Effects of s-ketamine and midazolam on respiratory variability: A randomized controlled pilot trial
Bibliographic record
Abstract
S-ketamine and midazolam are frequently used to provide sedation while maintaining spontaneous respiration. However, the effects of these agents on respiratory variability, which reflects the adaptability of the respiratory system, have not been thoroughly explored. We evaluated these effects in a randomized controlled pilot trial. This study was conducted as part of a randomized controlled trial originally designed to assess the effects of s-ketamine conditioning on pain sensitivity in patients with fibromyalgia syndrome. Participants were randomly assigned to receive an infusion of either s-ketamine (0.3 mg kg-1 h-1), midazolam (0.05 mg kg-1 h-1), or saline in a blinded fashion. Mean respiratory rate, variability of respiratory rate (VRR), and variability of tidal volume (VTV) were measured continuously and non-invasively with a bio-impedance method. Changes during drug infusion were compared in a linear mixed model to assess the effects of s-ketamine and midazolam compared to saline. Data were analyzed for 57 experiments in 28 participants. Their median baseline variabilities of respiratory rate and tidal volume were 0.19 (IQR: 0.16-0.25) and 0.23 (0.19-0.34), respectively. While mean respiratory rate was not affected, midazolam resulted in a significant decrease in both VRR (ß = -0.071, 95% CI: -0.120 to -0.021) and VTV (ß = -0.117, 95% CI: -0.170 to -0.062). In contrast, s-ketamine appeared to produce a smaller decrease in VTV (ß = -0.062, 95% CI: -0.118 to -0.003) with VRR remaining unaffected (ß = -0.036, 95% CI: -0.092 to 0.019). In conclusion, our study demonstrates that midazolam reduces respiratory variability, potentially impairing the adaptability of the respiratory system. In contrast, s-ketamine largely preserved respiratory variability, suggesting it may be a safer alternative for sedation in patients with impaired spontaneous breathing. Further studies are needed to assess the clinical implications of these observations in patients undergoing sedation.
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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 | 0.007 | 0.009 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.005 | 0.003 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.003 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.003 | 0.003 |
| Insufficient payload (model declined to judge) | 0.007 | 0.001 |
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".