Testing methods to prevent decompression sickness during spacewalks

NASA Prebreathe Study

Phase 1 Interventional Duke University · NCT06740305

This study is testing new ways to prevent decompression sickness during spacewalks by having volunteers breathe pure oxygen and then spend time in a special chamber while doing tasks.

Quick facts

PhasePhase 1
Study typeInterventional
Enrollment12 (estimated)
Ages18 Years to 50 Years
SexAll
SponsorDuke University Academic / other
Locations1 site (Durham, North Carolina)
Trial IDNCT06740305 on ClinicalTrials.gov

What this trial studies

This study aims to validate experimental methods and facilities at the Duke Center for Hyperbaric Medicine & Environmental Physiology to support NASA's efforts in minimizing decompression sickness (DCS) risks during extravehicular activities (spacewalks). It involves four test days where volunteer subjects aged 18-50 will breathe 100% oxygen for six hours, followed by six hours in a hypobaric chamber at 1/3 atmosphere while performing various tasks. Data will be collected on bubble scores and DCS symptoms, with immediate treatment provided if symptoms develop. The study will also include a familiarization session for participants to ensure understanding of the protocol and safety procedures.

Who should consider this trial

Good fit: Ideal candidates for this study are healthy non-smoking individuals aged 18-50 with a VO2pk above 35 ml/kg/min for males and 30 ml/kg/min for females.

Not a fit: Patients with lung and heart diseases, hypertension, diabetes, or those requiring regular medications may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance astronaut safety during space missions by reducing the risk of decompression sickness.

How similar studies have performed: Other studies have explored decompression sickness in various contexts, but this specific approach in a space-related setting is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Non-smokers
* VO2pk \>35 ml/kg/min (males)
* VO2pk \>30 ml/kg/min (females)

Exclusion Criteria:

* Pregnancy
* Lung and heart disease
* Hypertension
* Diabetes
* Musculoskeletal pain conditions
* Need for regular medications such as analgesics

Where this trial is running

Durham, North Carolina

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Decompression SicknessSpaceMicrogravityDecompressionDecompression sicknessAltitude
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.