Hypercapnia: Cognitive Effects and Monitoring

Exercise Clinical Trial

Official title:

Hypercapnia: Cognitive Effects and Monitoring

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01782625
• Other study ID #: Pro00036937
• Secondary ID: SPS 181258
• Status: Completed
• Phase: N/A
• First received: January 31, 2013
• Last updated: May 24, 2016
• Start date: January 2013
• Est. completion date: February 2016

Study information

• Verified date: May 2016
• Source: Duke University
• Contact: n/a
• Is FDA regulated: No
• Health authority: United States: Institutional Review Board
• Study type: Interventional

Clinical Trial Summary

The investigators will simulate the conditions of a working, helmeted diver by using exercising, "head out" immersed subjects to test the following hypotheses:

1. An algorithm can be developed which predicts cognitive performance in immersed exercising divers, based on the exhaled carbon dioxide (PETCO2) and the diver's inspired partial pressures of oxygen and nitrogen (PIO2 and PIN2).

2. PETCO2 using mass spectrometry is an accurate estimate of arterial carbon dioxide (PaCO2) at rest and during immersed exercise and can be used as a PaCO2 surrogate at levels exceeding 50 mmHg and depths up to 158 fsw (gas density 6.4 g/l, similar to 165 fsw density of 6.8 g/l).

Recruitment information / eligibility

• Status: Completed
• Enrollment: 58
• Est. completion date: February 2016
• Est. primary completion date: February 2016
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 18 Years to 50 Years

Eligibility

Inclusion Criteria:

• healthy,

• male,

• age greater than 18,

• age less than 50

Exclusion Criteria:

• smoker,

• asthma,

• cardiac disease,

• inability to pedal a bicycle ergometer,

• inability to perform vigorous exercise

Study Design

Allocation: Randomized, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Diving
• Exercise
• Hypercapnia
• Immersion
• Nitrogen Narcosis

Intervention

Other:
• NO exercise at depth
Subjects will NOT exercise while at depth
• exercise at depth
Subjects will exercise while at depth

Locations

Country	Name	City	State
United States	Duke Center for Hyperbaric Medicine and Environmental Physiology	Durham	North Carolina

Sponsors (1)

Lead Sponsor	Collaborator
Duke University

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Is cognitive ability different while resting versus compared to cognitive ability while diving, breathing different gas mixtures and while exercising?	Subjects will undergo computerized cognitive testing before, during and after a simulated dive in the Duke Hyperbaric Chamber. Different exercise conditions (rest or exercise) and different breathing gas mixtures (added carbon dioxide or not)will be assessed and compared to the pre-dive conditions.	pre-dive to dive to post-dive (approximately 2 hours)	No
Secondary	How does exhaled (end tidal) carbon dioxide compare with arterial carbon dioxide?	Exhaled (end tidal) carbon dioxide will be compared to arterial carbon dioxide at the various experimental conditions of the study (at the surface versus during the dive, during exercise versus during rest, breathing gas with added carbon dioxide versus breathing gas without added carbon dioxide)	pre-dive to dive to post dive (approximately 2 hours)	No