Clinical trial NCT01993394: Effect of Hyperoxia and Hypergravity on Lung Ventilation and Perfusion
Official title: Influence of Hyperoxia and Hypergravity on Pulmonary Ventilation and Perfusion
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Atelectasis
Keywords: human centrifuge, oxygen, imaging, stroke volume, lung
Lead sponsor: Direction Centrale du Service de Santé des Armées
Sponsor class: OTHER
Collaborators: name: Val de Grâce Hospital
name: Uppsala University Hospital
First posted: 2013-11-25
Enrollment: 20
Sex: MALE
Minimum age (years): 25
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: BASIC_SCIENCE

Brief 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.

Detailed 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.

Eligibility criteria: 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)

Primary outcomes:
measure: change in regional ventilation distribution
timeFrame: baseline, 2hrs 30min
Secondary outcomes:
measure: change in regional pulmonary perfusion
timeFrame: baseline, 2hrs 30min
measure: cardiac output (L/min)
timeFrame: 2hrs
Other outcomes:
measure: tidal volume
timeFrame: 2hrs 30min
Locations:
city: Brétigny-sur-Orge
country: France
facility: Armed Forces Biomedical Research Institute
city: Paris
country: France
facility: Department of Nuclear Medicine, Val-de-Grâce hospital
Study officials:
affiliation: Armed Forces Biomedical Research Institute
name: Daniel Garin, MD, PhD
role: STUDY_CHAIR
References: