What does HBOT (Hyperbaric Oxygen Therapy) mean?

HBOT: Hyperbaric Oxygen Therapy

HBOT stands for Hyperbaric Oxygen Therapy, a medical treatment that delivers 100% oxygen to patients inside a specially designed pressurized chamber at pressures higher than normal atmospheric pressure (typically 1.5 to 3.0 atmospheres absolute). 1

How HBOT Works

Mechanism of oxygen delivery:

• The therapy exposes patients to 100% oxygen at pressures greater than 1 atmosphere absolute (ATA) in a sealed pressure vessel 1
• Treatment sessions typically last 60-120 minutes at pressures between 1.5 and 3.0 ATA, depending on the clinical indication 2
• This dramatically increases the partial pressure of oxygen (pO2) and the inspired oxygen fraction (fiO2), allowing for greatly increased oxygen delivery to tissues 2
• Unlike normal oxygen delivery that depends on hemoglobin, HBOT increases dissolved oxygen levels directly in blood plasma and tissues 3

Physiological effects:

• Reduces hypoxia and edema in ischemic tissues 1
• Stimulates fibroblast proliferation, collagen formation, and neovascularization in hypoxic wounds 4
• Enhances leukocyte microbial killing capacity 4
• Modulates inflammation and oxidative stress 3
• Has complex effects on immunity, oxygen transport, and hemodynamics 1

Approved Medical Indications

Emergency conditions where HBOT is established therapy:

• Carbon monoxide poisoning (reduces neurological sequelae at 6 weeks, 6 months, and 12 months when three treatments are given within 24 hours) 5
• Decompression sickness 6
• Air embolism stroke (physically reduces bubble size and increases dissolved oxygen to acutely ischemic tissue) 5, 7
• Gas embolisms 6

Other approved indications by the Undersea and Hyperbaric Medical Society (15 total):

• Compromised skin grafts and flaps 8
• Crush injuries 8
• Necrotizing soft tissue infections 8
• Non-healing ulcers with arterial insufficiencies 8
• Chronic wounds (including diabetic foot ulcers) 6

Emerging applications with variable evidence:

• Sudden sensorineural hearing loss (SSNHL) - may be offered within 2 weeks of onset combined with steroids, though evidence shows modest benefit 1
• Sports musculoskeletal injuries (investigational, requires further research) 8
• Severe COVID-19 (promising adjunctive treatment for hypoxemia and inflammation) 3

Treatment Parameters

Standard protocols:

• Pressures of 2.0 to 2.8 ATA are typical 8
• Sessions last 90 minutes once or twice daily for most indications 4
• Treatment duration varies: 3-10 sessions for sporting injuries, daily treatments for wound healing 8
• For sudden hearing loss, early treatment (within 2 weeks) is superior to late treatment 1

Important Limitations and Risks

Safety concerns:

• Potential complications include barotrauma (damage to ears, sinuses, lungs from pressure changes), seizures, claustrophobia, hypotension, cardiac arrhythmias, and pneumonia 9, 5
• Transport risks must be weighed against benefits when moving critically ill patients to hyperbaric facilities 9
• May further compromise physiologically unstable critically ill patients 9

Practical barriers:

• High cost and poor availability significantly limit access 9, 5
• Not widely available in the United States 1
• Requires specialized facilities and trained personnel 2
• Not FDA-approved for all conditions where it may have benefit (e.g., sudden hearing loss) 1

Conditions where HBOT is NOT recommended:

• Routine acute ischemic stroke (data do not support use; Class III: No Benefit) 9, 7
• Critical limb ischemia wound healing (effectiveness unknown) 9
• Dementia or chronic neurodegenerative conditions (no evidence of benefit) 5