Atelectasis Formation: Role of Positive Pressure Breathing, Hyperoxia, and Hypobaria

NCT03311347 | Unknown

• 1 other identifier: PDH1-SMO2-0714
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 2

Brief Summary

The primary aim of this project is to get further knowledge of the physiology of flight atelectasis and its prevention. We seek to: 1) assess whether low levels of positive pressure breathing can prevent atelectasis formation in humans during exposure to hyperoxia and +Gz-accelerations. 2) get further knowledge on the effects of hypobaria on regional ventilation and perfusion. A secondary aim is to evaluate the effect of anti G-trouser inflation on ventilation and regional perfusion.

Conditions

Pulmonary Atelectasis

Keywords

pulmonary ultrasound; hypergravity; human physiology; oxygen; lung ventilation; lung perfusion; computed tomography; electrical impedance tomography; altitude chamber

Outcome Measures

Primary Outcomes (3)

• atelectasis formation (change between pre and post-protocol)

  computerized tomography: 0-5 scale for size and localization

  pre-protocol (baseline) and 1h30 min after centrifuge stop

• change in pulmonary ventilation between 1 Gz, 1.6 Gz and 3.5 Gz

  electrical impedance tomography: deltaZ on regions of interest

  pre-protocol (baseline), baseline + 1hr, baseline +1h10 min, baseline +1h15 min

• change in pulmonary tissue density from baseline at centrifuge stop and 1h30 min after stop

  ultrasound: number of lung comets + localization

  pre protocol (baseline), at centrifuge stop (baseline + 1h15 min) and 1h30 min after centrifuge stop

Study Arms (2)

100%O2 breathing

EXPERIMENTAL

Primary aim, item 1

Other: +Gz accelerations and positive pressure breathing

Air breathing

EXPERIMENTAL

Primary aim, item 1

Other: +Gz accelerations and positive pressure breathing

Interventions

+Gz accelerations and positive pressure breathing OTHER

100%O2 breathing; Air breathing

Eligibility Criteria

• Age: 25 Years - 45 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• normal lung function checked by pulmonary function tests.
• normal ECG
• normal clinical examination

You may not qualify if:

• smoking
• myopia
• past medical history of heart or lung disease
• current medical treatment for heart or lung disease
• past medical history of back pain or spine trauma or disease
• otitis
• bad tolerance to +Gz accelerations (G-induced loss of consciousness, motion sickness)
• claustrophobia in the centrifuge gondola
• smoking
• past medical history of heart or lung disease
• current medical treatment for heart or lung disease
• otitis
• bad tolerance to the altitude chamber (15,000 ft): ear pain, claustrophobia

Sponsors & Collaborators

• Direction Centrale du Service de Santé des Armées: lead
• Uppsala University Hospital: collaborator
• Percy Hospital: collaborator

Study Sites (2)

Armed Forces Biomedical Research Institute

Brétigny-sur-Orge, 91 223, France

RECRUITING

Department of Radiology, Percy hospital

Clamart, 92140, France

ACTIVE NOT RECRUITING

Related Publications (2)

• Dussault C, Gontier E, Verret C, Soret M, Boussuges A, Hedenstierna G, Montmerle-Borgdorff S. Hyperoxia and hypergravity are independent risk factors of atelectasis in healthy sitting humans: a pulmonary ultrasound and SPECT/CT study. J Appl Physiol (1985). 2016 Jul 1;121(1):66-77. doi: 10.1152/japplphysiol.00085.2016. Epub 2016 Apr 21.

  PMID: 27103651 BACKGROUND

• Borges JB, Hedenstierna G, Bergman JS, Amato MB, Avenel J, Montmerle-Borgdorff S. First-time imaging of effects of inspired oxygen concentration on regional lung volumes and breathing pattern during hypergravity. Eur J Appl Physiol. 2015 Feb;115(2):353-63. doi: 10.1007/s00421-014-3020-9. Epub 2014 Oct 17.

  PMID: 25323531 RESULT

MeSH Terms

Conditions

Pulmonary Atelectasis

Interventions

Intermittent Positive-Pressure Ventilation

Condition Hierarchy (Ancestors)

Lung Diseases; Respiratory Tract Diseases

Intervention Hierarchy (Ancestors)

Positive-Pressure Respiration; Respiration, Artificial; Airway Management; Therapeutics; Respiratory Therapy

Study Officials

• Dominique Felten, MD

  Armed Forces Biomedical Research Institute

  STUDY CHAIR

Central Study Contacts

Stephanie S Montmerle-Borgdorff, MD, PhD

CONTACT

+33(1)78651249; stephanie.montmerle@intradef.gouv.fr

Catherine Verret, MD, PhD

CONTACT

+33(1)78651115; catherine.verret@intradef.gouv.fr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Two arms are studied, breathing air or 100%O2. In each arm, subjects are studied at two occasions: with and without positive pressure breathing. These occasions are randomized.

Study Record Dates

• First Submitted: April 5, 2017
• First Posted: October 17, 2017
• Study Start: September 14, 2015
• Primary Completion: June 30, 2019
• Study Completion: January 1, 2020
• Last Updated: May 14, 2019

Record last verified: 2019-05

Data Sharing

• IPD Sharing: Will not share

Locations

FR (2)