Reversive Loss of Pulmonary Function Induced by Acute Chest Syndrome: A Report from the National Acute Chest Syndrome Study Group (NACSG).
Bibliographic record
Abstract
Abstract Acute Chest Syndrome (ACS) remains the leading cause of death and hospitalization in patients (pts) with sickle cell disease (SCD). There is limited data on the effects of ACS on lung function. From 1993 to 1997, 30 centers participated in the NACSG and prospectively analyzed 671 episodes of ACS in 538 pts. Pulmonary function tests (PFTs) included forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), forced expiratory flow during 25% to 75% of FVC (FEF 25–75), peak expiratory flow rate (PEF) and the ratio of FEV1/FVC. Data is reported as percent-predicted of normal values based on age and height. 128 pts (mean 16yrs, 4 to 52 yr range) had PFTs during an ACS episode (within a mean of 2.5 days of diagnosis) and then 12 weeks later. 94% of pts had abnormal lung volumes, defined as either FEV1 or FVC < 80%. Mean lung volumes during ACS and at follow-up are shown below. Table 1: Decreased Lung Volumes During ACS PFT During ACS Follow-up p-value FEV1 52% 79% <.0001 FVC 55% 83% <.0001 FEF 25–75 50% 69% <.0001 PEF 61% 83% <.0001 Pts with abnormal lung volumes (FEV1 or FVC < 80%) and considered to have an obstructive pattern if the FEV1/FVC ratio was < to 85. Obstructive patterns in pts with abnormal lung volumes and the percent of pts who responded to bronchodilators (15% improvement in either FEV1 or FVC) are shown below. Table 2: Patterns of Abnormal Lung Volumes in SCD SCD Patients During ACS Follow-up Abnormal PFTs 94% 45% Obstructive Pattern 48% 46% Respond to bronchodilators 25% 8% In summary, ACS resulted in decreased pulmonary function in 94% of pts. It is striking that 49% pts had their PFTs reduced by half (FEV1 52% and FVC 55%). In pts with abnormal PFTs, 48% had evidence of obstruction and 25% of all pts tested improved with a bronchodilator. This is the first description of reversible abnormalities of pulmonary function occurring during ACS compared to baseline. An obstructive pattern is identified in a higher percentage of pts with SCD than in the local Oakland African American population (asthma prevalance 16%). While some pts PFTs improved with time, 45% remained abnormal at 12-week follow-up. ACS results in acute and chronic worsening of lung function. Future studies of ACS may reveal common pathogenic mechanisms with asthma, and lead to improved therapeutic interventions.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".