Hypercapnia, Oxygen Toxicity, Seizures
Conditions
Brief summary
The goal of this clinical trial is to learn about the mechanisms of oxygen toxicity in scuba divers. The main questions it aims to answer are: * How does the training of respiratory muscles affect oxygen toxicity? * How do environmental factors, such as sleep deprivation, the ingestion of commonly utilized medications, and chronic exposure to carbon dioxide, impact the risk of oxygen toxicity? * How does immersion in water affect the development of oxygen toxicity? Participants will be asked to do the following: * Undergo a basic screening exam composed of health history, vital signs, and some respiratory function tests * Train their respiratory muscles at regular intervals * Exercise on a cycle ergometer both in dry conditions and underwater/under pressure in the context of medication, sleep deprivation, or carbon dioxide exposure Researchers will compare the performance of each subject before and after the possible interventions described above to see if there are changes in exercise performance, respiratory function, cerebral blood flow, and levels of gene expression.
Interventions
BEHAVIORALSleep Deprivation
24 hours sleep deprivation
DRUGCaffeine
Oral administration of caffeine
DRUGMethylphenidate
Oral administration of methylphenidate
DRUGCarbon Dioxide
Oral administration of sodium bicarbonate to simulate carbon dioxide exposure
Sponsors
Duke University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Equal numbers of male and female * Non-smokers * Aged 18-45 years * Males will be required to have VO2 peak \> or equal to mL/kg min * and females \> or equal to 30 mL/kg min
Exclusion criteria
* Pregnancy * Cardiorespiratory disease, including hypertension * Neuromuscular disease * Anemia * History of hemoglobinopathy, including sick cell disease and trait
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Hypercapnic ventilatory response | 3 months |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Lactate, pyruvate | 3 months | — |
| Arterial PCO2 | Baseline and after Intervention/arm | — |
| Integrated diaphragmatic function (IDF) composite score | Baseline and after Intervention/arm, which averages 3 months | A composite score comprised of maximum breathing capacity (MBC), maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), and diaphragmatic thickness will be used as the measure of Integrated diaphragmatic function (IDF). |
| Cerebral blood oxygenation | Baseline and after Intervention/arm, which averages 3 months | — |
| Hormone levels (leptin, adiponectin) | Baseline and after Intervention/arm, which averages 3 months | — |
Countries
United States
Contacts
Primary ContactDerek B Covington, MD
Backup ContactRichard Moon, MD
Outcome results
None listed