Effect of Ascorbic Acid on the Incidence of Postoperative Delirium Among Elderly Patients Undergoing Cardiovascular Surgery: A Pilot Study
Bibliographic record
Abstract
Background: Ascorbic acid is a strong antioxidant that prevents postoperative delirium by inhibiting reactive oxygen species production. This pilot study was designed to investigate the prevalence of postoperative delirium among older patients undergoing cardiovascular surgery, who received perioperative ascorbic acid administration, to estimate an appropriate sample size for further randomized controlled trials. Methods: This single-arm prospective interventional study enrolled patients aged > 70 years scheduled to undergo elective cardiovascular surgery using cardiopulmonary bypass. Ascorbic acid (500 mg) was administered intravenously every 6 h for a total of eight times following the induction of general anesthesia. The incidence of postoperative delirium was evaluated until discharge using the Confusion Assessment Method for the Intensive Care Unit. Results: Data from 48 patients were analyzed. Of the 48 patients, 16 developed postoperative delirium (33.3%). Patients in the delirium group had more severe heart failure (New York Heart Association Classification), higher European System for Cardiac Operative Risk Evaluation scores, lower intraoperative Bispectral Index, longer duration of cardiopulmonary bypass and surgery, incidence of postoperative cerebral infarction, longer intubation time, and length of intensive care unit stay. Conclusions: The incidence of postoperative delirium among older patients undergoing cardiovascular surgery who received ascorbic acid perioperatively (2 g/day for 2 days) was 33%. This incidence was comparable to that observed in a previous observational study, suggesting that ascorbic acid administration may not be effective in preventing the incidence of postoperative delirium.
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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 | 0.002 | 0.005 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".