Regional CO <sub>2</sub> tension quantitatively mediates homeostatic redistribution of ventilation following acute pulmonary thromboembolism in pigs
Bibliographic record
Abstract
Previous studies reported that regional CO(2) tension might affect regional ventilation (V) following acute pulmonary thromboembolism (APTE). We investigated the pathophysiology and magnitude of these changes. Eight anesthetized and ventilated piglets received autologous clots at time = 0 min until mean pulmonary artery pressure was 2.5 times baseline. The distribution of V and perfusion (Q) at four different times (-5, 30, 60, 120 min) was mapped by fluorescent microspheres. Regional V and Q were examined postmortem by sectioning the air-dried lung into 900-1,000 samples of approximately 2 cm(3) each. After the redistribution of regional Q by APTE, but in the scenario assuming that no V shift had yet occurred, CO(2) tension in different lung regions at 30 min post-APTE (P(X)CO(2)) was estimated from the V/Q data and divided into four distinct clusters: i.e., P(X)CO(2) < 10 Torr; 10 < P(X)CO(2) < 25 Torr; 25 < P(X)CO(2) < 50 Torr; P(X)CO(2) > 50 Torr. Our data showed that the clusters in higher V/Q regions (with a P(X)CO(2) < 25 Torr) received approximately 35% less V when measured within 30 min of APTE, whereas, in contrast, the lower V/Q regions showed no statistically significant increases in their V. However, after 30 min, there was minimal further redistribution of V. We conclude that there are significant compensatory V shifts out of regions of low CO(2) tension soon following APTE, and that these variations in regional CO(2) tension, which initiate CO(2)-dependent changes in airway resistance and lung parenchymal compliance, can lead to improved gas exchange.
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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) | 0.001 | 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".