Effect of travelling to 2590m on 6-minute walk distance, blood gases and symptoms of acute mountain sickness in COPD patients
Bibliographic record
Abstract
Introduction The aim of the current study was to evaluate the exercise performance and health effects of altitude travel in patients with COPD. Methods 40 COPD patients, GOLD 2-3, living at < 800m, mean±SD age 65±6 years, FEV1 58±14 % predicted were studied at Zurich (490m), and in Swiss Alpine villages at 1650m and 2590m, for 2 days each in random order. 6-minute walk distance (6-MWD), arterial blood gases and symptoms were assessed at all locations. Results On the first morning at 2590m, patients perceived mild symptoms of acute mountain sickness, 5 required nocturnal oxygen because of discomfort or severe hypoxemia. They were able to remain at altitude and felt well thereafter. One patient refused to ascend to 2590m because of insomnia at 1650m. Compared to 490m, the 6-MWD at altitude was reduced, arterial oxygen saturation, pO2 and pCO2 were decreased. 490 m 2590 m Day 1 Day 1 Day 2 Acute mountain sickness score# 0.1 ± 0.2 0.3 ± 0.3* 0.1 ± 0.1¶ 6-MWD, m 533 ± 83 473 ± 149* 500 ± 112*¶ Oxygen saturation, % 94 ± 2 88 ± 6* 89 ± 4* PaO2, kPa 8.9 ± 1.2 6.9 ± 1.1* PaCO2, kPa 5.6 ± 0.6 5.0 ± 0.5* Means±SD, n = 40. #Environmental symptoms questionnaire cerebral score ranges from 0 to 5 with increasing severity of acute mountain sickness. *P <0.05 vs. 490 m, ¶ P <0.05 vs. 2590 m, day 1. Conclusions Travelling to 2590m was well tolerated by lowlanders with COPD, GOLD grade 2-3. None required an unscheduled descent. However, some suffered from mild symptoms of acute mountain sickness or required nocturnal oxygen. The stay at moderate altitude was associated with a reduced 6-MWD and hypoxemia. Grant: Swiss National Science Foundation, Zurich Lung League.
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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 | 0.001 |
| 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) | 0.002 | 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".