Impact of Gas Masks on the Work of Breathing and Breathing Pattern in Subjects With Stable COPD
Bibliographic record
Abstract
BACKGROUND: The gas mask constitutes the main respiratory protective equipment in a chemical, biological, radiological, or nuclear environment. The aim of the study was to evaluate the impact of the gas mask on respiratory pattern, gas exchange, and indexes of respiratory effort in patients with moderate to severe stable COPD. METHODS: Crossover evaluation with 3 randomized-order, 10-min conditions: at rest and with and without a gas mask using 2 different filtered cartridges, each with a distinct inspiratory resistance (cartridge A = 3.5 cm H 2 O; cartridge B = 2.2 cm H 2 O, both at 1 L/s). The study involved 8 subjects with COPD, and breathing patterns, indexes of respiratory effort, and capillary blood gases were evaluated. Comparisons of these parameters were made between the tested conditions. RESULTS: Mean subject age was 69 y, and mean FEV 1 = 1.3 L (47% predicted). Short-term utilization of the gas mask was associated with a significant increase in the indexes of effort in comparison to baseline without a mask. The esophageal product-time product significantly increased in comparison with baseline (cartridge A = 281 ± 65 cm H 2 O/s/min, cartridge B = 253 ± 47 cm H 2 O/s/min, and baseline = 184 ± 46 cm H 2 O/s/min, P < .001). There were negligible changes in the breathing pattern and gas exchange. CONCLUSIONS: Indexes of respiratory effort increased slightly in subjects with stable COPD while using a gas mask. This effect was likely related to increased inspiratory resistance when the mask was worn. These data are reassuring for the potential short-duration use of such protection for patients with moderate to severe COPD.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".