Diaphragm Function and Diver Endurance

NCT04679402 | Completed

• 1 other identifier: Pro00107090
• Study Type: interventional
• Target: 45
• Locations: 1 country
• Sites: 1

Brief Summary

This project will test the following hypotheses:

1. 1.Training of the inspiratory muscles increases underwater endurance and reduces hypercapnia in divers.
2. 2.Inspiratory muscle training while breathing low concentration carbon monoxide (200 ppm) for 30 minutes daily improves diaphragm performance to a greater degree than the same training breathing air.
3. 3.Inspiratory muscle training increases hypercapnia ventilatory response (gain) in those individuals with a low gain.
4. 4.Variability in oxygen (O2) and carbon dioxide (CO2) permeability of erythrocyte membranes is a determining factor in underwater exercise performance.

Conditions

Respiratory Muscles

Keywords

Control of breathing; Diaphragm function; Gas channels; Blood gases

Outcome Measures

Primary Outcomes (3)

• Underwater endurance change

  Endurance during continuous underwater exercise at a depth of 50 ft below the surface

  Baseline, 6 weeks

• Arterial PCO2 change

  Blood gases during and at end of exercise

  Baseline, 6 weeks

• Ventilatory chemosensitivity change

  Hypercapnic ventilatory response (VE.min-1.mmHg)

  Baseline, 6 weeks

Secondary Outcomes (1)

• Erythrocyte gas channel analysis

  Baseline

Study Arms (2)

Respiratory Muscle Training Breathing Low Dose Carbon Monoxide

EXPERIMENTAL

Carbon monoxide 200 ppm in air breathing during daily 30 minute inspiratory loading training sessions. Subjects will breathe the experimental gas through a mouthpiece with nose-clip in place.

Other: Carbon monoxide 200 ppm in air

Respiratory Muscle Training Breathing Air

SHAM COMPARATOR

Air breathing during daily 30 minute inspiratory loading training sessions. Subjects will breathe air through a mouthpiece with nose-clip in place.

Other: Carbon monoxide 200 ppm in air

Interventions

Carbon monoxide 200 ppm in air OTHER

Low dose carbon monoxide

Respiratory Muscle Training Breathing Air; Respiratory Muscle Training Breathing Low Dose Carbon Monoxide

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Normal volunteers
• Non-smokers
• Range of hypercapnic ventilatory responses
• VO2peak ≥35 mL.kg-1.min-1 (males)
• ≥30 mL.kg-1.min-1 (females)

You may not qualify if:

• Pregnancy
• Cardiorespiratory disease, including hypertension
• Neuromuscular disease
• Anemia
• Hemoglobinopathy, including sickle cell disease and trait

Sponsors & Collaborators

• Duke University: lead
• Case Western Reserve University: collaborator

Study Sites (1)

Duke University Medical Center

Durham, North Carolina, 27710, United States

Location

MeSH Terms

Interventions

Air

Intervention Hierarchy (Ancestors)

Atmosphere; Environment; Ecological and Environmental Phenomena; Biological Phenomena; Meteorological Concepts; Environment and Public Health

Study Officials

• Richard E Moon, MD

  Duke University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The only person who will know the breathing gas is the trial coordinator. Since carbon monoxide is a colorless, tasteless gas, the subject will be unaware of the group they are in. The gas labeling will be blinded.
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Mixed model with repeated measures

Study Record Dates

• First Submitted: December 17, 2020
• First Posted: December 22, 2020
• Study Start: April 14, 2022
• Primary Completion: April 30, 2024
• Study Completion: April 30, 2024
• Last Updated: June 13, 2024

Record last verified: 2024-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)