gas embolism may require compression to pressures up to 6 ATA.

How many HBOT treatments does a patient need?

The treatment's pressure and duration, as well as the number of treatments received, is determined by the hyperbaric doctor. This decision is based on the patient's diagnosis and their body's response to the therapy. Most wound healing patients receive one treatment per day (Monday – Friday) for 20 – 30 days. In general, patients with chronic conditions usually receive a longer series of treatments than patients with acute conditions.

Does insurance cover the cost of HBOT treatments?

Most insurance companies cover hyperbaric oxygen therapy. We will assist in obtaining verification of coverage from an insurance company prior to starting treatments.

Will the referring doctor still remain the patient's doctor?

Yes. The hyperbaric doctor serves as a consultant who will work closely with the patient's doctor to manage the treatment program.

What are the risks or possible side effects of HBOT?

Under proper supervision, the risks of HBOT are very minimal. The most common side effect is ear pain, and patients are monitored closely for this. Rarely, oxygen toxicity, pulmonary barotrauma and vision change can be experienced.

The following list of potential side effects is reviewed with each patient prior to beginning therapy.

  1. Otic Barotrauma (pain in the ears or sinuses). Some patients may experience pain in their ears or sinuses. If they are not able to equalize their ears or sinuses, the pressurization will be slowed or halted and suitable remedies will be applied.
  2. Serous Otitis. Fluid in the ears sometimes accumulates as a result of breathing high concentrations of oxygen. It may occasionally feel like having a "pillow over the ear." This disappears after hyperbaric treatment ceases and often can be eased with decongestants.
  3. Oxygen Toxicity. The risk of oxygen toxicity is minimized by never exposing patients to greater pressure or longer times than are known to be safe for the body and its organs. The risk is less than one in 10,000 treatments.
  4. Visual Changes (blurring, worsening of near-sightedness [myopia], temporary improvement in far-sightedness [presbyopia]). After 20 or more treatments, especially for those over 40 years old, some patients may experience a change in vision. This is usually temporary and in the majority of patients, vision returns to its pre-treatment level about six weeks after the cessation of therapy. It is not advisable to get a new prescription for glasses or contacts until at least eight weeks after ending hyperbaric oxygen therapy.
  5. Maturing or Ripening Cataracts. Individuals with cataracts have occasionally had a maturing or ripening of cataracts.
  6. Cerebral Air Embolism and Pneumothorax. Whenever there is a rapid change in ambient pressure, there is the possibility of rupture of the lungs with escape of air into the arteries or into the chest cavity outside the lungs. This can only occur if the normal passage of air out of the lungs is blocked during decompression. Only slow decompressions are used in HBOT to obviate this possibility. It is important for patients to breathe normally during during treatment and not hold their breath.
  7. Fatigue. Some people may subjectively feel fatigue following hyperbaric treatment, but this is not a consistent finding.
  8. Risk of Fire. With the use of oxygen in any form there is always an increased risk of fire. However, strict precautions have been taken to prevent this and all applicable codes have been complied with. There has never been a fire involving a hyperbaric chamber at Aurora Health Care.

How exactly is HBOT administered?

Monoplace chamber: Before going into the monoplace chamber, the patient is required to remove all clothing and put on a 100% cotton gown. Once they are lying comfortably on the transfer gurney, it will be slid into the chamber. After the door closes, the gentle "hiss" of the incoming oxygen used to pressurize the chamber will be heard.

As pressure develops in the chamber, the patient will notice a slight warming. They will also feel a fullness in their ears and should begin ear clearing procedures. When compression is complete, the need for ear clearing ceases. The patient may now rest, watch TV, view a video tape or listen to music.

During decompression, the chamber becomes cooler and the patient will feel a slight popping sensation in their ears as they adjust to the changing pressure. There is no need to clear the ears during decompression. No oxygen mask is required in this chamber because the entire chamber is filled with oxygen.

Multiplace chamber: Treatment in the multiplace chamber is usually accompanied by the same physical sensations of temperature change, ear fullness and popping as experienced in the monoplace chamber. Most patients walk in and are seated in chairs and some are wheeled in on carts or wheelchairs. Oxygen is delivered via a tight fitting mask or a clear plastic head tent, because multiplace chambers are compressed with air, not 100% oxygen. Patients are able to read, listen to music or rest.

Are there any contraindications to hyperbaric oxygen therapy?

The only absolute contraindication to HBOT is an untreated tension pneumothorax (an accumulation of air or gas in the pleural cavity of the lungs). There are several conditions in which caution must be observed. It is important that the hyperbaric physician is aware of the following conditions prior to beginning treatment:

  • Chronic sinusitis
  • Congenital spherocytosis
  • Emphysema with CO2 retention
  • History of optic neuritis
  • History of reconstructive ear surgery
  • History of spontaneous pneumothorax
  • History of thorax surgery
  • Pulmonary lesions in routine X-ray or CT scan
  • Seizure disorders
  • Sickle cell anemia
  • Uncontrolled high fever
  • Upper respiratory infections
  • Viral infections