Deep dive: USF research combats oxygen toxicity in Navy divers

USF Health’s Dominic D’Agostino conducts the Office of Naval Research-sponsored study using specialized hyperbaric chambers simulating underwater conditions

For the first time, ketone esters — oral supplements useful in epilepsy treatment — are being studied to fight seizures caused by hyperbaric oxygen toxicity, a life-threatening byproduct of breathing too much oxygen that impacts deep-water divers.

Dominic D’Agostino, PhD, an assistant professor in the Department of Molecular Pharmacology and Physiology, University of South Florida Morsani College of Medicine, is conducting this research supported by the Office of Naval Research.

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Dominic D’Agostino, PhD, in the University of South Florida Hyperbaric Biomedical Research Laboratory. With support from the Office of Naval Research, D’Agostino is studying ketone esters-oral supplements useful in epilepsy treatment-to fight seizures caused by hyperbaric oxygen toxicity, a life-threatening byproduct of breathing too much oxygen that impacts deep-water divers.

“This work represents a renaissance in how therapies are repurposed for other applications,” said Dr. William D’Angelo, a program manager in ONR’s Undersea Medicine Program. “Traditionally, certain therapies were only used to treat specific conditions. There’s now a movement to explore how drugs and other therapies already approved by the Food and Drug Administration for one type of treatment could treat more than one ailment.”

In a cruel twist of irony, oxygen toxicity stems from a Navy diver’s most precious commodity-oxygen itself. While divers need oxygen to breathe underwater, that ratio can become hazardous the deeper they plunge. Basically, the deeper the dive, the greater the danger.

Special Operations divers such as Navy SEALs are especially at risk. Divers can encounter dangerous levels of nitrogen and carbon dioxide gasses when breathing underwater, requiring a rebreather to mitigate the toxicity. But Special Operations divers use a closed-circuit rebreather that filters out the gasses in such a way that bubbles don’t appear on the water’s surface—useful when trying to avoid detection by enemy combatants.

However, this additional stealth increases how much oxygen the divers breathe and, combined with mission stress and physical exertion, can lead to seizures, convulsions, nausea, dizziness and even coma or death—all symptoms of oxygen toxicity.

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