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Test of Chamber Pressure to Divers and Chamber Attendants (TOP-DIVER)

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Intermountain Health Care, Inc.
ClinicalTrials.gov Identifier:
NCT01430325
First received: September 2, 2011
Last updated: February 12, 2013
Last verified: December 2012
History of Changes
  Purpose

SCUBA divers and chamber inside attendants will undergo a brief hyperbaric chamber excursion and will be asked to what chamber pressure they were compressed and what gas they breathed.


Condition Intervention
Traumatic Brain Injury
 Drug: Hyperbaric Oxygen (1.5 atm abs)
Drug: Sham Chamber Session

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Official Title: Test of Chamber Pressure to Divers and Chamber Attendants: A Blinded Trial to Investigate if "Pressure-familiar" Individuals Can Determine Pressure

Resource links provided by NLM:

U.S. FDA Resources

Further study details as provided by Intermountain Health Care, Inc.:

Primary Outcome Measures:
  • Participants Indicating "I do Not Know" on Depth Questionnaire. [ Time Frame: Within 15 minutes of chamber excursion ] [ Designated as safety issue: No ]
    Participants indicating "I do not know" on depth questionnaire instead of providing a free response guess.

  • Participant Perception of Depth [ Time Frame: Within 15 minutes of chamber excursion ] [ Designated as safety issue: No ]
    Mean depth perception for participants providing a free response.

  • Participant Perception of Breathing Gas [ Time Frame: Within 15 minutes of chamber excursion ] [ Designated as safety issue: No ]
    Percent of participants in each arm guessing that their breathing gas was 100% oxygen.


Enrollment: 42
Study Start Date: July 2011
Study Completion Date: October 2011
Primary Completion Date: October 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Sham Comparator: Sea Level Equivalent 1.2 atm abs (air)

Sham Chamber Session

Sea Level Equivalent 1.2 atm abs (2.6 psig) breathing regular air 20-chamber excursion

 Drug: Sham Chamber Session
Sham control chamber session: regular air delivered at a chamber pressure of 1.2 atm abs
Other Names:
  • Sham control
  • Air pressurization
Experimental: Sea Level Equivalent 1.5 atm abs (O2)

Hyperbaric Oxygen (1.5 atm abs)

Sea Level Equivalent 1.5 atm abs (6.2 psig) breathing 100% oxygen 20-minute chamber excursion

 Drug: Hyperbaric Oxygen (1.5 atm abs)
Hyperbaric oxygen (100% oxygen) delivered at a chamber pressure of 1.5 atm abs.
Other Names:
  • HBO2
  • HBO
  • HBOT
Sham Comparator: Altitude Equivalent 1.2 atm abs (air)

Sham Chamber Session

Altitude Equivalent 1.2 atm abs (5.1 psig) breathing regular air 20-minute chamber excursion

 Drug: Sham Chamber Session
Sham control chamber session: regular air delivered at a chamber pressure of 1.2 atm abs
Other Names:
  • Sham control
  • Air pressurization
Experimental: Altitude Equivalent 1.5 atm abs (O2)

Hyperbaric Oxygen (1.5 atm abs)

Altitude Equivalent 1.5 atm abs (9.6 psig) breathing 100% oxygen 20-minute chamber excursion

 Drug: Hyperbaric Oxygen (1.5 atm abs)
Hyperbaric oxygen (100% oxygen) delivered at a chamber pressure of 1.5 atm abs.
Other Names:
  • HBO2
  • HBO
  • HBOT

Detailed Description:

In clinical trials evaluating hyperbaric oxygen, blinding can be challenging. Options for participant blinding include offering regular air at a lower pressure than the hyperbaric oxygen intervention, or compressing all participants to the same pressure but providing different gas mixes to the active and sham arms.

In some trials of hyperbaric oxygen for brain injury, investigators offer a sham chamber session (regular air at 1.2 atmospheres absolute [atm abs]) compared to the active intervention, hyperbaric oxygen (100% oxygen at 1.5 atm abs). It is unknown whether individuals familiar with pressure changes, such as divers and hyperbaric chamber inside attendants, could discern the difference between these pressures and thereby become unblinded to study allocation.

In this study, 80 experienced divers and chamber inside attendants will be enrolled and randomly assigned to one of four possible chamber pressures and one of two breathing gases. After a brief hyperbaric chamber excursion, they will be asked to what chamber pressure they were compressed and what gas they breathed. If participants can accurately report chamber pressure or breathing gas, pressure-familiar individuals should be excluded from blinded clinical trials of hyperbaric oxygen.

  Eligibility

Ages Eligible for Study:   18 Years to 65 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Adult, age 18 - 65 years
  • Completion of medical history questionnaire without concerns identified for exposure to increased pressure
  • Familiarity with atmospheric pressure change:
  • Experienced and active hyperbaric chamber inside attendant: more than 50 hyperbaric compressions, with more than 4 have been in the last 4 months; or
  • Experienced and active SCUBA diver: more than 20 lifetime compressed gas open water (not swimming pool) dives, with more than 10 in the last 12 months
  • Able to equalize middle ear pressure easily

Exclusion Criteria:

  • Pregnancy
  • Known risk for barotrauma, as identified on the medical history questionnaire, such as:
  • Recent (within 12 months) inner ear or sinus surgery
  • Spontaneous pneumothorax
  • Pulmonary cysts
  • Emphysema
  • Bullous lung disease
  • Chronic obstructive pulmonary disease needing chronic active therapy
  • Inability to tolerate chamber confinement or pressure
  • Presence of heart failure
  • Presence of any implanted electrical device, except hyperbaric-approved pacemakers
  • Presence of middle-ear tympanostomy tubes
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT01430325

Locations
United States, Utah
Intermountain Medical Center
Murray, Utah, United States, 84107
LDS Hospital
Salt Lake City, Utah, United States, 84143
Sponsors and Collaborators
Intermountain Health Care, Inc.
Investigators
Principal Investigator: Lindell K. Weaver, MD Intermountain Health Care, Inc.
  More Information

Publications:

Responsible Party: Intermountain Health Care, Inc.
ClinicalTrials.gov Identifier: NCT01430325     History of Changes
Other Study ID Numbers: 1023955
Study First Received: September 2, 2011
Results First Received: January 3, 2013
Last Updated: February 12, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by Intermountain Health Care, Inc.:
Hyperbaric oxygen

Additional relevant MeSH terms:
Brain Injuries
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
 Craniocerebral Trauma
Trauma, Nervous System
Wounds and Injuries

ClinicalTrials.gov processed this record on May 16, 2013