Understanding Hyperbaric Oxygen Therapy

Applications and Risks

Hyperbaric oxygen therapy (HBOT) is utilized in the treatment of at least 14 different medical conditions. Notably, one significant risk associated with this therapy is oxygen toxicity, which can result in seizures. Recent clinical research has investigated the potential of ketogenic supplements to delay oxygen-induced seizures, particularly in a preclinical setting.

Primary Uses of Hyperbaric Oxygen Treatment

The major applications of hyperbaric oxygen therapy include the treatment of diabetic wounds, carbon monoxide poisoning, decompression sickness, and gas embolisms. Additionally, recreational and military scuba divers may also be at risk for oxygen toxicity due to their exposure to high-pressure oxygen environments. Seizures resulting from oxygen toxicity can be fatal, especially when they occur underwater. This serious side effect poses limitations on the use of hyperbaric oxygen therapy and other high-pressure oxygen applications for divers.

Research on Dietary Influences

Previous Findings on Food Deprivation

Earlier studies have indicated that food deprivation may delay oxygen-induced seizures. Research conducted on rats showed that limiting glucose availability, the primary energy source for brain cells, encourages the circulation of free fatty acids. The liver then converts these fatty acids into ketone bodies, which can serve as an alternative energy source for the brain.

The Ketogenic Diet and Epilepsy

The ketogenic diet has also been examined as a treatment for epilepsy in animal studies. Children who do not respond to conventional anti-seizure medications are sometimes placed on a ketogenic diet to manage their seizures. Notably, the concentration of circulating ketone bodies in the bloodstream is linked to an anti-seizure effect, although the underlying mechanism remains unclear.

Preclinical Study Overview

Aim and Methodology

A study published in Physiological Reports sought to validate previous findings regarding the efficacy of ketogenic supplements in delaying seizures. The experiments were conducted on 18-month-old rats, an age that corresponds to middle-aged humans. The rats were divided into groups, each receiving different treatments: water, a 10g/kg dose of a ketogenic ester, a 5g/kg dose of a ketogenic ester, a 5g/kg dose with medium-chain triglycerides, or a ketogenic salt. Medium-chain triglycerides were included to enhance the elevation of ketone bodies in the blood.

All rats were fed a standard diet consisting of 75% carbohydrates. After treatment, they were placed in a hyperbaric chamber until a seizure occurred. Researchers from the University of South Florida hypothesized that the ketogenic supplements that resulted in the highest ketone body levels would be the most effective at delaying seizure onset.

Results of the Study

As anticipated, the time-to-seizure interval was significantly longer in the three groups of rats that received ketogenic supplements prior to entering the hyperbaric chamber. A notable difference was observed between the groups receiving the 10g/kg and 5g/kg doses. The higher dose exhibited more substantial anti-seizure activity compared to the control group. However, the rats receiving the lower dose and medium-chain triglycerides demonstrated a greater delay in seizure onset, albeit not significantly more than those on the high-dose ketogenic supplements. Rats administered ketone salts did not show a remarkable difference compared to the control group.

Severity of Seizures

Blinded researchers evaluated the severity of seizures once they occurred. The group receiving the high-dose ketogenic supplements exhibited significantly lower seizure severity compared to the control group. In contrast, the other groups receiving either lower doses of supplements or medium-chain triglycerides did not show a significant decrease in severity scores.

In all groups receiving ketogenic supplements, blood levels of ketone bodies were notably elevated. The treatment with high-dose ketogenic supplements resulted in the highest concentrations of circulating ketone bodies, demonstrating a strong correlation between ketone body levels and the delay in seizure occurrence.

Conclusion and Future Research Directions

This preclinical study assessed the effects of varying doses of ketogenic supplements and the use of medium-chain triglycerides on seizure timing following exposure to high-pressure oxygen. Results indicated significant increases in the delay of seizure activity for rats receiving higher doses of ketogenic supplements, as well as a lower seizure severity score for those on high doses. Further efficacy and safety studies are necessary to explore the application of this therapy in patients undergoing hyperbaric oxygen treatment and in scuba divers exposed to high-pressure oxygen environments.

References

Ari, AP Koutnik, J DeBlasi, et al. Delaying latency to hyperbaric oxygen‐induced CNS oxygen toxicity seizures by combinations of exogenous ketone supplements. Physiol Rep. 2019
Bove, AA. Recompression Therapy. Merck Manual Professional Version. https://www.merckmanuals.com/professional/injuries-poisoning/injury-during-diving-or-work-in-compressed-air/recompression-therapy