Hypercapnic Ventilation Response in Patients with Lung Disease: Improved Accuracy by Correcting for Ventilation Ability
Bibliographic record
Abstract
The hypercapnic ventilation response (HCVR) is positively correlated with forced expired volume in 1 s (FEV1). Therefore, subjects of small stature or patients with lung disease have low values for HCVR. However, indexing the HCVR for the subject's predicted maximal voluntary ventilation (MVV) results in a corrected HCVR (CHCVR) which is not dependent on FEV1 in normal subjects [Respiration 1993;60:197-202]. We hypothesized that the CHCVR would also be useful in assessing chemosensitivity in patients with poor lung function. To obtain the predicted MVV, we used the linear regression for FEV1 vs. measured MVV obtained from 411 patients with a wide range of FEV1 values (MVV = 31.2 x FEV1 + 11.8, r = 0.90, p < 0.001). We compared HCVR and CHCVR to the occlusion pressure response to hypercapnia (OPRH) in 34 patients with chronic obstructive pulmonary disease (COPD) and in 19 patients with low FEV1 due to small stature. All patients had been referred for assessment of possible sleep apnea. The results for the two groups of patients were similar. For the COPD patients, the HCVR had high values for sensitivity (86%) and negative predictive value (94%), but specificity, positive predictive value and accuracy were low (59, 35 and 65%, respectively). In contrast, CHCVR had high values for all the foregoing (86, 96, 100, 100 and 97%, respectively). Our results suggest that the CHCVR is useful in assessing chemosensitivity in patients who are ventilation-limited.
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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 | 0.001 | 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) | 0.000 | 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".