Common Mechanisms of Dyspnea in Chronic Interstitial and Obstructive Lung Disorders
Bibliographic record
Abstract
RATIONALE: The mechanisms underlying dyspnea in interstitial lung disease (ILD) and chronic obstructive pulmonary disease (COPD) are unknown. OBJECTIVES: To examine whether the relationship between inspiratory neural drive to the diaphragm and exertional dyspnea intensity is different in ILD and COPD, given the marked differences in static respiratory mechanics between these conditions. METHODS: We compared sensory-mechanical relationships in patients with ILD, patients with COPD, and healthy control subjects (n = 16 each) during incremental cycle exercise with diaphragmatic electromyography (EMGdi) and respiratory pressure measurements. MEASUREMENTS AND MAIN RESULTS: In patients with mild to moderate ILD or COPD with similarly reduced inspiratory capacity, the peak oxygen uptake, work rate, and ventilation were lower (P < 0.05) than in healthy control subjects. EMGdi expressed as a percentage of the maximum (EMGdi/EMGdi,max), respiratory effort (esophageal pressure expressed as percentage of the maximum), and ventilation were higher (P < 0.05) at rest and during exercise in both patients with ILD and patients with COPD than in control subjects. Each of these measurements was similar in the ILD and COPD groups. A Vt inflection and critically reduced inspiratory reserve volume occurred at a lower (P < 0.05) ventilation in the ILD and COPD groups than in control subjects. Patients with ILD had greater diaphragmatic activity, whereas patients with COPD had greater expiratory muscle activity. The relationship between dyspnea intensity and EMGdi/EMGdi,max during exercise was similar in all three groups. In ILD and COPD, descriptors alluding to inspiratory difficulty were selected more frequently, with a greater disparity between EMGdi/EMGdi,max and Vt. CONCLUSIONS: Disease-specific differences in mechanics and respiratory muscle activity did not influence the key association between dyspnea intensity and inspiratory neural drive to the diaphragm.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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 source (direct Gemma or distilled Codex), 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".