Oxygen Toxicity: Mechanisms in Humans
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Sleep Deprivation, Caffeine, Methylphenidate, Carbon Dioxide.
- Who it may be relevant to
- Registry conditions: Oxygen Toxicity, Hypercapnia, Seizures. Basic parameters: 18 years — 45 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United States
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
Applied Physiology of Oxygen Toxicity: Mechanisms in Humans
Overview
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
- Behavioral Sleep Deprivation
24 hours sleep deprivation - Drug Caffeine
Oral administration of caffeine - Drug Methylphenidate
Oral administration of methylphenidate - Drug Carbon Dioxide
Oral administration of sodium bicarbonate to simulate carbon dioxide exposure
Primary outcome measures
- Hypercapnic ventilatory response [Time frame: 3 months]
Secondary outcome measures (5)
- Lactate, pyruvate [Time frame: 3 months]
- Arterial PCO2 [Time frame: Baseline and after Intervention/arm]
- Integrated diaphragmatic function (IDF) composite score [Time frame: Baseline and after Intervention/arm, which averages 3 months]
- Cerebral blood oxygenation [Time frame: Baseline and after Intervention/arm, which averages 3 months]
- Hormone levels (leptin, adiponectin) [Time frame: Baseline and after Intervention/arm, which averages 3 months]
Eligibility criteria
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
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Single blind
- Primary purpose
- Prevention
Study locations
United States · 1 center
- Duke University Health Sustem — Durham
Publications
- Dunworth SA, Natoli MJ, Cooter M, Cherry AD, Peacher DF, Potter JF, Wester TE, Freiberger JJ, Moon RE. Hypercapnia in diving: a review of CO(2) retention in submersed exercise at depth. Undersea Hyperb Med. 2017 May-Jun;44(3):191-209. doi: 10.22462/5.6.2017.1. PMID 28779577
- Drummond JC. Blood Pressure and the Brain: How Low Can You Go? Anesth Analg. 2019 Apr;128(4):759-771. doi: 10.1213/ANE.0000000000004034. PMID 30883421
- Lucas SJ, Tzeng YC, Galvin SD, Thomas KN, Ogoh S, Ainslie PN. Influence of changes in blood pressure on cerebral perfusion and oxygenation. Hypertension. 2010 Mar;55(3):698-705. doi: 10.1161/HYPERTENSIONAHA.109.146290. Epub 2010 Jan 18. PMID 20083726
- Wester TE, Cherry AD, Pollock NW, Freiberger JJ, Natoli MJ, Schinazi EA, Doar PO, Boso AE, Alford EL, Walker AJ, Uguccioni DM, Kernagis D, Moon RE. Effects of head and body cooling on hemodynamics during immersed prone exercise at 1 ATA. J Appl Physiol (1985). 2009 Feb;106(2):691-700. doi: 10.1152/japplphysiol.91237.2008. Epub 2008 Nov 20. PMID 19023017
- Pendergast DR, Moon RE, Krasney JJ, Held HE, Zamparo P. Human Physiology in an Aquatic Environment. Compr Physiol. 2015 Sep 20;5(4):1705-50. doi: 10.1002/cphy.c140018. PMID 26426465
- Linnarsson D, Ostlund A, Lind F, Hesser CM. Hyperbaric bradycardia and hypoventilation in exercising men: effects of ambient pressure and breathing gas. J Appl Physiol (1985). 1999 Oct;87(4):1428-32. doi: 10.1152/jappl.1999.87.4.1428. PMID 10517774
- Oppersma E, Doorduin J, van der Hoeven JG, Veltink PH, van Hees HWH, Heunks LMA. The effect of metabolic alkalosis on the ventilatory response in healthy subjects. Respir Physiol Neurobiol. 2018 Feb;249:47-53. doi: 10.1016/j.resp.2018.01.002. Epub 2018 Jan 4. PMID 29307724
- Cherry AD, Forkner IF, Frederick HJ, Natoli MJ, Schinazi EA, Longphre JP, Conard JL, White WD, Freiberger JJ, Stolp BW, Pollock NW, Doar PO, Boso AE, Alford EL, Walker AJ, Ma AC, Rhodes MA, Moon RE. Predictors of increased PaCO2 during immersed prone exercise at 4.7 ATA. J Appl Physiol (1985). 2009 Jan;106(1):316-25. doi: 10.1152/japplphysiol.00885.2007. Epub 2008 Sep 11. PMID 18787095
Identifiers
NCT: NCT05761756 · Pro00112396