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The Gas Mask: the Effects on Respiration!

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ClinicalTrials.gov Identifier: NCT02782936
Recruitment Status : Completed
First Posted : May 26, 2016
Last Update Posted : September 29, 2016
Sponsor:
Collaborators:
Pierre-Alexandre Bouchard, RT.
Captain (Ret) Stephane Bourassa, RN.
Information provided by (Responsible Party):
François Lellouche, Laval University

Brief Summary:
Background: The gas mask is used to protect military and non-military subjects exposed to respiratory hazards (CBRN agents). The aim of the study was to evaluate the impact of the gas mask on respiratory patterns and indexes of the respiratory effort. Methods: We are completing our study with 14 healthy subjects to evaluate breathing patterns, index of respiratory efforts and blood gases. Seven conditions have been tested in a randomized order: at rest, during effort (on a tread mill, standardized at 7 METs for all subjects) and during induced hypoxemia with and without a mask (C4, Airboss Defence, Bromont, Canada). Airway pressure, inspiratory and expiratory flows were measured. An esophageal catheter was introduced at the beginning of the study to measure esophageal pressure (Peso) and calculate indexes of respiratory effort (PTPeso, WOB). SpO2 was continuously measured and capillary blood bases were drawn at the end of each condition. Each condition lasted 10 minutes, data of the last 2 minutes at a steady state were considered for analyses. Results: The preliminary analyses based on 10 subjects are presented here. Comparing the wearing of the gas mask and without, most of the respiratory index increased in the tested conditions (at rest, during induced hypoxemia and during effort). At rest, in 8 out of 10 healthy subject the indexes of effort were higher with the gas mask, a statistical trend was observed with the WOB (0.22±0.13 vs. 0.28±0.10 J/cycle; p = 0.059), the PTPes (101±35 vs. 122±47 cmH2O*s; p=0.21) and SwingPeso (4.4±2.0 vs. 5.3±2.0 cmH2O; p=0.13). During the effort, the respiratory index increased (WOB 4.0±2.6 vs. 5.6±3.2; p=0.10; PTPeso 406±211 vs. 606±65; p=0.04; SwingPeso 14.8±8.1 vs. 21.8±9.0; p=0.13). There was no difference for the breathing pattern and arterial blood gases data with and without mask. Data for induced hypoxemia are under analysis. We measured on bench the inspiratory and expiratory resistances of the tested gas mask (C4: inspiratory resistances = 3.2 cmH2O at 1 L/sec; expiratory resistances = 0.9 cmH2O at 1 L/sec). This may explain in part the increased work of breathing with masks. Conclusions: This study demonstrated an increase of the indexes of respiratory effort during an exercise with the gas mask. This study is the first to directly assess the indexes of efforts with esophageal pressure in this situation. Our results and method may be used as a reference for evaluating tolerance with different designs of gas masks.

Condition or disease Intervention/treatment Phase
Work of Breathing Other: measurement of the work of breathing Device: Gas mask Not Applicable

  Show Detailed Description

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 15 participants
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Health Services Research
Official Title: Impact of Gas Masks on Index of Efforts and Breathing Pattern
Study Start Date : June 2015
Actual Primary Completion Date : July 2016
Actual Study Completion Date : July 2016

Arm Intervention/treatment
Experimental: Baseline
Randomised baseline without and with gas mask.
Other: measurement of the work of breathing

We have been evaluating breathing patterns, index of respiratory efforts and blood gases in all randomized conditions. A gas mask has been used mask (C4, Airboss Defence, Bromont, Canada).

Airway pressure, inspiratory and expiratory flows have been measured. An esophageal catheter has been introduced at the beginning of the study to measure esophageal pressure (Peso) and calculate indexes of respiratory effort (PTPeso, WOB). SpO2 has been continuously measured and capillary blood bases were drawn at the end of each condition. Each condition lasted 10 minutes, data of the last 2 minutes at a steady state has been considered for analyses.


Device: Gas mask
During the conditions that involved a gas mask, the measurement of the work of breathing is achieved with a oesophageal catheter and two disposable pneumotachs. While the oesophageal catheter has been fixed to the mandibular with an hypo-allergic tape, the two pneumotachs are hooked respectively on the canister and exhalation port of the gas mask. Investigators have induced the hypoxemia with a mixture nitreous and medical gas in a plastic bag that has been setted up to the canister. The FiO2 level has been kept to 14 percent.
Other Name: Canadian Gas Mask C-4 manufactured by Airboss Defence, Bromont, Québec, Canada.

