A Single-Breath Method of Alveolar O <sub>2</sub> Determination
Bibliographic record
Abstract
We designed a single-breath method of alveolar O2 determination, requiring only a single tidal breath expirate and concomitant arterial blood sample. The PAO2 equation used in our method was derived by applying the Bohr equation to both O2 and CO2 and independant of VO2, VCO2 and RQ. In 35 patients with different degrees of airway obstruction, at rest and during exercise, the single-breath method agreed well with the classic method of PAO2 determination which required 3 min of expired gas collection and derivation of VO2, VCO2 and RQ. The mean difference between the PAO2 estimates by the two methods was 0.36 mm Hg as calculated for all patients, both at rest and during exercise. At rest, in 2 out of 35 cases the difference was greater than 2 mm Hg and such difference happened only in 1 case during exercise. A good correlation existed between the two PAO2 estimates by the two methods (r ranging from 0.977 to 0.996). The data indicated that single-breath method of PAO2 determination was reliable. Its extreme simplicity would facilitate greatly the assessment of gas exchange efficiency in situations where both patient's cooperation and laborator equipment are less than optimum.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.002 |
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".