The Impact of the Work of Breathing and Gas Exchange for COPD Patient Using a Gas Mask.

The principal way of penetration of CBRNE agents is the respiratory system. The current technology of a gas mask has been used to protect the respiratory system as far back as the First World War. That originated from Dr Cluny Macpherson's initiatives whom was a Canadian military physician.

The military gas mask is part of the respirator classification but owes its specific features. Conventionally, the military gas mask covers a large spectrum of protection aspects and matched with their specific canisters. Consequently, gas masks are usually studied separately from other respirators and Self-Contained Breathing Apparatus (SBCA). While few studies have been about the gas mask technology, no-study addresses it in regards of the impact from a bad airway protection and consequences on the respiratory system.

The gas mask design and its components may lead to these respiratory load issues. At rest and from different resistances, what would be the impacts for the work of breathing and gas exchange? In order to avoid hypoxemia and hyperoxia, what would be the optimal means to restore proper oxygenation? We hypothesised on a: i. Heightened WOB and the respiratory demands related to wear of the gas mask; ii. An occurrence of hypoxemia will be manifesting during a continuous period. Our goal is to measure the impact of the work of breathing and the gas exchange for a gas mask user and also a COPD patient. We also measure what was the optimal means for correcting the hypoxemia with a subject.

9 COPD patients have been participating in a comparison and single-blind randomized experimental study. That was approved by the Ethical Review Committee. A written consent is obtained for all the subjects prior their acceptance. No rejection has happened during the recruiting so far. The eligibility criteria are: i. COPD diagnosis from mild-to-severe FEV 30-80%). The exclusion criteria are: i. Refusals relate to wear the oesophageal catheter and for capillary punctures; ii. Claustrophobia; iii. Oesophageal wounds backgrounds; iv. No coronary background and stroke history; v. No face morphology incompatibility with the mask. Spirometry and usual health screening is also done before starting the clinical trial.

Design comprises three 10-minute testing conditions split in two parts. All has been at rest and sitting on a chair: i. Baseline without gas mask; ii. Gas mask and Canister A; iii. Gas Mask and Canister B. Between the condition a 5-minute wash-out takes place.