Consequences of Inhibition of Deep Inspiration in Isolated Sheep Lungs: Spontaneous Increase in Lung Resistance and Air Trapping
Bibliographic record
Abstract
Abstract Background: Deep inspiration (DI) reverses and prevents bronchoconstriction in healthy individuals but fails to do so in asthmatic patients. Understanding DI's role in healthy lungs can provide insights into the pathophysiology of asthma. Air trapping, common in chronic obstructive pulmonary disease (COPD) and asthma, involves air being trapped during exhalation due to airway narrowing and closure. This study hypothesizes that in healthy lungs DI prevention allows spontaneous airway smooth muscle (ASM) tone to close airways over time, and DI and bronchodilator can prevent or alleviate air trapping. Methods: Physiological respiration was simulated in ex vivo sheep lungs. Lung resistance, elastance, and lung volume (estimated from the lateral lung profile) were measured during the experiment using small tidal volume (120 ml), 0.25 and 2 Hz frequencies, and 7.5 cmH2O transpulmonary pressure to examine the effects of DI absence on air trapping. A DI maneuver, involving rapid inflation to total lung capacity (TLC) followed by deflation to 0 pressure, assessed air trapping resolution. Post-DI, resistance and elastance were recorded. The experiments were also conducted in the presence of salbutamol to assess the role of ASM. Results: Ventilation without DI increased resistance, elastance, and estimated lung volume, suggesting the development of air trapping. DI effectively resolved air trapping, restoring resistance and elastance to initial states. Both DI and salbutamol alleviated increased resistance and elastance, and mitigated air trapping. Conclusion: DI plays a crucial role in preventing air trapping and reducing resistance and elastance, likely by inhibiting bronchoconstriction. These findings suggest that therapeutic interventions aimed at restoring the beneficial effects of DI in patients with asthma and COPD will likely reduce air trapping and improve lung function.
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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 | 0.000 | 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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".