Emergency HBOT for Decompression Sickness | NorCal Hyperbarics Concord, CA

Decompression sickness (DCS) occurs when dissolved nitrogen in body tissues comes out of solution and forms bubbles, typically due to ascending too rapidly from a scuba dive or other hyperbaric exposure. During a dive, the increased ambient pressure causes nitrogen (and other gases) to dissolve into the blood and tissues at concentrations far above normal. When a diver ascends, this dissolved nitrogen must be released slowly — through carefully controlled decompression stops that allow the gas to come out of solution gradually and be exhaled by the lungs. If ascent is too rapid or decompression protocols are violated, nitrogen exits solution as bubbles within tissues, joints, the spinal cord, the brain, and the pulmonary vasculature.

Decompression sickness can also occur in compressed air workers (caisson workers, tunnel workers), military divers, commercial divers, and — rarely — in unpressurized aircraft at altitude. The Bay Area's proximity to the Pacific Ocean, Monterey Bay, and the California coast creates a significant recreational diving community, and Northern California is home to commercial dive operations along the coast. DCS is an occupational hazard for these divers as well.

DCS is an approved UHMS indication for HBOT and represents one of the clearest, most mechanistically established applications of hyperbaric medicine. Arterial gas embolism (AGE) — a related but distinct condition caused by lung overexpansion and arterial introduction of gas bubbles — is treated with the same HBOT protocols and carries an even higher urgency for immediate treatment.

HBOT treats decompression sickness through mechanisms that address every component of bubble-induced injury simultaneously, and no other intervention does what HBOT does for DCS.

The first and most immediate mechanism is physical: according to Boyle’s Law, pressurizing the patient to 2.8 atmospheres (the pressure used in the standard US Navy Treatment Table 6) compresses nitrogen bubbles to approximately one-third of their original volume. This physical compression immediately reduces the mechanical obstruction of blood vessels and lymphatics, relieves tissue distension, and partially restores perfusion to downstream tissues. Simultaneously, breathing 100% pure oxygen at this pressure creates an enormous nitrogen partial pressure gradient between the bubble interior and the surrounding oxygen-saturated blood, driving rapid diffusion of nitrogen out of the bubble and into the blood plasma, where it can be transported to the lungs and exhaled. The combination of compression and accelerated nitrogen elimination causes the bubbles to rapidly shrink and eventually disappear.

While this is happening, the hyperoxic conditions provide supranormal oxygen delivery to every tissue in the body — including the ischemic regions downstream of the bubbles. This oxygen delivery preserves cell viability, limits neuronal injury in spinal cord and brain DCS, and reduces the extent of permanent injury. HBOT also reduces the secondary inflammatory cascade triggered by bubble-endothelial interaction: downregulating neutrophil activation, reducing platelet aggregation, and suppressing the inflammatory mediators that would otherwise continue to damage tissue even after the bubbles are gone. Prompt treatment is essential — outcomes are substantially better when HBOT is initiated within hours of symptom onset. Contact NorCal Hyperbarics immediately if DCS is suspected.