Abstract O-03: DIURNAL PATTERN OF MELATONIN SECRETION IS HETEROGENEOUSLY MAINTAINED IN CRITICALLY ILL CHILDREN
Bibliographic record
Abstract
Aims & Objectives: Melatonin secretion patterns in critically ill children are poorly understood. This study examined whether diurnal variation of melatonin secretion was maintained during the early phase of PICU admission. Methods Prospective, observational study of children (3 months to 18 years) within 24 hours of PICU admission with access for urinary sampling and PRISM III of ≥1. Urine samples collected at 4-hour intervals for 24 hours, stored at -80oC, and 6-sulfatoxymelatonin (aMT6s) was determined in duplicate by direct ELISA. Results Fifty patients, heterogeneous for diagnosis, median age of 97.2 (IQR = 73.2) months, and median PRISM III of 10 (IQR=8). Mean (SD) total daily aMT6s production was higher than literature normal values (p<0.01) in the age <3 year group (13.6[10.2]mcg, n=14) and similar (p=0.86) for the 3–18 years group (37.7[27.5], n=30). Mean aMT6s production fit a periodic function, with amplitude 326ng/hour, peak excretion 1568ng/hour from 04:00 to 08:00, and nadir from 16:00 to 20:00 (F=4.43, p=0.01). Patients with respiratory failure requiring intubation and deep sedation (n=8) demonstrated a non-reliable amplitude of 117ng/hour (p=0.36), and model fit for a periodic function was poor (F=0.44, p=0.67), Figure 1. Similar results were demonstrated for patients with neurologic injury (n=6; amplitude 586ng/hour, p=0.22; F=0.74, p=0.49; Figure 2), and with sepsis (n=14; amplitude 147ng/hour, p=0.41; F=0.33, p=0.72; Figure 3)Conclusions Diurnal variation of aMT6s production and excretion is heterogeneously maintained early in pediatric critical illness, though this may not hold true for specific diagnostic categories.
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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 | 0.002 |
| 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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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".