What is hyperbaric oxygen therapy?
Although hyperbaric oxygen therapy has its place in smoke inhalation, carbon monoxide poisoning, and diving complications, its role in wound healing centers on correcting hypoxia to tissues compromised by trauma, infection, or the elements.
The physics of hyperbaric oxygen therapy is based on gas dissolving into solutions proportionately with its pressure. Delivering oxygen under pressure augments the oxygen content in the tissue, thereby addressing acute or chronic ischemia. This is an important advantage in wound healing.
Hyperbaric oxygen therapy is an adjunctive therapy for acute traumatic and ischemic injuries, such as crush injuries, compartment syndromes, and situations of vascular compromise.
It increases the survival of skin grafts and reconstructive flaps that have compromised blood flow. This prevents tissue breakdown by improving local vascularity. Previous graft failure sites benefit from prophylactic hyperbaric therapy.
Once hyperbaric oxygen therapy raises the amount of oxygen in tissues in the healing process, the effects of injury, ischemia, and inflammation are diminished. These damaging effects are mediated by oxygen free radicals and hydrogen and nitrogen split-products which are all mitigated by the augmentation of oxygen saturation. This hyperoxia causes vasoconstriction to reduce edema, limits leukocyte (white blood cell) influx, helps fibroblast proliferation, and promotes neovascularization (new blood vessels) that enhance the healing process. It also has antimicrobial effects.
Hyperbaric chambers are designed to accommodate either one person or more than one. The only absolute contraindication to a hyperbaric chamber is pneumothorax. Relative contraindications include severe COPD. Pregnancy is not a contraindication.
- Middle ear trauma, more common in those undergoing multiple treatments. Rupture of the eardrum is possible, but rare.
- Sinus trauma due to the pressure, which occurs in those with upper respiratory infections.
- Pulmonary trauma, unusual; it is accompanied by pulmonary edema.
- Pulmonary toxicity: chest tightness, cough, and reversible pulmonary function impairment.
- Rare seizures due to nervous system oxygen toxicity is more of a risk in those exposed to >90-120 minutes or >2.8 atmospheres.