Effect of Hyperoxia and Hypergravity on Lung Ventilation and Perfusion

Atelectasis Clinical Trial

Official title:

Influence of Hyperoxia and Hypergravity on Pulmonary Ventilation and Perfusion

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01993394
• Other study ID #: 10co706
• Status: Completed
• Phase: N/A
• First received: November 14, 2013
• Last updated: November 20, 2013
• Start date: October 2011
• Est. completion date: July 2012

Study information

• Verified date: November 2013
• Source: Direction Centrale du Service de Santé des Armées
• Contact: n/a
• Is FDA regulated: No
• Health authority: France: Ministry of Health
• Study type: Interventional

Clinical Trial Summary

The primary aim of this project is to get further knowledge on the effects of + Gz accelerations and hyperoxia on lung ventilation in humans. The secondary aim is to study lung perfusion and cardiovascular function in these conditions.

Description:

Experiments were conducted in a human centrifuge. The protocol aimed at mimicking a routine peacetime flight in combat aircraft, and included 10-min exposure to +1.4 - +3.5 Gz. Subjects were exposed three times to this sequence, breathing air, 44.5% O2 or 100% O2.

Ten volunteers wearing anti-G trousers participated in the study. The Ethics Committee Ile-de-France III and the French National Agency for Drug Safety (ANSM) approved the protocol (number 2009-A01092-55).

Three different imaging techniques, electrical impedance tomography (EIT), pulmonary ultrasound and chest SPECT/CT were used and compared. EIT enabled ventilation monitoring in the human centrifuge, whereas pulmonary ultrasound and SPECT/CT gave functional and topographical information before and after exposure to +Gz accelerations. EIT analysis focused on regional ventilation, SPECT on global lung ventilation and perfusion, CT on the presence of atelectasis, and pulmonary ultrasound analysis looked for comet tails in 64 chest areas. Arterial blood pressure was recorded continuously by finger photoplethysmography. Cardiac output and stroke volume were computed from these recordings, using three different algorithms. Echocardiography was used as reference non-invasive technique for stroke volume determination and performed before and after exposure to +Gz accelerations.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 20
• Est. completion date: July 2012
• Est. primary completion date: July 2012
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 25 Years to 45 Years

Eligibility

Inclusion Criteria:

• normal lung function checked by pulmonary function tests

Part 1 exclusion Criteria:

• past medical history of heart or lung disease

• current medical treatment for heart or lung disease

• smoking

• bad tolerance to +Gz accelerations (G-induced loss of consciousness, motion sickness)

Part 2 exclusion criteria:

• past medical history of heart or lung disease

• current medical treatment for heart or lung disease

• smoking

• The use of medication for hypertension

• asymmetric values of left/right humeral arterial blood pressure

• significant echocardiographic abnormalities or bad echogenicity

• bad tolerance to +Gz accelerations (G-induced loss of consciousness, motion sickness)

Study Design

Endpoint Classification: Safety Study, Intervention Model: Single Group Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Atelectasis

Intervention

Other:
• hypergravity
1hr sitting rest followed by 10 min of hypergravity (2 centrifuge runs)
• gas mixture
breathing air, 44.5%O2 or 100%O2

Locations

Country	Name	City	State
France	Armed Forces Biomedical Research Institute	Brétigny-sur-Orge
France	Department of Nuclear Medicine, Val-de-Grâce hospital	Paris

Sponsors (3)

Lead Sponsor	Collaborator
Direction Centrale du Service de Santé des Armées	Uppsala University Hospital, Val de Grâce Hospital

Country where clinical trial is conducted

France, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	tidal volume	global (mL, area under the flow versus time curve) and regional (% change per quadrant at 5th intercostal space level)	2hrs 30min	Yes
Primary	change in regional ventilation distribution	"per lobe and per quadrant at 5th intercostal space level"	baseline, 2hrs 30min	Yes
Secondary	change in regional pulmonary perfusion	"per lobe and per quadrant at 5th intercostal space level"	baseline, 2hrs 30min	Yes
Secondary	cardiac output (L/min)	"echocardiography (sub-aortic diameter), photoplethysmography (Liljestrand, systolic area and Windkessel algorithms)"	2hrs	Yes