Hyperbaric Oxygen Therapy

Hyperbaric oxygen therapy is a treatment in which a patient breathes pure oxygen inside a pressurised chamber, allowing the body to absorb far more oxygen than it could at normal air pressure.

Under higher pressure, oxygen dissolves directly into the blood plasma (the liquid part of blood), not just into red blood cells. This oxygen-rich blood reaches tissues that are starved of oxygen — for example, a poorly healing wound or an area damaged by infection. The extra oxygen helps new blood vessels grow, supports the immune system in fighting bacteria, and speeds up the body's natural repair process.

Hyperbaric oxygen therapy is used when tissues in the body are not getting enough oxygen to heal properly, or when certain infections or injuries need a high-oxygen environment to recover. A doctor will assess whether the condition is likely to respond to this treatment.

• Diabetic foot wounds — sores on the feet of people with diabetes that are slow to heal
• Chronic non-healing wounds — ulcers (open sores) that have not improved with standard wound care
• Radiation tissue damage — injury to skin, bone, or soft tissue caused by radiotherapy (cancer radiation treatment)
• Gas gangrene and necrotising fasciitis — severe, fast-spreading bacterial infections that destroy tissue
• Carbon monoxide poisoning — when someone has inhaled carbon monoxide gas
• Decompression sickness — a condition divers get when they rise to the surface too quickly
• Arterial gas embolism — air bubbles that enter the bloodstream and block blood flow
• Crush injuries — serious damage to limbs caused by heavy impact or compression
• Compromised skin grafts or flaps — transplanted skin that is not receiving enough blood after surgery
• Osteomyelitis (bone infection) that has not responded to antibiotics alone

Hyperbaric oxygen therapy is not suitable for everyone. Doctors will usually avoid it or take extra precautions in certain situations.

• Untreated pneumothorax (a collapsed lung) — pressure changes can make this life-threatening
• Certain lung diseases where air can become trapped, such as severe emphysema (a condition where the air sacs in the lungs are damaged)
• Recent ear or sinus surgery, or a perforated eardrum (a hole in the eardrum)
• Uncontrolled high fever
• Some heart conditions — your treating doctor will evaluate the risk
• Claustrophobia (fear of enclosed spaces) that cannot be managed — though many chambers are large enough to reduce discomfort
• Pregnancy — used only when the benefit clearly outweighs any potential risk, as assessed by the doctor

Hyperbaric oxygen therapy is generally considered a low-risk treatment when performed in a properly equipped facility under medical supervision, but some side effects and complications can occur.

• Ear or sinus barotrauma (pressure-related discomfort or pain) — the most common side effect, similar to the ear-popping feeling during a flight
• Temporary changes in vision — some patients find their eyesight becomes slightly short-sighted during a course of treatment; this usually reverses after therapy ends
• Oxygen toxicity seizures (fits caused by breathing very high levels of oxygen) — rare, but the chamber staff are trained to manage this
• Tooth or jaw discomfort — air spaces in dental fillings or cavities can be affected by pressure
• Feeling lightheaded or mildly anxious inside the chamber
• Claustrophobia during the session — staff can communicate with the patient throughout
• Fire risk — pure oxygen is highly flammable; strict rules about what can be brought into the chamber greatly reduce this risk
• Lung barotrauma (pressure injury to the lungs) — very rare when the patient is breathing normally

Before starting a course of hyperbaric oxygen therapy, the medical team will carry out a thorough assessment to make sure the treatment is safe and appropriate for you. Some everyday habits and medications need to be reviewed in advance.

On the day of each session, most centres ask patients to avoid alcohol and carbonated drinks, as these can make pressure-related discomfort worse. Smoking is strongly discouraged throughout the course of treatment, because smoking reduces the body's ability to use oxygen — the very thing therapy is trying to deliver. Some medications, particularly certain chemotherapy drugs and blood thinners, may interact with high-pressure oxygen; the doctor will review all current medications before treatment begins. Patients are not usually required to fast, but individual facility guidelines may differ.

Before the first session, the following assessments are commonly carried out:

• A physical examination, with particular attention to the ears, sinuses, and lungs
• Chest X-ray to check for any lung conditions that could be worsened by pressure
• Blood sugar check — especially important for diabetic patients
• Ear examination to ensure the eardrums can handle pressure changes
• Review of all current medications and any recent surgeries
• In some cases, additional imaging such as CT or MRI scans of the wound area

Here is what typically happens during a hyperbaric oxygen therapy session:

• 1. The patient changes into a cotton gown provided by the facility — synthetic fabrics are not allowed inside the chamber because of the fire risk.
• 2. Any prohibited items are left outside: lighters, hearing aids with batteries, petroleum-based skin products, and personal electronic devices.
• 3. The patient enters the chamber, which may be a large multi-person room or a single-person tube, depending on the facility.
• 4. Staff seal the chamber and slowly increase the pressure inside — this is called pressurisation (compression). Patients may feel their ears pop, similar to descending in an aircraft.
• 5. Once the target pressure is reached, the patient breathes pure oxygen through a mask or hood for the main treatment period. The duration of this phase varies and is decided by the doctor.
• 6. Staff gradually reduce the pressure in the chamber — this is called depressurisation (decompression). Patients may again feel mild ear pressure.
• 7. The chamber is opened and the patient is assisted out. A short rest period may follow before the patient leaves.

Most patients are able to go home shortly after each session, as hyperbaric oxygen therapy does not require general anaesthesia (being put fully to sleep) or surgical cuts. However, the full course of treatment usually involves multiple sessions over several weeks, so ongoing care and monitoring are an important part of the process.

• Rest: Mild fatigue or lightheadedness is common after a session; patients are usually advised to rest for a short period before driving or returning to normal activities.
• Ear care: If ear discomfort occurred during the session, the medical team may teach techniques to equalise ear pressure, or recommend a review by an ear specialist.
• Wound care: The wound that is being treated still needs regular cleaning and dressing changes between sessions, as guided by the wound care team.
• Blood sugar monitoring: Diabetic patients are often asked to check their blood sugar levels more frequently during the course of treatment, as oxygen therapy can affect blood sugar.
• Smoking: Continuing to smoke reduces the benefit of therapy; the medical team will usually discuss this with the patient.
• Alcohol: Many centres advise limiting or avoiding alcohol during the treatment course.
• Follow-up appointments: The doctor will assess the wound or condition at regular intervals — usually before each session or at set points in the schedule — to decide whether more sessions are needed.
• Vision changes: If any change in vision is noticed during treatment, patients are advised to report it to their doctor, as this usually resolves after the course ends.
• Emergency signs: Patients are told to seek medical help promptly if they experience chest pain, severe shortness of breath, or sudden hearing loss after a session.