Experimental: Induced Hypoxemia
Randomised hypoxemia: i. without gas mask; ii. with gas mask; and iii. correction with FreeO2 and gas mask.
Other: measurement of the work of breathing

We have been evaluating breathing patterns, index of respiratory efforts and blood gases in all randomized conditions. A gas mask has been used mask (C4, Airboss Defence, Bromont, Canada).

Airway pressure, inspiratory and expiratory flows have been measured. An esophageal catheter has been introduced at the beginning of the study to measure esophageal pressure (Peso) and calculate indexes of respiratory effort (PTPeso, WOB). SpO2 has been continuously measured and capillary blood bases were drawn at the end of each condition. Each condition lasted 10 minutes, data of the last 2 minutes at a steady state has been considered for analyses.


Device: Gas mask
During the conditions that involved a gas mask, the measurement of the work of breathing is achieved with a oesophageal catheter and two disposable pneumotachs. While the oesophageal catheter has been fixed to the mandibular with an hypo-allergic tape, the two pneumotachs are hooked respectively on the canister and exhalation port of the gas mask. Investigators have induced the hypoxemia with a mixture nitreous and medical gas in a plastic bag that has been setted up to the canister. The FiO2 level has been kept to 14 percent.
Other Name: Canadian Gas Mask C-4 manufactured by Airboss Defence, Bromont, Québec, Canada.

Experimental: Effort
Randomised effort without and with gas mask
Other: measurement of the work of breathing

We have been evaluating breathing patterns, index of respiratory efforts and blood gases in all randomized conditions. A gas mask has been used mask (C4, Airboss Defence, Bromont, Canada).

Airway pressure, inspiratory and expiratory flows have been measured. An esophageal catheter has been introduced at the beginning of the study to measure esophageal pressure (Peso) and calculate indexes of respiratory effort (PTPeso, WOB). SpO2 has been continuously measured and capillary blood bases were drawn at the end of each condition. Each condition lasted 10 minutes, data of the last 2 minutes at a steady state has been considered for analyses.


Device: Gas mask
During the conditions that involved a gas mask, the measurement of the work of breathing is achieved with a oesophageal catheter and two disposable pneumotachs. While the oesophageal catheter has been fixed to the mandibular with an hypo-allergic tape, the two pneumotachs are hooked respectively on the canister and exhalation port of the gas mask. Investigators have induced the hypoxemia with a mixture nitreous and medical gas in a plastic bag that has been setted up to the canister. The FiO2 level has been kept to 14 percent.
Other Name: Canadian Gas Mask C-4 manufactured by Airboss Defence, Bromont, Québec, Canada.




Primary Outcome Measures :
  1. indexes of respiratory effort [ Time Frame: 10 minutes ]
    In this study, we speculate the work of breathing is increasing with the use of a gas mask at rest, under hypoxemia condition and during physical effort.



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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion

  • Having no significant cardiac and respiratory pathology
  • Having no history of epilepsy
  • Having no severe and chronic pathology that requires medication
  • Not being pregnant
  • Face size: medium

Exclusion

  • Refuse to participate in the study for one of the following reasons: i. wearing a oesophageal catheter; ii. wearing the gas mask; iii. giving blood sample; iv. claustrophobia.
  • Oesophageal background wounds
  • Facial anthropometrical issues.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02782936


Locations
Canada, Quebec
Institut de recheche universitaire de cardiologie et pneumologie de Québec
Québec, Quebec, Canada, G1V4G5
Sponsors and Collaborators
Laval University
Pierre-Alexandre Bouchard, RT.
Captain (Ret) Stephane Bourassa, RN.
Investigators
Principal Investigator: Francois Lellouche, Doctorate Institut de Recherche Universitaire de Cardiologie et Pneumologie de Québec

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: François Lellouche, Physician, Laval University
ClinicalTrials.gov Identifier: NCT02782936     History of Changes
Other Study ID Numbers: 21140
2015-2448 ( Other Identifier: CRIUCPQ )
First Posted: May 26, 2016    Key Record Dates
Last Update Posted: September 29, 2016
Last Verified: September 2016
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

Keywords provided by François Lellouche, Laval University:
Work of Breathing; Hypoxemia; Respiratory Acidosis; Respiratory effort

Additional relevant MeSH terms:
Respiratory Aspiration
Respiration Disorders
Respiratory Tract Diseases
Pathologic Processes