Hyperbaric oxygen therapy for decompression sickness

Hyperbaric oxygen therapy (HBOT) is effective in treating various diseases. The FDA has approved this therapy for 14 conditions, including severe gangrene, certain infections, burns, radiation injuries, and crush injuries. Among these, the two conditions that best highlight its life-saving potential are carbon monoxide poisoning and decompression sickness (DCS).  

According to data from the International Diving Safety Association, cases of decompression sickness are surging globally each year, with 30% of patients suffering joint deformities or neurological damage due to delayed treatment. A diving instructor’s firsthand account serves as a warning: "After surfacing, I felt a sharp pain in my elbow. Six hours later, I lost sensation in my legs—only when I was placed in a hyperbaric oxygen chamber did I manage to survive."

Why does this acute condition, caused by gas bubbles "exploding" inside the body, achieve a remarkable 95% cure rate in a sealed oxygen chamber? Today, Oliveoxygen will provide you with an in-depth explanation of how hyperbaric oxygen chambers treat decompression sickness (DCS).

What is Decompression Sickness? (DCS)

Decompression Sickness (DCS) is a condition caused by the rapid reduction of external pressure, leading to the formation of gas bubbles from dissolved gases in the body, which then trigger systemic pathological damage.

• Definition and causes of decompression sickness

Decompression sickness, also known as diver's disease or caisson disease, occurs due to the following core mechanisms:  

1. Gas Dissolution Under High Pressure – In environments with increased pressure, such as diving, caisson work, or high-altitude flights, gases like nitrogen dissolve into the blood and tissues at higher concentrations.  

2. Bubble Formation Due to Rapid Decompression – When pressure drops suddenly (e.g., a diver surfacing too quickly), dissolved gases exceed their saturation limit and form free gas bubbles, which can obstruct blood vessels or compress surrounding tissues.  

3. Pathological Damage– These bubbles cause mechanical injuries (such as embolism and tissue compression) and biochemical reactions (such as inflammation and coagulation), leading to multi-organ dysfunction.

Types of Decompression Sickness (DCS)

• Mild Decompression Sickness (Type I)  

Skin Symptoms: Itching, rashes, mottled skin (subcutaneous gas bubbles), localized swelling.  

Muscle and Joint Symptoms: Limb soreness and swelling, flexion contracture (bending joints to relieve pain).  

Typical Case: A diver experiences skin itching and mottled patterns after insufficient decompression.  

• Moderate Decompression Sickness  

Joint and Muscle Pain: Severe pain in large joints (shoulders, elbows, knees) and surrounding muscles, leading to restricted movement.  

Lymphatic System Damage: Swollen lymph nodes and blocked lymphatic vessels.  

Case Example: A caisson worker develops sharp knee pain after work, requiring knee flexion for relief.  

• Severe Decompression Sickness (Type II)

Nervous System Damage: Paralysis, limb numbness, confusion, vision/hearing impairment (caused by spinal cord or brain embolism).  

Circulatory & Respiratory System Effects: Chest tightness, chest pain (pulmonary embolism), shock, breathing difficulties (choking sensation).  

Digestive System Issues: Nausea, vomiting, abdominal pain.  

Fatal Risks: Without timely treatment, DCS can be life-threatening (e.g., coronary artery embolism leading to sudden death).

How Hyperbaric Oxygen Therapy Works for DCS

Mechanism of HBOT for DCS

• Physical Dissolution of Gas Bubbles

In a high-pressure environment (typically 2.0–2.8 ATA), gas bubble volume decreases, accelerating nitrogen dissolution into the blood and its elimination through respiration.

Studies show that at 2.8 ATA, bubble volume shrinks to one-third of its original size, and the dissolution rate increases threefold.

• Improving Tissue Oxygenation and Microcirculation

HBOT significantly increases blood oxygen partial pressure (up to 14 times the normal level), with dissolved oxygen reaching 6.4 ml per 100 ml of blood.

Oxygen directly diffuses through the plasma into ischemic tissues (such as the spinal cord and brain), alleviating hypoxic damage.

• Inhibiting Inflammation and Oxidative Stress

HBOT suppresses neutrophil adhesion and reduces the release of inflammatory factors (TNF-α, IL-6), minimizing endothelial damage and secondary inflammatory responses.

