Influences of Spinal Anesthesia on Exercise Tolerance in Patients with Chronic Obstructive Pulmonary Disease
Bibliographic record
Abstract
RATIONALE: Lower limb muscle dysfunction contributes to exercise intolerance in chronic obstructive pulmonary disease (COPD). We hypothesized that signaling from lower limb muscle group III/IV sensory afferents to the central motor command could be involved in premature cycling exercise termination in COPD. OBJECTIVES: To evaluate the effects of spinal anesthesia, which presumably inhibited central feedback from the lower limb muscle group III/IV sensory afferents on exercise tolerance and cardiorespiratory response during constant work-rate cycling exercise in patients with COPD. METHODS: In a crossover and double-blind randomized design, eight patients with COPD (FEV(1), 67 ± 8% predicted) completed a constant work-rate cycling exercise after sham (NaCl, interspinous L(3)-L(4)) or active (fentanyl 25 μg, intrathecal L(3)-L(4)) spinal anesthesia. MEASUREMENTS AND MAIN RESULTS: When compared with placebo, endurance time was significantly prolonged after spinal anesthesia with fentanyl (639 ± 87 s vs. 423 ± 38 s [mean ± SEM]; P = 0.01). Ventilation and respiratory rate were reduced at isotime points under the fentanyl condition, whereas ventilatory efficiency and dead space ventilation were improved. Patients exhibited less dynamic hyperinflation at isotime points with spinal anesthesia. Consequently, the rise in dyspnea was significantly flatter during the fentanyl condition than with placebo. CONCLUSIONS: Spinal anesthesia enhanced cycling exercise tolerance in patients with COPD, mostly by reducing ventilatory response and dyspnea during exercise; these effects were possibly mediated through the inhibition of group III/IV lower limb sensory muscle afferents.
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 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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.003 |
| 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".