Effects of Pre-dive Ketone Food Products on Latency to CNS Oxygen Toxicity (Aim 2)

NCT05831228 | Completed

• 1 other identifier: Pro00111000_1
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to understand how ketogenic food products affect oxygen toxicity in undersea divers. Oxygen toxicity affecting the central nervous system, mainly the brain, is a result of breathing higher than normal oxygen levels at elevated pressures as can be seen in SCUBA diving or inside a hyperbaric (pressure) chamber. This is a condition that may cause a wide variety of symptoms such as: vision disturbances, ear-ringing, nausea, twitching, irritability, dizziness, and potentially loss of consciousness or seizure. Because nutritional ketosis has been used to reduce or eliminate seizures in humans, it may be beneficial to reduce oxygen toxicity as well. The investigators hope this study will provide a help to develop practical and useful methods for improving the safety of undersea Navy divers, warfighters and submariners.

Conditions

Oxygen Toxicity

Outcome Measures

Primary Outcomes (1)

• Latency to central nervous system oxygen toxicity (CNSOT)

  Assessment of latency to CNSOT in a simulated working dive breathing 100% oxygen at 2.06 ATA, immersed in water (head out), in a hyperbaric chamber while performing exercise. Endpoint is time to development of signs or symptoms of CNSOT. Maximum duration 120 minutes.

  2 hours

Secondary Outcomes (9)

• Cognitive performance

  Day 1

• Level of nutritional ketosis as detected by serume beta hydroxybutyrate levels

  Day 1

• Number of participants with change in EEG

  Day 1

• Change in qEEG alpha/delta power ratio (ratio of power in alpha frequency band to power in delta frequency band)

  Day 1

• Change in end-tidal CO2

  Day 1

Study Arms (2)

Experimental: Ketogenic food products

EXPERIMENTAL

Dietary Supplement: Ketogenic food products Participants will be given a ketogenic food product prior to the hyperbaric oxygen exposure.

Dietary Supplement: Ketogenic food products

Control: Placebo

PLACEBO COMPARATOR

Dietary Supplement comparator

Dietary Supplement: Control: Placebo

Interventions

Ketogenic food products DIETARY_SUPPLEMENT

Participants will be given a ketogenic food product prior to the hyperbaric oxygen exposure.

Experimental: Ketogenic food products

Control: Placebo DIETARY_SUPPLEMENT

Participants will be given a dietary supplement comparator prior to the hyperbaric oxygen exposure.

Control: Placebo

Eligibility Criteria

• Age: 18 Years - 39 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Males \& females between 18 and 39 years old.
• Measured (Phase 2) VO2max ≥ 30 ml/kg/min (female) or 35 ml/kg/min (male).
• BMI ≤ 30.0 unless VO2max and baseline exercise profile is deemed appropriate for the study by the PI.
• (Phase 2 only) Able to exercise continuously on cycle ergometer for 2 hours.
• (Phase 2 only) Able to equalize middle ears and tolerate hyperbaric chamber exposure test.

You may not qualify if:

• Prolonged QTc on initial ECG
• Currently pregnant or attempting to become pregnant.
• Have a medical history of:
• Smoking history deemed significant by PI
• Known significant electrolyte disorders
• Coronary artery disease
• Cardiac arrhythmia deemed significant by PI
• Lung disease
• Hypertension
• Seizures
• Psychiatric disorder deemed significant by PI
• Previous pneumothorax or pneumomediastinum
• Hypo- or hyperglycemia
• Diabetes
• Inability to equalize middle ear spaces during hyperbaric compression

Sponsors & Collaborators

• Duke University: lead
• United States Navy: collaborator

Study Sites (1)

Duke University Hospital

Durham, North Carolina, 27710, United States

Location

Study Officials

• Bruce Derrick, MD

  Duke Health

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 24, 2023
• First Posted: April 26, 2023
• Study Start: September 1, 2023
• Primary Completion: March 31, 2025
• Study Completion: March 31, 2025
• Last Updated: May 31, 2025

Record last verified: 2025-05

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)