• Promoting Nerve Repair

HBOT stimulates the secretion of vascular endothelial growth factor (VEGF), promoting angiogenesis and axonal regeneration, aiding in the recovery of neurological dysfunction caused by DCS.

Key benefits of hyperbaric oxygen therapy for DCS

• Rapid Symptom Relief

For acute DCS patients (e.g., joint pain, and breathing difficulties), symptom relief can reach 70%-90% after the first treatment.

• Shortened Recovery Time

DCS patients who receive early HBOT typically experience 30%- 50% shorter hospital stays and a reduced incidence of chronic sequelae (such as bone necrosis).

• Reduced Long-term Complications

By improving oxygen supply to the spinal cord and brain, HBOT lowers the risk of neurological deficits, such as paralysis and cognitive impairments.

• Supporting Other Treatments

When combined with anticoagulants or anti-inflammatory medications, HBOT can enhance treatment effectiveness and reduce reperfusion injury after thrombolytic therapy.

Safety and Risks of Hyperbaric Oxygen Therapy (HBOT) for Decompression Sickness (DCS)

• Safety

Minimal risk with proper procedures: When following strict pressure-time protocols, complication rates are <1%.

Broad applicability: Suitable for most DCS patients, including severe cases, but contraindications must be considered (e.g., untreated pneumothorax, active bleeding).

• Common Side Effects

Barotrauma: Middle ear or sinus barotrauma occurs in 5%-10% of cases but can be prevented by voluntary eustachian tube adjustment or using decongestants.

Oxygen toxicity: Rare (0.01% incidence), usually caused by excessive pressure or prolonged oxygen exposure, leading to seizures or lung damage.

• Contraindications

Absolute contraindications:

  Untreated pneumothorax

  Severe emphysema

  Active intracranial bleeding

Relative contraindications:

  Epilepsy

  Claustrophobia

  Early pregnancy

How to prevent decompression sickness?

• Strictly Follow Decompression Rules

Use staged decompression techniques, ascending gradually according to a time-based schedule to avoid rapid pressure changes.

• Regular Health Checkups

Undergo pre-employment and periodic medical evaluations to exclude individuals unsuitable for high-pressure environments, such as those with cardiovascular conditions or obesity.

• Healthy Lifestyle Habits

Get adequate rest before work to avoid fatigue.

Avoid alcohol consumption before diving.

Maintain a balanced diet and supplement with vitamin E to support vascular health.

• Post-Dive Care

Keep warm after diving.

Take a hot shower to improve blood circulation, aiding nitrogen elimination.

• Medication Prevention (Under Medical Supervision)

Follow a doctor’s guidance for potential preventive medication when necessary.

FAQs on Hyperbaric Oxygen Therapy (HBOT)  

Do I feel uncomfortable while undergoing hyperbaric oxygen therapy?

Most patients find hyperbaric oxygen therapy (HBOT) to be a comfortable experience. The most common sensation is ear pressure, similar to what you feel during an airplane takeoff or landing. This happens due to the increased atmospheric pressure inside the chamber. You can relieve this discomfort by yawning, swallowing, or performing the Valsalva maneuver. Some people may feel warm initially, but the chamber is usually kept at a comfortable temperature.  

Does Medicare cover hyperbaric treatments?

Medicare does cover hyperbaric oxygen therapy, but only for certain medical conditions. These include diabetic foot ulcers, chronic refractory osteomyelitis, decompression sickness, carbon monoxide poisoning, radiation injuries, and a few other conditions. Coverage may vary depending on the specific Medicare plan and whether the treatment meets the medical necessity criteria. It's best to check with your healthcare provider or Medicare directly for detailed coverage information.  

Can hyperbaric oxygen therapy completely eradicate decompression sickness (DCS)?

Hyperbaric oxygen therapy is the primary treatment for decompression sickness (DCS) and is highly effective in reducing symptoms and preventing long-term complications. However, the effectiveness depends on factors like the severity of DCS, how quickly treatment is administered, and individual patient response. While many patients recover fully with HBOT, some may experience residual symptoms, especially if treatment is delayed.