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NCT05168501

Assessing Variability of the Ventilatory Response to Duffin's Rebreathing Procedure

Completed NA Results posted Last updated 15 July 2024
What this trial tests

NA trial testing Rebreathing procedure in Ventilation in 7 participants. Completed in 18 February 2022.

Timeline
27 December 2021
Primary endpoint
18 February 2022
18 February 2022

Quick facts

Lead sponsorFood and Drug Administration (FDA)
PhaseNA
StatusCompleted
Study typeINTERVENTIONAL
Allocationna
Designsingle group
Maskingnone
Primary purposeother
Enrollment7
Start date27 December 2021
Primary completion18 February 2022
Estimated completion18 February 2022
Sites1 location across United States

Drugs / interventions tested

Conditions studied

Sponsor

Food and Drug Administration (FDA) — full company profile →

Who can join

Adults 18 to 50, any sex, with Ventilation or Reproducibility. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

Baseline Minute Ventilation Primary · 0, 2, 4, 6 and 24 hours

Minute ventilation during the rebreathing assessment when end tidal PCO2 (partial pressure carbon dioxide) is less than the ventilatory recruitment threshold (represents non-chemoreflex drives to breathe; 'flat' portion of minute ventilation versus end tidal PCO2 relationship). Data was analyzed using linear-mixed effects regression of baseline minute ventilation with random effects for between subject, between day, and between occasion variability. Reported value is the mean for the treatment group across all individuals, days, and times.

GroupValue95% CI
Hyperoxic Rebreathing11.6± 3.4
Hypoxic Rebreathing12.0± 2.9
Ventilatory Recruitment Threshold Primary · 0, 2, 4, 6 and 24 hours

The end tidal PCO2 point above which minute ventilation starts to increase linearly with further increases in end tidal PCO2. Data was analyzed using linear-mixed effects regression of ventilatory recruitment threshold with random effects for between subject, between day, and between occasion variability. Reported value is the mean for the treatment group across all individuals, days, and times.

GroupValue95% CI
Hyperoxic Rebreathing43.0± 3.0
Hypoxic Rebreathing38.1± 1.7
Slope of the PCO2-ventilatory Response Curve Primary · 0, 2, 4, 6 and 24 hours

Slope of the minute ventilation versus end tidal PCO2 curve that reflects the increase in minute ventilation relative to the increase in end tidal PCO2. Data was analyzed using linear-mixed effects regression of Slope of the PCO2-ventilatory response curve with random effects for between subject, between day, and between occasion variability. Reported value is the mean for the treatment group across all individuals, days, and times.

GroupValue95% CI
Hyperoxic Rebreathing3.19± 2.46
Hypoxic Rebreathing3.28± 2.41
Extrapolated Ventilatory Recruitment Threshold Primary · 0, 2, 4, 6 and 24 hours

Intersection of the slope of the PCO2-ventilation response curve with the X axis. Data was analyzed using linear-mixed effects regression of extrapolated ventilatory recruitment threshold with random effects for between subject, between day, and between occasion variability. Reported value is the mean for the treatment group across all individuals, days, and times.

GroupValue95% CI
Hyperoxic Rebreathing36.8± 7.1
Hypoxic Rebreathing32.7± 5.9

Sponsor's own description

This study will combine Duffin's rebreathing procedure with additional study procedures, such as quantitative pupillometry, that are planned for subsequent clinical studies in order to confirm feasibility and gather reproducibility data using the procedure. The reproducibility of Duffin rebreathing has been assessed previously by Mahamed and Duffin (2001) performing hyperoxic and hypoxic rebreathing procedures measured once daily for 14 consecutive days and then by Jensen et al. (2010) performing 4 pairs of hyperoxic and hypoxic rebreathing procedures in 1 day followed by 1 pair on 4 additional days separated by weeks to more than a month. The present study is an unblinded reproducibility assessment to assess variability of the ventilatory response to Duffin's rebreathing procedure. Subjects will report to the study site for screening between Days -28 to -2 and then will return to the site on Day -1 for baseline assessments and check-in. After check-in (Day -1), subjects will remain in study site for PD assessments on Day 1 and check out on Day 2. Paired rebreathing procedures (i.e., at two different isoxic end tidal PO2 \[partial pressure oxygen\] levels) will be performed on Day 1 at 0, 2, 4, and 6 hours. An additional pair of rebreathing procedures will be performed on Day 2 before checkout (approximately 24 hours). Subjects will not be administered any drugs in this study.

Publications & conference data

No peer-reviewed publications indexed yet for this trial. Completed trials usually publish results within 12-18 months.

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Data sources for this page

Drug Landscape aggregates and links these public records for informational use only. Always verify against the primary source before clinical or regulatory decisions. Canonical URL: https://druglandscape.com/trial/NCT05168501.

Primary sources · FDA · ClinicalTrials.gov · EMA · SEC EDGAR · ChEMBL · Wikidata · full sourcing