207: BASELINE SHOCK INDEX AND AUTONOMIC FUNCTION IN OLDER ADULTS
Bibliographic record
Abstract
Introduction: Elevations in shock index (SI), defined as heart rate (HR)/systolic blood pressure (BP) is an important indicator of acute critical illness in the setting of shock due to hypovolemia, trauma, and sepsis. Possibly due to age-related autonomic changes, SI has been shown to be less discriminative of impending circulatory collapse in the older adult population, although the underlying mechanisms for this remain unclear. Methods: 51 older adults without critical illness (29 women, 23 men, age >= 65; mean age 77.8±0.9 years) were recruited from outpatient clinics in an academic center. SI, the modified shock index (MSI, HR/mean BP), and the age corrected SI (Age * SI) were measured at rest and during 3 minutes orthostatic stress. Baroreflex function (using the sequence method), and heart rate variability (HRV) were also measured at baseline. Results: SI, the modified shock index (MSI, HR/mean BP), and the age corrected SI (Age * SI) were measured at rest and during orthostatic stress. Baroreflex function (using the sequence method), and heart rate variability (HRV) were also measured at baseline. Age * SI had a significant positive association with baroreflex sensitivity (BRS, p=0.016) but this was not present for either SI (p=0.093) or MSI (p=0.139). All shock indices also showed a significant positive association with BRS for upward blood pressure swings (SI, p=0.007; MSI, p=0.007; age * SI, p=0.001). Age * SI also showed a significant correlation with high frequency HRV (p=0.044). By repeated measures analysis of variance, all shock indices increased over time with increasing duration of orthostatic stress (SI, p< 0.001; MSI, p< 0.001; age * SI, p< 0.001). Conclusions: Autonomic dysfunction is associated with lower shock indices at baseline in older adults that are not critically ill. Although more work needs to be done, age and chronic illness-related changes in autonomic function might be one of the explanations for the reduced diagnostic power of shock indices in the older adult population.
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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 | 0.000 | 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) | 0.002 | 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 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".